Econstudentlog

Random stuff

i. Your Care Home in 120 Seconds. Some quotes:

“In order to get an overall estimate of mental power, psychologists have chosen a series of tasks to represent some of the basic elements of problem solving. The selection is based on looking at the sorts of problems people have to solve in everyday life, with particular attention to learning at school and then taking up occupations with varying intellectual demands. Those tasks vary somewhat, though they have a core in common.

Most tests include Vocabulary, examples: either asking for the definition of words of increasing rarity; or the names of pictured objects or activities; or the synonyms or antonyms of words.

Most tests include Reasoning, examples: either determining which pattern best completes the missing cell in a matrix (like Raven’s Matrices); or putting in the word which completes a sequence; or finding the odd word out in a series.

Most tests include visualization of shapes, examples: determining the correspondence between a 3-D figure and alternative 2-D figures; determining the pattern of holes that would result from a sequence of folds and a punch through folded paper; determining which combinations of shapes are needed to fill a larger shape.

Most tests include episodic memory, examples: number of idea units recalled across two or three stories; number of words recalled from across 1 to 4 trials of a repeated word list; number of words recalled when presented with a stimulus term in a paired-associate learning task.

Most tests include a rather simple set of basic tasks called Processing Skills. They are rather humdrum activities, like checking for errors, applying simple codes, and checking for similarities or differences in word strings or line patterns. They may seem low grade, but they are necessary when we try to organise ourselves to carry out planned activities. They tend to decline with age, leading to patchy, unreliable performance, and a tendency to muddled and even harmful errors. […]

A brain scan, for all its apparent precision, is not a direct measure of actual performance. Currently, scans are not as accurate in predicting behaviour as is a simple test of behaviour. This is a simple but crucial point: so long as you are willing to conduct actual tests, you can get a good understanding of a person’s capacities even on a very brief examination of their performance. […] There are several tests which have the benefit of being quick to administer and powerful in their predictions.[..] All these tests are good at picking up illness related cognitive changes, as in diabetes. (Intelligence testing is rarely criticized when used in medical settings). Delayed memory and working memory are both affected during diabetic crises. Digit Symbol is reduced during hypoglycaemia, as are Digits Backwards. Digit Symbol is very good at showing general cognitive changes from age 70 to 76. Again, although this is a limited time period in the elderly, the decline in speed is a notable feature. […]

The most robust and consistent predictor of cognitive change within old age, even after control for all the other variables, was the presence of the APOE e4 allele. APOE e4 carriers showed over half a standard deviation more general cognitive decline compared to noncarriers, with particularly pronounced decline in their Speed and numerically smaller, but still significant, declines in their verbal memory.

It is rare to have a big effect from one gene. Few people carry it, and it is not good to have.

ii. What are common mistakes junior data scientists make?

Apparently the OP had second thoughts about this query so s/he deleted the question and marked the thread nsfw (??? …nothing remotely nsfw in that thread…). Fortunately the replies are all still there, there are quite a few good responses in the thread. I added some examples below:

“I think underestimating the domain/business side of things and focusing too much on tools and methodology. As a fairly new data scientist myself, I found myself humbled during this one project where I had I spent a lot of time tweaking parameters and making sure the numbers worked just right. After going into a meeting about it became clear pretty quickly that my little micro-optimizations were hardly important, and instead there were X Y Z big picture considerations I was missing in my analysis.”

[…]

  • Forgetting to check how actionable the model (or features) are. It doesn’t matter if you have amazing model for cancer prediction, if it’s based on features from tests performed as part of the post-mortem. Similarly, predicting account fraud after the money has been transferred is not going to be very useful.

  • Emphasis on lack of understanding of the business/domain.

  • Lack of communication and presentation of the impact. If improving your model (which is a quarter of the overall pipeline) by 10% in reducing customer churn is worth just ~100K a year, then it may not be worth putting into production in a large company.

  • Underestimating how hard it is to productionize models. This includes acting on the models outputs, it’s not just “run model, get score out per sample”.

  • Forgetting about model and feature decay over time, concept drift.

  • Underestimating the amount of time for data cleaning.

  • Thinking that data cleaning errors will be complicated.

  • Thinking that data cleaning will be simple to automate.

  • Thinking that automation is always better than heuristics from domain experts.

  • Focusing on modelling at the expense of [everything] else”

“unhealthy attachments to tools. It really doesn’t matter if you use R, Python, SAS or Excel, did you solve the problem?”

“Starting with actual modelling way too soon: you’ll end up with a model that’s really good at answering the wrong question.
First, make sure that you’re trying to answer the right question, with the right considerations. This is typically not what the client initially told you. It’s (mainly) a data scientist’s job to help the client with formulating the right question.”

iii. Some random wikipedia links: Ottoman–Habsburg wars. Planetshine. Anticipation (genetics). Cloze test. Loop quantum gravity. Implicature. Starfish Prime. Stall (fluid dynamics). White Australia policy. Apostatic selection. Deimatic behaviour. Anti-predator adaptation. Lefschetz fixed-point theorem. Hairy ball theorem. Macedonia naming dispute. Holevo’s theorem. Holmström’s theorem. Sparse matrix. Binary search algorithm. Battle of the Bismarck Sea.

iv. 5-HTTLPR: A Pointed Review. This one is hard to quote, you should read all of it. I did however decide to add a few quotes from the post, as well as a few quotes from the comments:

“…what bothers me isn’t just that people said 5-HTTLPR mattered and it didn’t. It’s that we built whole imaginary edifices, whole castles in the air on top of this idea of 5-HTTLPR mattering. We “figured out” how 5-HTTLPR exerted its effects, what parts of the brain it was active in, what sorts of things it interacted with, how its effects were enhanced or suppressed by the effects of other imaginary depression genes. This isn’t just an explorer coming back from the Orient and claiming there are unicorns there. It’s the explorer describing the life cycle of unicorns, what unicorns eat, all the different subspecies of unicorn, which cuts of unicorn meat are tastiest, and a blow-by-blow account of a wrestling match between unicorns and Bigfoot.

This is why I start worrying when people talk about how maybe the replication crisis is overblown because sometimes experiments will go differently in different contexts. The problem isn’t just that sometimes an effect exists in a cold room but not in a hot room. The problem is more like “you can get an entire field with hundreds of studies analyzing the behavior of something that doesn’t exist”. There is no amount of context-sensitivity that can help this. […] The problem is that the studies came out positive when they shouldn’t have. This was a perfectly fine thing to study before we understood genetics well, but the whole point of studying is that, once you have done 450 studies on something, you should end up with more knowledge than you started with. In this case we ended up with less. […] I think we should take a second to remember that yes, this is really bad. That this is a rare case where methodological improvements allowed a conclusive test of a popular hypothesis, and it failed badly. How many other cases like this are there, where there’s no geneticist with a 600,000 person sample size to check if it’s true or not? How many of our scientific edifices are built on air? How many useless products are out there under the guise of good science? We still don’t know.”

A few more quotes from the comment section of the post:

“most things that are obviously advantageous or deleterious in a major way aren’t gonna hover at 10%/50%/70% allele frequency.

Population variance where they claim some gene found in > [non trivial]% of the population does something big… I’ll mostly tend to roll to disbelieve.

But if someone claims a family/village with a load of weirdly depressed people (or almost any other disorder affecting anything related to the human condition in any horrifying way you can imagine) are depressed because of a genetic quirk… believable but still make sure they’ve confirmed it segregates with the condition or they’ve got decent backing.

And a large fraction of people have some kind of rare disorder […]. Long tail. Lots of disorders so quite a lot of people with something odd.

It’s not that single variants can’t have a big effect. It’s that really big effects either win and spread to everyone or lose and end up carried by a tiny minority of families where it hasn’t had time to die out yet.

Very few variants with big effect sizes are going to be half way through that process at any given time.

Exceptions are

1: mutations that confer resistance to some disease as a tradeoff for something else […] 2: Genes that confer a big advantage against something that’s only a very recent issue.”

“I think the summary could be something like:
A single gene determining 50% of the variance in any complex trait is inherently atypical, because variance depends on the population plus environment and the selection for such a gene would be strong, rapidly reducing that variance.
However, if the environment has recently changed or is highly variable, or there is a trade-off against adverse effects it is more likely.
Furthermore – if the test population is specifically engineered to target an observed trait following an apparently Mendelian inheritance pattern – such as a family group or a small genetically isolated population plus controls – 50% of the variance could easily be due to a single gene.”

v. Less research is needed.

“The most over-used and under-analyzed statement in the academic vocabulary is surely “more research is needed”. These four words, occasionally justified when they appear as the last sentence in a Masters dissertation, are as often to be found as the coda for a mega-trial that consumed the lion’s share of a national research budget, or that of a Cochrane review which began with dozens or even hundreds of primary studies and progressively excluded most of them on the grounds that they were “methodologically flawed”. Yet however large the trial or however comprehensive the review, the answer always seems to lie just around the next empirical corner.

With due respect to all those who have used “more research is needed” to sum up months or years of their own work on a topic, this ultimate academic cliché is usually an indicator that serious scholarly thinking on the topic has ceased. It is almost never the only logical conclusion that can be drawn from a set of negative, ambiguous, incomplete or contradictory data.” […]

“Here is a quote from a typical genome-wide association study:

“Genome-wide association (GWA) studies on coronary artery disease (CAD) have been very successful, identifying a total of 32 susceptibility loci so far. Although these loci have provided valuable insights into the etiology of CAD, their cumulative effect explains surprisingly little of the total CAD heritability.”  [1]

The authors conclude that not only is more research needed into the genomic loci putatively linked to coronary artery disease, but that – precisely because the model they developed was so weak – further sets of variables (“genetic, epigenetic, transcriptomic, proteomic, metabolic and intermediate outcome variables”) should be added to it. By adding in more and more sets of variables, the authors suggest, we will progressively and substantially reduce the uncertainty about the multiple and complex gene-environment interactions that lead to coronary artery disease. […] We predict tomorrow’s weather, more or less accurately, by measuring dynamic trends in today’s air temperature, wind speed, humidity, barometric pressure and a host of other meteorological variables. But when we try to predict what the weather will be next month, the accuracy of our prediction falls to little better than random. Perhaps we should spend huge sums of money on a more sophisticated weather-prediction model, incorporating the tides on the seas of Mars and the flutter of butterflies’ wings? Of course we shouldn’t. Not only would such a hyper-inclusive model fail to improve the accuracy of our predictive modeling, there are good statistical and operational reasons why it could well make it less accurate.”

vi. Why software projects take longer than you think – a statistical model.

Anyone who built software for a while knows that estimating how long something is going to take is hard. It’s hard to come up with an unbiased estimate of how long something will take, when fundamentally the work in itself is about solving something. One pet theory I’ve had for a really long time, is that some of this is really just a statistical artifact.

Let’s say you estimate a project to take 1 week. Let’s say there are three equally likely outcomes: either it takes 1/2 week, or 1 week, or 2 weeks. The median outcome is actually the same as the estimate: 1 week, but the mean (aka average, aka expected value) is 7/6 = 1.17 weeks. The estimate is actually calibrated (unbiased) for the median (which is 1), but not for the the mean.

A reasonable model for the “blowup factor” (actual time divided by estimated time) would be something like a log-normal distribution. If the estimate is one week, then let’s model the real outcome as a random variable distributed according to the log-normal distribution around one week. This has the property that the median of the distribution is exactly one week, but the mean is much larger […] Intuitively the reason the mean is so large is that tasks that complete faster than estimated have no way to compensate for the tasks that take much longer than estimated. We’re bounded by 0, but unbounded in the other direction.”

I like this way to conceptually frame the problem, and I definitely do not think it only applies to software development.

“I filed this in my brain under “curious toy models” for a long time, occasionally thinking that it’s a neat illustration of a real world phenomenon I’ve observed. But surfing around on the interwebs one day, I encountered an interesting dataset of project estimation and actual times. Fantastic! […] The median blowup factor turns out to be exactly 1x for this dataset, whereas the mean blowup factor is 1.81x. Again, this confirms the hunch that developers estimate the median well, but the mean ends up being much higher. […]

If my model is right (a big if) then here’s what we can learn:

  • People estimate the median completion time well, but not the mean.
  • The mean turns out to be substantially worse than the median, due to the distribution being skewed (log-normally).
  • When you add up the estimates for n tasks, things get even worse.
  • Tasks with the most uncertainty (rather the biggest size) can often dominate the mean time it takes to complete all tasks.”

vii. Attraction inequality and the dating economy.

“…the relentless focus on inequality among politicians is usually quite narrow: they tend to consider inequality only in monetary terms, and to treat “inequality” as basically synonymous with “income inequality.” There are so many other types of inequality that get air time less often or not at all: inequality of talent, height, number of friends, longevity, inner peace, health, charm, gumption, intelligence, and fortitude. And finally, there is a type of inequality that everyone thinks about occasionally and that young single people obsess over almost constantly: inequality of sexual attractiveness. […] One of the useful tools that economists use to study inequality is the Gini coefficient. This is simply a number between zero and one that is meant to represent the degree of income inequality in any given nation or group. An egalitarian group in which each individual has the same income would have a Gini coefficient of zero, while an unequal group in which one individual had all the income and the rest had none would have a Gini coefficient close to one. […] Some enterprising data nerds have taken on the challenge of estimating Gini coefficients for the dating “economy.” […] The Gini coefficient for [heterosexual] men collectively is determined by [-ll-] women’s collective preferences, and vice versa. If women all find every man equally attractive, the male dating economy will have a Gini coefficient of zero. If men all find the same one woman attractive and consider all other women unattractive, the female dating economy will have a Gini coefficient close to one.”

“A data scientist representing the popular dating app “Hinge” reported on the Gini coefficients he had found in his company’s abundant data, treating “likes” as the equivalent of income. He reported that heterosexual females faced a Gini coefficient of 0.324, while heterosexual males faced a much higher Gini coefficient of 0.542. So neither sex has complete equality: in both cases, there are some “wealthy” people with access to more romantic experiences and some “poor” who have access to few or none. But while the situation for women is something like an economy with some poor, some middle class, and some millionaires, the situation for men is closer to a world with a small number of super-billionaires surrounded by huge masses who possess almost nothing. According to the Hinge analyst:

On a list of 149 countries’ Gini indices provided by the CIA World Factbook, this would place the female dating economy as 75th most unequal (average—think Western Europe) and the male dating economy as the 8th most unequal (kleptocracy, apartheid, perpetual civil war—think South Africa).”

Btw., I’m reasonably certain “Western Europe” as most people think of it is not average in terms of Gini, and that half-way down the list should rather be represented by some other region or country type, like, say Mongolia or Bulgaria. A brief look at Gini lists seemed to support this impression.

Quartz reported on this finding, and also cited another article about an experiment with Tinder that claimed that that “the bottom 80% of men (in terms of attractiveness) are competing for the bottom 22% of women and the top 78% of women are competing for the top 20% of men.” These studies examined “likes” and “swipes” on Hinge and Tinder, respectively, which are required if there is to be any contact (via messages) between prospective matches. […] Yet another study, run by OkCupid on their huge datasets, found that women rate 80 percent of men as “worse-looking than medium,” and that this 80 percent “below-average” block received replies to messages only about 30 percent of the time or less. By contrast, men rate women as worse-looking than medium only about 50 percent of the time, and this 50 percent below-average block received message replies closer to 40 percent of the time or higher.

If these findings are to be believed, the great majority of women are only willing to communicate romantically with a small minority of men while most men are willing to communicate romantically with most women. […] It seems hard to avoid a basic conclusion: that the majority of women find the majority of men unattractive and not worth engaging with romantically, while the reverse is not true. Stated in another way, it seems that men collectively create a “dating economy” for women with relatively low inequality, while women collectively create a “dating economy” for men with very high inequality.”

I think the author goes a bit off the rails later in the post, but the data is interesting. It’s however important keeping in mind in contexts like these that sexual selection pressures apply at multiple levels, not just one, and that partner preferences can be non-trivial to model satisfactorily; for example as many women have learned the hard way, males may have very different standards for whom to a) ‘engage with romantically’ and b) ‘consider a long-term partner’.

viii. Flipping the Metabolic Switch: Understanding and Applying Health Benefits of Fasting.

“Intermittent fasting (IF) is a term used to describe a variety of eating patterns in which no or few calories are consumed for time periods that can range from 12 hours to several days, on a recurring basis. Here we focus on the physiological responses of major organ systems, including the musculoskeletal system, to the onset of the metabolic switch – the point of negative energy balance at which liver glycogen stores are depleted and fatty acids are mobilized (typically beyond 12 hours after cessation of food intake). Emerging findings suggest the metabolic switch from glucose to fatty acid-derived ketones represents an evolutionarily conserved trigger point that shifts metabolism from lipid/cholesterol synthesis and fat storage to mobilization of fat through fatty acid oxidation and fatty-acid derived ketones, which serve to preserve muscle mass and function. Thus, IF regimens that induce the metabolic switch have the potential to improve body composition in overweight individuals. […] many experts have suggested IF regimens may have potential in the treatment of obesity and related metabolic conditions, including metabolic syndrome and type 2 diabetes.()”

“In most studies, IF regimens have been shown to reduce overall fat mass and visceral fat both of which have been linked to increased diabetes risk.() IF regimens ranging in duration from 8 to 24 weeks have consistently been found to decrease insulin resistance.(, , , , , , , , , ) In line with this, many, but not all,() large-scale observational studies have also shown a reduced risk of diabetes in participants following an IF eating pattern.”

“…we suggest that future randomized controlled IF trials should use biomarkers of the metabolic switch (e.g., plasma ketone levels) as a measure of compliance and the magnitude of negative energy balance during the fasting period. It is critical for this switch to occur in order to shift metabolism from lipidogenesis (fat storage) to fat mobilization for energy through fatty acid β-oxidation. […] As the health benefits and therapeutic efficacies of IF in different disease conditions emerge from RCTs, it is important to understand the current barriers to widespread use of IF by the medical and nutrition community and to develop strategies for broad implementation. One argument against IF is that, despite the plethora of animal data, some human studies have failed to show such significant benefits of IF over CR [Calorie Restriction].() Adherence to fasting interventions has been variable, some short-term studies have reported over 90% adherence,() whereas in a one year ADMF study the dropout rate was 38% vs 29% in the standard caloric restriction group.()”

ix. Self-repairing cells: How single cells heal membrane ruptures and restore lost structures.

June 2, 2019 Posted by | Astronomy, Biology, Data, Diabetes, Economics, Evolutionary biology, Genetics, Geography, History, Mathematics, Medicine, Physics, Psychology, Statistics, Wikipedia | Leave a comment

The Ice Age (I)

I’m currently reading this book. Some observations and links related to the first half of the book below:

“It is important to appreciate from the outset that the Quaternary ice age was not one long episode of unremitting cold climate. […] By exploring the landforms, sediments, and fossils of the Quaternary Period we can identify glacials: periods of severe cold climate when great ice sheets formed in the high middle latitudes of the northern hemisphere and glaciers and ice caps advanced in mountain regions around the world. We can also recognize periods of warm climate known as interglacials when mean air temperatures in the middle latitudes were comparable to, and sometimes higher than, those of the present. As the climate shifted from glacial to interglacial mode, the large ice sheets of Eurasia and North America retreated allowing forest biomes to re-colonize the ice free landscapes. It is also important to recognize that the ice age isn’t just about advancing and retreating ice sheets. Major environmental changes also took place in the Mediterranean region and in the tropics. The Sahara, for example, became drier, cooler, and dustier during glacial periods yet early in the present interglacial it was a mosaic of lakes and oases with tracts of lush vegetation. A defining feature of the Quaternary Period is the repeated fluctuation in climate as conditions shifted from glacial to interglacial, and back again, during the course of the last 2.5 million years or so. A key question in ice age research is why does the Earth’s climate system shift so dramatically and so frequently?”

“Today we have large ice masses in the Polar Regions, but a defining feature of the Quaternary is the build-up and decay of continental-scale ice sheets in the high middle latitudes of the northern hemisphere. […] the Laurentide and Cordilleran ice sheets […] covered most of Canada and large tracts of the northern USA during glacial stages. Around 22,000 years ago, when the Laurentide ice sheet reached its maximum extent during the most recent glacial stage, it was considerably larger in both surface area and volume (34.8 million km3) than the present-day East and West Antarctic ice sheets combined (27 million km3). With a major ice dome centred on Hudson Bay greater than 4 km thick, it formed the largest body of ice on Earth. This great mass of ice depressed the crust beneath its bed by many hundreds of metres. Now shed of this burden, the crust is still slowly recovering today at rates of up to 1 cm per year. Glacial ice extended out beyond the 38th parallel across the lowland regions of North America. Chicago, Boston, and New York all lie on thick glacial deposits left by the Laurentide ice sheet. […] With huge volumes of water locked up in the ice sheets, global sea level was about 120 m lower than present at the Last Glacial Maximum (LGM), exposing large expanses of continental shelf and creating land bridges that allowed humans, animals, and plants to move between continents. Migration from eastern Russia to Alaska, for example, was possible via the Bering land bridge.”

“Large ice sheets also developed in Europe. […] The British Isles lie in an especially sensitive location on the Atlantic fringe of Europe between latitudes 50 and 60° north. Because of this geography, the Quaternary deposits of Britain record especially dramatic shifts in environmental conditions. The most extensive glaciation saw ice sheets extend as far south as the Thames Valley with wide braided rivers charged with meltwater and sediment from the ice margin. Beyond the glacial ice much of southern Britain would have been a treeless, tundra steppe environment with tracts of permanently frozen ground […]. At the LGM […] [t]he Baltic and North Seas were dry land and Britain was connected to mainland Europe. Beyond the British and Scandinavian ice sheets, much of central and northern Europe was a treeless tundra steppe habitat. […] During warm interglacial stages […] [b]road-leaved deciduous woodland with grassland was the dominant vegetation […]. In the warmest parts of interglacials thermophilous […] insects from the Mediterranean were common in Britain whilst the large mammal fauna of the Last Interglacial (c.130,000 to 115,000 years ago) included even more exotic species such as the short tusked elephant, rhinoceros, and hippopotamus. In some interglacials, the rivers of southern Britain contained molluscs that now live in the Nile Valley. For much of the Quaternary, however, climate would have been in an intermediate state (either warming or cooling) between these glacial and interglacial extremes.”

“Glaciologists make a distinction between three main types of glacier (valley glaciers, ice caps, and ice sheets) on the basis of scale and topographic setting. A glacier is normally constrained by the surrounding topography such as a valley and has a clearly defined source area. An ice cap builds up as a dome-like form on a high plateau or mountain peak and may feed several outlet glaciers to valleys below. Ice sheets notionally exceed 50,000 km2 and are not constrained by topography.”

“We live in unusual times. For more than 90 per cent of its 4.6-billion-year history, Earth has been too warm — even at the poles — for ice sheets to form. Ice ages are not the norm for our planet. Periods of sustained (over several million years) large-scale glaciation can be called glacial epochs. Tillites in the geological record tells us that the Quaternary ice age is just one of at least six great glacial epochs that have taken place over the last three billion years or so […]. The Quaternary itself is the culmination of a much longer glacial epoch that began around 35 million years ago (Ma) when glaciers and ice sheets first formed in Antarctica. This is known as the Cenozoic glacial epoch. There is still much to learn about these ancient glacial epochs, especially the so-called Snowball Earth states of the Precambrian (before 542 Ma) when the boundary conditions for the global climate system were so different to those of today. […] This book is concerned with the Quaternary ice age – it has the richest and most varied records of environmental change. Because its sediments are so recent they have not been subjected to millions of years of erosion or deep burial and metamorphism. […] in aquatic settings, such as lakes and peat bogs, organic materials such as insects, leaves, and seeds, as well as microfossils such as pollen and fungal spores can be exceptionally well preserved in the fossil record. This allows us to create very detailed pictures of past ecosystems under glacial and interglacial conditions. This field of research is known as Quaternary paeloecology.”

“An erratic […] is a piece of rock that has been transported from its place of origin. […] Many erratics stand out because they lie on bedrock that is very different to their source. […] Erratics are normally associated with transport by glaciers or ice sheets, but in the early 19th century mechanisms such as the great deluge or rafting on icebergs were commonly invoked. […] Enormous erratic boulders […] were well known to 18th- and 19th-centery geologists. […] Their origin was a source of lively and protracted debate […] Early observers of Alpine glaciers had noted the presence of large boulders on the surface of active glaciers or forming part of the debris pile at the glacier snout. These were readily explainable, but erratic boulders had long been noted in locations that defied rational explanations. The erratics found at elevations far above their known sources, and in places such as Britain where glaciers were absent, were especially problematic for early students of landscape history. […] A huge deluge […] was commonly invoked to explain the disposition of such boulders and many saw them as more hard evidence in support of the Biblical flood. […] At this time, the Church of England held a strong influence over much of higher education and especially so in Cambridge and Oxford.”

Venetz [in the early 19th century] produced remarkably detailed topographic maps of lateral and terminal moraines that lay far down valley of the modern glaciers. He was able to show that many glaciers had advanced and retreated in the historical period. His was the first systematic analysis of climate-glacier-landscape interactions. […] In 1821, Venetz presented his findings to the Société Helvétiques des Sciences Naturelles, setting out Perraudin’s ideas alongside his own. The paper had little impact, however, and would not see publication until 1833. […] Jean de Charpentier [in his work] paid particular attention to the disposition of large erratic blocks and the occurrence of polished and striated bedrock surfaces in the deep valleys of western Switzerland. A major step forward was Charpentier’s recognition of a clear relationship between the elevation of the erratic blocks in the Rhône Valley and the vertical extent of glacially smoothed rock walls. He noted that the bedrock valley sides above the erratic blocks were not worn smooth because they must have been above the level of the ancient glacier surface. The rock walls below the erratics always bore the hallmarks of contact with glacial ice. We call this boundary the trimline. It is often clearly marked in hard bedrock because the texture of the valley sides above the glacier surface is fractured due to attack by frost weathering. The detachment of rock particles above the trimline adds debris to lateral moraines and the glacier surface. These insights allowed Charpentier to reconstruct the vertical extent of former glaciers for the first time. Venetz and Perraudin had already shown how to demarcate the length and width of glaciers using the terminal and lateral moraines in these valleys. Charpentier described some of the most striking erratic boulders in the Alps […]. As Charpentier mapped the giant erratics, polished bedrock surfaces, and moraines in the Rhône Valley, it became clear to him that the valley must once have been occupied by a truly enormous glacier or ‘glacier-monstre’ as he called it. […] In 1836, Charpentier published a key paper setting out the main findings of their [his and Venetz’] glacial work”.

“Even before Charpentier was thinking about large ice masses in Switzerland, Jens Esmark (1763-1839) […] had suggested that northern European glaciers had been much more extensive in the past and were responsible for the transport of large erratic boulders and the formation of moraines. Esmark also recognized the key role of deep bedrock erosion by glacial ice in the formation of the spectacular Norwegian fjords. He worked out that glaciers in Norway had once extended down to sea level. Esmark’s ideas were […] translated into English and published […] in 1826, a decade in advance of Charpentier’s paper. Esmark discussed a large body of evidence pointing to an extensive glaciation of northern Europe. […] his thinking was far in advance of his contemporaries […] Unfortunately, even Esmark’s carefully argued paper held little sway in Britain and elsewhere […] it would be many decades before there was general acceptance within the geological community that glaciers could spread out across low gradient landscapes. […] in the lecture theatres and academic societies of Paris, Berlin, and London, the geological establishment was slow to take up these ideas, even though they were published in both English and French and were widely available. Much of the debate in the 1820s and early 1830s centred on the controversy over the evolution of valleys between the fluvialists (Hutton, Playfair, and others), who advocated slow river erosion, and the diluvialists (Buckland, De la Beche, and others) who argued that big valleys and large boulders needed huge deluges. The role of glaciers in valley and fjord formation was not considered. […] The key elements of a glacial theory were in place but nobody was listening. […] It would be decades before a majority accepted that vast tracts of Eurasia and North America had once been covered by mighty ice sheets.”

