i. “‘Intuition’ comes first. Reasoning comes second.” (Llewelyn & Doorn, Clinical Psychology: A Very Short Introduction, Oxford University Press)

ii. “We tend to cope with difficulties in ways that are familiar to us — acting in ways that were helpful to us in the past, even if these ways are now ineffective or destructive.” (-ll-)

iii. “We all thrive when given attention, and being encouraged and praised is more effective at changing our behaviour than being punished. The best way to increase the frequency of a behaviour is to reward it.” (-ll-)

iv. “You can’t make people change if they don’t want to, but you can support and encourage them to make changes.” (-ll-)

v. “You shall know a word by the company it keeps” (John Rupert Firth, as quoted in Thierry Poibeau’s Machine Translation, MIT Press).

vi. “The basic narrative of sedentism and agriculture has long survived the mythology that originally supplied its charter. From Thomas Hobbes to John Locke to Giambattista Vico to Lewis Henry Morgan to Friedrich Engels to Herbert Spencer to Oswald Spengler to social Darwinist accounts of social evolution in general, the sequence of progress from hunting and gathering to nomadism to agriculture (and from band to village to town to city) was settled doctrine. Such views nearly mimicked Julius Caesar’s evolutionary scheme from households to kindreds to tribes to peoples to the state (a people living under laws), wherein Rome was the apex […]. Though they vary in details, such accounts record the march of civilization conveyed by most pedagogical routines and imprinted on the brains of schoolgirls and schoolboys throughout the world. The move from one mode of subsistence to the next is seen as sharp and definitive. No one, once shown the techniques of agriculture, would dream of remaining a nomad or forager. Each step is presumed to represent an epoch-making leap in mankind’s well-being: more leisure, better nutrition, longer life expectancy, and, at long last, a settled life that promoted the household arts and the development of civilization. Dislodging this narrative from the world’s imagination is well nigh impossible; the twelve-step recovery program required to accomplish that beggars the imagination. I nevertheless make a small start here. It turns out that the greater part of what we might call the standard narrative has had to be abandoned once confronted with accumulating archaeological evidence.” (James C. Scott, Against the Grain, Yale University Press)

vii. “Thanks to hominids, much of the world’s flora and fauna consist of fire-adapted species (pyrophytes) that have been encouraged by burning. The effects of anthropogenic fire are so massive that they might be judged, in an evenhanded account of the human impact on the natural world, to overwhelm crop and livestock domestications.” (-ll-)

viii. “Most discussions of plant domestication and permanent settlement […] assume without further ado that early peoples could not wait to settle down in one spot. Such an assumption is an unwarranted reading back from the standard discourses of agrarian states stigmatizing mobile populations as primitive. […] Nor should the terms “pastoralist,” “agriculturalist,” “hunter,” or “forager,” at least in their essentialist meanings, be taken for granted. They are better understood as defining a spectrum of subsistence activities, not separate peoples […] A family or village whose crops had failed might turn wholly or in part to herding; pastoralists who had lost their flocks might turn to planting. Whole areas during a drought or wetter period might radically shift their subsistence strategy. To treat those engaged in these different activities as essentially different peoples inhabiting different life worlds is again to read back the much later stigmatization of pastoralists by agrarian states to an era where it makes no sense.” (-ll-)

ix. “Neither holy, nor Roman, nor an empire” (Voltaire, on the Holy Roman Empire, as quoted in Joachim Whaley’s The Holy Roman Empire: A Very Short Introduction, Oxford University Press)

x. “We don’t outgrow difficult conversations or get promoted past them. The best workplaces and most effective organizations have them. The family down the street that everyone thinks is perfect has them. Loving couples and lifelong friends have them. In fact, we can make a reasonable argument that engaging (well) in difficult conversations is a sign of health in a relationship. Relationships that deal productively with the inevitable stresses of life are more durable; people who are willing and able to “stick through the hard parts” emerge with a stronger sense of trust in each other and the relationship, because now they have a track record of having worked through something hard and seen that the relationship survived.” (Stone et al., Difficult Conversations, Penguin Publishing Group)

xi. “[D]ifficult conversations are almost never about getting the facts right. They are about conflicting perceptions, interpretations, and values. […] They are not about what is true, they are about what is important. […] Interpretations and judgments are important to explore. In contrast, the quest to determine who is right and who is wrong is a dead end. […] When competent, sensible people do something stupid, the smartest move is to try to figure out, first, what kept them from seeing it coming and, second, how to prevent the problem from happening again. Talking about blame distracts us from exploring why things went wrong and how we might correct them going forward.” (-ll-)

xii. “[W]e each have different stories about what is going on in the world. […] In the normal course of things, we don’t notice the ways in which our story of the world is different from other people’s. But difficult conversations arise at precisely those points where important parts of our story collide with another person’s story. We assume the collision is because of how the other person is; they assume it’s because of how we are. But really the collision is a result of our stories simply being different, with neither of us realizing it. […] To get anywhere in a disagreement, we need to understand the other person’s story well enough to see how their conclusions make sense within it. And we need to help them understand the story in which our conclusions make sense. Understanding each other’s stories from the inside won’t necessarily “solve” the problem, but […] it’s an essential first step.” (-ll-)

xiii. “I am really nervous about the word “deserve”. In some cosmic sense nobody “deserves” anything – try to tell the universe you don’t deserve to grow old and die, then watch it laugh at [you] as you die anyway.” (Scott Alexander)

xiv. “How we spend our days is, of course, how we spend our lives.” (Annie Dillard)

xv. “If you do not change direction, you may end up where you are heading.” (Lao Tzu)

xvi. “The smart way to keep people passive and obedient is to strictly limit the spectrum of acceptable opinion, but allow very lively debate within that spectrum.” (Chomsky)

xvii. “If we don’t believe in free expression for people we despise, we don’t believe in it at all.” (-ll-)

xviii. “I weigh the man, not his title; ’tis not the king’s stamp can make the metal better.” (William Wycherley)

xix. “Money is the fruit of evil as often as the root of it.” (Henry Fielding)

xx. “To whom nothing is given, of him can nothing be required.” (-ll-)

March 26, 2021 Posted by | Archaeology, Books, History, Psychology, Quotes/aphorisms | Leave a comment

Learning Phylogeny Through Simple Statistical Genetics

From a brief skim I concluded that a lot of the stuff Patterson talks about in this lecture, particularly in terms of the concepts and methods part (…which, as he also alludes to in his introduction, makes up a substantial proportion of the talk), is included/covered in this Ancient Admixture in Human History paper he coauthored, so if you’re either curious to know more, or perhaps just wondering what the talk might be about, it’s probably worth checking it out. In the latter case I would also recommend perhaps just watching the first few minutes of the talk; he provides a very informative outline of the talk in the first four and a half minutes of the video.

A few other links of relevance:

Martingale (probability theory).
GitHub – DReichLab/AdmixTools.
Human Genome Diversity Project.
Jackknife resampling.
Ancient North Eurasian.
Upper Palaeolithic Siberian genome reveals dual ancestry of Native Americans (Raghavan et al, 2014).
General theory for stochastic admixture graphs and F-statistics. This one is only very slightly related to the talk; I came across it while looking for stuff about admixture graphs, a topic he does briefly discuss in the lecture.

July 29, 2019 Posted by | Archaeology, Biology, Genetics, Lectures, Molecular biology, Statistics | Leave a comment


A few quotes from the book and some related links below. Here’s my very short goodreads review of the book.


“The main naturally occurring radionuclides of primordial origin are uranium-235, uranium-238, thorium-232, their decay products, and potassium-40. The average abundance of uranium, thorium, and potassium in the terrestrial crust is 2.6 parts per million, 10 parts per million, and 1% respectively. Uranium and thorium produce other radionuclides via neutron- and alpha-induced reactions, particularly deeply underground, where uranium and thorium have a high concentration. […] A weak source of natural radioactivity derives from nuclear reactions of primary and secondary cosmic rays with the atmosphere and the lithosphere, respectively. […] Accretion of extraterrestrial material, intensively exposed to cosmic rays in space, represents a minute contribution to the total inventory of radionuclides in the terrestrial environment. […] Natural radioactivity is [thus] mainly produced by uranium, thorium, and potassium. The total heat content of the Earth, which derives from this radioactivity, is 12.6 × 1024 MJ (one megajoule = 1 million joules), with the crust’s heat content standing at 5.4 × 1021 MJ. For comparison, this is significantly more than the 6.4 × 1013 MJ globally consumed for electricity generation during 2011. This energy is dissipated, either gradually or abruptly, towards the external layers of the planet, but only a small fraction can be utilized. The amount of energy available depends on the Earth’s geological dynamics, which regulates the transfer of heat to the surface of our planet. The total power dissipated by the Earth is 42 TW (one TW = 1 trillion watts): 8 TW from the crust, 32.3 TW from the mantle, 1.7 TW from the core. This amount of power is small compared to the 174,000 TW arriving to the Earth from the Sun.”

“Charged particles such as protons, beta and alpha particles, or heavier ions that bombard human tissue dissipate their energy locally, interacting with the atoms via the electromagnetic force. This interaction ejects electrons from the atoms, creating a track of electron–ion pairs, or ionization track. The energy that ions lose per unit path, as they move through matter, increases with the square of their charge and decreases linearly with their energy […] The energy deposited in the tissues and organs of your body by ionizing radiation is defined absorbed dose and is measured in gray. The dose of one gray corresponds to the energy of one joule deposited in one kilogram of tissue. The biological damage wrought by a given amount of energy deposited depends on the kind of ionizing radiation involved. The equivalent dose, measured in sievert, is the product of the dose and a factor w related to the effective damage induced into the living matter by the deposit of energy by specific rays or particles. For X-rays, gamma rays, and beta particles, a gray corresponds to a sievert; for neutrons, a dose of one gray corresponds to an equivalent dose of 5 to 20 sievert, and the factor w is equal to 5–20 (depending on the neutron energy). For protons and alpha particles, w is equal to 5 and 20, respectively. There is also another weighting factor taking into account the radiosensitivity of different organs and tissues of the body, to evaluate the so-called effective dose. Sometimes the dose is still quoted in rem, the old unit, with 100 rem corresponding to one sievert.”

“Neutrons emitted during fission reactions have a relatively high velocity. When still in Rome, Fermi had discovered that fast neutrons needed to be slowed down to increase the probability of their reaction with uranium. The fission reaction occurs with uranium-235. Uranium-238, the most common isotope of the element, merely absorbs the slow neutrons. Neutrons slow down when they are scattered by nuclei with a similar mass. The process is analogous to the interaction between two billiard balls in a head-on collision, in which the incoming ball stops and transfers all its kinetic energy to the second one. ‘Moderators’, such as graphite and water, can be used to slow neutrons down. […] When Fermi calculated whether a chain reaction could be sustained in a homogeneous mixture of uranium and graphite, he got a negative answer. That was because most neutrons produced by the fission of uranium-235 were absorbed by uranium-238 before inducing further fissions. The right approach, as suggested by Szilárd, was to use separated blocks of uranium and graphite. Fast neutrons produced by the splitting of uranium-235 in the uranium block would slow down, in the graphite block, and then produce fission again in the next uranium block. […] A minimum mass – the critical mass – is required to sustain the chain reaction; furthermore, the material must have a certain geometry. The fissile nuclides, capable of sustaining a chain reaction of nuclear fission with low-energy neutrons, are uranium-235 […], uranium-233, and plutonium-239. The last two don’t occur in nature but can be produced artificially by irradiating with neutrons thorium-232 and uranium-238, respectively – via a reaction called neutron capture. Uranium-238 (99.27%) is fissionable, but not fissile. In a nuclear weapon, the chain reaction occurs very rapidly, releasing the energy in a burst.”

“The basic components of nuclear power reactors, fuel, moderator, and control rods, are the same as in the first system built by Fermi, but the design of today’s reactors includes additional components such as a pressure vessel, containing the reactor core and the moderator, a containment vessel, and redundant and diverse safety systems. Recent technological advances in material developments, electronics, and information technology have further improved their reliability and performance. […] The moderator to slow down fast neutrons is sometimes still the graphite used by Fermi, but water, including ‘heavy water’ – in which the water molecule has a deuterium atom instead of a hydrogen atom – is more widely used. Control rods contain a neutron-absorbing material, such as boron or a combination of indium, silver, and cadmium. To remove the heat generated in the reactor core, a coolant – either a liquid or a gas – is circulating through the reactor core, transferring the heat to a heat exchanger or directly to a turbine. Water can be used as both coolant and moderator. In the case of boiling water reactors (BWRs), the steam is produced in the pressure vessel. In the case of pressurized water reactors (PWRs), the steam generator, which is the secondary side of the heat exchanger, uses the heat produced by the nuclear reactor to make steam for the turbines. The containment vessel is a one-metre-thick concrete and steel structure that shields the reactor.”