“Most geologists in 1840 saw Agassiz’s great ice sheet as a retrograde step. It was just too catastrophist — a blatant violation of hard-won uniformitarian principles. It was the antithesis of the new rational geology and was not underpinned by carefully assembled field data. So, for many, as an explanation for the superficial deposits of the Quaternary, it was no more convincing than the deluge. […] Ancient climates were [also] supposed to be warmer not colder. The suggestion of a freezing glacial epoch in the recent geological past, followed by the temperate climate of the present, still jarred with the conventional wisdom that Earth history, from its juvenile molten state to the present, was an uninterrupted record of long-term cooling without abrupt change. Lyell’s drift ice theory [according to which erratics (and till) had been transported by icebergs drifting in water, instead of glaciers transporting the material over land – US] also provided an attractive alternative to Agassiz’s ice age because it did not demand a period of cold glacial climate in areas that now enjoy temperate conditions. […] If anything, the 1840 sessions at the Geological Society had galvanized support for floating ice as a mechanism for drift deposition in the lowlands. Lyell’s model proved to be remarkably resilient—its popularity proved to be the major obstacle to the wider adoption of the land ice theory. […] many refused to believe that glacier ice could advance across gently sloping lowland terrain. This was a reasonable objection at this time since the ice sheets of Greenland and Antarctica had not yet been investigated from a glaciological point of view. It is not difficult to understand why many British geologists rejected the glacial theory when the proximity and potency of the sea was so obvious and nobody knew how large ice sheets behaved.”

Hitchcock […] was one of the first Americans to publicly embrace Agassiz’s ideas […] but he later stepped back from a full endorsement, leaving a role for floating ice. This hesitant beginning set the tone for the next few decades in North America as its geologists began to debate whether they could see the work of ice sheets or icebergs. There was a particularly strong tradition of scriptural geology in 19th-century North America. Its practitioners attempted to reconcile their field observations with the Bible and there were often close links with like-minded souls in Britain. […] If the standing of Lyell extended the useful lifespan of the iceberg theory, it was gradually worn down by a growing body of field evidence from Europe and North America that pointed to the action of glacier ice. […] The continental glacial theory prevailed in North America because it provided a much better explanation for the vast majority of the features recorded in the landscape. The striking regularity and fixed alignment of many features could not be the work of icebergs whose wanderings were governed by winds and ocean currents. The southern limit of the glacial deposits is often marked by pronounced ridges in an otherwise low-relief landscape. These end moraines mark the edge of the former ice sheet and they cannot be formed by floating ice. It took a long time to put all the pieces of evidence together in North America because of the vast scale of the territory to be mapped. Once the patterns of erratic dispersal, large-scale scratching of bedrock, terminal moraines, drumlin fields, and other features were mapped, their systematic arrangement argued strongly against the agency of drifting ice. Unlike their counterparts in Britain, who were never very far from the sea, geologists working deep in the continental interior of North America found it much easier to dismiss the idea of a great marine submergence. Furthermore, icebergs just did not transport enough sediment to account for the enormous extent and great thickness of the Quaternary deposits. It was also realized that icebergs were just not capable of planing off hard bedrock to create plateau surfaces. Neither were they able to polish, scratch, or cut deep grooves into ancient bedrock. All these features pointed to the action of land-based glacial ice. Slowly, but surely, the reality of vast expanses of glacier ice covering much of Canada and the northern states of the USA became apparent.”

Links:

Quaternary.
The Parallel Roads of Glen Roy.
William Boyd Dawkins.
Adams mammoth.
Georges Cuvier.
Cryosphere.
Cirque (geology). Arête. Tarn. Moraine. Drumlin. Till/Tillite. Glacier morphology.
James Hutton.
William Buckland.
Diluvium.
Charles Lyell.
Giétro Glacier.
Cwm Idwal.
Timothy Abbott Conrad. Charles Whittlesey. James Dwight Dana.

February 23, 2018 Posted by | Books, Ecology, Geography, Geology, History, Paleontology | Leave a comment

Rivers (II)

Some more observations from the book and related links below.

“By almost every measure, the Amazon is the greatest of all the large rivers. Encompassing more than 7 million square kilometres, its drainage basin is the largest in the world and makes up 5% of the global land surface. The river accounts for nearly one-fifth of all the river water discharged into the oceans. The flow is so great that water from the Amazon can still be identified 125 miles out in the Atlantic […] The Amazon has some 1,100 tributaries, and 7 of these are more than 1,600 kilometres long. […] In the lowlands, most Amazonian rivers have extensive floodplains studded with thousands of shallow lakes. Up to one-quarter of the entire Amazon Basin is periodically flooded, and these lakes become progressively connected with each other as the water level rise.”

“To hydrologists, the term ‘flood’ refers to a river’s annual peak discharge period, whether the water inundates the surrounding landscape or not. In more common parlance, however, a flood is synonymous with the river overflowing it’s banks […] Rivers flood in the natural course of events. This often occurs on the floodplain, as the name implies, but flooding can affect almost all of the length of the river. Extreme weather, particularly heavy or protracted rainfall, is the most frequent cause of flooding. The melting of snow and ice is another common cause. […] River floods are one of the most common natural hazards affecting human society, frequently causing social disruption, material damage, and loss of life. […] Most floods have a seasonal element in their occurence […] It is a general rule that the magnitude of a flood is inversely related to its frequency […] Many of the less predictable causes of flooding occur after a valley has been blocked by a natural dam as a result of a landslide, glacier, or lava flow. Natural dams may cause upstream flooding as the blocked river forms a lake and downstream flooding as a result of failure of the dam.”

“The Tigris-Euphrates, Nile, and Indus are all large, exotic river systems, but in other respects they are quite different. The Nile has a relatively gentle gradient in Egypt and a channel that has experienced only small changes over the last few thousand years, by meander cut-off and a minor shift eastwards. The river usually flooded in a regular and predictable way. The stability and long continuity of the Egyptian civilization may be a reflection of its river’s relative stability. The steeper channel of the Indus, by contrast, has experienced major avulsions over great distances on the lower Indus Plain and some very large floods caused by the failure of glacier ice dams in the Himalayan mountains. Likely explanations for the abandonment of many Harappan cities […] take account of damage caused by major floods and/or the disruption caused by channel avulsion leading to a loss of water supply. Channel avulsion was also a problem for the Sumerian civilization on the alluvial plain called Mesopotamia […] known for the rise and fall of its numerous city states. Most of these cities were situated along the Euphrates River, probably because it was more easily controlled for irrigation purposes than the Tigris, which flowed faster and carried much more water. However, the Euphrates was an anastomosing river with multiple channels that diverge and rejoin. Over time, individual branch channels ceased to flow as others formed, and settlements located on these channels inevitably declined and were abandoned as their water supply ran dry, while others expanded as their channels carried greater amounts of water.”

“During the colonization of the Americas in the mid-18th century and the imperial expansion into Africa and Asia in the late 19th century, rivers were commonly used as boundaries because they were the first, and frequently the only, features mapped by European explorers. The diplomats in Europe who negotiated the allocation of colonial territories claimed by rival powers knew little of the places they were carving up. Often, their limited knowledge was based solely on maps that showed few details, rivers being the only distinct physical features marked. Today, many international river boundaries remain as legacies of those historical decisions based on poor geographical knowledge because states have been reluctant to alter their territorial boundaries from original delimitation agreements. […] no less than three-quarters of the world’s international boundaries follow rivers for at least part of their course. […] approximately 60% of the world’s fresh water is drawn from rivers shared by more than one country.”

“The sediments carried in rivers, laid down over many years, represent a record of the changes that have occurred in the drainage basin through the ages. Analysis of these sediments is one way in which physical geographers can interpret the historical development of landscapes. They can study the physical and chemical characteristics of the sediments itself and/or the biological remains they contain, such as pollen or spores. […] The simple rate at which material is deposited by a river can be a good reflection of how conditions have changed in the drainage basin. […] Pollen from surrounding plants is often found in abundance in fluvial sediments, and the analysis of pollen can yield a great deal of information about past conditions in an area. […] Very long sediment cores taken from lakes and swamps enable us to reconstruct changes in vegetation over very long time periods, in some cases over a million years […] Because climate is a strong determinant of vegetation, pollen analysis has also proved to be an important method for tracing changes in past climates.”

“The energy in flowing and falling water has been harnessed to perform work by turning water-wheels for more than 2,000 years. The moving water turns a large wheel and a shaft connected to the wheel axle transmits the power from the water through a system of gears and cogs to work machinery, such as a millstone to grind corn. […] The early medieval watermill was able to do the work of between 30 and 60 people, and by the end of the 10th century in Europe, waterwheels were commonly used in a wide range of industries, including powering forge hammers, oil and silk mills, sugar-cane crushers, ore-crushing mills, breaking up bark in tanning mills, pounding leather, and grinding stones. Nonetheless, most were still used for grinding grains for preparation into various types of food and drink. The Domesday Book, a survey prepared in England in AD 1086, lists 6,082 watermills, although this is probably a conservative estimate because many mills were not recorded in the far north of the country. By 1300, this number had risen to exceed 10,000. [..] Medieval watermills typically powered their wheels by using a dam or weir to concentrate the falling water and pond a reserve supply. These modifications to rivers became increasingly common all over Europe, and by the end of the Middle Ages, in the mid-15th century, watermills were in use on a huge number of rivers and streams. The importance of water power continued into the Industrial Revolution […]. The early textile factories were built to produce cloth using machines driven by waterwheels, so they were often called mills. […] [Today,] about one-third of all countries rely on hydropower for more than half their electricity. Globally, hydropower provides about 20% of the world’s total electricity supply.”

“Deliberate manipulation of river channels through engineering works, including dam construction, diversion, channelization, and culverting, […] has a long history. […] In Europe today, almost 80% of the total discharge of the continent’s major rivers is affected by measures designed to regulate flow, whether for drinking water supply, hydroelectric power generation, flood control, or any other reason. The proportion in individual countries is higher still. About 90% of rivers in the UK are regulated as a result of these activities, while in the Netherlands this percentage is close to 100. By contrast, some of the largest rivers on other continents, including the Amazon and the Congo, are hardly manipulated at all. […] Direct and intentional modifications to rivers are complemented by the impacts of land use and land use changes which frequently result in the alteration of rivers as an unintended side effect. Deforestation, afforestation, land drainage, agriculture, and the use of fire have all had significant impacts, with perhaps the most extreme effects produced by construction activity and urbanization. […] The major methods employed in river regulation are the construction of large dams […], the building of run-of-river impoundments such as weirs and locks, and by channelization, a term that covers a range of river engineering works including widening, deepening, straightening, and the stabilization of banks. […] Many aspects of a dynamic river channel and its associated ecosystems are mutually adjusting, so a human activity in a landscape that affects the supply of water or sediment is likely to set off a complex cascade of other alterations.”

“The methods of storage (in reservoirs) and distribution (by canal) have not changed fundamentally since the earliest river irrigation schemes, with the exception of some contemporary projects’ use of pumps to distribute water over greater distances. Nevertheless, many irrigation canals still harness the force of gravity. Half the world’s large dams (defined as being 15 metres or higher) were built exclusively or primarily for irrigation, and about one-third of the world’s irrigated cropland relies on reservoir water. In several countries, including such populous nations as India and China, more than 50% of arable land is irrigated by river water supplied from dams. […] Sadly, many irrigation schemes are not well managed and a number of environmental problems are frequently experienced as a result, both on-site and off-site. In many large networks of irrigation canals, less than half of the water diverted from a river or reservoir actually benefits crops. A lot of water seeps away through unlined canals or evaporates before reaching the fields. Some also runs off the fields or infiltrates through the soil, unused by plants, because farmers apply too much water or at the wrong time. Much of this water seeps back into nearby streams or joins underground aquifers, so can be used again, but the quality of water may deteriorate if it picks up salts, fertilizers, or pesticides. Excessive applications of irrigation water often result in rising water tables beneath fields, causing salinization and waterlogging. These processes reduce crop yields on irrigation schemes all over the world.”

“[Deforestation can contribute] to the degradation of aquatic habitats in numerous ways. The loss of trees along river banks can result in changes in the species found in the river because fewer trees means a decline in plant matter and insects falling from them, items eaten by some fish. Fewer trees on river banks also results in less shade. More sunlight reaching the river results in warmer water and the enhanced growth of algae. A change in species can occur as fish that feed on falling food are edged out by those able to feed on algae. Deforestation also typically results in more runoff and more soil erosion. This sediment may cover spawning grounds, leading to lower reproduction rates. […] Grazing and trampling by livestock reduces vegetation cover and causes the compaction of soil, which reduces its infiltration capacity. As rainwater passes over or through the soil in areas of intensive agriculture, it picks up residues from pesticides and fertilizers and transport them to rivers. In this way, agriculture has become a leading source of river pollution in certain parts of the world. Concentration of nitrates and phosphates, derived from fertilizers, have risen notably in many rivers in Europe and North America since the 1950s and have led to a range of […] problems encompassed under the term ‘eutrophication’ – the raising of biological productivity caused by nutrient enrichment. […] In slow-moving rivers […] the growth of algae reduces light penetration and depletes the oxygen in the water, sometimes causing fish kills.”

“One of the most profound ways in which people alter rivers is by damming them. Obstructing a river and controlling its flow in this way brings about a raft of changes. A dam traps sediments and nutrients, alters the river’s temperature and chemistry, and affects the processes of erosion and deposition by which the river sculpts the landscape. Dams create more uniform flow in rivers, usually by reducing peak flows and increasing minimum flows. Since the natural variation in flow is important for river ecosystems and their biodiversity, when dams even out flows the result is commonly fewer fish of fewer species. […] the past 50 years or so has seen a marked escalation in the rate and scale of construction of dams all over the world […]. At the beginning of the 21st century, there were about 800,000 dams worldwide […] In some large river systems, the capacity of dams is sufficient to hold more than the entire annual discharge of the river. […] Globally, the world’s major reservoirs are thought to control about 15% of the runoff from the land. The volume of water trapped worldwide in reservoirs of all sizes is no less than five times the total global annual river flow […] Downstream of a reservoir, the hydrological regime of a river is modified. Discharge, velocity, water quality, and thermal characteristics are all affected, leading to changes in the channel and its landscape, plants, and animals, both on the river itself and in deltas, estuaries, and offshore. By slowing the flow of river water, a dam acts as a trap for sediment and hence reduces loads in the river downstream. As a result, the flow downstream of the dam is highly erosive. A relative lack of silt arriving at a river’s delta can result in more coastal erosion and the intrusion of seawater that brings salt into delta ecosystems. […] The dam-barrier effect on migratory fish and their access to spawning grounds has been recognized in Europe since medieval times.”

“One of the most important effects cities have on rivers is the way in which urbanization affects flood runoff. Large areas of cities are typically impermeable, being covered by concrete, stone, tarmac, and bitumen. This tends to increase the amount of runoff produced in urban areas, an effect exacerbated by networks of storm drains and sewers. This water carries relatively little sediment (again, because soil surfaces have been covered by impermeable materials), so when it reaches a river channel it typically causes erosion and widening. Larger and more frequent floods are another outcome of the increase in runoff generated by urban areas. […] It […] seems very likely that efforts to manage the flood hazard on the Mississippi have contributed to an increased risk of damage from tropical storms on the Gulf of Mexico coast. The levées built along the river have contributed to the loss of coastal wetlands, starving them of sediment and fresh water, thereby reducing their dampening effect on storm surge levels. This probably enhanced the damage from Hurricane Katrina which struck the city of New Orleans in 2005.”

Links:

Onyx River.
Yangtze. Yangtze floods.
Missoula floods.
Murray River.
Ganges.
Thalweg.
Southeastern Anatolia Project.
Water conflict.
Hydropower.
Fulling mill.
Maritime transport.
Danube.
Lock (water navigation).
Hydrometry.
Yellow River.
Aswan High Dam. Warragamba Dam. Three Gorges Dam.
Onchocerciasis.
River restoration.

January 16, 2018 Posted by | Biology, Books, Ecology, Engineering, Geography, Geology, History | Leave a comment

Rivers (I)

I gave the book one star on goodreads. My review on goodreads explains why. In this post I’ll disregard the weak parts of the book and only cover ‘the good stuff’. Part of the reason why I gave the book one star instead of two was that I wanted to punish the author for wasting my time with irrelevant stuff when it was clear to me that he could actually have been providing useful information instead; some parts of the book are quite good.

Some quotes and links below.

“[W]ater is continuously on the move, being recycled between the land, oceans, and atmosphere: an eternal succession known as the hydrological cycle. Rivers play a key role in the hydrological cycle, draining water from the land and moving it ultimately to the sea. Any rain or melted snow that doesn’t evaporate or seep into the earth flows downhill over the land surface under the influence of gravity. This flow is channelled by small irregularities in the topography into rivulets that merge to become gullies that feed into larger channels. The flow of rivers is augmented with water flowing through the soil and from underground stores, but a river is more than simply water flowing to the sea. A river also carries rocks and other sediments, dissolved minerals, plants, and animals, both dead and alive. In doing so, rivers transport large amounts of material and provide habitats for a great variety of wildlife. They carve valleys and deposit plains, being largely responsible for shaping the Earth’s continental landscapes. Rivers change progressively over their course from headwaters to mouth, from steep streams that are narrow and turbulent to wider, deeper, often meandering channels. From upstream to downstream, a continuum of change occurs: the volume of water flowing usually increases and coarse sediments grade into finer material. In its upper reaches, a river erodes its bed and banks, but this removal of earth, pebbles, and sometimes boulders gives way to the deposition of material in lower reaches. In tune with these variations in the physical characteristics of the river, changes can also be seen in the types of creatures and plants that make the river their home. […] Rivers interact with the sediments beneath the channel and with the air above. The water flowing in many rivers comes both directly from the air as rainfall – or another form of precipitation – and also from groundwater sources held in rocks and gravels beneath, both being flows of water through the hydrological cycle.”

“One interesting aspect of rivers is that they seem to be organized hierarchically. When viewed from an aircraft or on a map, rivers form distinct networks like the branches of a tree. Small tributary channels join together to form larger channels which in turn merge to form still larger rivers. This progressive increase in river size is often described using a numerical ordering scheme in which the smallest stream is called first order, the union of two first-order channels produces a second-order river, the union of two second-order channels produces a third-order river, and so on. Stream order only increases when two channels of the same rank merge. Very large rivers, such as the Nile and Mississippi, are tenth-order rivers; the Amazon twelfth order. Each river drains an area of land that is proportional to its size. This area is known by several different terms: drainage basin, river basin, or catchment (‘watershed’ is also used in American English, but this word means the drainage divide between two adjacent basins in British English). In the same way that a river network is made up of a hierarchy of low-order rivers nested within higher-order rivers, their drainage basins also fit together to form a nested hierarchy. In other words, smaller units are repeating elements nested within larger units. All of these units are linked by flows of water, sediment, and energy. Recognizing rivers as being made up of a series of units that are arranged hierarchically provides a potent framework in which to study the patterns and processes associated with rivers. […] processes operating at the upper levels of the hierarchy exert considerable influence over features lower down in the hierarchy, but not the other way around. […] Generally, the larger the spatial scale, the slower the processes and rates of change.”

The stuff above incidentally – and curiously – links very closely with the material covered in Holland’s book on complexity, which I finished just the day before I started reading this one. That book has a lot more stuff about things like nested hierarchies and that ‘potent framework’ mentioned above, and how to go about analyzing such things. (I found that book hard to blog – at least at first, which is why I’m right now covering this book instead; but I do hope to get to it later, it was quite interesting).

“Measuring the length of a river is more complicated than it sounds. […] Disagreements about the true source of many rivers have been a continuous feature of [the] history of exploration. […] most rivers typically have many tributaries and hence numerous sources. […] But it gets more confusing. Some rivers do not have a mouth. […] Some rivers have more than one channel. […] Yet another important part of measuring the length of a river is the scale at which it is measured. Fundamentally, the length of a river varies with the map scale because different amounts of detail are generalized at different scales.”

“Two particularly important properties of river flow are velocity and discharge – the volume of water moving past a point over some interval of time […]. A continuous record of discharge plotted against time is called a hydrograph which, depending on the time frame chosen, may give a detailed depiction of a flood event over a few days, or the discharge pattern over a year or more. […] River flow is dependent upon many different factors, including the area and shape of the drainage basin. If all else is equal, larger basins experience larger flows. A river draining a circular basin tends to have a peak in flow because water from all its tributaries arrives at more or less the same time as compared to a river draining a long, narrow basin in which water arrives from tributaries in a more staggered manner. The surface conditions in a basin are also important. Vegetation, for example, intercepts rainfall and hence slows down its movement into rivers. Climate is a particularly significant determinant of river flow. […] All the rivers with the greatest flows are almost entirely located in the humid tropics, where rainfall is abundant throughout the year. […] Rivers in the humid tropics experience relatively constant flows throughout the year, but perennial rivers in more seasonal climates exhibit marked seasonality in flow. […] Some rivers are large enough to flow through more than one climate region. Some desert rivers, for instance, are perennial because they receive most of their flow from high rainfall areas outside the desert. These are known as ‘exotic’ rivers. The Nile is an example […]. These rivers lose large amounts of water – by evaporation and infiltration into soils – while flowing through the desert, but their volumes are such that they maintain their continuity and reach the sea. By contrast, many exotic desert rivers do not flow into the sea but deliver their water to interior basins.”

…and in rare cases, so much water is contributed to the interior basin that that basin’s actually categorized as a ‘sea’. However humans tend to mess such things up. Amu Darya and Syr Darya used to flow into the Aral Sea, until Soviet planners decided they shouldn’t do that anymore. Goodbye Aral Sea – hello Aralkum Desert!

“An important measure of the way a river system moulds its landscape is the ‘drainage density’. This is the sum of the channel length divided by the total area drained, which reflects the spacing of channels. Hence, drainage density expresses the degree to which a river dissects the landscape, effectively controlling the texture of relief. Numerous studies have shown that drainage density has a great range in different regions, depending on conditions of climate, vegetation, and geology particularly. […] Rivers shape the Earth’s continental landscapes in three main ways: by the erosion, transport, and deposition of sediments. These three processes have been used to recognize a simple three-part classification of individual rivers and river networks according to the dominant process in each of three areas: source, transfer, and depositional zones. The first zone consists of the river’s upper reaches, the area from which most of the water and sediment are derived. This is where most of the river’s erosion occurs, and this eroded material is transported through the second zone to be deposited in the third zone. These three zones are idealized because some sediment is eroded, stored, and transported in each of them, but within each zone one process is dominant.”

“The flow of water carries […] sediment in three ways: dissolved material […] moves in solution; small particles are carried in suspension; and larger particles are transported along the stream bed by rolling, sliding, or a bouncing movement known as ‘saltation’. […] Globally, it is estimated that rivers transport around 15 billion tonnes of suspended material annually to the oceans, plus about another 4 billion tonnes of dissolved material. In its upper reaches, a river might flow across bedrock but further downstream this is much less likely. Alluvial rivers are flanked by a floodplain, the channel cut into material that the river itself has transported and deposited. The floodplain is a relatively flat area which is periodically inundated during periods of high flow […] When water spills out onto the floodplain, the velocity of flow decreases and sediment begins to settle, causing fresh deposits of alluvium on the floodplain. Certain patterns of alluvial river channels have been seen on every continent and are divided at the most basic level into straight, meandering, and braided. Straight channels are rare in nature […] The most common river channel pattern is a series of bends known as meanders […]. Meanders develop because erosion becomes concentrated on the outside of a bend and deposition on the inside. As these linked processes continue, the meander bend can become more emphasized, and a particularly sinuous meander may eventually be cut off at its narrow neck, leaving an oxbow lake as evidence of its former course. Alluvial meanders migrate, both down and across their floodplain […]. This lateral migration is an important process in the formation of floodplains. Braided rivers can be recognized by their numerous flows that split off and rejoin each other to give a braided appearance. These multiple intersecting flows are separated by small and often temporary islands of alluvium. Braided rivers typically carry abundant sediment and are found in areas with a fairly steep gradient, often near mountainous regions.”

“The meander cut-off creating an oxbow lake is one way in which a channel makes an abrupt change of course, a characteristic of some alluvial rivers that is generally referred to as ‘avulsion’. It is a natural process by which flow diverts out of an established channel into a new permanent course on the adjacent floodplain, a change in course that can present a major threat to human activities. Rapid, frequent, and often significant avulsions have typified many rivers on the Indo-Gangetic plains of South Asia. In India, the Kosi River has migrated about 100 kilometres westward in the last 200 years […] Why a river suddenly avulses is not understood completely, but earthquakes play a part on the Indo-Gangetic plains. […] Most rivers eventually flow into the sea or a lake, where they deposit sediment which builds up into a landform known as a delta. The name comes from the Greek letter delta, Δ, shaped like a triangle or fan, one of the classic shapes a delta can take. […] Material laid down at the end of a river can continue underwater far beyond the delta as a deep-sea fan.”

“The organisms found in fluvial ecosystems are commonly classified according to the methods they use to gather food and feed. ‘Shredders’ are organisms that consume small sections of leaves; ‘grazers’ and ‘scrapers’ consume algae from the surfaces of objects such as stones and large plants; ‘collectors’ feed on fine organic matter produced by the breakdown of other once-living things; and ‘predators’ eat other living creatures. The relative importance of these groups of creatures typically changes as one moves from the headwaters of a river to stretches further downstream […] small headwater streams are often shaded by overhanging vegetation which limits sunlight and photosynthesis but contributes organic matter by leaf fall. Shredders and collectors typically dominate in these stretches, but further downstream, where the river is wider and thus receives more sunlight and less leaf fall, the situation is quite different. […] There’s no doubting the numerous fundamental ways in which a river’s biology is dependent upon its physical setting, particularly in terms of climate, geology, and topography. Nevertheless, these relationships also work in reverse. The biological components of rivers also act to shape the physical environment, particularly at more local scales. Beavers provide a good illustration of the ways in which the physical structure of rivers can be changed profoundly by large mammals. […] rivers can act both as corridors for species dispersal but also as barriers to the dispersal of organisms.”

 

Drainage system (geomorphology).
Perennial stream.
Nilometer.
Mekong.
Riverscape.
Oxbow lake.
Channel River.
Long profile of a river.
Bengal fan.
River continuum concept.
Flood pulse concept.
Riparian zone.

 

January 11, 2018 Posted by | Books, Ecology, Geography, Geology | Leave a comment

The Antarctic

“A very poor book with poor coverage, mostly about politics and history (and a long collection of names of treaties and organizations). I would definitely not have finished it if it were much longer than it is.”

That was what I wrote about the book in my goodreads review. I was strongly debating whether or not to blog it at all, but I decided in the end to just settle for some very lazy coverage of the book, only consisting of links to content covered in the book. I only cover the book here to at least have some chance of remembering which kinds of things were covered in the book later on.

If you’re interested enough in the Antarctic to read a book about it, read Scott’s Last Expedition instead of this one (here’s my goodreads review of Scott).

Links:

Antarctica (featured).
Antarctic Convergence.
Antarctic Circle.
Southern Ocean.
Antarctic Circumpolar Current.
West Antarctic Ice Sheet.
East Antarctic Ice Sheet.
McMurdo Dry Valleys.
Notothenioidei.
Patagonian toothfish.
Antarctic krill.
Fabian Gottlieb von Bellingshausen.
Edward Bransfield.
James Clark Ross.
United States Exploring Expedition.
Heroic Age of Antarctic Exploration (featured).
Nimrod Expedition (featured).
Roald Amundsen.
Wilhelm Filchner.
Japanese Antarctic Expedition.
Terra Nova Expedition (featured).
Lincoln Ellsworth.
British Graham Land expedition.
German Antarctic Expedition (1938–1939).
Operation Highjump.
Operation Windmill.
Operation Deep Freeze.
Commonwealth Trans-Antarctic Expedition.
Caroline Mikkelsen.
International Association of Antarctica Tour Operators.
Territorial claims in Antarctica.
International Geophysical Year.
Antarctic Treaty System.
Operation Tabarin.
Scientific Committee on Antarctic Research.
United Nations Convention on the Law of the Sea.
Convention on the Continental Shelf.
Council of Managers of National Antarctic Programs.
British Antarctic Survey.
International Polar Year.
Antarctic ozone hole.
Gamburtsev Mountain Range.
Pine Island Glacier (‘good article’).
Census of Antarctic Marine Life.
Lake Ellsworth Consortium.
Antarctic fur seal.
Southern elephant seal.
Grytviken (whaling-related).
International Convention for the Regulation of Whaling.
International Whaling Commission.
Ocean Drilling Program.
Convention on the Regulation of Antarctic Mineral Resource Activities.
Agreement on the Conservation of Albatrosses and Petrels.

July 3, 2017 Posted by | Biology, Books, Geography, Geology, History, Wikipedia | Leave a comment

Random stuff

i. Fire works a little differently than people imagine. A great ask-science comment. See also AugustusFink-nottle’s comment in the same thread.

ii.

iii. I was very conflicted about whether to link to this because I haven’t actually spent any time looking at it myself so I don’t know if it’s any good, but according to somebody (?) who linked to it on SSC the people behind this stuff have academic backgrounds in evolutionary biology, which is something at least (whether you think this is a good thing or not will probably depend greatly on your opinion of evolutionary biologists, but I’ve definitely learned a lot more about human mating patterns, partner interaction patterns, etc. from evolutionary biologists than I have from personal experience, so I’m probably in the ‘they-sometimes-have-interesting-ideas-about-these-topics-and-those-ideas-may-not-be-terrible’-camp). I figure these guys are much more application-oriented than were some of the previous sources I’ve read on related topics, such as e.g. Kappeler et al. I add the link mostly so that if I in five years time have a stroke that obliterates most of my decision-making skills, causing me to decide that entering the dating market might be a good idea, I’ll have some idea where it might make sense to start.

iv. Stereotype (In)Accuracy in Perceptions of Groups and Individuals.

“Are stereotypes accurate or inaccurate? We summarize evidence that stereotype accuracy is one of the largest and most replicable findings in social psychology. We address controversies in this literature, including the long-standing  and continuing but unjustified emphasis on stereotype inaccuracy, how to define and assess stereotype accuracy, and whether stereotypic (vs. individuating) information can be used rationally in person perception. We conclude with suggestions for building theory and for future directions of stereotype (in)accuracy research.”

A few quotes from the paper:

Demographic stereotypes are accurate. Research has consistently shown moderate to high levels of correspondence accuracy for demographic (e.g., race/ethnicity, gender) stereotypes […]. Nearly all accuracy correlations for consensual stereotypes about race/ethnicity and  gender exceed .50 (compared to only 5% of social psychological findings; Richard, Bond, & Stokes-Zoota, 2003).[…] Rather than being based in cultural myths, the shared component of stereotypes is often highly accurate. This pattern cannot be easily explained by motivational or social-constructionist theories of stereotypes and probably reflects a “wisdom of crowds” effect […] personal stereotypes are also quite accurate, with correspondence accuracy for roughly half exceeding r =.50.”

“We found 34 published studies of racial-, ethnic-, and gender-stereotype accuracy. Although not every study examined discrepancy scores, when they did, a plurality or majority of all consensual stereotype judgments were accurate. […] In these 34 studies, when stereotypes were inaccurate, there was more evidence of underestimating than overestimating actual demographic group differences […] Research assessing the accuracy of  miscellaneous other stereotypes (e.g., about occupations, college majors, sororities, etc.) has generally found accuracy levels comparable to those for demographic stereotypes”

“A common claim […] is that even though many stereotypes accurately capture group means, they are still not accurate because group means cannot describe every individual group member. […] If people were rational, they would use stereotypes to judge individual targets when they lack information about targets’ unique personal characteristics (i.e., individuating information), when the stereotype itself is highly diagnostic (i.e., highly informative regarding the judgment), and when available individuating information is ambiguous or incompletely useful. People’s judgments robustly conform to rational predictions. In the rare situations in which a stereotype is highly diagnostic, people rely on it (e.g., Crawford, Jussim, Madon, Cain, & Stevens, 2011). When highly diagnostic individuating information is available, people overwhelmingly rely on it (Kunda & Thagard, 1996; effect size averaging r = .70). Stereotype biases average no higher than r = .10 ( Jussim, 2012) but reach r = .25 in the absence of individuating information (Kunda & Thagard, 1996). The more diagnostic individuating information  people have, the less they stereotype (Crawford et al., 2011; Krueger & Rothbart, 1988). Thus, people do not indiscriminately apply their stereotypes to all individual  members of stereotyped groups.” (Funder incidentally talked about this stuff as well in his book Personality Judgment).

One thing worth mentioning in the context of stereotypes is that if you look at stuff like crime data – which sadly not many people do – and you stratify based on stuff like country of origin, then the sub-group differences you observe tend to be very large. Some of the differences you observe between subgroups are not in the order of something like 10%, which is probably the sort of difference which could easily be ignored without major consequences; some subgroup differences can easily be in the order of one or two orders of magnitude. The differences are in some contexts so large as to basically make it downright idiotic to assume there are no differences – it doesn’t make sense, it’s frankly a stupid thing to do. To give an example, in Germany the probability that a random person, about whom you know nothing, has been a suspect in a thievery case is 22% if that random person happens to be of Algerian extraction, whereas it’s only 0,27% if you’re dealing with an immigrant from China. Roughly one in 13 of those Algerians have also been involved in a case of ‘body (bodily?) harm’, which is the case for less than one in 400 of the Chinese immigrants.

v. Assessing Immigrant Integration in Sweden after the May 2013 Riots. Some data from the article:

“Today, about one-fifth of Sweden’s population has an immigrant background, defined as those who were either born abroad or born in Sweden to two immigrant parents. The foreign born comprised 15.4 percent of the Swedish population in 2012, up from 11.3 percent in 2000 and 9.2 percent in 1990 […] Of the estimated 331,975 asylum applicants registered in EU countries in 2012, 43,865 (or 13 percent) were in Sweden. […] More than half of these applications were from Syrians, Somalis, Afghanis, Serbians, and Eritreans. […] One town of about 80,000 people, Södertälje, since the mid-2000s has taken in more Iraqi refugees than the United States and Canada combined.”

“Coupled with […] macroeconomic changes, the largely humanitarian nature of immigrant arrivals since the 1970s has posed challenges of labor market integration for Sweden, as refugees often arrive with low levels of education and transferable skills […] high unemployment rates have disproportionately affected immigrant communities in Sweden. In 2009-10, Sweden had the highest gap between native and immigrant employment rates among OECD countries. Approximately 63 percent of immigrants were employed compared to 76 percent of the native-born population. This 13 percentage-point gap is significantly greater than the OECD average […] Explanations for the gap include less work experience and domestic formal qualifications such as language skills among immigrants […] Among recent immigrants, defined as those who have been in the country for less than five years, the employment rate differed from that of the native born by more than 27 percentage points. In 2011, the Swedish newspaper Dagens Nyheter reported that 35 percent of the unemployed registered at the Swedish Public Employment Service were foreign born, up from 22 percent in 2005.”

“As immigrant populations have grown, Sweden has experienced a persistent level of segregation — among the highest in Western Europe. In 2008, 60 percent of native Swedes lived in areas where the majority of the population was also Swedish, and 20 percent lived in areas that were virtually 100 percent Swedish. In contrast, 20 percent of Sweden’s foreign born lived in areas where more than 40 percent of the population was also foreign born.”

vi. Book recommendations. Or rather, author recommendations. A while back I asked ‘the people of SSC’ if they knew of any fiction authors I hadn’t read yet which were both funny and easy to read. I got a lot of good suggestions, and the roughly 20 Dick Francis novels I’ve read during the fall I’ve read as a consequence of that thread.

vii. On the genetic structure of Denmark.

viii. Religious Fundamentalism and Hostility against Out-groups: A Comparison of Muslims and Christians in Western Europe.

“On the basis of an original survey among native Christians and Muslims of Turkish and Moroccan origin in Germany, France, the Netherlands, Belgium, Austria and Sweden, this paper investigates four research questions comparing native Christians to Muslim immigrants: (1) the extent of religious fundamentalism; (2) its socio-economic determinants; (3) whether it can be distinguished from other indicators of religiosity; and (4) its relationship to hostility towards out-groups (homosexuals, Jews, the West, and Muslims). The results indicate that religious fundamentalist attitudes are much more widespread among Sunnite Muslims than among native Christians, even after controlling for the different demographic and socio-economic compositions of these groups. […] Fundamentalist believers […] show very high levels of out-group hostility, especially among Muslims.”

ix. Portal: Dinosaurs. It would have been so incredibly awesome to have had access to this kind of stuff back when I was a child. The portal includes links to articles with names like ‘Bone Wars‘ – what’s not to like? Again, awesome!

x. “you can’t determine if something is truly random from observations alone. You can only determine if something is not truly random.” (link) An important insight well expressed.

xi. Chessprogramming. If you’re interested in having a look at how chess programs work, this is a neat resource. The wiki contains lots of links with information on specific sub-topics of interest. Also chess-related: The World Championship match between Carlsen and Karjakin has started. To the extent that I’ll be following the live coverage, I’ll be following Svidler et al.’s coverage on chess24. Robin van Kampen and Eric Hansen – both 2600+ elo GMs – did quite well yesterday, in my opinion.

xii. Justified by More Than Logos Alone (Razib Khan).

“Very few are Roman Catholic because they have read Aquinas’ Five Ways. Rather, they are Roman Catholic, in order of necessity, because God aligns with their deep intuitions, basic cognitive needs in terms of cosmological coherency, and because the church serves as an avenue for socialization and repetitive ritual which binds individuals to the greater whole. People do not believe in Catholicism as often as they are born Catholics, and the Catholic religion is rather well fitted to a range of predispositions to the typical human.”

November 12, 2016 Posted by | Books, Chemistry, Chess, Data, dating, Demographics, Genetics, Geography, immigration, Paleontology, Papers, Physics, Psychology, Random stuff, Religion | Leave a comment

Water Supply in Emergency Situations (II)

Here’s my first post about the book. In this post I’ve added a few more quotes from a couple of the last chapters of the book:

“Due to the high complexity of the [water supply] systems, and the innumerable possible points of contaminant insertion, complete prevention of all possible terror attacks (chemical, biological, or radiological) on modern drinking water supplying systems […] seems to be an impossible goal. For example, in the USA there are about 170,000 water systems, with about 8,100 very large systems that serve 90% of the population who get water from a community water system […] The prevailing approach to the problem of drinking water contamination is based on the implementation of surveillance measures and technologies for “risk reduction” such as improvement of physical security measures of critical assets (high-potential vulnerability to attacks), [and] installation of online contaminant monitoring systems (OCMS) with capabilities to detect and warn in real time on relevant contaminants, as part of standard operating procedures for quality control (QC) and supervisory control and data acquisition (SCADA) systems. […] Despite the impressive technical progress in online water monitoring technologies […] detection with complete certainty of pollutants is expensive, and remains problematic.”

“A key component of early warning systems is the availability of a mathematical model for predicting the transport and fate of the spill or contaminant so that downstream utilities can be warned. […] Simulation tools (i.e. well-calibrated hydraulic and water quality models) can be linked to SCADA real-time databases allowing for continuous, high-speed modeling of the pressure, flow, and water quality conditions throughout the water distribution network. Such models provide the operator with computed system status data within the distribution network. These “virtual sensors” complement the measured data. Anomalies between measured and modeled data are automatically observed, and computed values that exceed predetermined alarm thresholds are automatically flagged by the SCADA system.”

“Any given tap receives water, which arrives though a number of pipes in the supply network, the transport route, and ultimately comes from a source […] in order to achieve maximum supply security in case of pipe failures or unusual demand patterns (e.g. fire flows) water supply networks are generally designed as complicated, looped systems, where each tap typically can receive water from several sources and intermediate storage facilities. This means that the water from any given tap can arrive through several different routes and can be a mixture of water from several sources. The routes and sources for a given tap can vary over time […] A model can show: *Which sources (well-fields, reservoirs, and tanks) contribute to the supply of which parts of the city? *Where does the water come from (percentage distribution) at any specific location in the system (any given tap or pipe)? *How long has the water been traveling in the pipe system, before it reaches a specific location?
One way to reduce the risk – and simplify the response to incidents – is by compartmentalizing the water supply system. If each tap receives water from one and only one reservoir pollution of one reservoir will affect one well-defined and relatively smaller part of the city. Compartmentalizing the water supply system will reduce the spreading of toxic substances. On the flip side, it may increase the concentration of the toxic substance. It is also likely to have a negative impact on the supply of water for fire flow and on the robustness of the water supply network in case of failures of pipes or other elements.”

An important point in the context of that part of the coverage is that if you want online (i.e. continuous, all-the-time) monitoring of drinking water, well, that’s going to be expensive regardless of how precisely you’re going to go about doing it. Another related problem is that it’s actually not really a simple matter to figure out what it even makes sense to test for when you’re analyzing the water (you can’t test for ‘everything’ all the time, and so the leading approach in monitoring systems employed today is according to the authors based on the idea of using ‘surrogate parameters’ which may be particularly informative about any significant changes in the quality of the drinking water taking place.

“After the collapse of the Soviet Union, the countries of the South Caucasus gained their independence. However, they faced problems associated with national and transboundary water management. Transboundary water management remains one of the key issues leading to conflict in the region today. The scarcity of water especially in downstream areas is a major problem […] The fresh surface water resources of the South Caucasus mainly consist of runoff from the KuraAraz River basins. […] Being a water-poor region, water supply over the Azerbaijan Republic territory totals about 100,000 /km2, which amounts to an average of about 1,000 of water per person per year. Accordingly, Azerbaijan Republic occupies one of the lowest рlaces in the world in water availability. Water resources of the Republic are distributed very irregularly over administrative districts.”

Water provision [in Azerbaijan] […] is carried out by means of active hydrotechnical constructions, which are old-fashioned and many water intake facilities and treatment systems cannot operate during high flooding, water turbidity, and extreme pollution. […] Tap water satisfies [the] needs of only 50% of the population, and some areas experience lack of drinking water. Due to the lack of water supply networks and deteriorated conditions of those existing, about half of the water is lost within the distribution system. […] The sewage system of the city of Baku covers only 70% of its territory and only about half of sewage is treated […] Owing to rapid growth of turbidity of Kura (and its inflows) during high water the water treatment facilities are rendered inoperable thus causing failures in the water supply of the population of the city of Baku. Such situations mainly take place in autumn and spring on the average 3–5 times a year for 1–2 days. In the system of centralized water supply of the city of Baku about 300 emergency cases occur annually […] Practically nobody works with the population to promote efficient water use practices.”

October 31, 2016 Posted by | Books, Engineering, Geography, Microbiology | Leave a comment

Water Supply in Emergency Situations (I)

I didn’t think much of this book (here’s my goodreads review), but I did learn some new things from reading it. Some of the coverage in the book overlapped a little bit with stuff I’d read before, e.g. coverage provided in publications such as Rodricks and Fong and Alibek, but I read those books in 2013 and 2014 respectively (so I’ve already forgot a great deal) and most of the stuff in the book was new stuff. Below I’ve added a few observations and data from the first half of the publication.

“Mediterranean basin demands for water are high. Today, the region uses around 300 billion cubic meters per year. Two thirds of Mediterranean countries now use over 500  per year per inhabitant mainly because of heavy use of irrigation. But these per capita demands are irregular and vary across a wide range – from a little over 100 to more than 1,000 per year. Globally, demand has doubled since the beginning of the 20th century and increased by 60% over the last 25 years. […] the Middle East ecosystems […]  populate some 6% of the world population, but have only some 1% of its renewable fresh water. […] Seasonality of both supply and demand due to tourism […] aggravate water resource problems. During the summer months, water shortages become more frequent. Distribution networks left unused during the winter period face overload pressures in the summer. On the other hand, designing the system with excess capability to satisfy tourism-related summer peak demands raises construction and maintenance costs significantly.”

“There are over 30,000 km of mains within London and over 30% of these are over 150 years old, they serve 7.5 million people with 2,500 million liters of water a day.”

“A major flooding of the Seine River would have tremendous consequences and would impact very significantly the daily life of the 10 million people living in the Parisian area. A deep study of the impacts of such a catastrophic natural hazard has recently been initiated by the French authorities. […] The rise of the water level in the Seine during the last two major floods occurred slowly over several weeks which may explain their low number of fatalities: 50 deaths in 1658 and only one death in 1910. The damage and destruction to buildings and infrastructure, and the resulting effect on economic activity were, however, of major proportions […] Dams have been constructed on the rivers upstream from Paris, but their capacity to stock water is only 830 million cubic meters, which would be insufficient when compared to the volume of 4 billion cubic meters of water produced by a big flood. […] The drinkable water supply system in Paris, as well as that of the sewer network, is still constrained by the decisions and orientations taken during the second half of the 19th century during the large public works projects realized under Napoleon III. […] two of the three water plants which treat river water and supply half of Paris with drinkable water existed in 1910. Water treatment technology has radically changed, but the production sites have remained the same. New reservoirs for potable water have been added, but the principles of distribution have not changed […] The average drinking water production in Paris is 615,000 /day.”

They note in the chapter from which the above quotes are taken that a flood comparable to that which took place in 1910 would in 2005 have resulted in 20% of the surface of Paris being flooded, and 600.000 people being without electricity, among other things. The water distribution system currently in place would also be unable to deal with the load, however a plan for how to deal with this problem in an emergency setting does exist. In that context it’s perhaps worth noting that Paris is hardly unique in terms of the structure of the distribution system – elsewhere in the book it is observed that: “The water infrastructure developed in Europe during the 19th century and still applied, is almost completely based on options of centralized systems: huge supply and disposal networks with few, but large waterworks and sewage treatment plants.” Having both centralized and decentralized systems working at the same time/in the same area tends to increase costs, but may also lower risk; it’s observed in the book during the coverage of an Indonesian case-study that in that region the centralized service provider may take a long time to repair broken water pipes, which is … not very nice if you live in a tropical climate and prefer to have drinking water available to you.

“Water resources management challenges differ enormously in Romania, depending on the type of human settlement. The spectrum of settlement types stretches from the very low-density scattered single dwellings found in rural areas, through villages and small towns, to the much more dense and crowded cities. […] Water resources management will always face the challenge of balancing the needs of different water users. This is the case both in large urban or relatively small rural communities. The water needs of the agricultural production, energy and industrial sectors are often in competition. […] Romania’s water resources are relatively poor and unequally distributed in time and space […] There is a vast differential between urban and rural settlements when it comes to centralized drinking water systems; all the 263 municipalities and towns have such systems, while only 17% of rural communities benefit from this service. […] In Braila and Harghita counties, no village has a sewage network, and Giurgiu and Ialomita counties have only one a piece each. Around 47 of the largest cities which do not have wastewater treatment plants (Bucharest, Braila, Craiova, Turnu Severin Tulcea, etc.) produce ∼20 /s of wastewater, which is directly discharged untreated into surface water.”

There is a difference in quality between water from centralized and decentralized supply systems [in the Ukraine (and likely elsewhere as well)]. Water quality in decentralized systems is the worst (some 30% of samples fail to meet standards, compared to 5.7% in the centralized supply). […] The Sanitary epidemiological stations draw random samples from 1,139 municipal, 6,899 departmental, and 8,179 rural pipes, and from 158,254 points of decentralized water supply, including 152,440 wells, 996 springs, and 4,818 artesian wells. […] From the first day following the accident at Chernobyl Nuclear Power Plant (ChNPP), one of the most serious problems was to prevent general contamination of the Dnieper water system and to guarantee safe water consumption for people living in the affected zone. The water protection and development of monitoring programs for the affected water bodies were among the most important post-accident countermeasures taken by the Government Bodies in Ukraine. […] To solve the water quality problem for Kiev, an emergency water intake at the Desna River was constructed within a very short period. […] During 1986 and the early months of 1987, over 130 special filtration dams […] with sorbing screens containing zeolite (klinoptilolite) were installed for detaining radionuclides while letting the water through. […] After the spring flood of 1987, the construction of new dams was terminated and the decision was made to destroy most of the existing dams. It was found that the 90Sr concentration reduction by the dams studied was insignificant […] Although some countermeasures and cleanup activities applied to radionuclides sources on catchments proved to have positive effects, many other actions were evaluated as ineffective and even useless. […] The most effective measures to reduce radioactivity in drinking water are those, which operate at the water treatment and distribution stage.

“Diversification and redundancy are important technical features to make infrastructure systems less vulnerable to natural and social (man-made) hazards. […] risk management does not only encompass strategies to avoid the occurrence of certain events which might lead to damages or catastrophes, but also strategies of adaptation to limit damages.

The loss of potable water supply typically leads to waterborne diseases, such as typhus and cholera.”

Water velocity in a water supply system is about 1 \s. Therefore, time is a primordial factor in contamination spread along the system. In order to minimize the damage caused by contamination of water, it is essential to act with maximum speed to achieve minimum spread of the contaminant”

October 21, 2016 Posted by | Books, Engineering, Geography, Infectious disease, Microbiology | Leave a comment

Deserts

I recently read Nick Middleton’s short publication on this topic and decided it was worth blogging it here. I gave the publication 3 stars on goodreads; you can read my goodreads review of the book here.

In this post I’ll quote a bit from the book and add some details I thought were interesting.

“None of [the] approaches to desert definition is foolproof. All have their advantages and drawbacks. However, each approach delivers […] global map[s] of deserts and semi-deserts that [are] broadly similar […] Roughly, deserts cover about one-quarter of our planet’s land area, and semi-deserts another quarter.”

“High temperatures and a paucity of rainfall are two aspects of climate that many people routinely associate with deserts […] However, desert climates also embrace other extremes. Many arid zones experience freezing temperatures and snowfall is commonplace, particularly in those situated outside the tropics. […] For much of the time, desert skies are cloud-free, meaning deserts receive larger amounts of sunshine than any other natural environment. […] Most of the water vapour in the world’s atmosphere is supplied by evaporation from the oceans, so the more remote a location is from this source the more likely it is that any moisture in the air will have been lost by precipitation before it reaches continental interiors. The deserts of Central Asia illustrate this principle well: most of the moisture in the air is lost before it reaches the heart of the continent […] A clear distinction can be made between deserts in continental interiors and those on their coastal margins when it comes to the range of temperatures experienced. Oceans tend to exert a moderating influence on temperature, reducing extremes, so the greatest ranges of temperature are found far from the sea while coastal deserts experience a much more limited range. […] Freezing temperatures occur particularly in the mid-latitude deserts, but by no means exclusively so. […] snowfall occurs at the Algerian oasis towns of Ouagla and Ghardaia, in the northern Sahara, as often as once every 10 years on average.”

“[One] characteristic of rainfall in deserts is its variability from year to year which in many respects makes annual average statistics seem like nonsense. A very arid desert area may go for several years with no rain at all […]. It may then receive a whole ‘average’ year’s rainfall in just one storm […] Rainfall in deserts is also typically very variable in space as well as time. Hence, desert rainfall is frequently described as being ‘spotty’. This spottiness occurs because desert storms are often convective, raining in a relatively small area, perhaps just a few kilometres across. […] Climates can vary over a wide range of spatial scales […] Changes in temperature, wind, relative humidity, and other elements of climate can be detected over short distances, and this variability on a small scale creates distinctive climates in small areas. These are microclimates, different in some way from the conditions prevailing over the surrounding area as a whole. At the smallest scale, the shade given by an individual plant can be described as a microclimate. Over larger distances, the surface temperature of the sand in a dune will frequently be significantly different from a nearby dry salt lake because of the different properties of the two types of surface. […] Microclimates are important because they exert a critical control over all sorts of phenomena. These include areas suitable for plant and animal communities to develop, the ways in which rocks are broken down, and the speed at which these processes occur.”

“The level of temperature prevailing when precipitation occurs is important for an area’s water balance and its degree of aridity. A rainy season that occurs during the warm summer months, when evaporation is greatest, makes for a climate that is more arid than if precipitation is distributed more evenly throughout the year.”

“The extremely arid conditions of today[‘s Sahara Desert] have prevailed for only a few thousand years. There is lots of evidence to suggest that the Sahara was lush, nearly completely covered with grasses and shrubs, with many lakes that supported antelope, giraffe, elephant, hippopotamus, crocodile, and human populations in regions that today have almost no measurable precipitation. This ‘African Humid Period’ began around 15,000 years ago and came to an end around 10,000 years later. […] Globally, at the height of the most recent glacial period some 18,000 years ago, almost 50% of the land area between 30°N and 30°S was covered by two vast belts of sand, often called ‘sand seas’. Today, about 10% of this area is covered by sand seas. […] Around one-third of the Arabian subcontinent is covered by sandy deserts”.

“Much of the drainage in deserts is internal, as in Central Asia. Their rivers never reach the sea, but take water to interior basins. […] Salt is a common constituent of desert soils. The generally low levels of rainfall means that salts are seldom washed away through soils and therefore tend to accumulate in certain parts of the landscape. Large amounts of common salt (sodium chloride, or halite), which is very soluble in water, are found in some hyper-arid deserts.”

“Many deserts are very rich in rare and unique species thanks to their evolution in relative geographical isolation. Many of these plants and animals have adapted in remarkable ways to deal with the aridity and extremes of temperature. Indeed, some of these adaptations contribute to the apparent lifelessness of deserts simply because a good way to avoid some of the harsh conditions is to hide. Some small creatures spend hot days burrowed beneath the soil surface. In a similar way, certain desert plants spend most of the year and much of their lives dormant, as seeds waiting for the right conditions, brought on by a burst of rainfall. Given that desert rainstorms can be very variable in time and in space, many activities in the desert ecosystem occur only sporadically, as pulses of activity driven by the occasional cloudburst. […] The general scarcity of water is the most important, though by no means the only, environmental challenge faced by desert organisms. Limited supplies of food and nutrients, friable soils, high levels of solar radiation, high daytime temperatures, and the large diurnal temperature range are other challenges posed by desert conditions. These conditions are not always distributed evenly across a desert landscape, and the existence of more benign microenvironments is particularly important for desert plants and animals. Patches of terrain that are more biologically productive than their surroundings occur in even the most arid desert, geographical patterns caused by many factors, not only the simple availability of water.”

A small side note here: The book includes brief coverage of things like crassulacean acid metabolism and related topics covered in much more detail in Beer et al. I’m not going to go into that stuff here as this stuff was in my opinion much better covered in the latter book (some people might disagree, but people who would do that would at least have to admit that the coverage in Beer et al. is/was much more comprehensive than is Middleton’s coverage in this book). There are quite a few other topics included in the book which I did not include coverage of here in the post but I mention this topic in particular in part because I thought it was actually a good example underscoring how this book is very much just a very brief introduction; you can write book chapters, if not books, about some of the topics Middleton devotes a couple of paragraphs to in his coverage, which is but to be expected given the nature and range of coverage of the publication.

Plants aren’t ‘smart’ given any conventional definition of the word, but as I’ve talked about before here on the blog (e.g. here) when you look closer at the way they grow and ‘behave’ over the very long term, some of the things they do are actually at the very least ‘not really all that stupid’:

“The seeds of annuals germinate only when enough water is available to support the entire life cycle. Germinating after just a brief shower could be fatal, so mechanisms have developed for seeds to respond solely when sufficient water is available. Seeds germinate only when their protective seed coats have been broken down, allowing water to enter the seed and growth to begin. The seed coats of many desert species contain chemicals that repel water. These compounds are washed away by large amounts of water, but a short shower will not generate enough to remove all the water-repelling chemicals. Other species have very thick seed coats that are gradually worn away physically by abrasion as moving water knocks the seeds against stones and pebbles.”

What about animals? One thing I learned from this publication is that it turns out that being a mammal will, all else equal, definitely not give you a competitive edge in a hot desert environment:

“The need to conserve water is important to all creatures that live in hot deserts, but for mammals it is particularly crucial. In all environments mammals typically maintain a core body temperature of around 37–38°C, and those inhabiting most non-desert regions face the challenge of keeping their body temperature above the temperature of their environmental surrounds. In hot deserts, where environmental temperatures substantially exceed the body temperature on a regular basis, mammals face the reverse challenge. The only mechanism that will move heat out of an animal’s body against a temperature gradient is the evaporation of water, so maintenance of the core body temperature requires use of the resource that is by definition scarce in drylands.”

Humans? What about them?