“Nuclear energy contributed 2,518 TWh of the world’s electricity in 2011, about 14% of the global supply. As of February 2012, there are 435 nuclear power plants operating in 31 countries worldwide, corresponding to a total installed capacity of 368,267 MW (electrical). There are 63 power plants under construction in 13 countries, with a capacity of 61,032 MW (electrical).”

“Since the first nuclear fusion, more than 60 years ago, many have argued that we need at least 30 years to develop a working fusion reactor, and this figure has stayed the same throughout those years.”

“[I]onizing radiation is […] used to improve many properties of food and other agricultural products. For example, gamma rays and electron beams are used to sterilize seeds, flour, and spices. They can also inhibit sprouting and destroy pathogenic bacteria in meat and fish, increasing the shelf life of food. […] More than 60 countries allow the irradiation of more than 50 kinds of foodstuffs, with 500,000 tons of food irradiated every year. About 200 cobalt-60 sources and more than 10 electron accelerators are dedicated to food irradiation worldwide. […] With the help of radiation, breeders can increase genetic diversity to make the selection process faster. The spontaneous mutation rate (number of mutations per gene, for each generation) is in the range 10-8–10-5. Radiation can increase this mutation rate to 10-5–10-2. […] Long-lived cosmogenic radionuclides provide unique methods to evaluate the ‘age’ of groundwaters, defined as the mean subsurface residence time after the isolation of the water from the atmosphere. […] Scientists can date groundwater more than a million years old, through chlorine-36, produced in the atmosphere by cosmic-ray reactions with argon.”

“Radionuclide imaging was developed in the 1950s using special systems to detect the emitted gamma rays. The gamma-ray detectors, called gamma cameras, use flat crystal planes, coupled to photomultiplier tubes, which send the digitized signals to a computer for image reconstruction. Images show the distribution of the radioactive tracer in the organs and tissues of interest. This method is based on the introduction of low-level radioactive chemicals into the body. […] More than 100 diagnostic tests based on radiopharmaceuticals are used to examine bones and organs such as lungs, intestines, thyroids, kidneys, the liver, and gallbladder. They exploit the fact that our organs preferentially absorb different chemical compounds. […] Many radiopharmaceuticals are based on technetium-99m (an excited state of technetium-99 – the ‘m’ stands for ‘metastable’ […]). This radionuclide is used for the imaging and functional examination of the heart, brain, thyroid, liver, and other organs. Technetium-99m is extracted from molybdenum-99, which has a much longer half-life and is therefore more transportable. It is used in 80% of the procedures, amounting to about 40,000 per day, carried out in nuclear medicine. Other radiopharmaceuticals include short-lived gamma-emitters such as cobalt-57, cobalt-58, gallium-67, indium-111, iodine-123, and thallium-201. […] Methods routinely used in medicine, such as X-ray radiography and CAT, are increasingly used in industrial applications, particularly in non-destructive testing of containers, pipes, and walls, to locate defects in welds and other critical parts of the structure.”

“Today, cancer treatment with radiation is generally based on the use of external radiation beams that can target the tumour in the body. Cancer cells are particularly sensitive to damage by ionizing radiation and their growth can be controlled or, in some cases, stopped. High-energy X-rays produced by a linear accelerator […] are used in most cancer therapy centres, replacing the gamma rays produced from cobalt-60. The LINAC produces photons of variable energy bombarding a target with a beam of electrons accelerated by microwaves. The beam of photons can be modified to conform to the shape of the tumour, which is irradiated from different angles. The main problem with X-rays and gamma rays is that the dose they deposit in the human tissue decreases exponentially with depth. A considerable fraction of the dose is delivered to the surrounding tissues before the radiation hits the tumour, increasing the risk of secondary tumours. Hence, deep-seated tumours must be bombarded from many directions to receive the right dose, while minimizing the unwanted dose to the healthy tissues. […] The problem of delivering the needed dose to a deep tumour with high precision can be solved using collimated beams of high-energy ions, such as protons and carbon. […] Contrary to X-rays and gamma rays, all ions of a given energy have a certain range, delivering most of the dose after they have slowed down, just before stopping. The ion energy can be tuned to deliver most of the dose to the tumour, minimizing the impact on healthy tissues. The ion beam, which does not broaden during the penetration, can follow the shape of the tumour with millimetre precision. Ions with higher atomic number, such as carbon, have a stronger biological effect on the tumour cells, so the dose can be reduced. Ion therapy facilities are [however] still very expensive – in the range of hundreds of millions of pounds – and difficult to operate.”

“About 50 million years ago, a global cooling trend took our planet from the tropical conditions at the beginning of the Tertiary to the ice ages of the Quaternary, when the Arctic ice cap developed. The temperature decrease was accompanied by a decrease in atmospheric CO2 from 2,000 to 300 parts per million. The cooling was probably caused by a reduced greenhouse effect and also by changes in ocean circulation due to plate tectonics. The drop in temperature was not constant as there were some brief periods of sudden warming. Ocean deep-water temperatures dropped from 12°C, 50 million years ago, to 6°C, 30 million years ago, according to archives in deep-sea sediments (today, deep-sea waters are about 2°C). […] During the last 2 million years, the mean duration of the glacial periods was about 26,000 years, while that of the warm periods – interglacials – was about 27,000 years. Between 2.6 and 1.1 million years ago, a full cycle of glacial advance and retreat lasted about 41,000 years. During the past 1.2 million years, this cycle has lasted 100,000 years. Stable and radioactive isotopes play a crucial role in the reconstruction of the climatic history of our planet”.


CUORE (Cryogenic Underground Observatory for Rare Events).
Lawrence Livermore National Laboratory.
Marie Curie. Pierre Curie. Henri Becquerel. Wilhelm Röntgen. Joseph Thomson. Ernest Rutherford. Hans Geiger. Ernest Marsden. Niels Bohr.
Ruhmkorff coil.
Pitchblende (uraninite).
Polonium. Becquerel.
Alpha decay. Beta decay. Gamma radiation.
Plum pudding model.
Robert Boyle. John Dalton. Dmitri Mendeleev. Frederick Soddy. James Chadwick. Enrico Fermi. Lise Meitner. Otto Frisch.
Periodic Table.
Exponential decay. Decay chain.
Particle accelerator. Cockcroft-Walton generator. Van de Graaff generator.
Barn (unit).
Nuclear fission.
Manhattan Project.
Chernobyl disaster. Fukushima Daiichi nuclear disaster.
Electron volt.
Thermoluminescent dosimeter.
Silicon diode detector.
Enhanced geothermal system.
Chicago Pile Number 1. Experimental Breeder Reactor 1. Obninsk Nuclear Power Plant.
Natural nuclear fission reactor.
Gas-cooled reactor.
Generation I reactors. Generation II reactor. Generation III reactor. Generation IV reactor.
Nuclear fuel cycle.
Accelerator-driven subcritical reactor.
Thorium-based nuclear power.
Small, sealed, transportable, autonomous reactor.
Fusion power. P-p (proton-proton) chain reaction. CNO cycle. Tokamak. ITER (International Thermonuclear Experimental Reactor).
Sterile insect technique.
Phase-contrast X-ray imaging. Computed tomography (CT). SPECT (Single-photon emission computed tomography). PET (positron emission tomography).
Boron neutron capture therapy.
Radiocarbon dating. Bomb pulse.
Radioactive tracer.
Radithor. The Radiendocrinator.
Radioisotope heater unit. Radioisotope thermoelectric generator. Seebeck effect.
Accelerator mass spectrometry.
Atomic bombings of Hiroshima and Nagasaki. Treaty on the Non-Proliferation of Nuclear Weapons. IAEA.
Nuclear terrorism.
Swiss light source. Synchrotron.
Chronology of the universe. Stellar evolution. S-process. R-process. Red giant. Supernova. White dwarf.
Victor Hess. Domenico Pacini. Cosmic ray.
Allende meteorite.
Age of the Earth. History of Earth. Geomagnetic reversal. Uranium-lead dating. Clair Cameron Patterson.
Glacials and interglacials.
Taung child. Lucy. Ardi. Ardipithecus kadabba. Acheulean tools. Java Man. Ötzi.
Argon-argon dating. Fission track dating.

November 28, 2017 Posted by | Archaeology, Astronomy, Biology, Books, Cancer/oncology, Chemistry, Engineering, Geology, History, Medicine, Physics | Leave a comment

The fall of Rome

“According to the conventional view of things, the military and political disintegration of Roman power in the West precipitated the end of a civilization. Ancient sophistication died, leaving the western world in the grip of a ‘Dark Age’ of material and intellectual poverty, out of which it was only slowly to emerge. […] a much more comfortable vision of the end of empire [has been] spreading in recent years through the English-speaking world. […] There has been a sea change in the language used to describe post-Roman times. Words like ‘decline’ and ‘crisis’ […] have largely disappeared from historians’ vocabularies, to be replaced by neutral terms, like ‘transition’, ‘change’, and ‘transformation’. […] some historians in recent decades have also questioned the entire premiss that the dissolution of the Roman empire in the West was caused by hostile and violent invasion. […] some recent works […] present the theory of peaceful accommodation as a universally applicable model to explain the end of the Roman empire.”

Ward Perkins’ book is a work which sets out to show why he thinks those people are wrong, presenting along the way much evidence for widespread violence and disruption throughout the Western Empire towards the end. Despite the depressing topics covered therein I really enjoyed the book; Perkins spends a lot of time on material culture aspects and archaeological remains – it’s perhaps a telling fact that the book’s appendix deals with the properties of pottery and potsherds, and how important these kinds of material remains might be in terms of helping to make sense of things which happened in the far past. A general problem in a collapse setting is that when conditions deteriorate a lot, the sort of high-quality evidence that historians and archaeologists love to look at tend to disappear; censuses stop being taken (so you have to guess at how many people were around, instead of knowing it reasonably well – which can be particularly annoying if the disrupting factor was also killing people), innumeracy and illiteracy increase (translating to fewer written sources available), and so on. I should perhaps interpose that these sorts of issues do not just pertain to historical sources from the past; similar problems also arise in various analytical contexts today. Countries in a state of crisis (war, epidemics) tend to produce poor and questionable data, if any data can be gathered at all, a point I recall being covered in Newman & DeRouen’s book; related topics were also discussed in M’ikanatha & Iskander’s book as people working in public health sometimes face these problems as well (that work was of course focused on disease surveillance aspects, and in that context I might mention that the authors mentioned that poor data availability does not really necessarily mean that no data is ‘available’; for example in such settings (cheap) proxy data of various kinds may sometimes be usefully employed to inform resource allocation decisions, even if the use of such data would not be cost-effective or meaningful in a different setting). Another point of relevance is of course that some types of evidence survive the passage of time much better than others; pottery is much harder to destroy than low-quality parchment.

The point of looking at things like pottery and coins (a related topic I recall Webster covering in some detail in his book about The Roman Invasion of Britain) is not mainly that it’s super interesting to look at different types of pottery or coins – the point is that these types of material remains tend to be extremely informative about many things besides the artifacts themselves. Pottery was used for storing goods, and those goods aren’t around any longer but the pottery still is. And ‘pottery’ is not just ‘pottery’; different types of pottery required different levels of skill, and an important variable here is the level of standardization – Roman pottery was in general of high quality and was highly standardized; by examining e.g. clay content you can actually often tell where the pottery was made; specific producers produced pottery that was easily date-able. Coins were used for purchasing things and widespread use of them implies the existence of trading networks not relying on barter trade. Different coins had different values and there are important insights to be gathered from the properties of these artifacts; Joseph Tainter e.g. talks in his book about how the silver content of Roman coins gradually decreased over time, indicating at some periods that the empire was apparently undergoing quite severe inflation (the Roman military was compensated in coin, not goods, so by tweaking the amount of copper or silver in those coins the emperors could save a bit of money – which many of them did). If the amount of low-denomination coins drops a lot this might be an indication that people were reverting to barter trade. And so on. If you find some Roman coins in a field in Britain, it might mean that there used to be a Roman garrison there. If people used to use roof tiles and build buildings out of stone, rather than wood, and you observe that they stopped doing that, that’s also a clue that something changed.

A lot of the kind of evidence Perkins looks at in his book is to some extent indirect evidence, but the point is that there’s a lot of it, and if different sources tell roughly similar stories it sort of starts getting hard to argue against. To give a sense of the scale of the material remains available, one single source in Rome, Monte Testaccio, is made up entirely of broken oil amphorae imported to Rome from south-western Spain during the 2nd and 3rd century and is estimated to contain the remains of 53 million amphorae. An image of how the remains of one particular pottery manufacturer operating in Oxford in the 3rd and 4th century are distributed throughout Britain yield something like 100 different English sites where that pottery has been found. Again, the interesting thing here is not only the pottery itself, but also all the things people transported using those vessels, and all those other things (lost from the archaeological record) that might have been transported from A to B if they were willing to transport brittle pottery vessels that far around. And it’s very interesting to see distributions like that and then start comparing them with the sort of distributions you’ll get if you look for stuff produced, say, 200 years later. Coins, pottery, roof tiles, amphorae, animal bones (there’s evidence that Roman cows were larger than their Early Medieval counterparts), new construction (e.g. temples) – look at what people left behind, compare the evidence you get from the time of the Empire with what came after; this is a very big part of what Perkins does in his book.