“Certain aspects of a traditional mobile lifestyle have changed significantly for some groups of nomadic peoples. Herders in the Gobi desert in Mongolia pursue a way of life that in many ways has changed little since the times of the greatest of all nomadic leaders, Chinggis Khan, 750 years ago. They herd the same animals, eat the same foods, wear the same clothes, and still live in round felt-covered tents, traditional dwellings known in Mongolian as gers. Yet many gers now have a set of solar panels on the roof that powers a car battery, allowing an electric light to extend the day inside the tent. Some also have a television set.” (these remarks incidentally somehow reminded me of this brilliant Gary Larson cartoon)

“People have constructed dams to manage water resources in arid regions for thousands of years. One of the oldest was the Marib dam in Yemen, built about 3,000 years ago. Although this structure was designed to control water from flash floods, rather than for storage, the diverted flow was used to irrigate cropland. […] Although groundwater has been exploited for desert farmland using hand-dug underground channels for a very long time, the discovery of reserves of groundwater much deeper below some deserts has led to agricultural use on much larger scales in recent times. These deep groundwater reserves tend to be non-renewable, having built up during previous climatic periods of greater rainfall. Use of this fossil water has in many areas resulted in its rapid depletion.”

“Significant human impacts are thought to have a very long history in some deserts. One possible explanation for the paucity of rainfall in the interior of Australia is that early humans severely modified the landscape through their use of fire. Aboriginal people have used fire extensively in Central Australia for more than 20,000 years, particularly as an aid to hunting, but also for many other purposes, from clearing passages to producing smoke signals and promoting the growth of preferred plants. The theory suggests that regular burning converted the semi-arid zone’s mosaic of trees, shrubs, and grassland into the desert scrub seen today. This gradual change in the vegetation could have resulted in less moisture from plants reaching the atmosphere and hence the long-term desertification of the continent.” (I had never heard about this theory before, and so I of course have no idea if it’s correct or not – but it’s an interesting idea).

A few wikipedia links of interest:
Yardang.
Karakum Canal.
Atacama Desert.
Salar de Uyuni.
Taklamakan Desert.
Dust Bowl.
Namib Desert.
Dzud.

August 27, 2016 Posted by | Anthropology, Biology, Books, Botany, Ecology, Engineering, Geography, Zoology | Leave a comment

Civil Wars (II)

Here’s my first post about the book. In this post I’ll continue my coverage where I left off in my first post. A few of the chapters covered below I did not think very highly of, but other parts of the coverage are about as good as you could expect (given problems such as e.g. limited data etc.). Some of the stuff I found quite interesting. As people will note in the coverage below the book does address the religious dimension to some extent, though in my opinion far from to the extent that the variable deserves. An annoying aspect of the chapter on religion was to me that although the author of the chapter includes data which to me cannot but lead to some very obvious conclusions, the author seems to be very careful avoiding drawing those conclusions explicitly. It’s understandable, but still annoying. For related reasons I also got annoyed at him for presumably deliberately completely disregarding which seems in the context of his own coverage to be an actually very important component of Huntington’s thesis, that conflict at the micro level seems to very often be between muslims and ‘the rest’. Here’s a relevant quote from Clash…, p. 255:

“ethnic conflicts and fault line wars have not been evenly distributed among the world’s civilizations. Major fault line fighting has occurred between Serbs and Croats in the former Yugoslavia and between Buddhists and Hindus in Sri Lanka, while less violent conflicts took place between non-Muslim groups in a few other places. The overwhelming majority of fault line conflicts, however, have taken place along the boundary looping across Eurasia and Africa that separates Muslims from non-Muslims. While at the macro or global level of world politics the primary clash of civilizations is between the West and the rest, at the micro or local level it is between Islam and the others.”

This point, that conflict at the local level – which seems to be the type of conflict level you’re particularly interested in if you’re researching civil wars, as also argued in previous chapters in the coverage – according to Huntington seems to be very islam-centric, is completely overlooked (ignored?) in the handbook chapter, and if you haven’t read Huntington and your only exposure to him is through the chapter in question you’ll probably conclude that Huntington was wrong, because that seems to be the conclusion the author draws, arguing that other models are more convincing (I should add here that these other models do seem useful, at least in terms of providing (superficial) explanations; the point is just that I feel the author is misrepresenting Huntington and I dislike this). Although there are parts of the coverage in that chapter where I feel that it’s obvious the author and I do not agree, I should note that the fact that he talks about the data and the empirical research makes up for a lot of other stuff.

Anyway, on to the coverage – it’s perhaps worth noting, in light of the introductory remarks above, that the post has stuff on a lot of things besides religion, e.g. the role of natural resources, regime types, migration, and demographics.

“Elites seeking to end conflict must: (1) lead followers to endorse and support peaceful solutions; (2) contain spoilers and extremists and prevent them from derailing the process of peacemaking; and (3) forge coalitions with more moderate members of the rival ethnic group(s) […]. An important part of the two-level nature of the ethnic conflict is that each of the elites supporting the peace process be able to present themselves, and the resulting terms of the peace, as a “win” for their ethnic community. […] A strategy that a state may pursue to resolve ethnic conflict is to co-opt elites from the ethnic communities demanding change […]. By satisfying elites, it reduces the ability of the aggrieved ethnic community to mobilize. Such a process of co-option can also be used to strengthen ethnic moderates in order to undermine ethnic extremists. […] the co-opted elites need to be careful to be seen as still supporting ethnic demands or they may lose all credibility in their respective ethnic community. If this occurs, the likely outcome is that more extreme ethnic elites will be able to capture the ethnic community, possibly leading to greater violence.
It is important to note that “spoilers,” be they an individual or a small sub-group within an ethnic community, can potentially derail any peace process, even if the leaders and masses support peace (Stedman, 2001).”

“Three separate categories of international factors typically play into identity and ethnic conflict. The first is the presence of an ethnic community across state boundaries. Thus, a single community exists in more than one state and its demands become international. […] This division of an ethnic community can occur when a line is drawn geographically through a community […], when a line is drawn and a group moves into the new state […], or when a diaspora moves a large population from one state to another […] or when sub-groups of an ethnic community immigrate to the developed world […] When ethnic communities cross state boundaries, the potential for one state to support an ethnic community in the other state exists. […] There is also the potential for ethnic communities to send support to a conflict […] or to lobby their government to intervene […]. Ethnic groups may also form extra-state militias and cross international borders. Sometimes these rebel groups can be directly or indirectly sponsored by state governments, leading to a very complex situation […] A second set of possible international factors is non-ethnic international intervention. A powerful state may decide to intervene in an ethnic conflict for a variety of reasons, ranging from humanitarian support, to peacekeeping, to outright invasion […] The third and last factor is the commitment of non-governmental organizations (NGOs) or third-party mediators to a conflict. […] The record of international interventions in ethnic civil wars is quite mixed. There are many difficulties associated with international action [and] international groups cannot actually change the underlying root of the ethnic conflict (Lake and Rothchild, 1998; Kaufman, 1996).”

“A relatively simple way to think of conflict onset is to think that for a rebellion to occur two conditions need to be satisfactorily fulfilled: There must be a motivation and there must be an opportunity to rebel.3 First, the rebels need a motive. This can be negative – a grievance against the existing state of affairs – or positive – a desire to capture resource rents. Second, potential rebels need to be able to achieve their goal: The realization of their desires may be blocked by the lack of financial means. […] Work by Collier and Hoeffler (1998, 2004) was crucial in highlighting the economic motivation behind civil conflicts. […] Few conflicts, if any, can be characterized purely as “resource conflicts.” […] It is likely that few groups are solely motivated by resource looting, at least in the lower rank level. What is important is that valuable natural resources create opportunities for conflicts. To feed, clothe, and arm its members, a rebel group needs money. Unless the rebel leaders are able to raise sufficient funds, a conflict is unlikely to start no matter how severe the grievances […] As a consequence, feasibility of conflict – that is, valuable natural resources providing opportunity to engage in violent conflict – has emerged as a key to understanding the relation between valuable resources and conflict.”

“It is likely that some natural resources are more associated with conflict than others. Early studies on armed civil conflict used resource measures that aggregated different types of resources together. […] With regard to financing conflict start-up and warfare the most salient aspect is probably the ease with which a resource can be looted. Lootable resources can be extracted with simple methods by individuals or small groups, are easy to transport, and can be smuggled across borders with limited risks. Examples of this type of resources are alluvial gemstones and gold. By contrast, deep-shaft minerals, oil, and natural gas are less lootable and thus less likely sources of financing. […] Using comprehensive datasets on all armed civil conflicts in the world, natural resource production, and other relevant aspects such as political regime, economic performance, and ethnic composition, researchers have established that at least some high-value natural resources are related to higher risk of conflict onset. Especially salient in this respect seem to be oil and secondary diamonds[7] […] The results regarding timber […] and cultivation of narcotics […] are inconclusive. […] [An] important conclusion is that natural resources should be considered individually and not lumped together. Diamonds provide an illustrative example: the geological form of the diamond deposit is related to its effect on conflict. Secondary diamonds – the more lootable form of two deposit types – makes conflict more likely, longer, and more severe. Primary diamonds on the other hand are generally not related to conflict.”

“Analysis on conflict duration and severity confirm that location is a salient factor: resources matter for duration and severity only when located in the region where the conflict is taking place […] That the location of natural resources matters has a clear and important implication for empirical conflict research: relying on country-level aggregates can lead to wrong conclusions about the role of natural resources in armed civil conflict. As a consequence of this, there has been effort to collect location-specific data on oil, gas, drug cultivation, and gemstones”.

“a number of prominent studies of ethnic conflict have suggested that when ethnic groups grow at different rates, this may lead to fears of an altered political balance, which in turn might cause political instability and violent conflict […]. There is ample anecdotal evidence for such a relationship [but unfortunately little quantitative research…]. The civil war in Lebanon, for example, has largely been attributed to a shift in the delicate ethnic balance in that state […]. Further, in the early 1990s, radical Serb leaders were agitating for the secession of “Serbian” areas in Bosnia-Herzegovina by instigating popular fears that Serbs would soon be outnumbered by a growing Muslim population heading for the establishment of a Shari’a state”.

“[One] part of the demography-conflict literature has explored the role of population movements. Most of this literature […] treats migration and refugee flows as a consequence of conflict rather than a potential cause. Some scholars, however, have noted that migration, and refugee migration in particular, can spur the spread of conflict both between and within states […]. Existing work suggests that environmentally induced migration can lead to conflict in receiving areas due to competition for scarce resources and economic opportunities, ethnic tensions when migrants are from different ethnic groups, and exacerbation of socioeconomic “fault lines” […] Salehyan and Gleditsch (2006) point to spill-over effects, in the sense that mass refugee migration might spur tensions in neighboring or receiving states by imposing an economic burden and causing political stability [sic]. […] Based on a statistical analysis of refugees from neighboring countries and civil war onset during the period 1951–2001, they find that countries that experience an influx of refugees from neighboring states are significantly more likely to experience wars themselves. […] While the youth bulge hypothesis [large groups of young males => higher risk of violence/war/etc.] in general is supported by empirical evidence, indicating that countries and areas with large youth cohorts are generally at a greater risk of low-intensity conflict, the causal pathways relating youth bulges to increased conflict propensity remain largely unexplored quantitatively. When it comes to the demographic factors which have so far received less attention in terms of systematic testing – skewed sex ratios, differential ethnic growth, migration, and urbanization – the evidence is somewhat mixed […] a clear challenge with regard to the study of demography and conflict pertains to data availability and reliability. […] Countries that are undergoing armed conflict are precisely those for which we need data, but also those in which census-taking is hampered by violence.”

“Most research on the duration of civil war find that civil wars in democracies tend to be longer than other civil wars […] Research on conflict severity finds some evidence that democracies tend to see fewer battledeaths and are less likely to target civilians, suggesting that democratic institutions may induce some important forms of restraints in armed conflict […] Many researchers have found that democratization often precedes an increase in the risk of the onset of armed conflict. Hegre et al. (2001), for example, find that the risk of civil war onset is almost twice as high a year after a regime change as before, controlling for the initial level of democracy […] Many argue that democratic reforms come about when actors are unable to rule unilaterally and are forced to make concessions to an opposition […] The actual reforms to the political system we observe as democratization often do not suffice to reestablish an equilibrium between actors and the institutions that regulate their interactions; and in its absence, a violent power struggle can follow. Initial democratic reforms are often only partial, and may fail to satisfy the full demands of civil society and not suffice to reduce the relevant actors’ motivation to resort to violence […] However, there is clear evidence that the sequence matters and that the effect [the increased risk of civil war after democratization, US] is limited to the first election. […] civil wars […] tend to be settled more easily in states with prior experience of democracy […] By our count, […] 75 percent of all annual observations of countries with minor or major armed conflicts occur in non-democracies […] Democracies have an incidence of major armed conflict of only 1 percent, whereas nondemocracies have a frequency of 5.6 percent.”

“Since the Iranian revolution in the late 1970s, religious conflicts and the rise of international terror organizations have made it difficult to ignore the facts that religious factors can contribute to conflict and that religious actors can cause or participate in domestic conflicts. Despite this, comprehensive studies of religion and domestic conflict remain relatively rare. While the reasons for this rarity are complex there are two that stand out. First, for much of the twentieth century the dominant theory in the field was secularization theory, which predicted that religion would become irrelevant and perhaps extinct in modern times. While not everyone agreed with this extreme viewpoint, there was a consensus that religious influences on politics and conflict were a waning concern. […] This theory was dominant in sociology for much of the twentieth century and effectively dominated political science, under the title of modernization theory, for the same period. […] Today supporters of secularization theory are clearly in the minority. However, one of their legacies has been that research on religion and conflict is a relatively new field. […] Second, as recently as 2006, Brian Grim and Roger Finke lamented that “religion receives little attention in international quantitative studies. Including religion in cross-national studies requires data, and high-quality data are in short supply” […] availability of the necessary data to engage in quantitative research on religion and civil wars is a relatively recent development.”

“[Some] studies [have] found that conflicts involving actors making religious demands – such as demanding a religious state or a significant increase in religious legislation – were less likely to be resolved with negotiated settlements; a negotiated settlement is possible if the settlement focused on the non-religious aspects of the conflict […] One study of terrorism found that terror groups which espouse religious ideologies tend to be more violent (Henne, 2012). […] The clear majority of quantitative studies of religious conflict focus solely on inter-religious conflicts. Most of them find religious identity to influence the extent of conflict […] but there are some studies which dissent from this finding”.

“Terror is most often selected by groups that (1) have failed to achieve their goals through peaceful means, (2) are willing to use violence to achieve their goals, and (3) do not have the means for higher levels of violence.”

“the PITF dataset provides an accounting of the number of domestic conflicts that occurred in any given year between 1960 and 2009. […] Between 1960 and 2009 the modified dataset includes 817 years of ethnic war, 266 years of genocides/politicides, and 477 years of revolutionary wars. […] Cases were identified as religious or not religious based on the following categorization:
1 Not Religious.
2 Religious Identity Conflict: The two groups involved in the conflict belong to different religions or different denominations of the same religion.[11]
3 Religious Wars: The two sides of the conflict belong to the same religion but the description of the conflict provided by the PITF project identifies religion as being an issue in the conflict. This typically includes challenges by religious fundamentalists to more secular states. […]
The results show that both numerically and as a proportion of all conflict, religious state failures (which include both religious identity conflicts and religious wars) began increasing in the mid-1970s. […] As a proportion of all conflict, religious state failures continued to increase and became a majority of all state failures in 2002. From 2002 onward, religious state failures were between 55 percent and 62 percent of all state failures in any given year.”

“Between 2002 and 2009, eight of 12 new state failures were religious. All but one of the new religious state failures were ongoing as of 2009. These include:
• 2002: A rebellion in the Muslim north of the Ivory Coast (ended in 2007)
• 2003: The beginning of the Sunni–Shia violent conflict in Iraq (ongoing)
• 2003: The resumption of the ethnic war in the Sudan [97% muslims, US] (ongoing)
• 2004: Muslim militants challenged Pakistan’s government in South and North Waziristan. This has been followed by many similar attacks (ongoing)
• 2004: Outbreak of violence by Muslims in southern Thailand (ongoing)
• 2004: In Yemen [99% muslims, US], followers of dissident cleric Husain Badr al-Din al-Huthi create a stronghold in Saada. Al-Huthi was killed in September 2004, but serious fighting begins again in early 2005 (ongoing)
• 2007: Ethiopia’s invasion of southern Somalia causes a backlash in the Muslim (ethnic- Somali) Ogaden region (ongoing)
• 2008: Islamist militants in the eastern Trans-Caucasus region of Russia bordering on Georgia (Chechnya, Dagestan, and Ingushetia) reignited their violent conflict against Russia[12] (ongoing)” [my bold]

“There are few additional studies which engage in this type of longitudinal analysis. Perhaps the most comprehensive of such studies is presented in Toft et al.’s (2011) book God’s Century based on data collected by Toft. They found that religious conflicts – defined as conflicts with a religious content – rose from 19 percent of all civil wars in the 1940s to about half of civil wars during the first decade of the twenty-first century. Of these religious conflicts, 82 percent involved Muslims. This analysis includes only 135 civil wars during this period. The lower number is due to a more restrictive definition of civil war which includes at least 1,000 battle deaths. This demonstrates that the findings presented above also hold when looking at the most violent of civil wars.” [my bold]

April 22, 2015 Posted by | Anthropology, Books, Data, Demographics, Geography, History, Religion | Leave a comment

Wikipedia articles of interest

i. Lock (water transport). Zumerchik and Danver’s book covered this kind of stuff as well, sort of, and I figured that since I’m not going to blog the book – for reasons provided in my goodreads review here – I might as well add a link or two here instead. The words ‘sort of’ above are in my opinion justified because the book coverage is so horrid you’d never even know what a lock is used for from reading that book; you’d need to look that up elsewhere.

On a related note there’s a lot of stuff in that book about the history of water transport etc. which you probably won’t get from these articles, but having a look here will give you some idea about which sort of topics many of the chapters of the book are dealing with. Also, stuff like this and this. The book coverage of the latter topic is incidentally much, much more detailed than is that wiki article, and the article – as well as many other articles about related topics (economic history, etc.) on the wiki, to the extent that they even exist – could clearly be improved greatly by adding content from books like this one. However I’m not going to be the guy doing that.

ii. Congruence (geometry).

iii. Geography and ecology of the Everglades (featured).

I’d note that this is a topic which seems to be reasonably well covered on wikipedia; there’s for example also a ‘good article’ on the Everglades and a featured article about the Everglades National Park. A few quotes and observations from the article:

“The geography and ecology of the Everglades involve the complex elements affecting the natural environment throughout the southern region of the U.S. state of Florida. Before drainage, the Everglades were an interwoven mesh of marshes and prairies covering 4,000 square miles (10,000 km2). […] Although sawgrass and sloughs are the enduring geographical icons of the Everglades, other ecosystems are just as vital, and the borders marking them are subtle or nonexistent. Pinelands and tropical hardwood hammocks are located throughout the sloughs; the trees, rooted in soil inches above the peat, marl, or water, support a variety of wildlife. The oldest and tallest trees are cypresses, whose roots are specially adapted to grow underwater for months at a time.”

“A vast marshland could only have been formed due to the underlying rock formations in southern Florida.[15] The floor of the Everglades formed between 25 million and 2 million years ago when the Florida peninsula was a shallow sea floor. The peninsula has been covered by sea water at least seven times since the earliest bedrock formation. […] At only 5,000 years of age, the Everglades is a young region in geological terms. Its ecosystems are in constant flux as a result of the interplay of three factors: the type and amount of water present, the geology of the region, and the frequency and severity of fires. […] Water is the dominant element in the Everglades, and it shapes the land, vegetation, and animal life of South Florida. The South Florida climate was once arid and semi-arid, interspersed with wet periods. Between 10,000 and 20,000 years ago, sea levels rose, submerging portions of the Florida peninsula and causing the water table to rise. Fresh water saturated the limestone, eroding some of it and creating springs and sinkholes. The abundance of fresh water allowed new vegetation to take root, and through evaporation formed thunderstorms. Limestone was dissolved by the slightly acidic rainwater. The limestone wore away, and groundwater came into contact with the surface, creating a massive wetland ecosystem. […] Only two seasons exist in the Everglades: wet (May to November) and dry (December to April). […] The Everglades are unique; no other wetland system in the world is nourished primarily from the atmosphere. […] Average annual rainfall in the Everglades is approximately 62 inches (160 cm), though fluctuations of precipitation are normal.”

“Between 1871 and 2003, 40 tropical cyclones struck the Everglades, usually every one to three years.”

“Islands of trees featuring dense temperate or tropical trees are called tropical hardwood hammocks.[38] They may rise between 1 and 3 feet (0.30 and 0.91 m) above water level in freshwater sloughs, sawgrass prairies, or pineland. These islands illustrate the difficulty of characterizing the climate of the Everglades as tropical or subtropical. Hammocks in the northern portion of the Everglades consist of more temperate plant species, but closer to Florida Bay the trees are tropical and smaller shrubs are more prevalent. […] Islands vary in size, but most range between 1 and 10 acres (0.40 and 4.05 ha); the water slowly flowing around them limits their size and gives them a teardrop appearance from above.[42] The height of the trees is limited by factors such as frost, lightning, and wind: the majority of trees in hammocks grow no higher than 55 feet (17 m). […] There are more than 50 varieties of tree snails in the Everglades; the color patterns and designs unique to single islands may be a result of the isolation of certain hammocks.[44] […] An estimated 11,000 species of seed-bearing plants and 400 species of land or water vertebrates live in the Everglades, but slight variations in water levels affect many organisms and reshape land formations.”

“Because much of the coast and inner estuaries are built by mangroves—and there is no border between the coastal marshes and the bay—the ecosystems in Florida Bay are considered part of the Everglades. […] Sea grasses stabilize sea beds and protect shorelines from erosion by absorbing energy from waves. […] Sea floor patterns of Florida Bay are formed by currents and winds. However, since 1932, sea levels have been rising at a rate of 1 foot (0.30 m) per 100 years.[81] Though mangroves serve to build and stabilize the coastline, seas may be rising more rapidly than the trees are able to build.[82]

iv. Chang and Eng Bunker. Not a long article, but interesting:

Chang (Chinese: ; pinyin: Chāng; Thai: จัน, Jan, rtgsChan) and Eng (Chinese: ; pinyin: Ēn; Thai: อิน In) Bunker (May 11, 1811 – January 17, 1874) were Thai-American conjoined twin brothers whose condition and birthplace became the basis for the term “Siamese twins”.[1][2][3]

I loved some of the implicit assumptions in this article: “Determined to live as normal a life they could, Chang and Eng settled on their small plantation and bought slaves to do the work they could not do themselves. […] Chang and Adelaide [his wife] would become the parents of eleven children. Eng and Sarah [‘the other wife’] had ten.”

A ‘normal life’ indeed… The women the twins married were incidentally sisters who ended up disliking each other (I can’t imagine why…).

v. Genie (feral child). This is a very long article, and you should be warned that many parts of it may not be pleasant to read. From the article:

Genie (born 1957) is the pseudonym of a feral child who was the victim of extraordinarily severe abuse, neglect and social isolation. Her circumstances are prominently recorded in the annals of abnormal child psychology.[1][2] When Genie was a baby her father decided that she was severely mentally retarded, causing him to dislike her and withhold as much care and attention as possible. Around the time she reached the age of 20 months Genie’s father decided to keep her as socially isolated as possible, so from that point until she reached 13 years, 7 months, he kept her locked alone in a room. During this time he almost always strapped her to a child’s toilet or bound her in a crib with her arms and legs completely immobilized, forbade anyone from interacting with her, and left her severely malnourished.[3][4][5] The extent of Genie’s isolation prevented her from being exposed to any significant amount of speech, and as a result she did not acquire language during childhood. Her abuse came to the attention of Los Angeles child welfare authorities on November 4, 1970.[1][3][4]

In the first several years after Genie’s early life and circumstances came to light, psychologists, linguists and other scientists focused a great deal of attention on Genie’s case, seeing in her near-total isolation an opportunity to study many aspects of human development. […] In early January 1978 Genie’s mother suddenly decided to forbid all of the scientists except for one from having any contact with Genie, and all testing and scientific observations of her immediately ceased. Most of the scientists who studied and worked with Genie have not seen her since this time. The only post-1977 updates on Genie and her whereabouts are personal observations or secondary accounts of them, and all are spaced several years apart. […]

Genie’s father had an extremely low tolerance for noise, to the point of refusing to have a working television or radio in the house. Due to this, the only sounds Genie ever heard from her parents or brother on a regular basis were noises when they used the bathroom.[8][43] Although Genie’s mother claimed that Genie had been able to hear other people talking in the house, her father almost never allowed his wife or son to speak and viciously beat them if he heard them talking without permission. They were particularly forbidden to speak to or around Genie, so what conversations they had were therefore always very quiet and out of Genie’s earshot, preventing her from being exposed to any meaningful language besides her father’s occasional swearing.[3][13][43] […] Genie’s father fed Genie as little as possible and refused to give her solid food […]

In late October 1970, Genie’s mother and father had a violent argument in which she threatened to leave if she could not call her parents. He eventually relented, and later that day Genie’s mother was able to get herself and Genie away from her husband while he was out of the house […] She and Genie went to live with her parents in Monterey Park.[13][20][56] Around three weeks later, on November 4, after being told to seek disability benefits for the blind, Genie’s mother decided to do so in nearby Temple City, California and brought Genie along with her.[3][56]

On account of her near-blindness, instead of the disabilities benefits office Genie’s mother accidentally entered the general social services office next door.[3][56] The social worker who greeted them instantly sensed something was not right when she first saw Genie and was shocked to learn Genie’s true age was 13, having estimated from her appearance and demeanor that she was around 6 or 7 and possibly autistic. She notified her supervisor, and after questioning Genie’s mother and confirming Genie’s age they immediately contacted the police. […]

Upon admission to Children’s Hospital, Genie was extremely pale and grossly malnourished. She was severely undersized and underweight for her age, standing 4 ft 6 in (1.37 m) and weighing only 59 pounds (27 kg) […] Genie’s gross motor skills were extremely weak; she could not stand up straight nor fully straighten any of her limbs.[83][84] Her movements were very hesitant and unsteady, and her characteristic “bunny walk”, in which she held her hands in front of her like claws, suggested extreme difficulty with sensory processing and an inability to integrate visual and tactile information.[62] She had very little endurance, only able to engage in any physical activity for brief periods of time.[85] […]

Despite tests conducted shortly after her admission which determined Genie had normal vision in both eyes she could not focus them on anything more than 10 feet (3 m) away, which corresponded to the dimensions of the room she was kept in.[86] She was also completely incontinent, and gave no response whatsoever to extreme temperatures.[48][87] As Genie never ate solid food as a child she was completely unable to chew and had very severe dysphagia, completely unable to swallow any solid or even soft food and barely able to swallow liquids.[80][88] Because of this she would hold anything which she could not swallow in her mouth until her saliva broke it down, and if this took too long she would spit it out and mash it with her fingers.[50] She constantly salivated and spat, and continually sniffed and blew her nose on anything that happened to be nearby.[83][84]

Genie’s behavior was typically highly anti-social, and proved extremely difficult for others to control. She had no sense of personal property, frequently pointing to or simply taking something she wanted from someone else, and did not have any situational awareness whatsoever, acting on any of her impulses regardless of the setting. […] Doctors found it extremely difficult to test Genie’s mental age, but on two attempts they found Genie scored at the level of a 13-month-old. […] When upset Genie would wildly spit, blow her nose into her clothing, rub mucus all over her body, frequently urinate, and scratch and strike herself.[102][103] These tantrums were usually the only times Genie was at all demonstrative in her behavior. […] Genie clearly distinguished speaking from other environmental sounds, but she remained almost completely silent and was almost entirely unresponsive to speech. When she did vocalize, it was always extremely soft and devoid of tone. Hospital staff initially thought that the responsiveness she did show to them meant she understood what they were saying, but later determined that she was instead responding to nonverbal signals that accompanied their speaking. […] Linguists later determined that in January 1971, two months after her admission, Genie only showed understanding of a few names and about 15–20 words. Upon hearing any of these, she invariably responded to them as if they had been spoken in isolation. Hospital staff concluded that her active vocabulary at that time consisted of just two short phrases, “stop it” and “no more”.[27][88][99] Beyond negative commands, and possibly intonation indicating a question, she showed no understanding of any grammar whatsoever. […] Genie had a great deal of difficulty learning to count in sequential order. During Genie’s stay with the Riglers, the scientists spent a great deal of time attempting to teach her to count. She did not start to do so at all until late 1972, and when she did her efforts were extremely deliberate and laborious. By 1975 she could only count up to 7, which even then remained very difficult for her.”

“From January 1978 until 1993, Genie moved through a series of at least four additional foster homes and institutions. In some of these locations she was further physically abused and harassed to extreme degrees, and her development continued to regress. […] Genie is a ward of the state of California, and is living in an undisclosed location in the Los Angeles area.[3][20] In May 2008, ABC News reported that someone who spoke under condition of anonymity had hired a private investigator who located Genie in 2000. She was reportedly living a relatively simple lifestyle in a small private facility for mentally underdeveloped adults, and appeared to be happy. Although she only spoke a few words, she could still communicate fairly well in sign language.[3]

April 20, 2015 Posted by | Biology, Books, Botany, Ecology, Engineering, Geography, History, Mathematics, Psychology, Wikipedia, Zoology | Leave a comment

The Voyage of the Beagle (III)

This will be my last post about the book.

I have for some time, probably roughly since the internet problems I had earlier this year were resolved, structured my reading in a way so that I’ll more or less never read fiction/’pure enjoyment’ books while at home. I now only read fiction when I’m out taking walks, and then I limit my book reading to non-fiction while I’m at home. I take long(ish) walks most days so I guess I still finish a fiction book every week or so at the current rate. This change in my reading habits is relevant to my reading of this book because back when I implemented this change, I’d mentally classified the Darwin book as a fiction book/’pure enjoyment’ book – the kind of book I should only be reading while taking walks. It isn’t really fiction, but it is a very enjoyable book to read and in many ways it’s conceptually really much closer to normal fiction stories than it is to a Springer publication about heart disease or mathematics. As it’s often raining in Denmark, it’s often not convenient to take walks while reading ‘paper books’, and my edition of Darwin is a ‘paper book’; I sometimes bring paper books on my walks, but if there’s a risk of rain I’ll usually much prefer to bring my e-reader, which can deal quite well with a few drops of water. A different problem is that I always highlight and write notes in my books, which means that the more interesting and well-written a paper book is, the more inconvenient it is to bring it on walks; I can’t highlight or take notes while walking (I’ve tried, but it doesn’t work), so I have to stop walking every time I come across an interesting sequence which I’d like to highlight or comment upon, of which there are many more in good books than in bad books, and taking a lot of breaks like that can be bothersome in the long run. Some paper books are also too big/heavy to conveniently bring on my walks; however this particular book is not one of those.

What all of above stuff means is of course that for quite a while I didn’t really read very much in this book because I’d settled on not reading it while I was at home, but I also usually had a different book on my e-reader which it was easier and more convenient to bring on my walks. At the end I decided that I should really read the rest of this book because it’s quite good (before I started rereading the book it was on my list of favourites on goodreads, and it still is), and so I decided to read it at home.

The book is really nice. If you liked the quotes I included either in my previous posts about the book and/or in this post, it’s worth considering taking the time to read the book. I may be wrong, but I could easily imagine this being the sort of book that many people might think to themselves that they’ll read when they get old, but then when they reach the pension age they’ll never get around to actually doing it; if this impression is correct, that’s just a damn shame. Reading books like this one or perhaps something like Mark Twain’s The Innocents Abroad (available for free here) will, aside from giving you some enjoyable experiences in the company of good writers, probably make it easier for you to think about the world in a slightly different manner than the one you’re used to.

The book is full of good stuff and so I had to leave out a lot of good stuff in my posts. Below I have added a few more illustrative quotes from the book.

“I heard also of an old lady who, at a dinner at Coquimbo, remarked how wonderfully strange it was that she should have lived to dine in the same room with an Englishman; for she remembered as a girl, that twice, at the mere cry of “Los Ingleses,” every soul, carrying what valuables they could, had taken to the mountains.”

“The connection between earthquakes and the weather has been often disputed: it appears to me to be a point of great interest, which is little understood.”

“My geological examination of the country generally created a good deal of surprise amongst the Chilenos: it was long before they could be convinced that I was not hunting for mines. This was sometimes troublesome: I found the most ready way of explaining my employment, was to ask them how it was that they themselves were not curious concerning earthquakes and volcanos? – why some springs were hot and others cold? – why there were mountains in Chile, and not a hill in La Plata? These bare questions at once satisfied and silenced the greater number; some, however (like a few in England who are a century behind hand), thought that all such inquiries were useless and impious; and that it was quite sufficient that God had thus made the mountains.”

“Our arrival in the offing caused some little apprehension. Peru was in a state of anarchy; and each party having demanded a contribution, the poor town of Iquique was in tribulation, thinking the evil hour was come. The people had also their domestic troubles; a short time before, three French carpenters had broken open, during the same night, the two churches, and stolen all the plate: one of the robbers, however, subsequently confessed, and the plate was recovered. The convicts were sent to Arequipa, which though the capital of this province, is two hundred leagues distant, the government there thought it a pity to punish such useful workmen, who could make all sorts of furniture; and accordingly liberated them. Things being in this state, the churches were again broken open, but this time the plate was not recovered. The inhabitants became dreadfully enraged, and declaring that none but heretics would thus “eat God Almighty,” proceeded to torture some Englishmen, with the intention of afterwards shooting them. At last the authorities interfered, and peace was established.”

“We did not reach the saltpetre-works till after sunset, having ridden all day across an undulating country, a complete and utter desert. The road was strewed with the bones and dried skins of many beasts of burden which had perished on it from fatigue. Excepting the Vultur aura, which preys on the carcasses, I saw neither bird, quadruped, reptile, nor insect. […] I cannot say I liked the very little I saw of Peru: in summer, however, it is said that the climate is much pleasanter. In all seasons, both inhabitants and foreigners suffer from severe attacks of ague. This disease is common on the whole coast of Peru, but is unknown in the interior. The attacks of illness which arise from miasma never fail to appear most mysterious. […] Callao is a filthy, ill-built, small seaport. The inhabitants, both here and at Lima, present every imaginable shade of mixture, between European, Negro, and Indian blood. They appear a depraved, drunken set of people.”

“Of land-birds I obtained twenty-six kinds, all peculiar to the group and found nowhere else, with the exception of one lark-like finch from North America […] The remaining land-birds form a most singular group of finches, related to each other in the structure of their beaks, short tails, form of body and plumage […] The most curious fact is the perfect gradation in the size of the beaks in the different species […] Seeing this gradation and diversity of structure in one small, intimately related group of birds, one might really fancy that from an original paucity of birds in this archipelago, one species had been taken and modified for different ends. […] With the exception of a wren with a fine yellow breast, and of a tyrant-flycatcher with a scarlet tuft and breast, none of the birds are brilliantly coloured, as might have been expected in an equatorial district. Hence it would appear probable, that the same causes which here make the immigrants of some peculiar species smaller, make most of the peculiar Galapageian species also smaller, as well as very generally more dusky coloured.” [For more on related topics, see incidentally this previous post of mine].

“As I at first observed, these islands are not so remarkable for the number of the species of reptiles, as for that of the [number of] individuals […] we must admit that there is no other quarter of the world where this Order replaces the herbivorous mammalia in so extraordinary a manner. […] by far the most remarkable feature in the natural history of this archipelago [is] that the different islands to a considerable extent are inhabited by a different set of beings. […] The inhabitants […] state that they can distinguish the tortoises from the different islands; and that they differ not only in size, but in other characters. […] I have strong reasons to suspect that some of the [finch] species of the sub-group Geospiza are confined to separate islands. If the different islands have their representatives of Geospiza, it may help to explain the singularly large number of the species of this sub-group in this one small archipelago, and as a probable consequence of their numbers, the perfectly graduated series in the size of their beaks. […] The distribution of the tenants of this archipelago would not be nearly so wonderful, if, for instance, one island had a mocking-thrush, and a second island some other quite distinct genus,- if one island had its genus of lizard, and a second island another distinct genus, or none whatever; -or if the different islands were inhabited, not by representative species of the same genera of plants, but by totally different genera […]. But it is the circumstance, that several of the islands possess their own species of the tortoise, mocking-thrush, finches, and numerous plants, these species having the same general habits, occupying analogous situations, and obviously filling the same place in the natural economy of this archipelago, that strikes me with wonder. It may be suspected that some of these representative species, at least in the case of the tortoise and of some of the birds, may hereafter prove to be only well-marked races; but this would be of equally great interest to the philosophical naturalist.”

“I was much disappointed in the personal appearance of the [Tahiti] women; they are far inferior in every respect to the men.” [Good luck writing anything like that today and getting it published…] […] After the main discussion was ended, several of the chiefs took the opportunity of asking Captain Fitz Roy many intelligent questions on international customs and laws, relating to the treatment of ships and foreigners. […] This Tahitian parliament lasted for several hours; and when it was over Captain Fitz Roy invited Queen Pomarre to pay the Beagle a visit. […] In the evening four boats were sent for her majesty; the ship was dressed with flags, and the yards manned on her coming on board. She was accompanied by most of the chiefs. The behaviour of all was very proper: they begged for nothing, and seemed much pleased with Captain Fitz Roy’s presents.”

“When I showed the chief a very small bundle, which I wanted carried, it became absolutely necessary for him to take a slave. These feelings of pride are beginning to wear away; but formerly a leading man would sooner have died, than undergone the indignity of carrying the smallest burden.”

“Some time ago, Mr. Bushby suffered a […] serious attack. A chief and a party of men tried to break into his house in the middle of the night, and not finding this so easy, commenced a brisk firing with their muskets. Mr. Bushby was slightly wounded, but the party was at length driven away. Shortly afterwards it was discovered who was the aggressor; and a general meeting of the chiefs was convened to consider the case. It was considered by the New Zealanders as very atrocious, inasmuch as it was a night attack, and that Mrs. Bushby was lying ill in the house: this latter circumstance, much to their honour, being considered in all cases as a protection. The chiefs agreed to confiscate the land of the aggressor to the King of England. The whole proceeding, however, in thus trying and punishing a chief was entirely without precedent. The aggressor, moreover, lost caste in the estimation of his equals and this was considered by the British as of more consequence than the confiscation of his land. […] a chief and a party of men volunteered to walk with us to Waiomio, a distance of four miles. The chief was at this time rather notorious from having lately hung one of his wives and a slave for adultery. When one of the missionaries remonstrated with him he seemed surprised, and said he thought he was exactly following the English method.”

“It is impossible to behold these waves without feeling a conviction that an island, though built of the hardest rock, let it be porphyry, granite, or quartz, would ultimately yield and be demolished by such an irresistible power. Yet these low, insignificant coral-islets stand and are victorious: for here another power, as an antagonist, takes part in the contest. The organic forces separate the atoms of carbonate of lime, one by one, from the foaming breakers, and unite them into a symmetrical structure. Let the hurricane tear up its thousand huge fragments; yet what will that tell against the accumulated labour of myriads of architects at work night and day, month after month? […] We feel surprise when travellers tell us of the vast dimensions of the Pyramids and other great ruins, but how utterly insignificant are the greatest of these, when compared to these mountains of stone accumulated by the agency of various minute and tender animals! This is a wonder which does not at first strike the eye of the body, but, after reflection, the eye of reason.”

“Those who look tenderly at the slave owner, and with a cold heart at the slave, never seem to put themselves into the position of the latter”

December 14, 2014 Posted by | Biology, Books, Evolutionary biology, Geography, Geology, History, Personal, Zoology | Leave a comment

Wikipedia articles of interest

i. Trade and use of saffron.

Saffron has been a key seasoning, fragrance, dye, and medicine for over three millennia.[1] One of the world’s most expensive spices by weight,[2] saffron consists of stigmas plucked from the vegetatively propagated and sterile Crocus sativus, known popularly as the saffron crocus. The resulting dried “threads”[N 1] are distinguished by their bitter taste, hay-like fragrance, and slight metallic notes. The saffron crocus is unknown in the wild; its most likely precursor, Crocus cartwrightianus, originated in Crete or Central Asia;[3] The saffron crocus is native to Southwest Asia and was first cultivated in what is now Greece.[4][5][6]

From antiquity to modern times the history of saffron is full of applications in food, drink, and traditional herbal medicine: from Africa and Asia to Europe and the Americas the brilliant red threads were—and are—prized in baking, curries, and liquor. It coloured textiles and other items and often helped confer the social standing of political elites and religious adepts. Ancient peoples believed saffron could be used to treat stomach upsets, bubonic plague, and smallpox.

Saffron crocus cultivation has long centred on a broad belt of Eurasia bounded by the Mediterranean Sea in the southwest to India and China in the northeast. The major producers of antiquity—Iran, Spain, India, and Greece—continue to dominate the world trade. […] Iran has accounted for around 90–93 percent of recent annual world production and thereby dominates the export market on a by-quantity basis. […]

The high cost of saffron is due to the difficulty of manually extracting large numbers of minute stigmas, which are the only part of the crocus with the desired aroma and flavour. An exorbitant number of flowers need to be processed in order to yield marketable amounts of saffron. Obtaining 1 lb (0.45 kg) of dry saffron requires the harvesting of some 50,000 flowers, the equivalent of an association football pitch’s area of cultivation, or roughly 7,140 m2 (0.714 ha).[14] By another estimate some 75,000 flowers are needed to produce one pound of dry saffron. […] Another complication arises in the flowers’ simultaneous and transient blooming. […] Bulk quantities of lower-grade saffron can reach upwards of US$500 per pound; retail costs for small amounts may exceed ten times that rate. In Western countries the average retail price is approximately US$1,000 per pound.[5] Prices vary widely elsewhere, but on average tend to be lower. The high price is somewhat offset by the small quantities needed in kitchens: a few grams at most in medicinal use and a few strands, at most, in culinary applications; there are between 70,000 and 200,000 strands in a pound.”

ii. Scramble for Africa.

“The “Scramble for Africa” (also the Partition of Africa and the Conquest of Africa) was the invasion and occupation, colonization and annexation of African territory by European powers during the period of New Imperialism, between 1881 and 1914. In 1870, 10 percent of Africa was under European control; by 1914 it was 90 percent of the continent, with only Abyssinia (Ethiopia) and Liberia still independent.”

Here’s a really neat illustration from the article:

Scramble-for-Africa-1880-1913

“Germany became the third largest colonial power in Africa. Nearly all of its overall empire of 2.6 million square kilometres and 14 million colonial subjects in 1914 was found in its African possessions of Southwest Africa, Togoland, the Cameroons, and Tanganyika. Following the 1904 Entente cordiale between France and the British Empire, Germany tried to isolate France in 1905 with the First Moroccan Crisis. This led to the 1905 Algeciras Conference, in which France’s influence on Morocco was compensated by the exchange of other territories, and then to the Agadir Crisis in 1911. Along with the 1898 Fashoda Incident between France and Britain, this succession of international crises reveals the bitterness of the struggle between the various imperialist nations, which ultimately led to World War I. […]

David Livingstone‘s explorations, carried on by Henry Morton Stanley, excited imaginations. But at first, Stanley’s grandiose ideas for colonisation found little support owing to the problems and scale of action required, except from Léopold II of Belgium, who in 1876 had organised the International African Association (the Congo Society). From 1869 to 1874, Stanley was secretly sent by Léopold II to the Congo region, where he made treaties with several African chiefs along the Congo River and by 1882 had sufficient territory to form the basis of the Congo Free State. Léopold II personally owned the colony from 1885 and used it as a source of ivory and rubber.

While Stanley was exploring Congo on behalf of Léopold II of Belgium, the Franco-Italian marine officer Pierre de Brazza travelled into the western Congo basin and raised the French flag over the newly founded Brazzaville in 1881, thus occupying today’s Republic of the Congo. Portugal, which also claimed the area due to old treaties with the native Kongo Empire, made a treaty with Britain on 26 February 1884 to block off the Congo Society’s access to the Atlantic.

By 1890 the Congo Free State had consolidated its control of its territory between Leopoldville and Stanleyville, and was looking to push south down the Lualaba River from Stanleyville. At the same time, the British South Africa Company of Cecil Rhodes was expanding north from the Limpopo River, sending the Pioneer Column (guided by Frederick Selous) through Matabeleland, and starting a colony in Mashonaland.

To the West, in the land where their expansions would meet, was Katanga, site of the Yeke Kingdom of Msiri. Msiri was the most militarily powerful ruler in the area, and traded large quantities of copper, ivory and slaves — and rumours of gold reached European ears. The scramble for Katanga was a prime example of the period. Rhodes and the BSAC sent two expeditions to Msiri in 1890 led by Alfred Sharpe, who was rebuffed, and Joseph Thomson, who failed to reach Katanga. Leopold sent four CFS expeditions. First, the Le Marinel Expedition could only extract a vaguely worded letter. The Delcommune Expedition was rebuffed. The well-armed Stairs Expedition was given orders to take Katanga with or without Msiri’s consent. Msiri refused, was shot, and the expedition cut off his head and stuck it on a pole as a “barbaric lesson” to the people. The Bia Expedition finished the job of establishing an administration of sorts and a “police presence” in Katanga.

Thus, the half million square kilometres of Katanga came into Leopold’s possession and brought his African realm up to 2,300,000 square kilometres (890,000 sq mi), about 75 times larger than Belgium. The Congo Free State imposed such a terror regime on the colonised people, including mass killings and forced labour, that Belgium, under pressure from the Congo Reform Association, ended Leopold II’s rule and annexed it in 1908 as a colony of Belgium, known as the Belgian Congo. […]

“Britain’s administration of Egypt and the Cape Colony contributed to a preoccupation over securing the source of the Nile River. Egypt was overrun by British forces in 1882 (although not formally declared a protectorate until 1914, and never an actual colony); Sudan, Nigeria, Kenya and Uganda were subjugated in the 1890s and early 20th century; and in the south, the Cape Colony (first acquired in 1795) provided a base for the subjugation of neighbouring African states and the Dutch Afrikaner settlers who had left the Cape to avoid the British and then founded their own republics. In 1877, Theophilus Shepstone annexed the South African Republic (or Transvaal – independent from 1857 to 1877) for the British Empire. In 1879, after the Anglo-Zulu War, Britain consolidated its control of most of the territories of South Africa. The Boers protested, and in December 1880 they revolted, leading to the First Boer War (1880–81). British Prime Minister William Gladstone signed a peace treaty on 23 March 1881, giving self-government to the Boers in the Transvaal. […] The Second Boer War, fought between 1899 and 1902, was about control of the gold and diamond industries; the independent Boer republics of the Orange Free State and the South African Republic (or Transvaal) were this time defeated and absorbed into the British Empire.”

There are a lot of unsourced claims in the article and some parts of it actually aren’t very good, but this is a topic about which I did not know much (I had no idea most of colonial Africa was acquired by the European powers as late as was actually the case). This is another good map from the article to have a look at if you just want the big picture.

iii. Cursed soldiers.

“The cursed soldiers (that is, “accursed soldiers” or “damned soldiers”; Polish: Żołnierze wyklęci) is a name applied to a variety of Polish resistance movements formed in the later stages of World War II and afterwards. Created by some members of the Polish Secret State, these clandestine organizations continued their armed struggle against the Stalinist government of Poland well into the 1950s. The guerrilla warfare included an array of military attacks launched against the new communist prisons as well as MBP state security offices, detention facilities for political prisoners, and concentration camps set up across the country. Most of the Polish anti-communist groups ceased to exist in the late 1940s or 1950s, hunted down by MBP security services and NKVD assassination squads.[1] However, the last known ‘cursed soldier’, Józef Franczak, was killed in an ambush as late as 1963, almost 20 years after the Soviet take-over of Poland.[2][3] […] Similar eastern European anti-communists fought on in other countries. […]

Armia Krajowa (or simply AK)-the main Polish resistance movement in World War II-had officially disbanded on 19 January 1945 to prevent a slide into armed conflict with the Red Army, including an increasing threat of civil war over Poland’s sovereignty. However, many units decided to continue on with their struggle under new circumstances, seeing the Soviet forces as new occupiers. Meanwhile, Soviet partisans in Poland had already been ordered by Moscow on June 22, 1943 to engage Polish Leśni partisans in combat.[6] They commonly fought Poles more often than they did the Germans.[4] The main forces of the Red Army (Northern Group of Forces) and the NKVD had begun conducting operations against AK partisans already during and directly after the Polish Operation Tempest, designed by the Poles as a preventive action to assure Polish rather than Soviet control of the cities after the German withdrawal.[5] Soviet premier Joseph Stalin aimed to ensure that an independent Poland would never reemerge in the postwar period.[7] […]

The first Polish communist government, the Polish Committee of National Liberation, was formed in July 1944, but declined jurisdiction over AK soldiers. Consequently, for more than a year, it was Soviet agencies like the NKVD that dealt with the AK. By the end of the war, approximately 60,000 soldiers of the AK had been arrested, and 50,000 of them were deported to the Soviet Union’s gulags and prisons. Most of those soldiers had been captured by the Soviets during or in the aftermath of Operation Tempest, when many AK units tried to cooperate with the Soviets in a nationwide uprising against the Germans. Other veterans were arrested when they decided to approach the government after being promised amnesty. In 1947, an amnesty was passed for most of the partisans; the Communist authorities expected around 12,000 people to give up their arms, but the actual number of people to come out of the forests eventually reached 53,000. Many of them were arrested despite promises of freedom; after repeated broken promises during the first few years of communist control, AK soldiers stopped trusting the government.[5] […]

The persecution of the AK members was only a part of the reign of Stalinist terror in postwar Poland. In the period of 1944–56, approximately 300,000 Polish people had been arrested,[21] or up to two million, by different accounts.[5] There were 6,000 death sentences issued, the majority of them carried out.[21] Possibly, over 20,000 people died in communist prisons including those executed “in the majesty of the law” such as Witold Pilecki, a hero of Auschwitz.[5] A further six million Polish citizens (i.e., one out of every three adult Poles) were classified as suspected members of a ‘reactionary or criminal element’ and subjected to investigation by state agencies.”

iv. Affective neuroscience.

Affective neuroscience is the study of the neural mechanisms of emotion. This interdisciplinary field combines neuroscience with the psychological study of personality, emotion, and mood.[1]

This article is actually related to the Delusion and self-deception book, which covered some of the stuff included in this article, but I decided I might as well include the link in this post. I think some parts of the article are written in a somewhat different manner than most wiki articles – there are specific paragraphs briefly covering the results of specific meta-analyses conducted in this field. I can’t really tell from this article if I actually like this way of writing a wiki article or not.

v. Hamming distance. Not a long article, but this is a useful concept to be familiar with:

“In information theory, the Hamming distance between two strings of equal length is the number of positions at which the corresponding symbols are different. In another way, it measures the minimum number of substitutions required to change one string into the other, or the minimum number of errors that could have transformed one string into the other. […]

The Hamming distance is named after Richard Hamming, who introduced it in his fundamental paper on Hamming codes Error detecting and error correcting codes in 1950.[1] It is used in telecommunication to count the number of flipped bits in a fixed-length binary word as an estimate of error, and therefore is sometimes called the signal distance. Hamming weight analysis of bits is used in several disciplines including information theory, coding theory, and cryptography. However, for comparing strings of different lengths, or strings where not just substitutions but also insertions or deletions have to be expected, a more sophisticated metric like the Levenshtein distance is more appropriate.”

vi. Menstrual synchrony. I came across that one recently in a book, and when I did it was obvious that the author had not read this article, and lacked some knowledge included in this article (the phenomenon was assumed to be real in the coverage, and theory was developed assuming it was real which would not make sense if it was not). I figured if that person didn’t know this stuff, a lot of other people – including people reading along here – probably also do not, so I should cover this topic somewhere. This is an obvious place to do so. Okay, on to the article coverage:

Menstrual synchrony, also called the McClintock effect,[2] is the alleged process whereby women who begin living together in close proximity experience their menstrual cycle onsets (i.e., the onset of menstruation or menses) becoming closer together in time than previously. “For example, the distribution of onsets of seven female lifeguards was scattered at the beginning of the summer, but after 3 months spent together, the onset of all seven cycles fell within a 4-day period.”[3]

Martha McClintock’s 1971 paper, published in Nature, says that menstrual cycle synchronization happens when the menstrual cycle onsets of two women or more women become closer together in time than they were several months earlier.[3] Several mechanisms have been hypothesized to cause synchronization.[4]

After the initial studies, several papers were published reporting methodological flaws in studies reporting menstrual synchrony including McClintock’s study. In addition, other studies were published that failed to find synchrony. The proposed mechanisms have also received scientific criticism. A 2013 review of menstrual synchrony concluded that menstrual synchrony is doubtful.[4] […] in a recent systematic review of menstrual synchrony, Harris and Vitzthum concluded that “In light of the lack of empirical evidence for MS [menstrual synchrony] sensu stricto, it seems there should be more widespread doubt than acceptance of this hypothesis.” […]

The experience of synchrony may be the result of the mathematical fact that menstrual cycles of different frequencies repeatedly converge and diverge over time and not due to a process of synchronization.[12] It may also be due to the high probability of menstruation overlap that occurs by chance.[6]

 

December 4, 2014 Posted by | Biology, Botany, Computer science, Cryptography, Geography, History, Medicine, Neurology, Psychology, Wikipedia | Leave a comment

Wikipedia articles of interest

(A minor note: These days when I’m randomly browsing wikipedia and not just looking up concepts or terms found in the books I read, I’m mostly browsing the featured content on wikipedia. There’s a lot of featured stuff, and on average such articles more interesting than random articles. As a result of this approach, all articles covered in the post below are featured articles. A related consequence of this shift may be that I may cover fewer articles in future wikipedia posts than I have in the past; this post only contains five articles, which I believe is slightly less than usual for these posts – a big reason for this being that it sometimes takes a lot of time to read a featured article.)

i. Woolly mammoth.

Ice_age_fauna_of_northern_Spain_-_Mauricio_Antón

“The woolly mammoth (Mammuthus primigenius) was a species of mammoth, the common name for the extinct elephant genus Mammuthus. The woolly mammoth was one of the last in a line of mammoth species, beginning with Mammuthus subplanifrons in the early Pliocene. M. primigenius diverged from the steppe mammoth, M. trogontherii, about 200,000 years ago in eastern Asia. Its closest extant relative is the Asian elephant. […] The earliest known proboscideans, the clade which contains elephants, existed about 55 million years ago around the Tethys Sea. […] The family Elephantidae existed six million years ago in Africa and includes the modern elephants and the mammoths. Among many now extinct clades, the mastodon is only a distant relative of the mammoths, and part of the separate Mammutidae family, which diverged 25 million years before the mammoths evolved.[12] […] The woolly mammoth coexisted with early humans, who used its bones and tusks for making art, tools, and dwellings, and the species was also hunted for food.[1] It disappeared from its mainland range at the end of the Pleistocene 10,000 years ago, most likely through a combination of climate change, consequent disappearance of its habitat, and hunting by humans, though the significance of these factors is disputed. Isolated populations survived on Wrangel Island until 4,000 years ago, and on St. Paul Island until 6,400 years ago.”