While looking at the evidence it becomes obvious that some regions were more severely affected than others, and Perkins goes into those details as well. In general it seems that Britain was the most severely affected region, with other regions doing somewhat better; the timing also varied greatly. Greece (and much of the Eastern Empire) actually experienced a period of expansion (increased density of settlements, new churches and monasteries, stone rural houses) during the fifth century but around 600 AD the Aegean was severely hit and experienced severe disruption where former great cities became little but abandoned ghost towns. Perkins also takes care to deal with the ‘barbarians’ in at least some detail (Peter Heather covers that stuff in a lot more detail in his book Empires and Barbarians, if people are curious to know more about these topics), not lumping them all together into One Great Alliance to Take Down the Empire (quite often these guys were at war with each other). The evidence is presented in some detail, which also means that if you walk away from the book still thinking Perkins hasn’t made a good case for his beliefs, well, you’ll at least know where the author is coming from and why he holds the views he does.

I’ve added some more quotes from the book below. If you’re interested in these topics this book is a must read.

“The Germanic invaders of the western empire seized or extorted through the threat of force the vast majority of the territories in which they settled, without any formal agreement on how to share resources with their new Roman subjects. The impression given by some recent historians that most Roman territory was formally ceded to them as part of a treaty is quite simply wrong. Whenever the evidence is moderately full, as it is from the Mediterranean provinces, conquest or surrender to the threat of force was definitely the norm, not peaceful settlement. […] The experience of conquest was, of course, very varied across the empire. Some regions were overrun brutally but swiftly. […] Other regions, particularly those near the frontiers of the empire, suffered much more prolonged violence. […] Even those few regions that eventually passed relatively peacefully into Germanic control had all previously experienced invasion and devastation.”

“Throughout the time that the Roman empire existed, the soldiery of many towns were maintained at public expense for the defence of the frontier. When this practice fell into abeyance, both these troops and the frontier disappeared. […] It has rightly been observed that the deposition in 476 of the last emperor resident in Italy, Romulus Augustulus, caused remarkably little stir: the great historian of Antiquity, Momigliano, called it the ‘noiseless fall of an empire’.39 But the principal reason why this event passed almost unnoticed was because contemporaries knew that the western empire, and with it autonomous Roman power, had already disappeared in all but name. […] The story of the loss of the West is not a story of great set-piece battles, like Hadrianopolis, heroically lost by the Romans in the field. […] The West was lost mainly through failure to engage the invading forces successfully and to drive them back. This caution in the face of the enemy, and the ultimate failure to drive him out, are best explained by the severe problems that there were in putting together armies large enough to feel confident of victory. Avoiding battle led to a slow attrition of the Roman position, but engaging the enemy on a large scale would have risked immediate disaster […] Roman military dominance over the Germanic peoples was considerable, but never absolute and unshakable. […] even at the best of times, the edge that the Romans enjoyed over their enemies, through their superior equipment and organization, was never remotely comparable, say, to that of Europeans in the nineteenth century […] although normally the Romans defeated barbarians when they met them in battle, they could and did occasionally suffer disasters.”

“Italy suffered from the presence of large hostile armies in 401-2 (Alaric and the Goths), in 405-6 (Radagaisus), and again from 408 to 412 (Alaric, for the second time); Gaul was devastated in the years 407-9 by the Vandals, Alans, and Sueves; and the Iberian peninsula by the same peoples, from 409. The only regions of the western empire that had not been profoundly affected by violence by 410 were Africa and the islands of the Mediterranean […] Radagaisus’ incursion was successfully crushed, but it was immediately followed by a disastrous sequence of events: the crossing of the Rhine by Vandals, Sueves, and Alans at the very end of 406; the usurpation of Constantine III in 407, taking with him the resources of Britain and much of Gaul; and the Goths’ return to Italy in 408. […] Some of the lost territories were temporarily recovered in the second decade of the century; but much (the whole of Britain and a large part of Gaul and Spain) was never regained, and even reconquered provinces took many years to get back to full health […] the imperial recovery was only short-lived; in 429 it was brought definitely to an end by the successful crossing of the Vandals into Africa, and the devastation of the western empire’s last remaining secure tax base. […] There was, of course, a close connection between failure ‘abroad’ and the usurpations and rebellions ‘at home’. […] As in other periods of history, failure against foreign enemies and civil war were very closely linked, indeed feeding off each other.”

“Some accounts of the invasions [and maps of them] […] seem to be describing successive campaigns in a single war, with the systematic and progressive seizure of territory by the various armies of a united German coalition. If this had really been the case, the West would almost certainly have fallen definitely in the very early fifth century, and far less of the structures of imperial times would have survived into the post-Roman period. The reality was very much more messy and confused […] The different groups of incomers were never united, and fought each other, sometimes bitterly, as often as they fought the ‘Romans’ – just as the Roman side often gave civil strife priority over warfare against the invaders.35 When looked at in detail, the ‘Germanic invasions’ of the fifth century break down into a complex mosaic of different groups, some imperial, some local, and some Germanic, each jockeying for position against or in alliance with the others, with the Germanic groups eventually coming out on top. [As already mentioned, Heather is the book to read if you’re interested in these topics – US] […] Because the military position of the imperial government in the fifth century was weak, and because the Germanic invaders could be appeased, the Romans on occasion made treaties with particular groups, formally granting them territory on which to settle in return for their alliance. […] The interests of the centre when settling Germanic peoples, and those of the locals who had to live with the arrangements, certainly did not always coincide. […] The imperial government was entirely capable of selling its provincial subjects downriver, in the interests of short-term political and military gain. […] Sidonius Apollinaris, bishop of Clermont and a leader of the resistance to the Visigoths, recorded his bitterness: ‘We have been enslaved, as the price of other people’s security.41‘”

“[A]rchaeological evidence now available […] shows a startling decline in western standards of living during the fifth to seventh centuries.1 […] Ceramic vessels, of different shapes and sizes, play an essential part in the storage, preparation, cooking, and consumption of foodstuffs. They certainly did so in Roman times […] amphorae, not barrels, were the normal containers for transport and domestic storage of liquids. […] Pots are low-value, high-bulk items, with the additional disadvantage of being brittle […] and they are difficult and expensive to pack and transport, being heavy, bulky, and easy to break. If, despite these disadvantages, vessels (both fine tableware and more functional items) were being made to a high standard and in large quantities, and if they were travelling widely and percolating through even the lower levels of society – as they were in the Roman period – then it is much more likely than not that other goods, whose distribution we cannot document with the same confidence, were doing the same. […] There is, for instance, no reason to suppose that the huge markets in clothing, footware, and tools were less sophisticated than that in pottery. […] In the post-Roman West, almost all this material sophistication disappeared. Specialized production and all of the most local distribution became rare, unless for luxury goods; and the impressive range and quantity of high-quality functional goods, which had characterized the Roman period, vanished, or, at the very least, were drastically reduced. The middle and lower markets, which under the Romans had absorbed huge quantities of basic, but good-quality, items, seem to have almost entirely disappeared. […] There is no area of the post-Roman West that I know of where the range of pottery available in the sixth and seventh centuries matches that of the Roman period, and in most areas the decline in quality is startling. Furthermore, it was not only quality and diversity that declined; the overall quantities of pottery in circulation also fell dramatically. […] what had once been widely diffused products had become luxury items.”

“What we observe at the end of the Roman world is not a ‘recession’ […] with an essentially similar economy continuing to work at a reduced pace. Instead, what we see is a remarkable qualitative change, with the disappearance of entire industries and commercial networks. The economy of the post-Roman West is not that of the fourth century reduced in scale, but a very different and far less sophisticated entity.43 This is at its starkest and most obvious in Britain. A number of basic skills disappeared entirely during the fifth century, to be reintroduced only centuries later. […] All over Britain the art of making pottery on a wheel disappeared in the early fifth century, and was not reintroduced for almost 300 years. The potter’s wheel is not an instrument of cultural identity. Rather, it is a functional innovation that facilitates the rapid production of thin-walled ceramics; and yet it disappeared from Britain. […] post-Roman Britain in fact sank to a level of economic complexity well below that of the pre-Roman Iron Age. Southern Britain, in the years before the Roman conquest of AD 43, was importing quantities of Gaulish wine and Gaulish pottery; it had its own native pottery industries with regional distribution of their wares; it even had native silver coinages […] The settlement pattern of later iron-age Britain also reflects emerging economic complexity, with substantial coastal settlements […] which were at least partly dependent on trade. None of these features can be found reliably in fifth- and sixth-century post-Roman Britain. It is really only in about AD 700, three centuries after the disintegration of the Romano-British economy, that southern Britain crawled back to the level of economic complexity foudn in the pre-Roman Iron Age, with evidence of pots imported from the Continents, the first substantial and wheel-turned Anglo-Saxon pottery industry […], the striking of silver coins, and the emergence of coastal trading towns […] In the western Mediterranean, the economic regression was by no means as total as it was in Britain. […] But it must be remembered that in the Mediterranean world the level of economic complexity and sophistication reached in the Roman period was very considerably higher than anything ever attained in Britain. The fall in economic complexity may in fact have been as remarkable as that in Britain; but, since in the Mediterranean it started from a much higher point, it also bottomed out at a higher level. […] in some areas at least a very similar picture can be found to that sketched out above – of a regression, taking the economy way below levels of complexity reached in the pre-Roman period.”

“The enormity of the economic disintegration that occurred at the end of the empire was almost certainly a direct result of […] specialization. The post-Roman world reverted to levels of economic simplicity […] with little movement of goods, poor housing, and only the most basic manufactured items. The sophistication of the Roman period, by spreading high-quality goods widely in society, had destroyed the local skills and local networks that, in pre-Roman times, had provided lower-level economic complexity. It took centuries for people in the former empire to reacquire the skills and the regional networks that would take them back to these pre-Roman levels of sophistication. […] The Roman period is sometimes seen as enriching only the elite, rather than enhancing the standard of living of the population at large. […] I think this, and similar views, are mistaken. For, me, what is most striking about the Roman economy is precisely the fact that it was not solely an elite phenomenon, but one that made basic good-quality items available right down the social scale. […] good-quality pottery was widely available, and in regions like Italy even the comfort of tiled roofs. I would also seriously question the romantic assumption that economic simplicity meant a freer or more equal society.”

“There was no single moment, nor even a single century of collapse. The ancient economy disappeared at different times and at varying speeds across the empire. […] It was […] the fifth-century invasions that […] brought down the ancient economy in the West. However, this does not mean that the death of the sophisticated ancient world was intended by the Germanic peoples. The invaders entered the empire with a wish to share in its high standard of living, not to destroy it […] But, although the Germanic peoples did not intend it, their invasions, the disruptions these caused, and the consequent dismembering of the Roman state were undoubtedly the principal cause of death of the Roman economy.”

“Reading and writing (and a grounding in classical literature) were in Roman times an essential mark of status. […] illiterates amongst the Roman upper classes were very rare indeed. […] In a much simpler world, the urgent need to read and write declined, and with it went the social pressure on the secular elite to be literate. Widespread literacy in the post-Roman West definitely became confined to the clergy. […] It is a striking fact, and a major contrast with Roman times, that even great rulers could be illiterate in the early Middle Ages.”

“The changing perspectives of scholarship are always shaped in part by wider developments in modern society. There is inevitably a close connection between the way we view our own world and the way we interpret the past. […] [T]here is a real danger for the present day in a vision of the past that explicitly sets out to eliminate all crisis and all decline. The end of the Roman West […] destroyed a complex civilization, throwing the inhabitants of the West back to a standard of living typical of prehistoric times. Romans before the fall were as certain as we are today that their world would continue for ever substantially unchanged. They were wrong.”


September 18, 2017 Posted by | Archaeology, Books, History | Leave a comment

First Farmers (I?)


This year I have so far read 113 books and I have added 5 of those books to my list of favourite books on goodreads. I have mentioned Herriot here on the blog despite the fact that this type of book is not really the type of book I usually blog, and I blogged Yashin et al.‘s biodemography text in a decent amount of detail. I have posted a couple of posts about Horowitz and Samsom’s book and I intend to blog that book in more detail later this week. However there are a few great non-fiction books which I’ve read this year which I have not yet blogged at all, including Boyd and Richerson and the excellent book by Bellwood to which the title of this post refers. These books have one thing in common: They are ‘paper books’, not books stored in an electronic format, which means that blogging them take more time than is ideal. The extra amount of time it takes to blog paper books makes it hard for me to justify blogging such books in general, even books I think are great.