“The appearance and behaviour of this species are among the best studied of any prehistoric animal due to the discovery of frozen carcasses in Siberia and Alaska, as well as skeletons, teeth, stomach contents, dung, and depiction from life in prehistoric cave paintings. […] Fully grown males reached shoulder heights between 2.7 and 3.4 m (9 and 11 ft) and weighed up to 6 tonnes (6.6 short tons). This is almost as large as extant male African elephants, which commonly reach 3–3.4 m (9.8–11.2 ft), and is less than the size of the earlier mammoth species M. meridionalis and M. trogontherii, and the contemporary M. columbi. […] Woolly mammoths had several adaptations to the cold, most noticeably the layer of fur covering all parts of the body. Other adaptations to cold weather include ears that are far smaller than those of modern elephants […] The small ears reduced heat loss and frostbite, and the tail was short for the same reason […] They had a layer of fat up to 10 cm (3.9 in) thick under the skin, which helped to keep them warm. […] The coat consisted of an outer layer of long, coarse “guard hair”, which was 30 cm (12 in) on the upper part of the body, up to 90 cm (35 in) in length on the flanks and underside, and 0.5 mm (0.020 in) in diameter, and a denser inner layer of shorter, slightly curly under-wool, up to 8 cm (3.1 in) long and 0.05 mm (0.0020 in) in diameter. The hairs on the upper leg were up to 38 cm (15 in) long, and those of the feet were 15 cm (5.9 in) long, reaching the toes. The hairs on the head were relatively short, but longer on the underside and the sides of the trunk. The tail was extended by coarse hairs up to 60 cm (24 in) long, which were thicker than the guard hairs. It is likely that the woolly mammoth moulted seasonally, and that the heaviest fur was shed during spring.”

“Woolly mammoths had very long tusks, which were more curved than those of modern elephants. The largest known male tusk is 4.2 m (14 ft) long and weighs 91 kg (201 lb), but 2.4–2.7 m (7.9–8.9 ft) and 45 kg (99 lb) was a more typical size. Female tusks averaged at 1.5–1.8 m (4.9–5.9 ft) and weighed 9 kg (20 lb). About a quarter of the length was inside the sockets. The tusks grew spirally in opposite directions from the base and continued in a curve until the tips pointed towards each other. In this way, most of the weight would have been close to the skull, and there would be less torque than with straight tusks. The tusks were usually asymmetrical and showed considerable variation, with some tusks curving down instead of outwards and some being shorter due to breakage.”

“Woolly mammoths needed a varied diet to support their growth, like modern elephants. An adult of six tonnes would need to eat 180 kg (397 lb) daily, and may have foraged as long as twenty hours every day. […] Woolly mammoths continued growing past adulthood, like other elephants. Unfused limb bones show that males grew until they reached the age of 40, and females grew until they were 25. The frozen calf “Dima” was 90 cm (35 in) tall when it died at the age of 6–12 months. At this age, the second set of molars would be in the process of erupting, and the first set would be worn out at 18 months of age. The third set of molars lasted for ten years, and this process was repeated until the final, sixth set emerged when the animal was 30 years old. A woolly mammoth could probably reach the age of 60, like modern elephants of the same size. By then the last set of molars would be worn out, the animal would be unable to chew and feed, and it would die of starvation.[53]

“The habitat of the woolly mammoth is known as “mammoth steppe” or “tundra steppe”. This environment stretched across northern Asia, many parts of Europe, and the northern part of North America during the last ice age. It was similar to the grassy steppes of modern Russia, but the flora was more diverse, abundant, and grew faster. Grasses, sedges, shrubs, and herbaceous plants were present, and scattered trees were mainly found in southern regions. This habitat was not dominated by ice and snow, as is popularly believed, since these regions are thought to have been high-pressure areas at the time. The habitat of the woolly mammoth also supported other grazing herbivores such as the woolly rhinoceros, wild horses and bison. […] A 2008 study estimated that changes in climate shrank suitable mammoth habitat from 7,700,000 km2 (3,000,000 sq mi) 42,000 years ago to 800,000 km2 (310,000 sq mi) 6,000 years ago.[81][82] Woolly mammoths survived an even greater loss of habitat at the end of the Saale glaciation 125,000 years ago, and it is likely that humans hunted the remaining populations to extinction at the end of the last glacial period.[83][84] […] Several woolly mammoth specimens show evidence of being butchered by humans, which is indicated by breaks, cut-marks, and associated stone tools. It is not known how much prehistoric humans relied on woolly mammoth meat, since there were many other large herbivores available. Many mammoth carcasses may have been scavenged by humans rather than hunted. Some cave paintings show woolly mammoths in structures interpreted as pitfall traps. Few specimens show direct, unambiguous evidence of having been hunted by humans.”

“While frozen woolly mammoth carcasses had been excavated by Europeans as early as 1728, the first fully documented specimen was discovered near the delta of the Lena River in 1799 by Ossip Schumachov, a Siberian hunter.[90] Schumachov let it thaw until he could retrieve the tusks for sale to the ivory trade. [Aargh!] […] The 1901 excavation of the “Berezovka mammoth” is the best documented of the early finds. It was discovered by the Berezovka River, and the Russian authorities financed its excavation. Its head was exposed, and the flesh had been scavenged. The animal still had grass between its teeth and on the tongue, showing that it had died suddenly. […] By 1929, the remains of 34 mammoths with frozen soft tissues (skin, flesh, or organs) had been documented. Only four of them were relatively complete. Since then, about that many more have been found.”

ii. Daniel Lambert.

Daniel Lambert (13 March 1770 – 21 June 1809) was a gaol keeper[n 1] and animal breeder from Leicester, England, famous for his unusually large size. After serving four years as an apprentice at an engraving and die casting works in Birmingham, he returned to Leicester around 1788 and succeeded his father as keeper of Leicester’s gaol. […] At the time of Lambert’s return to Leicester, his weight began to increase steadily, even though he was athletically active and, by his own account, abstained from drinking alcohol and did not eat unusual amounts of food. In 1805, Lambert’s gaol closed. By this time, he weighed 50 stone (700 lb; 318 kg), and had become the heaviest authenticated person up to that point in recorded history. Unemployable and sensitive about his bulk, Lambert became a recluse.

In 1806, poverty forced Lambert to put himself on exhibition to raise money. In April 1806, he took up residence in London, charging spectators to enter his apartments to meet him. Visitors were impressed by his intelligence and personality, and visiting him became highly fashionable. After some months on public display, Lambert grew tired of exhibiting himself, and in September 1806, he returned, wealthy, to Leicester, where he bred sporting dogs and regularly attended sporting events. Between 1806 and 1809, he made a further series of short fundraising tours.

In June 1809, he died suddenly in Stamford. At the time of his death, he weighed 52 stone 11 lb (739 lb; 335 kg), and his coffin required 112 square feet (10.4 m2) of wood. Despite the coffin being built with wheels to allow easy transport, and a sloping approach being dug to the grave, it took 20 men almost half an hour to drag his casket into the trench, in a newly opened burial ground to the rear of St Martin’s Church.”

“Sensitive about his weight, Daniel Lambert refused to allow himself to be weighed, but sometime around 1805, some friends persuaded him to come with them to a cock fight in Loughborough. Once he had squeezed his way into their carriage, the rest of the party drove the carriage onto a large scale and jumped out. After deducting the weight of the (previously weighed) empty carriage, they calculated that Lambert’s weight was now 50 stone (700 lb; 318 kg), and that he had thus overtaken Edward Bright, the 616-pound (279 kg) “Fat Man of Maldon”,[23] as the heaviest authenticated person in recorded history.[20][24]

Despite his shyness, Lambert badly needed to earn money, and saw no alternative to putting himself on display, and charging his spectators.[20] On 4 April 1806, he boarded a specially built carriage and travelled from Leicester[26] to his new home at 53 Piccadilly, then near the western edge of London.[20] For five hours each day, he welcomed visitors into his home, charging each a shilling (about £3.5 as of 2014).[18][25] […] Lambert shared his interests and knowledge of sports, dogs and animal husbandry with London’s middle and upper classes,[27] and it soon became highly fashionable to visit him, or become his friend.[27] Many called repeatedly; one banker made 20 visits, paying the admission fee on each occasion.[17] […] His business venture was immediately successful, drawing around 400 paying visitors per day. […] People would travel long distances to see him (on one occasion, a party of 14 travelled to London from Guernsey),[n 5] and many would spend hours speaking with him on animal breeding.”

“After some months in London, Lambert was visited by Józef Boruwłaski, a 3-foot 3-inch (99 cm) dwarf then in his seventies.[44] Born in 1739 to a poor family in rural Pokuttya,[45] Boruwłaski was generally considered to be the last of Europe’s court dwarfs.[46] He was introduced to the Empress Maria Theresa in 1754,[47] and after a short time residing with deposed Polish king Stanisław Leszczyński,[44] he exhibited himself around Europe, thus becoming a wealthy man.[48] At age 60, he retired to Durham,[49] where he became such a popular figure that the City of Durham paid him to live there[50] and he became one of its most prominent citizens […] The meeting of Lambert and Boruwłaski, the largest and smallest men in the country,[51] was the subject of enormous public interest”

“There was no autopsy, and the cause of Lambert’s death is unknown.[65] While many sources say that he died of a fatty degeneration of the heart or of stress on his heart caused by his bulk, his behaviour in the period leading to his death does not match that of someone suffering from cardiac insufficiency; witnesses agree that on the morning of his death he appeared well, before he became short of breath and collapsed.[65] Bondeson (2006) speculates that the most consistent explanation of his death, given his symptoms and medical history, is that he had a sudden pulmonary embolism.[65]

iii. Geology of the Capitol Reef area.

Waterpocket_Fold_-_Looking_south_from_the_Strike_Valley_Overlook

“The exposed geology of the Capitol Reef area presents a record of mostly Mesozoic-aged sedimentation in an area of North America in and around Capitol Reef National Park, on the Colorado Plateau in southeastern Utah.

Nearly 10,000 feet (3,000 m) of sedimentary strata are found in the Capitol Reef area, representing nearly 200 million years of geologic history of the south-central part of the U.S. state of Utah. These rocks range in age from Permian (as old as 270 million years old) to Cretaceous (as young as 80 million years old.)[1] Rock layers in the area reveal ancient climates as varied as rivers and swamps (Chinle Formation), Sahara-like deserts (Navajo Sandstone), and shallow ocean (Mancos Shale).

The area’s first known sediments were laid down as a shallow sea invaded the land in the Permian. At first sandstone was deposited but limestone followed as the sea deepened. After the sea retreated in the Triassic, streams deposited silt before the area was uplifted and underwent erosion. Conglomerate followed by logs, sand, mud and wind-transported volcanic ash were later added. Mid to Late Triassic time saw increasing aridity, during which vast amounts of sandstone were laid down along with some deposits from slow-moving streams. As another sea started to return it periodically flooded the area and left evaporite deposits. Barrier islands, sand bars and later, tidal flats, contributed sand for sandstone, followed by cobbles for conglomerate and mud for shale. The sea retreated, leaving streams, lakes and swampy plains to become the resting place for sediments. Another sea, the Western Interior Seaway, returned in the Cretaceous and left more sandstone and shale only to disappear in the early Cenozoic.”

“The Laramide orogeny compacted the region from about 70 million to 50 million years ago and in the process created the Rocky Mountains. Many monoclines (a type of gentle upward fold in rock strata) were also formed by the deep compressive forces of the Laramide. One of those monoclines, called the Waterpocket Fold, is the major geographic feature of the park. The 100 mile (160 km) long fold has a north-south alignment with a steeply east-dipping side. The rock layers on the west side of the Waterpocket Fold have been lifted more than 7,000 feet (2,100 m) higher than the layers on the east.[23] Thus older rocks are exposed on the western part of the fold and younger rocks on the eastern part. This particular fold may have been created due to movement along a fault in the Precambrian basement rocks hidden well below any exposed formations. Small earthquakes centered below the fold in 1979 may be from such a fault.[24] […] Ten to fifteen million years ago the entire region was uplifted several thousand feet (well over a kilometer) by the creation of the Colorado Plateaus. This time the uplift was more even, leaving the overall orientation of the formations mostly intact. Most of the erosion that carved today’s landscape occurred after the uplift of the Colorado Plateau with much of the major canyon cutting probably occurring between 1 and 6 million years ago.”

iv. Problem of Apollonius.

“In Euclidean plane geometry, Apollonius’s problem is to construct circles that are tangent to three given circles in a plane (Figure 1).

396px-Apollonius_problem_typical_solution.svg

Apollonius of Perga (ca. 262 BC – ca. 190 BC) posed and solved this famous problem in his work Ἐπαφαί (Epaphaí, “Tangencies”); this work has been lost, but a 4th-century report of his results by Pappus of Alexandria has survived. Three given circles generically have eight different circles that are tangent to them […] and each solution circle encloses or excludes the three given circles in a different way […] The general statement of Apollonius’ problem is to construct one or more circles that are tangent to three given objects in a plane, where an object may be a line, a point or a circle of any size.[1][2][3][4] These objects may be arranged in any way and may cross one another; however, they are usually taken to be distinct, meaning that they do not coincide. Solutions to Apollonius’ problem are sometimes called Apollonius circles, although the term is also used for other types of circles associated with Apollonius. […] A rich repertoire of geometrical and algebraic methods have been developed to solve Apollonius’ problem,[9][10] which has been called “the most famous of all” geometry problems.[3]

v. Globular cluster.

“A globular cluster is a spherical collection of stars that orbits a galactic core as a satellite. Globular clusters are very tightly bound by gravity, which gives them their spherical shapes and relatively high stellar densities toward their centers. The name of this category of star cluster is derived from the Latin globulus—a small sphere. A globular cluster is sometimes known more simply as a globular.

Globular clusters, which are found in the halo of a galaxy, contain considerably more stars and are much older than the less dense galactic, or open clusters, which are found in the disk. Globular clusters are fairly common; there are about 150[2] to 158[3] currently known globular clusters in the Milky Way, with perhaps 10 to 20 more still undiscovered.[4] Large galaxies can have more: Andromeda, for instance, may have as many as 500. […]

Every galaxy of sufficient mass in the Local Group has an associated group of globular clusters, and almost every large galaxy surveyed has been found to possess a system of globular clusters.[8] The Sagittarius Dwarf galaxy and the disputed Canis Major Dwarf galaxy appear to be in the process of donating their associated globular clusters (such as Palomar 12) to the Milky Way.[9] This demonstrates how many of this galaxy’s globular clusters might have been acquired in the past.

Although it appears that globular clusters contain some of the first stars to be produced in the galaxy, their origins and their role in galactic evolution are still unclear.”

October 23, 2014 Posted by | Astronomy, Biology, Ecology, Geography, Geology, History, Mathematics, Paleontology, Wikipedia, Zoology | Leave a comment

An Introduction to Tropical Rain Forests (III)

This will be my last post about the book. I’ve included some observations from the second half of the book below.

“In the present chapter we look at […] time scales of a few years to a few centuries, up to the life spans of one or a few generations of trees. Change is examined in the context of development and disintegration of the forest canopy, the forest growth cycle […] There seems to be a general model of forest dynamics which holds in many different biomes, albeit with local variants. […] Two spatial scales of canopy dynamics can be distinguished: patch disturbance, which involves one or a few trees, and community-wide disturbance. Patch disturbance is sometimes called ‘forest gap-phase dynamics’ and since about the mid-1970s has been one of the main interests of forest scientists in many parts of the world.”

“Species differ in the microclimate in which they successfully regenerate. […] the microclimates within a rain forest […] are mainly determined by size of the canopy gap. The microclimate above the forest canopy, which is similar to that in a large clearing, is substantially different from that near the floor below mature phase forest. […] Outside, wind speeds during the day are higher, as is air temperature, while relative humidity is lower. […] The light climate within a forest is complex. There are four components, skylight coming through canopy holes, direct sunlight, seen as sunflecks on the forest floor, light transmitted through leaves, and light reflected from leaves, trunks and other surfaces. […] Both the quantity and quality of light reaching the plant is known to be of profound importance in the mechanisms of gap-phase dynamics […] The waveband 400 to 700 nm (which is approximately the visual spectrum) is utilized for photosynthesis and is known as photosynthetically active radiation or PAR. The forest floor only receives up to c. 2 per cent of the PAR incident on the forest canopy […] In addition to reduction in quantity of PAR within the forest canopy, PAR also changes in quality with a shift in the ratio of red to far-red wavelenghts […] the temporal pattern of sunfleck distribution through the day […] is of importance, not just the daily total PAR. […] The role of irradiance in seedling growth and release is easy to observe and has been much investigated. By contrast, little attention has been given to the potential role of plant mineral nutrients. […] So far, nutrients seem unimportant compared to radiation. […] Overall the shade/nutrient interaction story remains unresolved. One part of the picture is likely to be that there is no response to nutrients in dark conditions where irradiance is limiting, but a response at higher irradiances.”

“Canopy gaps have an aerial microclimate like that above the forest but the smaller the gap the less different it is from the forest interior […] Gaps were at first regarded as having a microclimate varying with their size, to be contrasted with closed-forest microclimate. But this is a simplification. […] gaps are neither homogenous holes nor are they sharply bounded. Within a gap the microclimate is most extreme towards the centre and changes outwards to the physical gap edge and beyond […] The larger the gap the more extreme the microclimate of its centre. […] there is much more variability between small gaps than large ones in microclimate [and] gap size is a poor surrogate measure of microclimate, most markedly over short periods.”

“tree species differ in the amount of solar radiation required for their regeneration. […] Ecologists and foresters continue to engage in vigorous debate as to whether species along [the] spectrum of light climates can be divided into clear, separate groups. […] some strong light-demanders require full light for both seed germination and seedling establishment. These are the pioneer species, set apart from all others by these two features.[168] By contrast, all other species have the capacity to germinate and establish below canopy shade. These may be called climax species. They are able to perpetuate in the same place, but are an extremely diverse group. […] Pioneer species germinate and establish in a gap after its creation […] They grow fast […] Below the canopy seedlings of climax species establish and, as the pioneer canopy breaks up after the death of individual trees, these climax species are ‘released’ […] and grow up as a second growth cycle. Succession has occurred as a group of climax species replaces the group of pioneer species.[…] Climax species as a group […] perpetuate themselves in situ, there is no directional change in species composition. This is called cyclic regeneration or replacement. In a small gap, pre-existing climax seedlings are released. In a large gap pioneers, which appear after gap creation, form the next forest growth cycle. One of the puzzles which remains unsolved is what determines gap-switch size. […] In all tropical rain forest floras there are fewer pioneer than climax species, and they mostly belong to a few families […] The most species-rich forested landscape will be one that includes both patches of secondary forest recovering from a big disturbance and consisting of pioneers, and also patches of primary forest composed of climax species.”

“Rain forest silviculture is the manipulation of the forest to favour species and thereby to enhance its value to humans. […] Timber properties, whether heavy or light, dark or pale, durable or not, are strongly correlated with growth rate and thus to the extent to which the species is light-demanding […]. Thus, the ecological basis of natural forest silviculture is the manipulation of the forest canopy. The biological principle of silviculture is that by controlling canopy gap size it is possible to influence species composition of the next growth cycle. The bigger the gaps the more fast-growing light-demanders will be favoured. This concept has been known in continental Europe since at least the twelth century. […] The silvicultural systems that have been applied to tropical rain forests belong to one of two kinds: the polycyclic and monocyclic systems, respectively […]. As the name implies, polycyclic systems are based on the repeated removal of selected trees in a continuing series of felling cycles, whose length is less than the time it takes the tree to mature [rotation age]. The aim is to remove trees before they begin to deteriorate from old age […] extraction on a polycyclic system tends to result in the formation of scattered small gaps in the forest canopy. By contrast, monocyclic systems remove all saleable trees at a single operation, and the length of the cycle more or less equals the rotation age of the trees. Except in those cases where there are few saleable trees, damage to the forest is more drastic than under a polycyclic system, the canopy is more extensively destroed, and bigger gaps are formed. […] the two kinds of system will tend to favour shade-bearing and light-demanding species, respectively, but the extent of the difference will depend on how many trees are felled at each cycle in a polycyclic system. […] Low intensity selective logging on a polycyclic system closely mimics the natural processes of forest dynamics and scarcely alters the composition. Monocyclic silvicultural systems, and polycyclic systems with many stems felled per hectare, shift species composition […] The amount of damage to the forest depends more on how many trees are felled than on timber volume extracted. It is commonly the case that for every tree removed for timber (logged) a second tree is totally smashed and a third tree receives damage from which it will recover”

“The essense of shifting agriculture (sometimes called swidden agriculture) is to fell a patch of forest, allow it to dry to the point where it will burn well, and then to set it on fire. The plant mineral nutrients are thereby mobilized and become available to plants in the ash. One or two fast-maturing crops of staple food species are grown […]. Yields then fall and the patch is abandoned to allow secondary forest to grow. Longer-lived species, such as chilli […] and fruit trees, and some root crops such as cassava […] are planted with the staples and continue to yield in the first years of the fallow period. Besides fruit and root crops the bush fallow, as it is often called, provides firewood, medicines, and building materials. After a minimum of 7 to 10 years the cycle can be repeated. There are many variants. Shifting agriculture was invented independently in all parts of the tropical world[253] and has proved sustainable over many centuries. […] It is now realized that shifting agriculture, as traditionally practised, is a sustainable low-input form of cultivation which can continue indefinitely on the infertile soils underlying most tropical rain forest […], provided the carrying capacity of the land is not exceeded. […] Shifting agriculture has the limitation that it can usually only support 10-20 persons km-2 […] because at any one time only c. 10 per cent of the area is under cultivation. It breaks down if either the bush fallow period is excessively shortened or if the period of cultivation is extended for too long, either of which is likely to occur if population increases and a land shortage develops. There is, however, another mode of shifting agriculture which is totally destructive […]. Farmers fell and burn the forest and grow crops on the released nutrients for several years in succession, continuing until coppicing potential and the soil seed bank are exhausted, pernicious weeds invade, and soil nutrients are seriously depleted. They then move on to a new patch of virgin forest. This is happening, for example, in parts of western Amazonia […] Replacement of forests by agriculture totally destroys them. If farmland is abandoned it is likely to take several centuries before all signs of forest succession have disappeared, and species-rich, structurally complex primary forest restored […] Agriculture is the main purpose for which rain forests are cleared. There are several major kinds of agriculture and their impact varies from place to place. Important detail is lost by pan-tropical generalization.”

“The mixed cultivation of trees and crops, agroforestry […], makes use of nutrient cycling by trees, as does shifting agriculture. Trees act as pumps, bringing nutrients into the superficial layers of the soil where shallow-rooted herbacious crops can utilize them. […] Early research led to the belief that nearly all the mineral nutrients in tropical rain forests are in the above-ground biomass and, despite much evidence to the contrary, this view is still sometimes expressed. [However] the popular belief that most of the nutrients of a tropical rain forest are in the biomass is seldom true.”

“Given a rich regional flora, forests are particularly favourable for the co-existence of many species in the same community, because they provide many different niches. […] The forest provides a whole array of different internal microclimates, both horizontally and vertically [recall this related observation from McMenamin & McMenamin: “One aspect of the environment that controls the number and types of organisms living in the environment is called its dimensionality […]. Two-dimensional (or Dimension 2) environments tend to be flat, whereas three-dimensional environments (Dimension 3) have, to a greater or lesser degree, a third dimension. This third dimension can be either in an upward or a downward direction, or a combination of both directions.” Additional dimensions add additional opportunities for specialization.] […] The same processes operate in all forests but forests have different degrees of complexity in canopy structure and differ in the number of species that occupy the many facets of what may be termed the ‘regeneration niche’. […] one-to-one specialization between a single plant and animal species as a factor of species richness exists only in a few cases […] Guilds of insects specialized to feed on (and where necessary detoxify) particular families or similar families of plants […] is a looser and commoner form of co-evolution and plays a more substantial role in the packing together of numerous sympatric species […] Browsing pressure (‘pest pressure’) of herbivores […] may be one factor that sometimes prevents any single species from attaining dominance, and acts to maintain species richness. In a similar manner dense seedling populations below a parent tree are often thinned out by disease or herbivory […] and this also therefore contributes to the prevention of single species dominance.”

“An important difference of tropical rain forests from others is the occurence of locally endemic species […]. This is one component of their species richness on the extensive scale. It means that in different places a particular niche may be occupied by different species which never compete because they never meet. It has the consequence that species are likely to become extinct when a rain forest is reduced in extent, more so than in other forest biomes. […] the main reasons why some tropical rain forests are extremely rich in species results from firstly, a long stable climatic history without episodes of extinction, in an equable environment, and in which there is no ‘climatic sieve’ to eliminate some species. Secondly, a forest canopy provides large numbers of spatial and temporal niches […] Thirdly, richness results from interactions with animals, mainly as pollinators, dispersers, or pests. Some of these factors underly species richness in other biomes also. […] The overall effeect of all of humankind’s many different impacts on tropical rain forests is to diminish the numerous dimensions of species richness. Not only does man destroy species, he also simplifies the ecosystems the remaining species inhabit.”

“the claim sometimes made that rain forests contain enormous numbers of drugs just awaiting exploitation does not survive critical examination.[319] Reality is more complex, and there are serious difficulties in developing an economic case for biodiversity conservation based on undiscovered pharmaceuticals. […] The cessation of logging is [likewise] not a realistic option, as too much money is at stake for both the nations and individuals involved.”

“Animal geneticists have given considerable thought to the question of how many individuals are necessary to maintain the full genetic integrity of a species in perpetuity.[425] Much has been learned from zoos. A simple but extremely crude rule-of-thumb is that a minimum population of 50 breeding adults maintains fitness in the short term, thus preserving a species ‘frozen’ at one instant of time. To prevent continual loss of genetic diversity (‘genetic erosion’) over the long term […] requires a big population, and a minimum of 500 breeding adults has been suggested to be necessary. This 50/500 rule is only a very rough approximation and can differ widely between species. […] Most difficult to conserve are animals (or indeed plants too) that live at very low population density (e.g. hornbills, tapir, and top carnivores, such as jaguar and tiger), or that have large territories (e.g. gaur, elephant) […] Increasingly in the future, tropical rain forest will only remain as fragments. […] There is a problem that such fragments may break the 50/500 rule […] and contain too few individuals of a species for its long-term genetic integrity. Species that occur at low density are especially vulnerable to genetic erosion, to chance extinction when numbers fall […], or to inbreeding depression. In particular, many trees live several centuries and may be persisting today but unable to breed, so the species is ‘living but dead’, doomed to extinction. […] small forest remnants may be too small to support certain species and this may have repercussions on other components of the ecosystem. […] Besides reduction in area, forest fragmentation also increases the proportion of edge relative to interior […] and if the fragments are surrounded by open land this will result in a change of microclimate.”

 

September 23, 2014 Posted by | Biology, Books, Botany, Ecology, Evolutionary biology, Genetics, Geography | Leave a comment

An Introduction to Tropical Rain Forests (II)

First an update on the issues I mentioned earlier this week: I had a guy come by and ‘fix the internet problem’ yesterday. Approximately an hour after he left I lost my connection, and it was gone for the rest of the day. I have internet now. If the problem is not solved by a second visit on Monday (they’ll send another guy over), the ISP just lost a customer – I’ll give them no more chances, I can’t live like this. The uncertainty is both incredibly stressful and frankly infuriating. I actually lost internet while writing this post. Down periods seem completely random and may last from 5 minutes to 12 hours. I’m much more dependent on the internet than are most people in part because most of my social interaction with others takes place online.

I’ve read four Christie novels within the last week and I finished The Gambler by Dostoyevsky earlier today – in case you were wondering why I’ve suddenly started reading a lot of fiction, the answer is simple: I’m awake for 16+ hours each day, and if I can’t go online to relax during my off hours I have to find some other way to distract-/enjoy-/whatever myself. Novels are one of the tools I’ve employed.

The internet issue is more important than the computer issue also in terms of the blogging context; the computer I’m using at the moment is unreliable, but seems to cause a limited amount of trouble when I’m doing simple stuff like blogging.

Okay, on to the book. I was rather harsh in my first post, but I did also mention that it had a lot of good stuff. I’ve included some of that stuff in this post below.

“Forests, because of their stature, have internal microclimates that differ from the general climate outside the canopy. […] In general terms, it is cool, humid, and dark near the floor of a mature patch of forest, progressively altering upwards to the canopy top. Different plants and animal species have specialized to the various forest interior microclimates […] Night is the winter of the tropics, because the diurnal range of mean daily temperature exceeds the annual range and is greater in drier months. […] Rain forests develop where every month is wet (with 100 mm rainfal or more), or there are only short dry periods which occur mainly as unpredictable spells lasting only a few days or weeks. Where there are several dry months (60 mm rainfal or less) of regular occurence, monsoon forests exist. Outside Asia these are usually called tropical seasonal forests. […] To the biologist […] there are major differences, and this book is about tropical rain forests, those which occur in the everwet (perhumid) climates, with only passing mention of monsoon forests.”

“Tropical rain forests occur in all three tropical land areas […]. Most extensive are the American or neotropical rain forests, about half the global total, 4 x 106 km2 in area, and one-sixth of the total broad-leaf forest of the world. […] The second largest block of tropical rain forest occurs in the Eastern tropics, and is estimated to cover 2.5 x 106 km2. It is centred on the Malay archipelago, the region known to botanists as Malesia. Indonesia[25] occupies most of the archipelago and is second to Brazil in the amount of rain forest it possesses. […] Africa has the smallest block of tropical rain forest, 1.8 x 106 km2. This is centred on the Congo basin, reaching from the high mountains at its eastern limit westwards to the Atlantic Ocean, with outliers in East Africa. […] Outside the Congo core the African rain forests have been extensively destroyed.”

“It is now believed that about half the world’s species occur in tropical rain forests although they only occupy about seven per cent of the land area. […] Just how many species the world’s rain forests contain is still […] only a matter of rough conjecture. For mammals, birds, and other larger animals there are roughly twice as many species in tropical regions as temperate ones […]. These groups are fairly well studied, insects and other invertebrates much less so […] The humid tropics are extremely rich in plant species. Of the total of approximately 250 000 species of flowering plants in the world, about two-thirds (170 000) occur in the tropics. Half of these are in the New World south of the Mexico/US frontier, 21 000 in tropical Africa (plus 10 000 in Madagascar) and 50 000 in tropical and subtropical Asia, with 36 000 in Malesia. […] There are similarities, especially at family level, between all three blocks of tropical rain forest, but there are fewer genera in common and not many species. […] In flora Africa has been called ‘the odd man out’;[52] there are fewer families, fewer genera, and fewer species in her rain forests than in either America or Asia. For example, there are 18 genera and 51 species of native palms on Singapore island,[53] as many as on the whole of mainland Africa (15 genera, 50 species) […] There are also differences within each rain forest region. […] meaningful discussions of species richness must specify scale.[60] For example, we may usefully compare richness within rain forests by counting tree species on plots of c. 1 ha. This within-community diversity has been called alpha diversity. At the other extreme we can record species richness of a whole landscape made up of several communities, and this has been called gamma diversity. The fynbos is very rich with 8500 species on 89 000 km2. It is made up of a mosaic of different floristic communities, each of which has rather few species. That is to say fynbos has low alpha and high gamma diversity. Within a single floristic community species replace each other from place to place. This gives a third component to richness, known as beta diversity. For example, within lowland rain forest there are differences in species within a single community between ridges, hillsides, and valleys.”

“Most rain forest trees […] exhibit intermittent shoot growth […] The intermittent growth of the shoot tips is seldom reflected by growth rings in the wood, and where it is these are not annual and often not annular either. Rain forest trees, unlike those of seasonal climates, cannot be aged by counting wood rings […] tree age cannot be measured directly. It has [also] been found that the fastest growing juvenile trees in a forest are the ones most likely to succeed, so growth rates averaged from a number of stems are misleading. […] we have very little reliable information on how long trees can live. […] Most of the root biomass is in the top 0.3 m or so of the soil and there is sometimes a concentration or root mat at the surface. […] Roots up to 2 mm in diameter form 20-50 per cent of the total root biomass[79] and their believed rapid turnover is probably a significant part of ecosystem nutrient cycles”

“Besides differences between the three tropical regions there are other differences within them. One major pattern is that within the African and American rain forests there are areas of especially high species richness, set like islands in a sea of relative poverty. […] No such patchiness has been detected in Asia, where the major pattern is set by Wallace’s Line, one of the sharpest zoogeographical boundaries in the world and which delimits the continental Asian faunas from the Australasian […]. These patterns are now realized to have explanations based on Earth[‘s] history […] Gondwanaland and Laurasia were [originally] separated by the great Tethys Ocean. Tethys was closed by the northwards movement of parts of Gondwanaland […]. First Africa and then India drifted north and collided with the southern margin of Laurasia. Further east the continental plate which comprised Antarctica/Australia/southern New Guinea moved northwards, broke in two leaving Antarctica behind, and, as a simplification, collided with the southeast extremity of Laurasia, at about 15 million years ago, the mid-Miocene; this created the Malay archipelago (Malesia) as it exists today. Both super-continents had their own sets of plants and animals. […] Western and eastern Malesia have very different animals, demarcated by a very sharp boundary, Wallace’s line. […] the evolution of the Malay archipelago was in fact more complex than a single collision.[145] Various shards progressively broke off Gondwana from the Jurassic onwards, drifted northwards, and became embedded in what is now continental Asia […]  The climate of the tropics has been continually changing. The old idea of fixity is quite wrong; climatic changes have had profound influences on species ranges.”

“Most knowledge about past climates is for the last 2 million years, the Quaternary period, during which there has been repeated alternation at high latitudes near the poles between Ice Ages or Glacial periods and Interglacials. During Glacial periods tropical climates were slightly cooler and drier, with lower and more seasonal rainfall. During these times rain forests became less extensive and seasonal forests expanded. Most of the Quaternary was like that; present-day climates are extreme and not typical of the period as a whole. Today we live at the height of an Interglacial. […] At the Glacial maxima sea levels were lower by as much as 180 m […] Sea surface temperature was cooler than today, by 5 ° C or more[147] at 18 000 BP in the tropics. […] Rain forests were more extensive than at any time in the Quaternary during the early Pliocene, parts of the Miocene, and especially the early Eocene; so these were all warm periods. Then, in the late Tertiary, fluctuations similar to those of the Quaternary occurred. […] Africa [as mentioned] has a much poorer flora than the other two rain forest regions.[152] This is believed to be because it was much more strongly dessicated during the Tertiary. […] Australia too suffered strong Tertiary dessication. At that time its mesic vegetation became mainly confined to the eastern seaboard. The strip of tropical rain forests found today in north Queensland is only 2-30 km wide and is of particular interest because it contains the relicts of the old mesic flora. This includes the ancestors from which many modern Australian species adapted to hot dry climates are believed to have evolved […] New Caledonia is a shard of Gondwanaland which drifted away eastwards from northeast Australia starting in the Upper Cretaceous 82 million BP. Because it is an island its vegetation has suffered less from the drier Glacial climates so more of the old flora has survived. The lands bordering the western Pacific have the greatest concentration of primitive flowering plants found anywhere […] It is most likely that they survived here as relicts.”

“rain forests have waxed and waned in extent during the Quaternary, and probably in the Tertiary too, and are not the ancient and immutable bastions where life originated which populist writings still sometimes suggest. In the present Interglacial they are as extensive as they have ever been, or nearly so. At glacial maxima lowland rain forests are believed to have contracted and only to have persisted in places where conditions remained favourable for them, as patches surrounded by tropical seasonal forests, like islands set in a sea. In subsequent Interglacials, as perhumid conditions returned, the rain forests expanded out of these patches, which have come to be called Pleistocene refugia. In the late 1960s it was shown that within Amazonia birds have areas of high species endemism and richness which are surrounded by relatively poorer areas. The same was soon demonstrated for lizards.[153] Subsequently many groups of animals have been shown to exhibit such patchiness […] The centres of concentration more or less coincide with each other […] These loci overlap with areas that geoscientific evidence suggests retained rain forest during Pleistocene glaciations […] In the African rain forests four groups of loci of species richness and endemism are now recognized […] Most parts of Malesia today are about as equally rich in species, including endemics, as the Pleistocene refugia of Africa and America. At the Glacial maxima the Sunda and Sahul continental shelves were exposed by falling sealevel. Rain forests were likely to have become confined to the more mountaineous places where there was more, orographic, rain. The main development of seasonal forests in this region is likely to have been on the newly exposed lowlands, and when sea-level rose again at the next Interglacial these and the physical signs of seasonal climates […] were drowned. The parts of Malesia that are above sea-level today probably remained, largely perhumid and covered by rain forest, which explains their extreme species richness and their lack of geoscientific evidence of seasonal past climates. […] Present-day lowland rain forest communities consist of plant and animal species that have survived past climatic vicissitudes or have immigrated since the climate ameliorated. Thus many species co-exist today as a result of historical chance, not because they co-evolved together. Their communities are neither immutable nor finely tuned. This point is of great importance to the ideas scientists have expressed concerning plant-animal interactions […] Those parts of the world’s tropical rain forests that are most rich in species are those that the evidence shows have been the most stable, where species have evolved and continued to accumulate with the passage of time without episodes of extinction caused by unfavourable climatic periods. This is similar to the pattern observed in other forest biomes”

September 20, 2014 Posted by | Biology, Books, Botany, climate, Ecology, Evolutionary biology, Geography, Geology | Leave a comment

Military Geography: For Professionals and the Public (III)

I’ve finished the book. You can read my other posts about the book here and here. I ended up at three stars on goodreads, even though the author actually commits what in my book is a capital offence; he uses acronyms/abbreviations without explaining what they mean in the text. There’s an addendum with stuff like that included in the book, but who the hell would want to frequently jump 100 pages just to understand what’s being said in a chapter? I sure don’t – I’d rather beat up the author for organizing this in a stupid manner. It isn’t that many terms which go unexplained, but you really need to not have any of them when a chapter is written in this manner:

“Option A left both nations within Pacific Command’s area of responsibility, where they had been since their establishment in 1954, and activated a unified command subordinate to CINCPAC; Option B envisaged an independent command on the same level as PACOM. The JCS recommended Option A, CINCPAC concurred, the Secretary of Defense approved, and U.S. Military Assistance Command Vietnam (MACV) emerged in 1962, but the new lashup never worked the way official “wiring diagrams” indicated. COMUSMACV often bypassed CINCPAC to deal directly with superiors in Washington, DC, including the President and Secretary of Defense, who played active parts in daily operations. CINCPAC conducted the air war and surface naval operations, while COMUSMACV took charge on the ground. […] The Navy, backed by the Marine Corps, resisted change because CINCNELM was thoroughly familiar with Middle East problems and the likelihood of major U.S. military involvement anywhere in Black Africa seemed remote. The Secretary of Defense found the Chairman’s arguments persuasive, added MEAFSA to CINCSTRIKE’s responsibilities, and disbanded NELM on December 1, 1963. […] CINCSOUTH and the Army Chief of Staff postulated that general war was a remote possibility, but if it did occur, LANTCOM would have to rivet attention on the Atlantic Ocean whereas Southern Command, armed with a wealth of Latin American experience, was ready, willing, and able to counter Communist activities that posed clear and present dangers to U.S. interests throughout the Caribbean. CINCLANT contended that it would be imprudent to pass responsibility for the Caribbean from his command to SOUTHCOM…”

(The quote is from chapter 16, on military areas of responsibility. I should point out that this chapter is far worse than any other chapter in this respect, and none of the others even come close).

Part three on political-military geography – the above quote is from this section – was in my opinion the weakest part of the coverage, whereas the last part – on area analyses – was okay and quite interesting at times; the latter contains one introductory chapter and then moves on to analyze in some detail the area analysis parts of Operation Neptune and Operation Plan El Paso (a military operation plan which was thought up during the Vietnam War, the goal of which was to stop traffic along the Ho Chi Minh Trail. As the author put it, the plan was stillborn – it never made it off the drawing board). I liked the chapter on Operation Neptune better than the one on the Vietnam War stuff, but both contain important insights related to how geographic factors can affect military operations and how important such aspects may be. Part three wasn’t bad as such, I just suspect that it wasn’t quite as interesting to me as it might have been given a different approach – some aspects covered there are really quite important in terms of understanding how this kind of stuff works, and I’ve added some of that stuff below. On the other hand some parts of it seemed a bit out of place; the chapter on geopolitical friction included paragraphs on atmospheric polution, hazardous waste disposal, and oil spills, and although such activities may well increase friction among neighbouring countries I think you’d be hard pressed to imagine a scenario where they’d lead to outright war. Singapore has e.g. suffered badly the last few years from the smoke caused by Indonesian forest fires, but it doesn’t seem like the military is getting ready to strike back anytime soon – they rather seem to deal with this in a different manner (“The Singaporean military has also reportedly suspended all outdoor training”).

Below I’ve added some final observations/quotes from the book. I decided against covering the chapter on the Normandy landings below despite really liking that chapter, mostly because at least some of the most important relevant geographic factors, including reasons for picking Normandy and the important role weather phenomena played in the decision process, are actually included in the wiki article to which I link above. I’m not really sure if I’d recommend the book, but if you’re interested in the kind of stuff that I’ve quoted in the previous posts and this one, and you want to learn more about stuff like this, it may be worth giving it a shot.

“Spokesmen for each Armed Service, who advise chiefs of state, foreign ministers, and senior defense officials, commonly possess dissimilar views concerning political-military problems and corrective actions, because they operate in distinctive geographic mediums and genuflect before different geopolitical gurus who variously advocate land, sea, air, or space power. Many (not all) members of each service are firmly convinced that their convictions are correct and believe competing opinions are flawed. The dominant school of thought in any country or long-standing coalition (such as NATO and the now defunct Warsaw Pact) consequently exerts profound effects on military roles, missions, strategies, tactics, plans, programs, and force postures. […] Army generals […] subdivide continents into theaters, areas of operation, and zones of action within which terrain features limit deployments, schemes of maneuver, weapon effectiveness, and logistical support. Ground forces engaged in conventional combat are loath to lose contact with adversaries until they emerge victorious and, if necessary, impose political-military control by occupying hostile territory. Armies once were self-sufficient, but dependence on aerial firepower currently is pronounced and, unless circumstances allow them to move overland, they can neither reach distant objective areas nor sustain themselves after arrival without adequate airlift and sealift. Senior army officials consequently tend to favor command structures and relationships that assure essential interservice support whenever and wherever required.”

“Free-wheeling marecentric forces, unlike armies, rely little on joint service cooperation, enjoy a global reach channelized only by geographic choke points, and generally determine unilaterally whether, where, and when to fight, because they most often are able to make or break contact with enemy formations as they see fit. Admirals as a rule accordingly resent bureaucratic restrictions on naval freedom of action and defy anybody to draw recognizable boundaries across their watery domain, which is a featureless plane except along littorals where land and sea meet […] Land-based air forces operate in a medium that surface navies might envy, where there are three dimensions rather than two, no choke points, no topographic impediments, and visibility to far distant horizons, being less limited by Earth’s curvature, is restricted only by clouds except in mountainous terrain. […] aerocentric generals (like admirals) prefer the greatest possible autonomy and are leery of boundaries that limit flexibility because, in the main, they believe that unfettered air power could be the decisive military instrument and make protracted wars obsolete. All services attach top priority to air superiority, without which most combat missions ashore or afloat become excessively costly, even infeasible.[11]”

Each service as it stands is superior in some environments and inferior in others. Armies generally function more efficiently than air forces in heavily forested regions and rugged terrain, whereas air power is especially advantageous over sparsely covered plains. Ballistic missile submarines at sea, being mobile as well as invisible to enemy targeteers, are less vulnerable to prelaunch attacks than “sitting duck” intercontinental ballistic missiles (ICBMs) in concrete silos ashore. Reasonable degrees of centralized control coupled with joint doctrines, joint education, and joint training programs that effectively integrate multiservice capabilities thus seem desirable.”

“Boundary disputes [between USSR and China] bubbled in earnest about 1960, when the Sino-Soviet entente started to split. The first large-scale clashes occurred in Xinjiang Province during early autumn 1964, when Muslim resentment against repressive Chinese rule motivated about 50,000 Kazakhs, Uighurs, and other ethnic groups to riot, then take shelter in the Soviet Union. Tensions along the Far Eastern frontier reached a fever pitch in 1967 after howling mobs besieged the Soviet Embassy in Beijing for more than 2 weeks. Both sides briefly massed a total of 600,000 troops along the border—nearly 40 divisions on the Soviet side and perhaps 50 or 60 Chinese counterparts. Damansky Island (Zhanbao to the Chinese) was twice the site of stiff fighting in March 1969, followed in August by confrontations at Xinjiang’s Dzungarian Gate, after which both sides took pains to defuse situations, partly because each at that point possessed nuclear weapons with delivery systems that could reach the other’s core areas.16 China, however, has never renounced its claims, which future leaders might vigorously pursue if Chinese military power continues to expand while Russian armed strength subsides.” (I never knew about that stuff. The wiki has more here and here.)

“Water requirements often outstrip sources in regions where agricultural and industrial expansion coincide with arid climates and rampant population growth creates unprecedented demands. Poor sanitation practices, contaminated runoff from tilled fields, industrial pollutants, and raw sewage discharged upstream make potable supplies a luxury in many such countries.[50]
Scarcities accompanied by fierce competition have spawned the term “hydropolitics” in the Middle East, where more than half of the people depend on water that originates in or passes through at least one foreign country before it reaches consumers [my emphasis]. […] Nearly all water in Egypt flows down the Nile from catch basins in eight other countries […]
Central and South Asia experience similar water supply problems. Deforestation in Nepal intensifies flooding along the Ganges while India, in turn, pursues water diversion projects that deprive delta dwellers in Bangladesh.”

“Theater commanders in chief, who exercise operational control over land, sea, air, and amphibious forces within respective jurisdictions, as a rule delegate to major subordinate commands authority and accountability over parts of their AORs [Areas Of Reponsibility, – US] for operational, logistical, and administrative purposes. Tactical areas of responsibility (TAORs) facilitate control and coordination at lower levels. The boundaries that CINCs [Commanders IN Chiefs, -US] and other commanders draw are designed to facilitate freedom of action within assigned zones, ensure adequate coverage of objectives and target suites yet avoid undesirable duplication of effort, prevent confusion, and reduce risks of fratricide from so-called “friendly fire.”
Theater and tactical AORs differ from global and regional subdivisions in several important respects: international sensitivities tend to diminish (but do not disappear), whereas interservice rivalries remain strong; areas of interest and influence tend to blur boundary lines; and TAORs are subject to frequent change during fluid operations. […] Operation plans and orders employed by land and amphibious forces at every level commonly prescribe boundaries and other control lines to prevent gaps and forestall interference by combat and support forces with friendly formations on either flank, to the front, or toward the rear. Well drafted boundaries wherever possible follow ridges, rivers, roads, city streets, and other geographic features that are clearly recognizable on maps as well as on the ground. They neither divide responsibility for dominant terrain between two or more commands nor position forces from one command on both sides of formidable obstacles unless sensible alternatives seem unavailable. […] Area analyses developed for combat forces emphasize critical terrain, avenues of approach, natural and manmade obstacles, cover, concealment, observation, and fields of fire […] Marked advantages accrue to armed forces that hold, control, or destroy critical (sometimes decisive) terrain, which is a lower level analog of strategically crucial core areas. Typical examples range from commanding heights and military headquarters to geographic choke points, telecommunication centers, logistical installations, power plants, dams, locks, airfields, seaports, railway marshaling yards, and road junctions. Features that qualify differ at each echelon, because senior commanders and their subordinates have different perspectives. Three- and four-star officers, for example, might see an entire peninsula as critical terrain while successively lower levels focus first on one coastal city, then on the naval shipyard therein, the next layer down on harbor facilities, and finally on pierside warehouses.”

“Perhaps the single most important lesson to be learned from the previous pages is the folly of slighting geographic factors during the preparation of any military plan, the conduct of any military operation, or the expenditure of scarce resources and funds on any military program.”

May 7, 2014 Posted by | Books, Geography, History | 3 Comments

Military Geography: For Professionals and the Public (II)

“Portions of this book may be quoted or reprinted without permission, provided that a standard source credit line is included.”

I allow myself to cover Collins’ book in a bit more detail than I do many other books, for the above reason (I shall assume that the link – along with the fact that I actually report the title of the book in the blog post title – corresponds to a ‘standard source credit line’).

I ended my coverage of the book in my first post when I got to chapter 7, although I’d read a bit further than that at that point. Chapters 7, 8, 9, 10, 11, 12, and 13 deal with: Inner and outer space, natural resources and raw materials, populations (this chapter is the first in the second part of the book, on cultural geography), urbanization, lines of communication, military bases, and fortresses and field fortifications, respectively. A few minor errors/inaccuracies pop up here and there, but this is to be expected of a book this size written by a single author, and as I’m learning something new in each chapter I don’t mind so much that he occasionally e.g. by mistake adds a zero to his kilometer-conversion of the distances reported in miles (“an area 350 by 250 miles — 5,630 by 3,220 kilometers”) because it’s not hard to tell when a mistake has been made and there aren’t that many of them. Though I have found some topics more interesting to read about than others, in general I’d say I like this book.

Although the chapter on warfare in space is in some sense the ‘least relevant’ chapter included in the book in terms of understanding the kinds of wars humans have engaged in so far, I thought it was a rather interesting chapter, especially as most media portrails take some, liberties, when dealing with such topics that make it hard to appreciate how this kind of stuff might actually play out (and no, I don’t think reading Ender’s Game is quite enough to get a good sense of these things). Here’s some stuff from the chapter:

“Space and the seas are superficially similar, but differences are dramatic:
• Continents bound all five oceans, which are liquid and almost opaque, whereas space has no shape and little substance.
• Earth’s curvature limits sea surface visibility to line-of-sight, whereas visibility as well as maneuver room are virtually limitless in space.
• Acoustics, an antisubmarine warfare staple, play no part in space, because sound cannot survive in a vacuum.
• Space welcomes electromagnetic radiation, whereas water is practically impervious to radio and radar waves.
• Day-night cycles and shock waves, which are prevalent everywhere on Earth, are nonexistent in space.
• Atmospheric phenomena and salt water interfere with light and focused energy rays on Earth, but neither refract in space.
Space moreover has no north, east, south, or west to designate locations and directions. A nonrotating celestial sphere of infinite radius, with its center at Earth’s core, is the reference frame. Declination, the astronomical analog of latitude, is the angular distance north or south of the celestial equator, right ascension is the counterpart of longitude, and the constellation Aries, against which spectators on Earth see the sun when it crosses Earth’s Equator in springtime, defines the prime meridian. Angular positions in space are measured from that celestial counterpart of Greenwich Observatory.”

“Geographic influences on nuclear, directed energy, chemical, biological, and conventional weapon effects are far-reaching and fundamental. Atmospheric interfaces, gravity, and vacuum are the most important factors. […]
Nuclear weapons detonated in Earth’s atmosphere create shock waves, violent winds, and intense heat that inflict severe damage and casualties well beyond ground zero.[13] No such effects would occur in space, because winds never blow in a vacuum, shock waves cannot develop where no air, water, or soil resists compression, and neither fireballs nor superheated atmosphere could develop more than 65 miles (105 kilometers) above Earth’s surface. Consequently, it would take direct hits or near misses to achieve required results with nuclear blast and thermal radiation. […] Self-contained biospheres in space afford a superlative environment for chemical and biological warfare compared with Earth, where weather and terrain virtually dictate delivery times, places, and techniques.[15] Most spacecraft and installations on the Moon, which must rely on closed-circuit life support systems that continuously recirculate air and recycle water, are conceivable targets for special operations forces armed with colorless, odorless, lethal, or incapacitating agents that would be almost impossible to spot before symptoms appear [for some coverage of (marginally?) related topics, see this]. Cumbersome masks and suits could protect individuals only if worn constantly. Sanctuaries comparable to the toxic-free citadels that eat up precious room on some ships would be infeasible for most spacecraft and safeguard only a few selected personnel. Any vehicle or structure victimized by persistent chemicals probably would become permanently uninhabitable, because vast quantities of water and solvents required for decontamination would be unavailable.”

“A one-month supply of oxygen, food, and drinking water just for a crew of three amounts to more than a ton stored at the expense of precious propellant and military payloads. Each crew member in turn would deposit an equal amount of waste in the form of feces, urine, perspiration, internal gases, carbon dioxide, and other exhalation vapors that could quickly reach toxic proportions in a sealed capsule unless quelled, expelled, or sterilized. Life support systems currently dump or stow organic waste on short missions, but such practices do little to alleviate long-term resupply problems. […] Motion sickness, somewhat like an aggravated form of sea sickness, afflicts about half of all space travelers whose responses to medical suppressants are unpredictable. It conceivably might undermine mission proficiency enough during the first few days of each flight to mark the difference between military success and failure”

“Military space forces at the bottom of Earth’s “gravity well” need immense energy to leave launch pads and climb quickly into space. Adversaries at the top, in positions analogous to “high ground,” have far greater maneuver room and freedom of action. Put simply, it is easier to drop objects down a well than to throw them out. […] L4 and L5, the two stable libration points, […] theoretically could dominate Earth and Moon because they look down both gravity wells. No other location is equally commanding.”

One assumption underlying much of the analysis in that chapter is that humans will actually be the ones doing the physical fighting that takes place in space as well – i.e. there’ll be humans in that space shuttle, and the humans will be the ones directing their lasers (or whatever) at the enemy. This is a weakness of the coverage in that chapter, I think, as strategies involving robotics as a key element seem to me an obvious way to try to work around a lot of the constraints imposed on organisms conducting war in space. Humans need a lot of stuff to survive in space, and if you can get machines to do the unpleasant stuff via remote control that seems like a no-brainer; yet that aspect isn’t really covered in the chapter. Humans have used space probes for decades and although we weren’t as far along in 1998 as we are now, we had been making progress for a long time. Humans sent a probe to the moon to pick up some lunar soil and return it to Earth – successfully – almost 30 years before the book was written. However it is just one chapter, and I think I’ve said enough about space for now – despite this shortcoming it’s still an interesting chapter.

Let’s talk a little bit about disease instead. Did you know that in World War II in the year 1944, 67% of U.S. military casualties in Europe were disease casualties? I didn’t. Only 23% were classified as combat casualties, with the last 10% being ‘noncombat casualties’. Presumably some of these were people who went insane – some of them committing suicide, others ‘just’ becoming unable to perform their military duties – because of the psychological strain, so it’s probably debatable to which extent they were all ‘non-combat’. As Fussell observed in his book:

“In war it is not just the weak soldiers, or the sensitive ones, or the highly imaginative or cowardly ones, who will break down. Inevitably, all will break down if in combat long enough […] As medical observers have reported, “There is no such thing as ‘getting used to combat’ … Each moment of combat imposes a strain so great that men will break down in direct relation to the intensity and duration of their experience.” Thus – and this is unequivocal: ‘Psychiatric casualties are as inevitable as gunshot and shrapnel wounds in warfare.”

On the other hand the 10% figure probably also includes stuff like accidents and desertions, at least some of which were not ‘battle-related’; the American army incidentally had 19.000 acknowledged deserters during WW2, and less than half of them (9000) had been found by 1948 – I again refer to Fussell’s book, p. 151.

Disease casualties made up an even larger proportion of the US WW2 casualties in the Southwest Pacific (83% disease, 5% combat, 12 percent non-combat) and China-Burma (90% disease, 2% combat, 8% non-combat). It’s perhaps important to keep in mind in this context that ‘casualties’ != ‘soldiers who died’ (it’s rather best thought of as ‘soldiers put out of action’) and that the proportion of dead people in the three groups may well be dissimilar. There’s also some conceptual overlap between the groups (bacterial infections in gunshot wounds) which it’s unclear how the source provided in the book has dealt with. However it’s still thoughtprovoking data. Of course Stevenson covered this kind of stuff as well, and in much greater detail – if you want to know more about these things, that’s a place to start. According to the source in the book, disease casualties incidentally accounted for two-thirds of casualties during the Vietnam War in 1969 (just like in Europe 25 years earlier – combat was 19% and noncombat 14%). Diseases vary a lot and different diseases will call for different prevention strategies; for example Fussell mentions in his book that contracting a sexually transmitted disease during WW2 was actually a punishable offence for US soldiers (p.108).

More quotes from Collins’ book below:

“Urban combat […] disrupts unit cohesion, complicates control, blunts offensive momentum, and causes casualties to soar on both sides.
Most military doctrines the world over consequently advise land force commanders to isolate or bypass built-up areas, but the subjugation of political, industrial, commercial, transportation, and communication centers even so may sometimes decisively affect the outcome of battles, campaigns, even wars. Military commanders in such events face an endless variety of structures and facilities the seizure or control of which demands esoteric plans, programs, and procedures, since no two cities are quite alike.”