Aside from the time expenditure there are at least two other major problems I have with justifying blogging such books. One problem is that this blog is not really the proper place for me to recommend books to others, a state of affairs of which I am well aware. I sometimes do it anyway, but I know perfectly well that very few people will ever know or care that I liked a particular book if I write about that book here. If I actually wanted others to know about books like these there would be lots of other channels of communication much better suited for such purposes; such as e.g. the comment sections of large blogs/reddit threads/etc. To a first approximation nobody reads this blog, which is the way I like it. The other major problem – in the context of me justifying to myself blogging such books – is that I actually usually spend quite a bit of effort while reading such (paper) books, e.g. in the form of note taking and highlighting. A major reason I have for blogging non-fiction books is that blogging books means that the content therein gets processed a few extra times, which helps aid recall and understanding. This incidentally goes both for the stuff that eventually finds its way into these posts, and to some extent also for the content that does not. When I’m reading paper books I tend to do a lot of this work while actively reading the books. Part of the reason why is actually precisely due to the fact that I know from experience that these kinds of books are bothersome to blog; if I know beforehand that I’m not particularly likely to blog a book I’ll usually spend a bit more time and effort while reading it. That extra amount of work of course makes me even less likely to end up blogging the book eventually; at some point diminishing marginal returns really kick in.

One take-away from all of the above is, I guess, that if you’re one of those three-four(?) people who semi-regularly read my blog and you also happen to actually care about which books I like and recommend, you should keep in mind that some of the really great books I read may end up not being covered here in ‘classical book posts’, simply because blogging great books may sometimes simply be too much work to justify the effort; and those books you may spot quite easily by having an occasional look at my book collection posts (see the sidebar) or my goodreads favourites.

What made me decide to finally write this post was that I had been considering whether or not to write a post about Tainter’s The Collapse of Complex Societies, which I didn’t really like all that much. While thinking about this stuff I realized that it would frankly be madness for me to cover that book (also a paper book) here before I’d at least talked a bit about Boyd and Richerson and Bellwood’s books, as those books are just much better and more interesting. And then I concluded that I really ought to cover Bellwood …and here we are.

I’ve read about some of the topics Bellwood covers elsewhere, e.g. here, here, and here, but the other works I’ve read on these topics have not covered the topics Bellwood covers in the amount of detail he does (if at all); one of the reasons why I really enjoyed Bellwood’s book was that it covers in a great amount of detail precisely some of the questions I’ve been asking myself while reading other works on related topics. The book covers things I had been looking for elsewhere, but hadn’t been able to find. This admittedly mainly relates to the agriculture and archaeology parts, rather than the linguistics part, but the linguistics is interesting as well.

If you’re interested in the origins of agriculture, this book is a must-read.

Below I’ve added some quotes from the book, as well as a few comments.

“This book suggests that major episodes of human movement occurred from time to time, in various parts of the world, as different populations developed or adopted agriculture and then spread farming, languages, and genes, in some cases across vast distances. […] In order to approach what often appears to be a debate in which specialists all talk past each other, concerned only with data from their own discipline, this book is framed around a fairly simple multidisciplinary hypothesis. The early farming dispersal hypothesis postulates that the spreads of early farming lifestyles were often correlated with prehistoric episodes of human population and language dispersal from agricultural homelands. The present-day distribution of language families and racially varied populations across the globe, allowing for the known reassortments that have ensued in historical times, still reflect to a high degree those early dispersals. […] [However] the early farming dispersal hypothesis is not claiming that only farmers ever dispersed into new lands or established language families in prehistory. Hunter-gatherers feature widely in this book since their lifestyle, in terms of long-term stability and reliability, has been the most successful in human history. It fueled the initial human colonization of the whole world, apart from a number of oceanic islands.”

“We have clear signs of relatively independent agricultural origins in western Asia, central China, the New Guinea highlands, Mesoamerica, the central Andes, the Mississippi basin, and possibly western Africa and southern India. These developments occurred at many different times between about 12,000 and 4,000 years ago. The agricultural systems concerned spread at remarkably different rates – some quickly, some slowly, some hardly at all.”

“This book owes its origin to a consideration of two primary observations: 1. Prior to the era of European colonization there existed (and still exist) a number of very widespread families of languages, the term “family” in this sense meaning that the languages concerned share common ancestry, having diverged from a common forebear […]. These language families exist because they have spread in some way from homeland regions, not because they have converged in place out of hundreds of formerly unrelated languages. 2. Within the early agricultural past of mankind there have existed many widespread archaeological complexes of closely linked artifactual style, shared economic basis, and relatively short-lived temporal placement. […] Again, these spreads have occurred from homeland regions, and most such complexes tend to become younger as one moves away from regions of agricultural origin […]. Most importantly, many agricultural homelands overlap geographically with major language family homelands, in highly significant ways.”

“The expansions of early farming populations that form the subject matter of this book reflect two consecutive processes: 1. the periodic genesis of new cultural (archaeological) or linguistic configurations in homeland circumstances; 2. the dispersal of such configurations into surrounding regions […] The transformations within such configurations, both during and after dispersal, can occur via adaptive or chance modifications to the inherited pattern (thus giving relationships of descent, or phylogeny), or via interactions with other contemporary human populations, including culturally and linguistically related as well as unrelated groups (thus giving rise to a process termed reticulation). […] One of the suggestions that will dominate the chapters in this book is that short bursts, or “punctuations,” of dispersal by closely related populations over very large areas have occurred from time to time in human prehistory, especially following the regional beginnings of agriculture or the acquisitions of some other material, demographic, or ideological advantages. Punctuations also occurred when humans first entered regions previously uninhabited, such as Australia, the Americas, and the Pacific Islands. These bursts have actually occupied very little of the total time span of human history. Often their effects are confusingly hidden beneath the reticulate interactive networks that have linked varied populations through the long millenia of subsequent history. But their underlying impact on the course of human history and on the generation of subsequent patterns of human diversity have been immense.”

“Many hunters and gatherers of the etnographic record have resource management skills that can mimic agriculture, and some have even adopted minor forms of casual cultivation. […] Resource management […] can be defined as any technique that propagates, tends, or protects a species, reduces competition, prolongs or increases the harvest, insures the appearance of a species at a particular time in a particular place, extends the range of or otherwise modifies the nature, distribution, and density of a species […]. Resource management is not synonymous with agriculture or cultivation and it has obviously been practiced to some degree by all plant and animal exploiters since long before agriculture began. Cultivation, an essential component of any agricultural system, defines a sequence of human activity whereby crops are planted […], protected, harvested, then deliberately sown again […] Domesticated plants […] are those that show recognizable indications of morphological change away from the wild phenotype, attributable to human interference in the genotype through cultivation […] For animals, the concept of domestication is invoked when there are relatively undisputed signs of human control and breeding of a species. Such signs can normally be claimed in situations where animals were transported out of their homeland regions […] In putative homeland areas for such animals, especially where there was exploitation of wild ancestral species in pre-agricultural times, it can often be difficult to distinguish animal husbandry from hunting in early agricultural contexts. […] the term agriculture will be used to apply in a general sense to all activities involving cultivation and domestication of plants.”

“In general, whereas a family of hunters and gatherers might need several square kilometers of territory for subsistence, an average family of shifting cultivators will be able to get by with a few hectares of crop-producing land. A family of irrigation agriculturalists will normally be able to manage with less than one hectare. Thus, along the scale of increasing intensification of production, less land is needed to feed a standard unit such as a family or individual. […] The reason why agriculturalists can live at much higher densities than hunters and collectors is because food is produced, on average, more intensively per unit of exploited area. Food-collecting mothers also tend to space births more widely than sedentary cultivators for reasons believed to relate in part to factors of mobility and diet2, leading in combination to biologically reduced frequencies of conception. This form of birth control maximizes the number of hunter-gatherer children able to survive to adulthood, but keeps the overall populations small.”

“With the Holocene amelioration of climate to conditions like those of the present, a rapid change that occurred about 11,500 years ago, the world’s climates became warmer, wetter, and a good deal more reliable on a short term basis […] It was this reliability that gave the early edge to farming […] Holocene climate was clearly the ultimate enabler of early farming, but it was not the proximate cause behind individual transitions. [The importance of climate was also emphasized in Boyd and RichersonUS.] […] A combined explanation of affluence alternating with mild environmental stress, especially in “risky” but highly productive early Holocene environments with periodic fluctuations in food supplies, is becoming widely favored by many archaeologists today as one explanation for the shift to early agriculture. […] It is necessary […] to emphasize that the regional beginnings of agriculture must have involved such a complex range of variables that we would be blind to ignore any of the above factors – prior sedentism, affluence and choice, human-plant co-evolution, environmental change and periodic stress, population pressure, and certainly the availability of suitable candidates for domestication. […] most suggested “causes” overlap so greatly that it is often hard to separate them. […] there can be no one-line explanation for the origins of agriculture.”

“[M]any recent hunter-gatherers have been observed to modify their environments to some degree to encourage food yields, whether by burning, replanting, water diversion, or keeping of decoy animals or domesticated dogs […] Most agriculturalists also hunt if the opportunity is presented and always have done so throughout the archaeological record. […] there is good evidence in recent societies for some degree of overlap between food collection and food production. But the whole issue here revolves around just what level of “food production” is implied. […] any idea that mobile hunters and gatherers can just shift in and out of agricultural (or pastoral) dependent lifestyle at will seems unrealistic in terms of the major scheduling shifts required by the annual calendars of resource availability, movement, and activity associated with the two basic modes of production. There are very few hints of such circumstances ever occurring in the ethnographic record […] Mobile foragers must give an increasing commitment to sedentism if agriculture is to become a successful mainstay of their economy […] In general for the Old World, we see that hunters and gatherers may practice a small amount of agriculture, and agriculturalists may practice a small amount of hunting and gathering, but the two modes of production most decisively do not merge or reveal a gentle cline. […] both Old and New World populations evidently found it problematic to shift in and out of agricultural dependence on a regular basis.”

“In order to approach the ethnographic record systematically and to extract useful comparative information, it is essential not to treat all recorded ethnographic hunter-gatherer societies as being one simple category, or as having had the same basic historical trajectories stretching back far into the Pleistocene past […] Hunter-gatherers have had histories just as tumultuous in many cases as have agriculturalists”.

Bellwood favours in his coverage of this topic a model with three different groups of hunter-gatherers. I’m not sure ‘favours’ is the right word; perhaps it’d be more accurate to state that he uses such a model to illustrate one of the ways in which different groups of hunters and gatherers are dissimilar, and why overlooking such dissimilarities may be problematic. In the model he presents in the book one group of hunter-gatherers consists of hunter-gatherers who live/d in close proximity to agricultural societies. These people tend to live in marginal areas where it’s hard to make agriculture work and they tend to be surrounded by agriculturalists (‘encapsulation’). Many places where you’d encounter such people, what you’d see/saw is/would be some sort of established exchange system, where farmers trade/d e.g. cereals in exchange for e.g. meat procured by the hunter-gatherers. One thing to always keep in mind here is that although long-term the hunter-gatherers were displaced and circumscribed by agricultural societies far from all interactions between these groups were hostile; mutually beneficial arrangements could be arrived at, even if they might not have been stable long-term. A related point is that hunter-gathering was probably a much more attractive option in the past than it is today, as the encapsulation process was not nearly so far advanced as it is today; they had better land, and despite not being farmers they might still benefit from the activities of some of those farmers who lived nearby. Bellwood is of course very interested in why agriculture spread originally, and he mentions in this context that although some such circumscribed hunter-gatherer societies may adopt agriculture eventually, such hunter-gatherer societies are not the place to look if you’re interested in the question of how agriculture originally spread throughout the world – which seems very reasonable to me. As he puts it in the notes, “while low-level food production can exist in theory, my feeling is that it has always been a child of marginal environments, where farmers necessarily retracted into food collection or where foragers were able to invest in minor cultivation without too much competition from other farmers. Such societies represent the ends, rather than the sources, of historical trajectories of agricultural expansion.”

The second group in Bellwood’s hunter-gatherer ‘model’ are ‘unenclosed’ hunter-gatherers. A few quotes:

“This group comprises those hunter-gatherers who inhabited agricultural latitudes in Australia, the Andaman Islands, and many regions of North America, especially in West Coast and Florida, but who (unlike the members of group 1) lived lives generally apart from farmers prior to European colonization. Many of these societies in North America lived in coastal regions with prolific maritime resources […] Some were also in periodic but non-threatening contact with farmers in adjacent regions in prehistory and thus had opportunities, never taken, to adopt agriculture […] Socially, […] such groups overlapped greatly with agriculturalists, indicating that social complexity of the chiefdom type can relate in terms of origin more to the intensity and reliability of resources and population density than to any simple presence of food production as opposed to hunting and gathering. […] The ranked and populous hunter-gatherer societies of norther California were no more interested in adopting agriculture than were Cape York Aborigines or the Semang, and perhaps even the majority of hunter-gatherers in prehistory. It does not follow that hunter-gatherers who have “complex” social institutions will necessarily become farmers whenever they are introduced to the farming concept.”