“Street fighting ensues whenever armed forces try to wrest urbanized terrain from stubborn defenders. It can be brutal but brief in villages and a lengthy, agonizing struggle between small, isolated units in cities where concrete canyons and culs-de-sac degrade technological advantages, severely limit vehicular mobility, render tactical communications unreliable, complicate intelligence collection, and swallow troops wholesale. Restrictive rules of engagement designed to reduce collateral damage and casualties may further decease benefits obtainable from aerial firepower as well as artillery and magnify dependence on foot soldiers.[22] […] Motorized troops must stick to streets and open spaces, whereas infantrymen fight three-dimensional wars at ground level, on rooftops, and in subterranean structures such as subways, sewers, and cellars, creeping over, under, or around each structure, blasting “mouseholes” through walls, ceilings, and floors when more convenient avenues are unavailable. Mines, booby traps, barbed wire, road blocks, rubble, and other obstacles abound […] Every inner city building becomes a potential strong point, particularly those that overlook key intersections or open spaces.[26] Clear fields of fire for flat-trajectory weapons seldom exceed 200 yards (185 meters) even in suburbs, where ornamental shrubbery and sweeping curves often limit lines-of-sight.”

“Tanks and other armored vehicles inch through inner cities at a snail’s pace, find little room to maneuver on narrow or rubble-clogged streets, cannot turn sharp corners, and are vulnerable beneath enemy-occupied buildings unless they “button up,” which limits visibility and invites ambush. Many lucrative targets remain beyond reach, because most range-finders produce fuzzy images close up, tank turrets cannot swivel freely in cramped quarters, and main guns on level ground can neither elevate nor depress enough to blast upper stories or basements nearby. […] Conventional urban combat consequently calls for few rather than many tanks, mainly to furnish close support for frontline infantry.[28] Exceptions to that rule normally involve opponents in disarray or other special circumstances […] Urban jungles, like their leafy analogs, discourage artillery. […] High-angle artillery fire in urban areas […] is often used mainly to clear rooftops and target troops in the open while mortars, which are more maneuverable and less destructive, handle most close support missions. […] Urban combat inhibits lighter crew-served arms as well. Backblast makes it dangerous to emplace recoilless weapons in small, unvented rooms or other cramped spaces where loose objects, glass, and combustible materials must be covered or removed. Enclosures so amplify explosive sounds that personnel without earplugs become deaf after a few experiences.”

“Low-level U.S. [air] raids against Japan, all at night, slighted high explosives in favor of incendiaries, mainly magnesium, white phosphorus, and jellied gasoline […] Successes destroyed 40 percent of 66 cities, left almost one-third of Japan’s population homeless, and inflicted far more casualties than Japanese Armed Forces suffered during all of World War II. The cataclysmic Tokyo raid of March 9 and 10, 1945, killed 83,000 when high winds among flimsy wooden and rice paper structures whipped up uncontrollable fire storms […] Japanese noncombatants felt shock effects many times greater than those that accompanied urban bombing campaigns against Germany, because attacks were concentrated in a much shorter period.[58]”

“Military requirements determine the number, characteristics, essential service life, and acceptable construction time of airfields in any area of operations. Topography, climatic conditions, vegetation, hydrology, soils, and logistical convenience strongly influence locations. Preferable sites feature the flattest terrain, the clearest weather, the most favorable winds, the fewest obstructions, the freest drainage, and easiest access to prominent land lines of communication but, if that ideal is unattainable for political, military, geographic, or cultural reasons, decisionmakers must compromise.
Primary runways generally parallel the direction of prevailing winds, taking high-velocity cross-currents into account. Runway lengths required by any given type aircraft would be standard everywhere if Planet Earth were a perfectly flat plain at sea level, all thermometers consistently registered any given temperature, the surface never was slick with rain, sleet, or snow, and all pilots were equally competent. Military airfield designers in the real world, however, must extend runways to compensate for increases in altitude and do likewise where temperatures of the warmest month average more than 59 °F (15 °C), because those factors singly or in combination create rarefied air that degrades engine performance and affords less lift. Takeoffs up inclines and landings downhill also require longer runways.”

Yes, there are actually algorithms for how to account for these variables in the field:

airfields

“No nation, not even the British Empire at its zenith, deployed armed forces at as many military installations beyond its borders as the United States of America did during the Cold War. They were unusual compared with most bases abroad, being sited on the sovereign territory of allies and other friends with whom the U.S. Government negotiated mutually acceptable Status of Forces Agreements that legally prescribed U.S. rights, privileges, and limitations. All such bases and facilities exploited geographical positions that promoted U.S. security interests, affirmed U.S. global involvement, extended U.S. military reach, and strengthened U.S. alliance systems. They also positioned U.S. Armed Forces to deter Soviet aggression and respond most effectively if required. […] Nearly 1,700 U.S. installations, large and small, eventually circled the Northern Hemisphere in locations selected especially to monitor military activities inside the Soviet Union, ensure early warning if Soviet Armed Forces attacked, and block the most likely land, sea, and air avenues of Soviet advance. […] Eighty-one Distant Early Warning (DEW) Stations, draped 4,000 miles (6,435 kilometers) along the 70th Parallel from the Aleutian Islands to the Atlantic Ocean, watched for enemy bombers in the early 1960s […] Mid-Canada and Pine Tree Lines, augmented by a generous group of gap-filler radars, provided back-ups farther south, but that complex shrank considerably as soon as better technologies became available.”

May 4, 2014 Posted by | Books, Geography | Leave a comment

Military Geography: For Professionals and the Public (I)

I’m currently reading this book by John Collins, ‘a retired U.S. Army colonel and a distinguished visiting research fellow at the National Defense University’, as they describe him here – perhaps other parts of that description are more impressive: He’s also a former ‘chief of the Strategic Research Group at the National War College’ and he was for 24 years ‘the senior specialist in national defense at the Congressional Research Service’. Long story short: It seems as if he knows what he’s talking about. I have encountered a few minor problems/inaccuracies, including this interesting remark: “Viking raiders invaded Ireland in the 6th century A.D” – but they haven’t subtracted much from the coverage. In that specific case I certainly felt compelled to give the author the benefit of the doubt and assume that this was a typo, with a ‘9’ turning into a ‘6’; the sixth century is a bit too early – see also this… The very early (supposed) Viking invasion mentioned in that sentence is incidentally completely unrelated to the rest of the coverage in that chapter, so the damage is very minimal anyway. In general it’s a rather neat little book so far.

The author argues in his introduction that military geography is a neglected topic:

“few schools and colleges conduct courses in military geography, none confers a degree, instructional materials seldom emphasize fundamentals, and most service manuals have tunnel vision […] My contacts in the Pentagon and Congress were bemused when I began to write this book, because they had never heard of a discipline called “military geography.””

…and I actually found this really quite interesting, because the kind of stuff covered in this book so far would be precisely the kind of stuff I’d expect any general to know and to have received education in. Things may have changed in the meantime as the book isn’t written yesterday (it’s from 1998, so obviously some aspects of military doctrine have changed since then), but even if things have changed it’s still very interesting to me that that was the state of affairs when the book was written.

Waging war in an optimal manner is a lot more complicated than it looks like in the movies, and this book provides you with a lot of information and details which make the complexity easier to appreciate. Most people know that soldiers who are to be deployed in a desert will require different types of equipment and supplies than will soldiers who are to be deployed in a rainforest, and that fighting conditions in flat terrain and -conditions in hilly terrain will be different from each other, but aside from a few obvious observations in such regards most people probably would be hard pressed to say much about how the environmental constraints affect deployment strategies, optimal supply chain management, fuel consumption, etc. Even an observation as simple as: ‘it is hot in the desert, so soldiers fighting there will need a lot of water’ arguably to some extent eluded German strategists during the North African Campaign, as this quote from the book illustrates:

“Sweat evaporates so rapidly in dry desert heat that humans commonly lose about 1 pint of water per hour even at rest, yet never notice adverse effects or feel thirsty until the deficit reaches four times that amount (2 quarts, or 2 liters), by which time heat prostration may be imminent. Heavy exertion requires much greater intake, but Rommel’s Afrika Korps in the summer of 1942 carried only 15 quarts per day for trucks and tanks as well as personnel. His parched troops made every drop count, yet still ran dry during one offensive and survived only because they captured British water supplies.[58] U.S. military personnel in Saudi Arabia and Kuwait, who were much better endowed logistically, consumed approximately 11 gallons per day (42 liters), plus 10 to 12 gallons more per vehicle.” (There’s more on this topic below).

One could also talk about the obvious need for providing soldiers with proper winter clothes if you’re planning on invading Russia (-ll-)… The book goes into a lot of detail about these kinds of things, because the physical environment affects all kinds of aspects of warfare in ways that are actually quite hard to imagine. I’ve added some observations from the book below. I’ve read roughly the first 200 pages and so far I like it.

“This consolidated guide, designed to fill undesirable gaps, has a threefold purpose:

• To provide a textbook for academic use
• To provide a handbook for use by political-military professionals
• To enhance public appreciation for the impact of geography on military affairs.

Parts One and Two, both of which are primers, view physical and cultural geography from military perspectives. Part Three probes the influence of political-military geography on service roles and missions, geographic causes of conflict, and complex factors that affect military areas of responsibility. Part Four describes analytical techniques that relate geography to sensible courses of military action, then puts principles into practice with two dissimilar case studies—one emphasizes geographic influences on combat operations, while the other stresses logistics.”

“Soil conditions and rock affect the performance of many conventional weapons and delivery vehicles. Rocky outcroppings and gravel magnify the lethal radius of conventional munitions, which ricochet on impact and scatter stone splinters like shrapnel, whereas mushy soil smothers high explosives that burrow before they detonate. Even light artillery pieces leave fairly heavy “footprints” in saturated earth, a peculiarity that limits (sometimes eliminates) desirable firing positions. Gunners struggled to keep towed artillery pieces on targets when they worked at or near maximum tube elevations on wet ground in Vietnam where it didn’t take many rounds to drive 155-mm howitzer trails so deeply into the mire that recoil mechanisms malfunctioned. […] Surface conditions likewise amplify or mute nuclear weapon effects. The diameters and depths of craters are less when soil is dry than when soaked, nuclear shock waves transmitted through wet clay are perhaps 50 times more powerful than those through loose sand, and the intensities as well as decay rates of nuclear radiation reflect soil compositions and densities.”

“Legitimate terrors confront warriors in dark woods, where armed forces battle like blindfolded boxers who cannot see their opponents, small-unit actions by foot troops predominate, control is uncertain, and fluid maneuvers are infeasible. State-of-the-art technologies confer few advantages regardless of the day and age:
• Vehicles of any kind are virtually useless, except on beaten paths.
• Tree trunks deflect flat-trajectory projectiles. […]
• Tanks can bulldoze small trees, but the vegetative pileups impede or stop progress.
• The lethal radius of conventional bombs and artillery shells is much less than in open terrain, although the “bonus” effect of flying wood splinters can be considerable.
• Hand grenades bounce aimlessly unless rolled at short ranges that sometimes endanger the senders.
• Napalm burns out rapidly in moist greenery; flares illuminate very little; and dense foliage deadens radio communications.”

“Atmospheric phenomena significantly affect the performance of weapon systems and munitions. Pressure changes and relative humidity alter barometric fusing and arming calculations, dense air reduces maximum effective ranges, gusty crosswinds near Earth’s surface make free rockets and guided missiles wobble erratically, while winds aloft influence ballistic trajectories. Rain-soaked soils deaden artillery rounds, but frozen ground increases fragmentation from contact-fused shells. Dense fog, which degrades visual surveillance and target acquisition capabilities, also makes life difficult for forward observers, whose mission is to adjust artillery fire. Line-of-sight weapons, such as tube-launched, optically tracked, wire-guided (TOW) antitank missiles, are worthless where visibility is very limited. Exhaust plumes that follow TOWs moreover form ice fog in cold, damp air, which conceals targets from gunners even on clear days, and reveals firing positions to enemy sharpshooters. Scorching heat makes armored vehicles too hot to touch without gloves, reduces sustained rates of fire for automatic weapons, artillery, and tank guns, and renders white phosphorus ammunition unstable. […] Nuclear weapons respond to weather in several ways, of which winds on the surface and aloft perhaps are most important. […] Low air bursts beneath clouds amplify thermal radiation by reflection, whereas the heat from bursts above cloud blankets bounces back into space. Heavy precipitation raises the temperature at which thermal radiation will ignite given materials and reduces the spread of secondary fires. Detonations after dark increase the range at which flashes from nuclear explosions blind unprotected viewers. Blasts on, beneath, or at low altitudes above Earth’s surface suck enormous amounts of debris up the stems of mushroom clouds that drift downwind. The heaviest, most contaminated chaff falls back near ground zero within a few minutes, but winds aloft waft a deadly mist hundreds or thousands of miles. The size, shape, and potency of resultant radioactive fallout patterns differ with wind speeds and directions, because terrain shadows, crosswinds, and local precipitation sometimes create hot spots and skip zones within each fan. Fallout from one test conducted atop a tower in Nevada, for example, drifted northeast and retained strong radioactive concentrations around ground zero, while a second test from the same tower on a different date featured a “furnace” that was seven times hotter than its immediate surroundings 60 miles (95 kilometers) northwest of the test (figure 18). Such erratic results are hard to predict even under ideal conditions.[35]”

“Dry cold below freezing encourages frostbite among poorly clothed and trained personnel. German Armed Forces in Russia suffered 100,000 casualties from that cause during the winter of 1941-1942, of which 15,000 required amputations. Human breath turned to icicles in that brutal cold, eyelids froze together, flesh that touched metal cold-welded, gasoline accidentally sprayed on bare skin raised blisters the size of golf balls, butchers’ axes rebounded like boomerangs from horse meat as solid as stone, and cooks sliced butter with saws. Dehydration, contrary to popular misconceptions, can be prevalent in frigid weather when personnel exhale bodily moisture with every breath. Low temperatures, which inhibit clotting, cause wounds to bleed more freely, and severe shock due to slow circulation sets in early unless treated expeditiously. […] Armed forces in enervating heat face a different set of difficulties. Water consumption soars to prevent dehydration, since exertions over an 8-hour period in 100 °F (38°C) heat demand about 15 quarts a day (14 liters). Logisticians in the desert are hard pressed to supply huge loads, which amount to 30 pounds per person, or 270 tons for an 18,000-man U.S. armored division. […] Myriad other matters attract concerted attention. […] The rate of gum accumulations in stored gasoline quadruples with each 20°F increase in temperature, which clogs filters and lowers octane ratings when forces deplete stockpiles slowly.”

“Cold clime logistical loads expand prodigiously in response to requirements for more of almost everything from rations, clothing, tents, water heaters, and stoves to whitewash, snow plows, antifreeze, batteries, repair parts, construction materials, and specialized accouterments such as snow shoes and skis. Armed forces in wintry weather burn fuel at outrageous rates. Motor vehicles churning through snow, for example, consume perhaps 25 percent more than on solid ground. It takes 10 gallons (38 liters) of diesel per day to keep a 10-man squad tent habitable when the thermometer registers -20 °F (-29 °C). […] Generous, lightweight, well-balanced, nutritious, and preferably warm rations are essential in very cold weather, especially for troops engaged in strenuous activities. The U.S. Army sets 4,500 calories per day as a goal, although Finnish counterparts with greater practical experience recommend 6,000. Sweets make excellent instant-energy snacks between regular meals. Commanders and cooks must constantly bear in mind that food not in well-insulated containers will freeze in transit between kitchens and consumers. Each individual moreover requires 4 to 6 quarts (liters) of drinking water per day to prevent dehydration in cold weather, although adequate sources are difficult to tap when streams turn to ice. Five-gallon (18-liter) cans as well as canteens freeze fast in subzero temperatures, even when first filled with hot water. […] Combat and support troops engaged in strenuous activities must guard against overdressing, which can be just as injurious as overexposure if excessive perspiration leads to exhaustion or evaporation causes bodies to cool too rapidly. […]

Big maintenance problems begin to develop at about -10°F (-23 °C) and intensify with every degree that thermometers drop thereafter:
• Lubricants stiffen.
• Metals lose tensile strength.
• Rubber loses plasticity.
• Plastics and ceramics become less ductile.
• Battery efficiencies decrease dramatically.
• Fuels vaporize incompletely.
• Glass cracks when suddenly heated.
• Seals are subject to failure.
• Static electricity increases.
• Gauges and dials stick.
Combustion engines are hard to start, partly because battery output at best is far below normal (practically zero at -40 °F and -40 °C).”

“Tropical rain forests, which never are neutral, favor well-prepared forces and penalize military leaders who fail to understand that:
• Small unit actions predominate.
• Overland movement invariably is slow and laborious.
• Troops mounted on horseback and motor vehicles are less mobile than foot soldiers.
• Natural drop zones, landing zones, and potential airstrips are small and scarce.
• Visibility and fields of fire for flat trajectory weapons are severely limited.
• Land navigation requires specialized techniques.
• Tanks, artillery, other heavy weapons, and close air support aircraft are inhibited.
• Command, control, communications, and logistics are especially difficult.
• Special operations forces and defenders enjoy distinctive advantages.
• Quantitative and technological superiority count less than adaptability. […]

Overland travel in jungles averages about ½ mile an hour where the going is good and ½ mile a day where it is not, unless troops follow well-trodden trails that invite adversaries to install mines, booby traps, road blocks, and ambushes. […] Jungles are filled with animate and inanimate objects that bite, sting, and stick, a host of microorganisms that are harmful to humans, fungus infections that troops affectionately call “jungle rot,” and steamy atmosphere that encourages profuse perspiration, body rashes, and heat exhaustion. […] More casualties could be traced to malaria than to hostile fire during World War II campaigns in the South Pacific.”

 

May 2, 2014 Posted by | Books, Geography | Leave a comment

Evolution of Island Mammals: Adaption and Extinction of Placental Mammals on Islands

I was spending time with family this weekend, and as the environment was somewhat noisier than usual I had difficulties reading the Handbook. So I decided to engage in some lighter reading, which is where this Wiley-Blackwell publication enters the picture. Along the way I realized it wasn’t actually much lighter reading, but I enjoyed it and so decided to keep going…

I was very uncertain if I should give the book three stars or four on goodreads, and when I finished it yesterday I gave it three stars. I have now changed that rating to four stars. It is a fascinating book, but it is a bit dry at times. It probably deserves two posts, but I couldn’t be bothered to write more than one. I watched this Gresham College lecture a while back, and that lecture provided part of the motivation for reading the book. Wilson touched upon some of the themes covered in the book as well – his name does come up, naturally. Still, it should be emphasized that there was a lot of stuff covered in this book which I’d never really thought about and about which I knew nothing, and reading books which deal with such things is always nice.

Say you have an island formed in the middle of the ocean. There’s water all around it, perhaps lots of water, and it’s always been far away from continents and other islands. Which kinds of animals turn up there, how many different kinds, and how do they get there? Does the size of the island matter, and how does it matter? What usually happens after a new visitor has become established on an island?

Animals don’t just pop up and start hanging around – we are used to there being so many species around us that it would be easy to forget that it’s not necessarily the natural state of affairs that there are hundreds of species of animals all around you. On an isolated island which literally rose from the ocean animals have to somehow establish themselves before they can start a life there, and until they get there and find mates and enough food to survive, the island will be rather boring from the biased perspective of living organisms such as ourselves. Some animals are better colonizers than others, and that goes for some species/genera/families of mammals as well. Not all islands incidentally rise from the ocean; some get separated from the continent from which they originated, perhaps due to a combination of plate tectonics and/or eustatic sea level rise. In biology islands in a more general sense, understood as habitats where some types of organisms are isolated from their conspecifics, play an important role in speciation processes, so there are many reasons why one might be interested to learn more about such things – though it should be pointed out here that this book only deals with ‘proper’ islands, i.e. the kinds with water around them and so on.

Some islands display a great deal of species diversity, whereas a lot of others have a very unbalanced and impoverished fauna. By impoverished, I mean really impoverished – it’s amazing how few types of mammals sometimes made it to a specific island and got themselves established before humans started messing around with stuff. Or perhaps the amazing thing is rather that any of them did at all? I don’t know. To take an example of an impoverished island fauna, Cyprus is a good illustrative example. The only mammals on Cyprus (that we know about) during the Pleistocene were pygmy hippopotami, dwarf elephants, and perhaps bats. No cats, no dogs, no mice or rats, no goats, no pigs, no bovids, no deer, no nothing. When I set out reading this book I had in my mind some not-particularly-well-thought-out ideas about which sorts of animals normally hang around in the environment, and sometimes reading books can really mess with such ‘ideas you were not even aware that you had’; the fact of the matter is that in the case of some specific islands every single mammal species you’ll encounter on that isolated island (which incidentally today may not actually seem particularly isolated on account of technology, human transport methods etc.) will have some unique and probably quite fascinating story, explaining how it got there – and members of species which don’t have such a story to tell simply aren’t/weren’t around at all. Of course many of the island species mentioned can’t tell their story either anymore because they’ve gone extinct – again Cyprus provides an example. We talked about Pleistocene – well, at the onset of the Holocene a few more species were added (a genet, a mouse, and some fruitbats). They did okay and nothing much changed. But then later on the island stasis was interrupted, presumably because of human agency, and all the mammals that had established themselves before that time went extinct. A wonderful story that makes you proud to be a human.

As mentioned rather than being isolated species-poor places, some island groups have large species diversity; the West Indies is an example of that type. The book deals with a lot of different islands, and although there are some common patterns and trends there is also a lot of variation – and the variation seems to be reasonably well understood in most cases, although lack of evidence sometimes make things a bit harder to figure out than one would like them to be. A thing I feel compelled to note and emphasize is that an impoverished fauna does not an uninteresting fauna make: Some awesome animals have inhabited various islands around the world, and I’ve occasionally been saddened to read a chapter because of the realization of what has been lost (after having been first greatly fascinated by what was actually there). I’ve probably have had in the past a tendency to think of mammals as the bad guys in the story of islands because of how anthropogenically introduced invasive species such as rats and rabbits have wreaked havoc around the world, but birds aren’t the only types of animals that colonize islands and lots of mammal species around the world have been natural elements of island ecosystems for millions of years. To get back to the awesome animals and our example of Cyprus from above, the pygmy hippopotamus which used to live there is estimated to have been about 125 cm long, with a shoulder height of about 70 cm. The dwarf elephant that lived there was a bit larger; it’s estimated to have had a shoulder height of 1.40 metres. These animals were actually much larger than the pygmy elephants which inhabited nearby Sicily roughly 450.000 years ago, which had female shoulder heights of about 0.9 metres and male shoulder heights of about 1,3 metres, and an estimated body weight of around 100 kg. Yep. You’re probably used to think of mammoths as huge creatures (I was), and in that case you may be interested to know that an estimate of the size of the Cretan pygmy mammoth (…yes, there were mammoths living on Crete! I know! I had no idea either!) is 1.5 meters. Proboscideans were incidentally quite successful island colonizers, showing up all over the world:

“Endemic proboscideans have been reported from islands all over the world. Apparently, proboscideans were the most successful lineage of large-sized island colonizers, ranging from stegodons and mastodons to mammoths and elephants. Everywhere they developed a smaller size, eventually reaching dwarf or even pygmy proportions compared with their mainland ancestors. It is hard to think of an island with a rich fossil record lacking any proboscidean remains. Exceptions are the Balearics, Gargano, the central Ryukyu Islands, and the West Indies.”

Again, I had no clue! Mammoths used to live as far apart as Crete and Japan… Lions and hyenas used to live on Sicily, and tigers used to inhabit Japan. Incidentally proboscideans got smaller on islands, but many small mammals have tended to grow in size instead once they established themselves on isolated islands. On Minorca there used to live giant hares weighing 14 kg, and giant rats still inhabit the island of Flores; these guys are up to 45 centimeters long, with tails up to 70 centimeters. Body size is not the only thing that tends to change on islands; a stockier build (shorter limbs, stiffer joints), and changes in dentition also often happens, but body size changes are certainly noteworthy. Note that size changes don’t just mean that animals will get smaller or larger; greater size variation on islands is common due to adaptive radiation. You’ll have both small and large animals of a similar species, at least to start with – if the process is allowed to continue for millions of years you may easily end up with multiple different species derived from the same ancestor. Lemurs are a good example of where you may end up. Life is different on islands. Generally intraspecific competition tend to increase and interspecific competition tend to decrease (as a general rule carnivores are much less likely to become established on islands than are herbivores), but interspecific competition is still very important; the existence or absence of competing taxa can have major effects on the course of evolution. For example the Sicilian pygmy elephants developed during a time period where there were no deer present on the island; during the time where there were deer on Sicily, proboscideans reached dwarf proportions but never went smaller than that (in the book they apply the pygmy label to species half the ancestral size or less, and the term dwarf for forms which are 80–60% of the ancestral body size).

The book has three parts. The first part is called ‘Beyond the mainland’, and aside from a few introductory remarks it briefly talks about the history of island studies and then moves on to talk about ‘how islands are different’ from the mainland and how this affects the fauna. Part two is the main part of the book, and it deals with how mammal species have lived, died, evolved etc. on many different islands around the world; each island is to some extent unique, so each chapter deals with one island. The islands included in the coverage are: Cyprus, Crete, Gargano, Sicily, Malta, Sardinia and Corsica, The Balearic Islands, Madagascar, Java, Flores, Sulawesi, The Philippines, Japan, the Southern and Central Ryukyu Islands (the northern islands are included in the coverage of Japan), the Californian Channel Islands, and the West Indies. So the book does give a reasonably global view of island mammal life, although there are many chapters dealing with the Mediterranean. The book deals with evolutionary biology, but in order to tackle this topic you also need to deal with other areas such as geology. For example the Mediterranean looked very different 5-6 million years ago, and such changes have had huge consequences for how species adapted and evolved to their local environments. Some of the most fascinating stuff in this book in my mind related to how different the world used to look like, even if you don’t go back all that far. Japan used to be part of the mainland, Crete was a submerged mountain chain at the bottom of the ocean a while back, and the island of Flores emerged above the sea during the Early Miocene. Roughly 2 million years ago much of the current island of Java was at the bottom of the ocean, but on the other hand 800.000 years ago the island, as well as Sumatra and Borneo, may well have been connected with the mainland due to changes in global sea levels. Madagascar and India stuck together when they left Africa a long time ago, but they picked different routes and ended up different places, with different fauna. The chapters in this part of the book also provides some history of how we came to know what we know, who were some of the key people involved in figuring these things out, and so on, which is often rather interesting. In a way you sort of have to deal with such matters to some extent e.g. because the taxonomy is sometimes a bit messy when analyzing island data. Lumpers and splitters will disagree violently about the number of species, and understanding how the people who first looked at the bones arrived at the conclusions they did is often interesting.

Part three of the book deals with ‘Species and Processes’. After dealing with all the various islands an attempt is made here to sum up what we’ve learned from the coverage; first by taking a closer look at the species we’ve encountered along the way, then towards the end of the book by adding some general remarks and observations. The species covered in this section are naturally the species which have engaged in most island colonization activities. I was a little frustrated along the way while reading the book that few general principles were formulated, and that the coverage focused a great deal on ‘the specifics’ of the island in question, but this part sort of partly makes up for it and some people would surely argue that the method applied is perfectly justified. The species covered in the chapters in this part of the book are: ‘Elephants, Mammoths, Stegodons and Mastodons’, ‘Rabbits, Hares and Pikas’, ‘Rats, Dormice, Hamsters, Caviomorphs and other Rodents’, ‘Insectivores and Bats’, ‘Cervids and Bovids’, ‘Hippopotamuses and Pigs’, and ‘Carnivores’. The last two chapters of the book deal with some general ‘Patterns and Trends’ as well as ‘Evolutionary Processes in Island Environments’; I’ve covered some of that stuff above already.

Overall I really liked the book. Aside from the small problems such as ‘too specific, a few too many remarks about Cuvier‘, the only problem I had with the book was that there was very little focus on mammalian interactions with non-mammals on the islands. But given the focus of the book this was perhaps only to be expected. It’s a nice book and I enjoyed reading it.

January 27, 2014 Posted by | Biology, Books, Ecology, Evolutionary biology, Geography, Geology, Zoology | Leave a comment