The third group in Bellwood’s model was really interesting to me, as it’s a group I’d previously wanted to read about and find quite fascinating. This is hunter-gatherers who used to be agriculturalists, i.e. former agriculturalists who later ‘reverted’ to hunter-gathering for one reason or another. A few quotes:

“Some hunter-gatherers appear to have descended from original farming or pastoralist societies, via specializations into environments where agriculture was not possible or decidedly marginal. Some also exist in direct contact with agriculturalist groups closely related in terms of cultural and biological ancestry. […] Some of the rain-forest hunters and gatherers of Island Southeast Asia […] descend from original agricultural populations, if the linguistic and biological data are any guide.16 In this view, the ancestral Punan and Kubu became hunter-gatherers, especially wild sago collectors in the case of the Punan, via conscious decisions to move into interfluvial rain-forest hunting and gathering in regions that riverine agriculturalists found hard to penetrate. Other hunter-gatherers descended from cultivators include some Bantu speakers in southern Africa, possibly the honey-collecting Dorobo or Okiek of the Kenyan Highlands of East Africa, probably [as he notes elsewhere, “this is a difficult group to deal with in terms of authentication”] some marginal sago-collecting groups […] in the Sepik basin of New Guinea, and some Indian groups such as the Chenchu and Birhor. […] the Numic-speaking Uto-Aztecan peoples of the Great Basin and adjacent areas […] appear to have abandoned a former agricultural lifestyle around 1,000 years ago. These people, linguistic descendants of original maize-cultivators in Mexico and the Southwest, eventually found themselves in a dry region where maize agriculture had become marginal or no longer possible [Joseph Tainter covers the collapse of the ‘Chacoans’ in some detail in his book – US] […] Group 3 hunter-gatherer societies are of especial interest because it is far easier for a relatively marginal food-producing community to turn to hunting and gathering than it is for hunters and gatherers to move in the opposite direction. Thus, it is a fair expectation that members of this third group of hunter-gatherers will always have been quite numerous, particularly around the ecological margins of expanding agricultural societies. […] the group 3 societies offer one trajectory of cultural evolution that can terminate for ever the idea that evolution from foraging to farming is a one-way street.”

“[I]t is certainly not being suggested here that ancient hunter-gatherers could never have adopted agriculture from outside sources. But they would only have been likely to do so in situations where they had some demographic or environmental advantage over any farmers in the vicinity, and where there would have been significant reasons why the normal hunter-gatherer disinterest in agricultural adoptions should be overturned. We cannot assume that hunter-gatherers would automatically adopt agriculture just because it was sitting under their noses. We also need to remember that many populations of hunters and gatherers survived alongside agriculturalists in many parts of the world for millenia, without adopting agriculture […] The following chapters will demonstrate that the spread of agriculture in the past could not simply have occurred only because hunter-gatherers everywhere adopted it. Agriculture spread in Neolithic/Formative circumstances mainly because the cultural and linguistic descendants of the early cultivators increased their demographic profiles and pushed their cultural and linguistic boundaries outwards.”

September 7, 2017 Posted by | Anthropology, Archaeology, Books, Language, Personal | Leave a comment

A few lectures

The sound quality of this lecture is not completely optimal – there’s a recurring echo popping up now and then which I found slightly annoying – but this should not keep you from watching the lecture. It’s a quite good lecture, and very accessible – I don’t really think you even need to know anything about genetics to follow most of what he’s talking about here; as far as I can tell it’s a lecture intended for people who don’t really know much about population genetics. He introduces key concepts as they are needed and he does not go much into the technical details which might cause people trouble (this of course also makes the lecture somewhat superficial, but you can’t get everything). If you’re the sort of person who wants details not included in the lecture you’re probably already reading e.g. Razib Khan (who incidentally recently blogged/criticized a not too dissimilar paper from the one discussed in the lecture, dealing with South Asia)…

I must admit that I actually didn’t like this lecture very much, but I figured I might as well include it in this post anyway.

I found some questions included and some aspects of the coverage a bit ‘too basic’ for my taste, but other people interested in chess reading along here may like Anna’s approach better; like Krause’s lecture I think it’s an accessible lecture, despite the fact that it actually covers many lines in quite a bit of detail. It’s a long lecture but I don’t think you necessarily need to watch all of it in one go (…or at all?) – the analysis of the second game, the Kortschnoj-Gheorghiu game, starts around 45 minutes in so that might for example be a good place to include a break, if a break is required.

February 1, 2016 Posted by | Anthropology, Archaeology, Chess, Computer science, Evolutionary biology, Genetics, History, Lectures, Molecular biology | Leave a comment

Wikipedia articles of interest

i. Motte-and-bailey castle (‘good article’).

“A motte-and-bailey castle is a fortification with a wooden or stone keep situated on a raised earthwork called a motte, accompanied by an enclosed courtyard, or bailey, surrounded by a protective ditch and palisade. Relatively easy to build with unskilled, often forced labour, but still militarily formidable, these castles were built across northern Europe from the 10th century onwards, spreading from Normandy and Anjou in France, into the Holy Roman Empire in the 11th century. The Normans introduced the design into England and Wales following their invasion in 1066. Motte-and-bailey castles were adopted in Scotland, Ireland, the Low Countries and Denmark in the 12th and 13th centuries. By the end of the 13th century, the design was largely superseded by alternative forms of fortification, but the earthworks remain a prominent feature in many countries. […]

Various methods were used to build mottes. Where a natural hill could be used, scarping could produce a motte without the need to create an artificial mound, but more commonly much of the motte would have to be constructed by hand.[19] Four methods existed for building a mound and a tower: the mound could either be built first, and a tower placed on top of it; the tower could alternatively be built on the original ground surface and then buried within the mound; the tower could potentially be built on the original ground surface and then partially buried within the mound, the buried part forming a cellar beneath; or the tower could be built first, and the mound added later.[25]

Regardless of the sequencing, artificial mottes had to be built by piling up earth; this work was undertaken by hand, using wooden shovels and hand-barrows, possibly with picks as well in the later periods.[26] Larger mottes took disproportionately more effort to build than their smaller equivalents, because of the volumes of earth involved.[26] The largest mottes in England, such as Thetford, are estimated to have required up to 24,000 man-days of work; smaller ones required perhaps as little as 1,000.[27] […] Taking into account estimates of the likely available manpower during the period, historians estimate that the larger mottes might have taken between four and nine months to build.[29] This contrasted favourably with stone keeps of the period, which typically took up to ten years to build.[30] Very little skilled labour was required to build motte and bailey castles, which made them very attractive propositions if forced peasant labour was available, as was the case after the Norman invasion of England.[19] […]

The type of soil would make a difference to the design of the motte, as clay soils could support a steeper motte, whilst sandier soils meant that a motte would need a more gentle incline.[14] Where available, layers of different sorts of earth, such as clay, gravel and chalk, would be used alternatively to build in strength to the design.[32] Layers of turf could also be added to stabilise the motte as it was built up, or a core of stones placed as the heart of the structure to provide strength.[33] Similar issues applied to the defensive ditches, where designers found that the wider the ditch was dug, the deeper and steeper the sides of the scarp could be, making it more defensive. […]

Although motte-and-bailey castles are the best known castle design, they were not always the most numerous in any given area.[36] A popular alternative was the ringwork castle, involving a palisade being built on top of a raised earth rampart, protected by a ditch. The choice of motte and bailey or ringwork was partially driven by terrain, as mottes were typically built on low ground, and on deeper clay and alluvial soils.[37] Another factor may have been speed, as ringworks were faster to build than mottes.[38] Some ringwork castles were later converted into motte-and-bailey designs, by filling in the centre of the ringwork to produce a flat-topped motte. […]

In England, William invaded from Normandy in 1066, resulting in three phases of castle building in England, around 80% of which were in the motte-and-bailey pattern. […] around 741 motte-and-bailey castles [were built] in England and Wales alone. […] Many motte-and-bailey castles were occupied relatively briefly and in England many were being abandoned by the 12th century, and others neglected and allowed to lapse into disrepair.[96] In the Low Countries and Germany, a similar transition occurred in the 13th and 14th centuries. […] One factor was the introduction of stone into castle building. The earliest stone castles had emerged in the 10th century […] Although wood was a more powerful defensive material than was once thought, stone became increasingly popular for military and symbolic reasons.”

ii. Battle of Midway (featured). Lots of good stuff in there. One aspect I had not been aware of beforehand was that Allied codebreakers also here (I was quite familiar with the works of Turing and others in Bletchley Park) played a key role:

“Admiral Nimitz had one priceless advantage: cryptanalysts had partially broken the Japanese Navy’s JN-25b code.[45] Since the early spring of 1942, the US had been decoding messages stating that there would soon be an operation at objective “AF”. It was not known where “AF” was, but Commander Joseph J. Rochefort and his team at Station HYPO were able to confirm that it was Midway; Captain Wilfred Holmes devised a ruse of telling the base at Midway (by secure undersea cable) to broadcast an uncoded radio message stating that Midway’s water purification system had broken down.[46] Within 24 hours, the code breakers picked up a Japanese message that “AF was short on water.”[47] HYPO was also able to determine the date of the attack as either 4 or 5 June, and to provide Nimitz with a complete IJN order of battle.[48] Japan had a new codebook, but its introduction had been delayed, enabling HYPO to read messages for several crucial days; the new code, which had not yet been cracked, came into use shortly before the attack began, but the important breaks had already been made.[49][nb 8]

As a result, the Americans entered the battle with a very good picture of where, when, and in what strength the Japanese would appear. Nimitz knew that the Japanese had negated their numerical advantage by dividing their ships into four separate task groups, all too widely separated to be able to support each other.[50][nb 9] […] The Japanese, by contrast, remained almost totally unaware of their opponent’s true strength and dispositions even after the battle began.[27] […] Four Japanese aircraft carriers — Akagi, Kaga, Soryu and Hiryu, all part of the six-carrier force that had attacked Pearl Harbor six months earlier — and a heavy cruiser were sunk at a cost of the carrier Yorktown and a destroyer. After Midway and the exhausting attrition of the Solomon Islands campaign, Japan’s capacity to replace its losses in materiel (particularly aircraft carriers) and men (especially well-trained pilots) rapidly became insufficient to cope with mounting casualties, while the United States’ massive industrial capabilities made American losses far easier to bear. […] The Battle of Midway has often been called “the turning point of the Pacific”.[140] However, the Japanese continued to try to secure more strategic territory in the South Pacific, and the U.S. did not move from a state of naval parity to one of increasing supremacy until after several more months of hard combat.[141] Thus, although Midway was the Allies’ first major victory against the Japanese, it did not radically change the course of the war. Rather, it was the cumulative effects of the battles of Coral Sea and Midway that reduced Japan’s ability to undertake major offensives.[9]

One thing which really strikes you (well, struck me) when reading this stuff is how incredibly capital-intensive the war at sea really was; this was one of the most important sea battles of the Second World War, yet the total Japanese death toll at Midway was just 3,057. To put that number into perspective, it is significantly smaller than the average number of people killed each day in Stalingrad (according to one estimate, the Soviets alone suffered 478,741 killed or missing during those roughly 5 months (~150 days), which comes out at roughly 3000/day).

iii. History of time-keeping devices (featured). ‘Exactly what it says on the tin’, as they’d say on TV Tropes.

It took a long time to get from where we were to where we are today; the horologists of the past faced a lot of problems you’ve most likely never even thought about. What do you do for example do if your ingenious water clock has trouble keeping time because variation in water temperature causes issues? Well, you use mercury instead of water, of course! (“Since Yi Xing’s clock was a water clock, it was affected by temperature variations. That problem was solved in 976 by Zhang Sixun by replacing the water with mercury, which remains liquid down to −39 °C (−38 °F).”).

iv. Microbial metabolism.

Microbial metabolism is the means by which a microbe obtains the energy and nutrients (e.g. carbon) it needs to live and reproduce. Microbes use many different types of metabolic strategies and species can often be differentiated from each other based on metabolic characteristics. The specific metabolic properties of a microbe are the major factors in determining that microbe’s ecological niche, and often allow for that microbe to be useful in industrial processes or responsible for biogeochemical cycles. […]

All microbial metabolisms can be arranged according to three principles:

1. How the organism obtains carbon for synthesising cell mass:

2. How the organism obtains reducing equivalents used either in energy conservation or in biosynthetic reactions:

3. How the organism obtains energy for living and growing:

In practice, these terms are almost freely combined. […] Most microbes are heterotrophic (more precisely chemoorganoheterotrophic), using organic compounds as both carbon and energy sources. […] Heterotrophic microbes are extremely abundant in nature and are responsible for the breakdown of large organic polymers such as cellulose, chitin or lignin which are generally indigestible to larger animals. Generally, the breakdown of large polymers to carbon dioxide (mineralization) requires several different organisms, with one breaking down the polymer into its constituent monomers, one able to use the monomers and excreting simpler waste compounds as by-products, and one able to use the excreted wastes. There are many variations on this theme, as different organisms are able to degrade different polymers and secrete different waste products. […]

Biochemically, prokaryotic heterotrophic metabolism is much more versatile than that of eukaryotic organisms, although many prokaryotes share the most basic metabolic models with eukaryotes, e. g. using glycolysis (also called EMP pathway) for sugar metabolism and the citric acid cycle to degrade acetate, producing energy in the form of ATP and reducing power in the form of NADH or quinols. These basic pathways are well conserved because they are also involved in biosynthesis of many conserved building blocks needed for cell growth (sometimes in reverse direction). However, many bacteria and archaea utilize alternative metabolic pathways other than glycolysis and the citric acid cycle. […] The metabolic diversity and ability of prokaryotes to use a large variety of organic compounds arises from the much deeper evolutionary history and diversity of prokaryotes, as compared to eukaryotes. […]

Many microbes (phototrophs) are capable of using light as a source of energy to produce ATP and organic compounds such as carbohydrates, lipids, and proteins. Of these, algae are particularly significant because they are oxygenic, using water as an electron donor for electron transfer during photosynthesis.[11] Phototrophic bacteria are found in the phyla Cyanobacteria, Chlorobi, Proteobacteria, Chloroflexi, and Firmicutes.[12] Along with plants these microbes are responsible for all biological generation of oxygen gas on Earth. […] As befits the large diversity of photosynthetic bacteria, there are many different mechanisms by which light is converted into energy for metabolism. All photosynthetic organisms locate their photosynthetic reaction centers within a membrane, which may be invaginations of the cytoplasmic membrane (Proteobacteria), thylakoid membranes (Cyanobacteria), specialized antenna structures called chlorosomes (Green sulfur and non-sulfur bacteria), or the cytoplasmic membrane itself (heliobacteria). Different photosynthetic bacteria also contain different photosynthetic pigments, such as chlorophylls and carotenoids, allowing them to take advantage of different portions of the electromagnetic spectrum and thereby inhabit different niches. Some groups of organisms contain more specialized light-harvesting structures (e.g. phycobilisomes in Cyanobacteria and chlorosomes in Green sulfur and non-sulfur bacteria), allowing for increased efficiency in light utilization. […]

Most photosynthetic microbes are autotrophic, fixing carbon dioxide via the Calvin cycle. Some photosynthetic bacteria (e.g. Chloroflexus) are photoheterotrophs, meaning that they use organic carbon compounds as a carbon source for growth. Some photosynthetic organisms also fix nitrogen […] Nitrogen is an element required for growth by all biological systems. While extremely common (80% by volume) in the atmosphere, dinitrogen gas (N2) is generally biologically inaccessible due to its high activation energy. Throughout all of nature, only specialized bacteria and Archaea are capable of nitrogen fixation, converting dinitrogen gas into ammonia (NH3), which is easily assimilated by all organisms.[14] These prokaryotes, therefore, are very important ecologically and are often essential for the survival of entire ecosystems. This is especially true in the ocean, where nitrogen-fixing cyanobacteria are often the only sources of fixed nitrogen, and in soils, where specialized symbioses exist between legumes and their nitrogen-fixing partners to provide the nitrogen needed by these plants for growth.

Nitrogen fixation can be found distributed throughout nearly all bacterial lineages and physiological classes but is not a universal property. Because the enzyme nitrogenase, responsible for nitrogen fixation, is very sensitive to oxygen which will inhibit it irreversibly, all nitrogen-fixing organisms must possess some mechanism to keep the concentration of oxygen low. […] The production and activity of nitrogenases is very highly regulated, both because nitrogen fixation is an extremely energetically expensive process (16–24 ATP are used per N2 fixed) and due to the extreme sensitivity of the nitrogenase to oxygen.” (A lot of the stuff above was of course for me either review or closely related to stuff I’ve already read in the coverage provided in Beer et al., a book I’ve talked about before here on the blog).

v. Uranium (featured). It’s hard to know what to include here as the article has a lot of stuff, but I found this part in particular, well, interesting:

“During the Cold War between the Soviet Union and the United States, huge stockpiles of uranium were amassed and tens of thousands of nuclear weapons were created using enriched uranium and plutonium made from uranium. Since the break-up of the Soviet Union in 1991, an estimated 600 short tons (540 metric tons) of highly enriched weapons grade uranium (enough to make 40,000 nuclear warheads) have been stored in often inadequately guarded facilities in the Russian Federation and several other former Soviet states.[12] Police in Asia, Europe, and South America on at least 16 occasions from 1993 to 2005 have intercepted shipments of smuggled bomb-grade uranium or plutonium, most of which was from ex-Soviet sources.[12] From 1993 to 2005 the Material Protection, Control, and Accounting Program, operated by the federal government of the United States, spent approximately US $550 million to help safeguard uranium and plutonium stockpiles in Russia.[12] This money was used for improvements and security enhancements at research and storage facilities. Scientific American reported in February 2006 that in some of the facilities security consisted of chain link fences which were in severe states of disrepair. According to an interview from the article, one facility had been storing samples of enriched (weapons grade) uranium in a broom closet before the improvement project; another had been keeping track of its stock of nuclear warheads using index cards kept in a shoe box.[45]

Some other observations from the article below:

“Uranium is a naturally occurring element that can be found in low levels within all rock, soil, and water. Uranium is the 51st element in order of abundance in the Earth’s crust. Uranium is also the highest-numbered element to be found naturally in significant quantities on Earth and is almost always found combined with other elements.[10] Along with all elements having atomic weights higher than that of iron, it is only naturally formed in supernovae.[46] The decay of uranium, thorium, and potassium-40 in the Earth’s mantle is thought to be the main source of heat[47][48] that keeps the outer core liquid and drives mantle convection, which in turn drives plate tectonics. […]

Natural uranium consists of three major isotopes: uranium-238 (99.28% natural abundance), uranium-235 (0.71%), and uranium-234 (0.0054%). […] Uranium-238 is the most stable isotope of uranium, with a half-life of about 4.468×109 years, roughly the age of the Earth. Uranium-235 has a half-life of about 7.13×108 years, and uranium-234 has a half-life of about 2.48×105 years.[82] For natural uranium, about 49% of its alpha rays are emitted by each of 238U atom, and also 49% by 234U (since the latter is formed from the former) and about 2.0% of them by the 235U. When the Earth was young, probably about one-fifth of its uranium was uranium-235, but the percentage of 234U was probably much lower than this. […]

Worldwide production of U3O8 (yellowcake) in 2013 amounted to 70,015 tonnes, of which 22,451 t (32%) was mined in Kazakhstan. Other important uranium mining countries are Canada (9,331 t), Australia (6,350 t), Niger (4,518 t), Namibia (4,323 t) and Russia (3,135 t).[55] […] Australia has 31% of the world’s known uranium ore reserves[61] and the world’s largest single uranium deposit, located at the Olympic Dam Mine in South Australia.[62] There is a significant reserve of uranium in Bakouma a sub-prefecture in the prefecture of Mbomou in Central African Republic. […] Uranium deposits seem to be log-normal distributed. There is a 300-fold increase in the amount of uranium recoverable for each tenfold decrease in ore grade.[75] In other words, there is little high grade ore and proportionately much more low grade ore available.”

vi. Radiocarbon dating (featured).

Radiocarbon dating (also referred to as carbon dating or carbon-14 dating) is a method of determining the age of an object containing organic material by using the properties of radiocarbon (14C), a radioactive isotope of carbon. The method was invented by Willard Libby in the late 1940s and soon became a standard tool for archaeologists. Libby received the Nobel Prize for his work in 1960. The radiocarbon dating method is based on the fact that radiocarbon is constantly being created in the atmosphere by the interaction of cosmic rays with atmospheric nitrogen. The resulting radiocarbon combines with atmospheric oxygen to form radioactive carbon dioxide, which is incorporated into plants by photosynthesis; animals then acquire 14C by eating the plants. When the animal or plant dies, it stops exchanging carbon with its environment, and from that point onwards the amount of 14C it contains begins to reduce as the 14C undergoes radioactive decay. Measuring the amount of 14C in a sample from a dead plant or animal such as piece of wood or a fragment of bone provides information that can be used to calculate when the animal or plant died. The older a sample is, the less 14C there is to be detected, and because the half-life of 14C (the period of time after which half of a given sample will have decayed) is about 5,730 years, the oldest dates that can be reliably measured by radiocarbon dating are around 50,000 years ago, although special preparation methods occasionally permit dating of older samples.

The idea behind radiocarbon dating is straightforward, but years of work were required to develop the technique to the point where accurate dates could be obtained. […]

The development of radiocarbon dating has had a profound impact on archaeology. In addition to permitting more accurate dating within archaeological sites than did previous methods, it allows comparison of dates of events across great distances. Histories of archaeology often refer to its impact as the “radiocarbon revolution”.”

I’ve read about these topics before in a textbook setting (e.g. here), but/and I should note that the article provides quite detailed coverage and I think most people will encounter some new information by having a look at it even if they’re superficially familiar with this topic. The article has a lot of stuff about e.g. ‘what you need to correct for’, which some of you might find interesting.

vii. Raccoon (featured). One interesting observation from the article:

“One aspect of raccoon behavior is so well known that it gives the animal part of its scientific name, Procyon lotor; “lotor” is neo-Latin for “washer”. In the wild, raccoons often dabble for underwater food near the shore-line. They then often pick up the food item with their front paws to examine it and rub the item, sometimes to remove unwanted parts. This gives the appearance of the raccoon “washing” the food. The tactile sensitivity of raccoons’ paws is increased if this rubbing action is performed underwater, since the water softens the hard layer covering the paws.[126] However, the behavior observed in captive raccoons in which they carry their food to water to “wash” or douse it before eating has not been observed in the wild.[127] Naturalist Georges-Louis Leclerc, Comte de Buffon, believed that raccoons do not have adequate saliva production to moisten food thereby necessitating dousing, but this hypothesis is now considered to be incorrect.[128] Captive raccoons douse their food more frequently when a watering hole with a layout similar to a stream is not farther away than 3 m (10 ft).[129] The widely accepted theory is that dousing in captive raccoons is a fixed action pattern from the dabbling behavior performed when foraging at shores for aquatic foods.[130] This is supported by the observation that aquatic foods are doused more frequently. Cleaning dirty food does not seem to be a reason for “washing”.[129] Experts have cast doubt on the veracity of observations of wild raccoons dousing food.[131]

And here’s another interesting set of observations:

“In Germany—where the racoon is called the Waschbär (literally, “wash-bear” or “washing bear”) due to its habit of “dousing” food in water—two pairs of pet raccoons were released into the German countryside at the Edersee reservoir in the north of Hesse in April 1934 by a forester upon request of their owner, a poultry farmer.[186] He released them two weeks before receiving permission from the Prussian hunting office to “enrich the fauna.” [187] Several prior attempts to introduce raccoons in Germany were not successful.[188] A second population was established in eastern Germany in 1945 when 25 raccoons escaped from a fur farm at Wolfshagen, east of Berlin, after an air strike. The two populations are parasitologically distinguishable: 70% of the raccoons of the Hessian population are infected with the roundworm Baylisascaris procyonis, but none of the Brandenburgian population has the parasite.[189] The estimated number of raccoons was 285 animals in the Hessian region in 1956, over 20,000 animals in the Hessian region in 1970 and between 200,000 and 400,000 animals in the whole of Germany in 2008.[158][190] By 2012 it was estimated that Germany now had more than a million raccoons.[191]

June 14, 2015 Posted by | Archaeology, Biology, Botany, Engineering, Geology, History, Microbiology, Physics, Wikipedia, Zoology | Leave a comment

The Origin and Evolution of Cultures (IV)

The first half of the book was not easy to read due to the technical nature of the coverage, and so I decided to put it away for a while. However I did pick it up again, and I’m really glad I did as there’s simply no way around the fact that this book is awesome. Some of the chapters in this book are chapters you need to read.

Highly recommended. Probably the best book I’ve read this year.”

I’ve finished the book – the above is my review of it on goodreads. I gave the book five stars.

The last part of it had (at least) two of those must-read chapters which I when I read them feel like I really ought to blog, and they both had a lot of stuff. The first of these chapters was an awesome chapter on agriculture. I wrote some stuff of my own about that stuff in my last post about the book (I’ve incidentally corrected a few minor inaccuracies in that post since it was posted – I thought I should mention this here), but I’m pretty sure I wouldn’t have done this if I’d known what was in that chapter; they cover this topic in a lot of detail and they do it really well. Many of the aspects they cover incidentally do not overlap with what I wrote though some of course do; you’ll surely get a lot out of reading this post despite having read my earlier comments on the topic (at least if you’re interested in these sorts of things). In my archaeology textbook, which is only a few years old, the idea that the dramatic climate change which took place around the Pleistocene/Holocene boundary was a crucial factor in the development of agriculture is taken for granted, but Boyd and Richerson’s coverage reminds us that archaeologists were not always so eager to accept this hypothesis (and it should be noted that other, weaker, hypotheses are mentioned/covered in the archaeology text as well – I was skeptical about some of these while reading the book (I wrote a couple of pretty harsh remarks in the margin) because they seemed implausible to me; Boyd and Richerson illustrates in the chapter e.g. through application of models of population dynamics that I had reason to be skeptical). I forgot to talk about climate in my last post on the topic probably because I assumed people knew this part, but it gets its fair share of the attention in this post anyway so I guess no harm is done.

The other chapter I consider to be best categorized as a ‘must-read’ chapter is chapter 19, on ‘Simple Models of Complex Phenomena’, which relates a little bit – but only a little – to a blog post of mine which has recently got some attention. When reading that chapter I was never in any doubt I’d cover that stuff here – this stuff is pure gold. The ‘Microevolutionary processes give rise to history’-chapter was also really interesting and the last chapter on memes there are probably more than a few people who’d benefit from reading, but I’ll not cover that stuff here; I don’t think I’d have problems writing 4 or 5 posts about the remaining parts of the book, and this is simply too much. I’ll talk about agriculture in this post and then I’ll probably cover the model chapter in a later post. It’s possible that the agriculture coverage in the book is less interesting to people with very limited knowledge of archaeology and human prehistory than it is to me (not that I’d say I know much about this stuff – actually on second thought I probably belong in the group of people with ‘very limited knowledge’ as well…), because a lot of things which relate closely to what they write about are perhaps hard to conceptualize without knowing anything about these things, but anyway I write about what I find interesting, so here we are.

Let’s move on to the book chapter coverage:

“Numerous subsequent investigations [after the Braidwood team] now provide a reasonably detailed picture of the origins of agriculture in several independent centers and its subsequent diffusion to almost all of the earth suitable for cultivation. These investigations have discovered no region in which agriculture developed earlier or faster than in the Near East, though a North Chinese center of domestication of millet may prove almost as early. Other centers seem to have developed later, or more slowly, or with a different sequence of stages, or all three. The spread of agriculture from centers of origin to more remote areas is well documented for Europe and North America [a major problem in relation to East Asia/China is incidentally the lack of ‘transitional sites’ dated around 8.000 to 6.000 years BC; we have very early sites and then we have “abundant and widespread evidence for sedentary Neolithic villages” by 6000 BC (Scarre et al.) – but we miss some evidence as to what happened in between – US]. Ethnography also gives us cases where hunters and gatherers persisted to recent times in areas seemingly highly suitable for agriculture, most notably much of western North America and Australia. Attempts to account for this rather complex pattern are a major focus of archaeology.”

“The processes involved in such a complex phenomenon as the origin of agriculture are many and densely entangled. Many authors have given climate change a key explanatory role […] The coevolution of human subsistence strategies and plant and animal domesticates must also play an important role […] Hunting-and-gathering subsistence may normally be a superior strategy to incipient agriculture […], and, if so, some local factor may be necessary to provide the initial impetus to heavier use of relatively low-quality, high-processing-effort plant resources that eventually result in plant domestication. Population pressure is perhaps the most popular candidate […] Quite plausibly, the complex details of local history entirely determine the evolutionary sequence leading to the origin and spread of agriculture in every region. Indeed, important advances in our understanding of the origins of agriculture have resulted from pursuit of the historical details of particular cases […] Nonetheless, we propose that much about the origin of agriculture can be understood in terms of two propositions:
Agriculture was impossible during the last glacial age. During the last glacial age, climates were variable and very dry over large areas. Atmospheric levels of CO2 were low. Probably most important, last-glacial climates were characterized by high-amplitude fluctuations on timescales of a decade or less to a millennium. Because agricultural subsistence systems are vulnerable to weather extremes, and because the cultural evolution of subsistence systems making heavy, specialized use of plant resources occurs relatively slowly, agriculture could not evolve.
In the long run, agriculture is compulsory in the holocene epoch. In contrast to the Pleistocene climates, stable Holocene climates allowed the evolution of agriculture in vast areas with relatively warm, wet climates, or access to irrigation. Prehistoric populations tended to grow rapidly to the carrying capacity set by the environment and the efficiency of the prevailing subsistence system. Local communities that discover or acquire more intensive subsistence strategies will increase in number and exert competitive pressure on smaller populations with less intensive strategies. Thus, in the Holocene epoch, such intergroup competition generated a competitive ratchet favoring the origin and diffusion of agriculture.”

This is the basic idea. But the chapter has a lot more:

“For the last 400,000 years, very high-resolution climate proxy data are available from ice cores taken from the deep ice sheets of Greenland and Antarctica. Resolution of events lasting little more than a decade is possible in Greenland ice 80,000 years old, improving to monthly resolution 3,000 years ago. During the last glacial, the ice core data show that the climate was highly variable on time scales of centuries to millennia […] The last glacial period was arid and extremely variable compared to the Holocene. Sharp millennial-scale excursions occur in estimated temperatures, atmospheric dust, and greenhouse gases. The intense variability of the last glacial carries right down to the limits of the nearly 10-year resolution of the ice core data. […] Even though diffusion and thinning within the ice core progressively erases high-frequency variation in the core […] the shift from full glacial conditions about 18,000 years ago to the Holocene interglacial is accompanied by a dramatic reduction in variation on timescales shorter than 150 years. The Holocene (the last relatively warm, ice-free 11,600 years) has been a period of very stable climate, at least by the standards of the last glacial age.[2] The climate fluctuations recorded in high-latitude ice cores are also recorded at latitudes where agriculture occurs today. Sediments overlain by anoxic water that inhibits sediment mixing by burrowing organisms are a source of low- and mid-latitude data with a resolution rivaling ice cores. Events recorded in North Atlantic sediment cores are closely coupled to those recorded in Greenland ice […], but so are records distant from Greenland. Hendy and Kennett (2000) report on water temperature proxies from sediment cores from the often-anoxic Santa Barbara Basin just offshore of central California. This data shows millennial- and submillennial-scale temperature fluctuations from 60–18 thousand years ago with an amplitude of about 8°C, compared to fluctuations of about 2°C in the Holocene epoch. As in the Greenland cores, the millennial-scale events often show very abrupt onsets and terminations and are often punctuated by brief spikes of warmth and cold.”

“We expect that opportunism was the most important strategy for managing the risks associated with plant foods during the last glacial age. Annual plants have dormant seed that spreads their risk of failure over many years, and perennials vary seed output or storage organ size substantially between years as weather dictates. In a highly variable climate, the specialization of exploitation on one or a few especially promising species would be highly unlikely, because ‘‘promise’’ in one year or even for a decade or two would turn to runs of years with little or no success. However, most years would likely be favorable for some species or another, so generalized plant-exploitation systems are compatible with highly variable climates. […] Plant food-rich diets take considerable time to develop. Plant foods are generally low in protein and often high in toxins. Some time is required to work out a balanced diet rich in plant foods, for example, by incorporating legumes to replace part of the meat in diets. Whether intensification and agriculture always lead to health declines due to nutritional inadequacy is debatable, but the potential for them to do so absent sometimes-subtle adaptations is clear […] The seasonal round of activities has to be much modified, and women’s customary activities have to be given more prominence relative to men’s hunting. Changes in social organization either by evolution in situ or by borrowing tend to be slow […] We doubt that even sophisticated last-glacial hunter-gatherers would have been able to solve the complex nutritional and scheduling problems associated with a plant-rich diet while coping with unpredictable high-amplitude change on timescales shorter than the equilibration time of plant migrations and shorter than actual Holocene trajectories of intensification.”

“Low mean productivity, along with greater variance in productivity, would have greatly decreased the attractiveness of plant resources during the last glacial age. Lower average rainfall and carbon dioxide during the last glacial age reduced the area of the earth’s surface suitable for agriculture […] On present evidence we cannot determine whether aridity, low CO2 levels, millennial-scale climate variability, or submillennial-scale weather variation was the main culprit in preventing the evolution of agriculture. Low CO2 and climate variation would handicap the evolution of dependence on plant foods everywhere and were surely more significant than behavioral or technological obstacles. Hominids evolved as plant-using omnivores (Milton, 2000), and the basic technology for plant exploitation existed at least 10 thousand years before the Holocene […] At least in favorable localities, appreciable use seems to have been made of plant foods, including large-seeded grasses, well back into the Pleistocene […] Significantly, we believe, the use of such technology over spans of last-glacial time that were sufficient for successive waves of intensification of subsistence in the Holocene led to only minor subsistence intensification, compared to the Mesolithic, Neolithic, and their ever-more-intensive successors. […] After 11,600 B.P., the Holocene period of relatively warm, wet, stable, CO2-rich environments began. Subsistence intensification and eventually agriculture followed. Thus, while not perfectly instantaneous, the shift from glacial to Holocene climates was a very large change and took place much more rapidly than cultural evolution could track.”

“Might we not expect agriculture to have emerged in the last interglacial 130,000 years ago or even during one of the even older interglacials? No archaeological evidence has come to light suggesting the presence of technologies that might be expected to accompany forays into intensive plant collecting or agriculture at this time. Anatomically modern humans may have appeared in Africa as early as 130,000 years ago […], but they were not behaviorally modern. Humans of the last interglacial were uniformly archaic in behavior. Very likely, then, the humans of the last interglacial were neither cognitively nor culturally capable of evolving agricultural subsistence. However, climate might also explain the lack of marked subsistence intensification during previous interglacials. Ice cores from the thick Antarctic ice cap at Vostok show that each of the last four interglacials over the last 420,000 years was characterized by a short, sharp peak of warmth, rather than the 11,600-year-long stable plateau of the Holocene (Petit et al., 1999).”

“Once a more productive subsistence system is possible, it will, over the long run, replace the less-productive subsistence system that preceded it. The reason is simple: all else being equal, any group that can use a tract of land more efficiently will be able to evict residents that use it less efficiently […] More productive uses support higher population densities, or more wealth per capita, or both. An agricultural frontier will tend to expand at the expense of hunter-gatherers as rising population densities on the farming side of the frontier motivate pioneers to invest in acquiring land from less-efficient users. […] Thus, subsistence improvement generates a competitive ratchet as successively more land-efficient subsistence systems lead to population growth and labor intensification. Locally, huntergatherers may win some battles (e.g., in the Great Basin; Madsen, 1994), but in the long run the more intensive strategies will win wherever environments are suitable for their deployment. The archaeology supports this argument […] Societies in all regions of the world undergo a very similar pattern of subsistence efficiency increase and population increase in the Holocene, albeit at very different rates. Holocene hunter-gatherers developed local equilibria that, while sometimes lasting for thousands of years, were almost always replaced by more intensive equilibria.”

“Cohen’s (1977) influential book argued that slowly accumulating global-scale population pressure was responsible for the eventual origins of agriculture beginning at the 11,600 B.P. time horizon. He imagines, quite plausibly, that subsistence innovation is driven by increases in population density, but, implausibly we believe, that a long, slow buildup of population gradually drove people to intensify subsistence systems to relieve shortages caused by population growth, eventually triggering a move to domesticates. Looked at one way, population pressure is just the population growth part of the competitive ratchet. However, this argument fails to explain why pre-agricultural hunter-gatherer intensification and the transition to agriculture began in numerous locations after 11,600 years ago […] Assuming that humans were essentially modern by the Upper Paleolithic, they would have had 30,000 years to build up a population necessary to generate pressures for intensification. Given any reasonable estimate of the human intrinsic rate of natural increase under hunting-and-gathering conditions (somewhat less than 1% yr-1 to 3% yr-1, populations substantially below carrying capacity will double in a century or less […] If agricultural technologies were quick and easy to develop, the population pressure argument would lead us to expect Pleistocene populations to shift in and out of agriculture and other intensive strategies as they find themselves in subsistence crises due to environmental deterioration or in periods of plenty due to amelioration. Most likely, minor intensifications and de-intensifications were standard operating procedure in the Pleistocene. However, the time needed to progress much toward plant-rich strategies was greater than the fluctuating climate allowed, especially given CO2- and aridity-limited plant production.”

This part is really important to understand, and I know I’ve talked about this before but I’ll say it again: Humans living, say, 25.000 years ago were not stupid. They weren’t monkeys walking around looking for berries in the woods. They probably tried and tried repeatedly to make this kind of stuff work, explore all kinds of creative ways to obtain enough/more food, always slightly adjusting their strategies in order to stay alive and keep having kids – but the climate wouldn’t allow them to ever achieve ‘take off’. As they put it towards the end of the chapter: “If climate variation did not limit intensification during the last glacial age to vanishingly slow rates compared to the Holocene epoch, the failure of intensive systems to evolve during the tens of millennia anatomically and culturally modern humans lived as sophisticated hunter-gatherers before the Holocene is a considerable mystery.” It seems climate is a big part of the explanation why we never got to where we are now before we did. Environmental constraints limit the activities of all lifeforms in all kinds of ways, and it would serve us well every once in a while to recall that we are in fact no different, even if we like to think we are, and that such effects may have played a crucial role in the history of our species.

I’ve added a bit more from the book. Some of the stuff below I talked about in the last post as well (do recall that I wrote that post before I read this chapter), but I figured it wouldn’t hurt to include it here anyway:

“The timing of initiation of agriculture varies quite widely […] The exact sequence of events also varies quite widely. For example, in the Near East, sedentism preceded agriculture, at least in the Levantine Natufian sequence, but in Mesoamerica crops seem to have been added to a hunting-and-gathering system that was dispersed and long remained rather mobile […] For example, squash seems to have been cultivated around 10,000 B.P. in Mesoamerica, some 4,000 years before corn and bean domestication began to lead to the origin of a fully agricultural subsistence system […] Some mainly hunting-and-gathering societies seem to have incorporated small amounts of domesticated plant foods into their subsistence system without this leading to full-scale agriculture for a very long time. […] the path forward through the whole intensification sequence varied considerably from case to case.”

“In all known cases, the independent centers of domestication show a late sequence of intensification beginning with a shift from a hunter-gatherer subsistence system based upon low-cost resources using minimal technological aids to a system based upon the procurement and processing of high-cost resources, including small game and especially plant seeds or other labor-intensive plant resources, using an increasing range of chipped and ground stone tools […] The reasons for this shift are the subject of much work among archaeologists […] The shifts at least accelerate and become widespread only in the latest Pleistocene or Holocene. However, a distinct tendency toward intensification is often suggested for the Upper Paleolithic more generally. […] Upper Paleolithic peoples often made considerable use of small mammals and birds in contrast to earlier populations. These species have much lower body fat than large animals, and excessive consumption causes ammonia buildup in the body due to limitations on the rate of urea synthesis […] Consequently, any significant reliance on low-fat small animals implies corresponding compensation with plant calories, and at least a few Upper Paleolithic sites, such as the Ohalo II settlement on the Sea of Galilee […], show considerable use of plant materials in Pleistocene diets. Large-seeded annual species like wild barley were no doubt attractive resources in the Pleistocene when present in abundance and would have been used opportunistically during the last glacial age. If our hypothesis is correct, in the last glacial age no one attractive species like wild barley would have been consistently abundant (or perhaps productive enough) for a long enough span of time in the same location to have been successfully targeted by an evolving strategy of intensification, even if their less intensive exploitation was common. The broad spectrum of species, including small game and plants, reflected in these cases is not per se evidence of intensification (specialized use of more costly but more productive resources using more labor and dedicated technology), as is sometimes argued […] In most hunter-gatherer systems, marginal diet cost and diet richness (number of species used) are essentially independent […], and prey size is far less important in determining prey cost than either mode or context of capture […] For all these reasons, quantitative features of subsistence technology are a better index of Pleistocene resource intensification than species used. We believe that the dramatic increase in the quantity and range of small chipped stone and groundstone tools only after 15,000 B.P. signals the beginning of the pattern of intensification that led to agriculture.”

“Early intensification of plant resource use would have tended to generate the same competitive ratchet as the later forms of intensification. Hunter-gatherers who subsidize hunting with plant-derived calories can maintain higher population densities and thus will tend to deplete big game to levels that cannot sustain hunting specialists […] Once the climate ameliorated, the rate of intensification accelerated immediately in the case of the Near East. In other regions changes right at the Pleistocene-Holocene transition were modest to invisible […] The full working out of agrarian subsistence systems took thousands of years. […] Fully agricultural subsistence systems in the sense of a dominance of domesticated species in the diet typically postdate the origin of agriculture [which they define as “dependence upon domesticated crops and animals for subsistence” – US] by a millennium or more. […] Zvelebil (1996) emphasizes the complexity and durability of frontiers between farmers and hunter-gatherers and the likelihood that in many places the diffusion of both genes and ideas about cultivation was a prolonged process of exchange across a comparatively stable ethnic and economic frontier.”

June 5, 2014 Posted by | Anthropology, Archaeology, Books, Botany, culture, Evolutionary biology | Leave a comment

The Origin and Evolution of Cultures (III)

I have read almost three-fourths of the book by now. In this post I have quoted extensively from chapter 14 because this chapter is somewhat different from most of the other chapters in the book; it has no math, but it has a lot of observations which relate to the work they’ve covered in previous chapters, and it’s much easier to blog than most of the stuff in this book.

I don’t always agree with the authors about the details and about the conclusions they draw, but this book is consistently interesting and provides high-quality coverage of the topic in question. Unless things go seriously downhill during the last part of the book, I’ll give it five stars on goodreads.

I wrote some comments and personal observations along the way when I wrote this post, many of which are not closely related to the book coverage. I have posted them below the quotes from the book, in the second half of the post proper. I actually did earlier on make the decision not to include the stuff I’d written in this post at all because I didn’t like what I’d written, but after making a few revisions I changed my mind. I may change it again. Either way writing about these things, rather than just reading about them, is a great way to force yourself to think more carefully about them.

“Evolutionary explanations are recursive. Individual behavior results from an interaction of inherited attributes and environmental contingencies. In most species, genes are the main inherited attributes, but inherited cultural information is also important for humans. Individuals with different inherited attributes may develop different behaviors in the same environment. Every generation, evolutionary processes — natural selection is the prototype — impose environmental effects on individuals as they live their lives. Cumulated over the whole population, these effects change the pool of inherited information, so that the inherited attributes of individuals in the next generation differ, usually subtly, from the attributes in the previous generation. Over evolutionary time, a lineage cycles through the recursive pattern of causal processes once per generation […] Note that in a recursive model, we explain individual behavior and population-level processes in the same model. Individual behavior depends, in any given generation, on the gene pool from which inherited attributes are sampled. The pool of inherited attributes depends in turn upon what happens to a population of individuals as they express those attributes. Evolutionary biologists have a long list of processes that change the gene frequencies, including natural selection, mutation, and genetic drift. However, no organism experiences natural selection. Organisms either live or die, or reproduce or fail to reproduce, for concrete reasons particular to the local environment and the organism’s own particular attributes. If, in a particular environment, some types of individuals do better than others, and if this variation has a heritable basis, then we label as “natural selection” the resulting changes in gene frequencies of populations. We use abstract categories like selection to describe such concrete events because we wish to build up — concrete case by concrete case — some useful generalizations about evolutionary process. Few would argue that evolutionary biology is the poorer for investing effort in this generalizing project. Although some of the processes that lead to cultural change are very different than those that lead to genetic change, the logic of the two evolutionary problems is very similar.”

“Evolutionary theory is always multi-level […] evolutionary theories are systemic, integrating every part of biology. In principle, everything that goes into causing change through time plays its proper part in the theory. […] In theorizing about human evolution, we must include processes affecting culture in our list of evolutionary processes along side those that affect genes. Culture is a system of inheritance. We acquire behavior by imitating other individuals much as we get our genes from our parents. A fancy capacity for high-fidelity imitation is one of the most important derived characters distinguishing us from our primate relatives […] We are also an unusually docile animal (Simon 1990) and unusually sensitive to expressions of approval and disapproval by parents and others (Baum 1994). Thus parents, teachers, and peers can rapidly, easily, and accurately shape our behavior compared to training other animals using more expensive material rewards and punishments. […] once children acquire language, parents and others can communicate new ideas quite economically. Our own contribution to the study of human behavior is a series of mathematical models in the Darwinian style of what we take to be the fundamental processes of cultural evolution”

“We make [the] claim that a dual gene-culture theory of some kind will be necessary to account for the evolution of human cooperative institutions. Understanding the evolution of contemporary human cooperation requires attention to two different time scales: First, a long period of evolution in the Pleistocene shaped the innate “social instincts” that underpin modern human behavior. During this period, much genetic change occurred as a result of humans living in groups with social institutions heavily influenced by culture, including cultural group selection […] On this timescale genes and culture coevolve, and cultural evolution is plausibly a leading rather than lagging partner in this process. We sometimes refer to the process as “culture-gene coevolution.” Then, only about 10,000 years ago, the origins of agricultural subsistence systems laid the economic basis for revolutionary changes in the scale of social systems. The evidence suggests that genetic changes in the social instincts over the last 10,000 years are insignificant. […] Our hypothesis is premised on the idea that selection between groups plays a much more important role in shaping culturally transmitted variation than it does in shaping genetic variation. As a result, humans have lived in social environments characterized by high levels of cooperation for as long as culture has played an im portant role in human development. […] We believe that the human capacity to live in larger scale forms of tribal social organization evolved through a coevolutionary ratchet generated by the interaction of genes and culture. Rudimentary cooperative institutions favored genotypes that were better able to live in more cooperative groups. Those individuals best able to avoid punishment and acquire the locally-relevant norms were more likely to survive. At first, such populations would have been only slightly more cooperative than typical nonhuman primates. However, genetic changes, leading to moral emotions like shame, and a capacity to learn and internalize local practices, would allow the cultural evolution of more sophisticated institutions that in turn enlarged the scale of cooperation. These successive rounds of coevolutionary change continued until eventually people were equipped with capacities for cooperation with distantly related people, emotional attachments to symbolically marked groups, and a willingness to punish others for transgression of group rules.”

“Upper Paleolithic societies were the culmination of a long period of coevolutionary increases in a tendency toward tribal social life. We suppose that the resulting “tribal instincts” are something like principles in the Chomskian linguists’ “principles and parameters” view of language […] The innate principles furnish people with basic predispositions, emotional capacities, and social dispositions that are implemented in practice through highly variable cultural institutions, the parameters. People are innately prepared to act as members of tribes, but culture tells us how to recognize who belongs to our tribes, what schedules of aid, praise, and punishment are due to tribal fellows, and how the tribe is to deal with other tribes — allies, enemies, and clients. […] Contemporary human societies differ drastically from the societies in which our social instincts evolved. Pleistocene hunter-gatherer societies were likely comparatively small, egalitarian, and lacking in powerful institutionalized leadership. […] To evolve largescale, complex social systems, cultural evolutionary processes, driven by cultural group selection, takes advantage of whatever support these instincts offer. […] cultural evolution must cope with a psychology evolved for life in quite different sorts of societies. Appropriate larger scale institutions must regulate the constant pressure from smaller-groups (coalitions, cabals, cliques), to subvert the large-group favoring rules. To do this cultural evolution often makes use of “work arounds” — mobilizing tribal instincts for new purposes. For example, large national and international (e.g. great religions) institutions develop ideologies of symbolically marked inclusion that often fairly successfully engage the tribal instincts on a much larger scale. Military and religious organizations (e.g., Catholic Church), for example, dress recruits in identical clothing (and haircuts) loaded with symbolic markings, and then subdivide them into small groups with whom they eat and engage in long-term repeated interaction. Such work-arounds are often awkward compromises […] In military and religious organizations, for example, excessive within-group loyalty often subverts higher-level goals […] Complex societies are, in effect, grand natural social-psychological experiments that stringently test the limits of our innate dispositions to cooperate.”

“Elements of coercive dominance are no doubt necessary to make complex societies work. Tribally legitimated self-help violence is a limited and expensive means of altruistic coercion. Complex human societies have to supplement the moralistic solidarity of tribal societies with formal police institutions. […] A common method of deepening and strengthening the hierarchy of command and control in complex societies is to construct a nested hierarchy of offices, using various mixtures of ascription and achievement principles to staff the offices. Each level of the hierarchy replicates the structure of a hunting and gathering band. A leader at any level interacts mainly with a few near-equals at the next level down in the system […] The hierarchical nesting of social units in complex societies gives rise to appreciable inefficiencies […] Leaders in complex societies must convey orders downward, not just seek consensus among their comrades. Devolving substantial leadership responsibility to sub-leaders far down the chain of command is necessary to create small-scale leaders with face-to-face legitimacy. However, it potentially generates great friction if lower-level leaders either come to have different objectives than the upper leader ship or are seen by followers as equally helpless pawns of remote leaders. Stratification often creates rigid boundaries so that natural leaders are denied promotion above a certain level, resulting in inefficient use of human resources and a fertile source of resentment to fuel social discontent. On the other hand, failure to properly articulate tribal scale units with more inclusive institutions is often highly pathological. Tribal societies often must live with chronic insecurity due to intertribal conflicts.”

“The high population density, division of labor, and improved communication made possible by the innovations of complex societies increased the scope for elaborating symbolic systems. The development of monumental architecture to serve mass ritual performances is one of the oldest archaeological markers of emerging complexity. Usually an established church or less formal ideological umbrella supports a complex society’s institutions. At the same time, complex societies extensively exploit the symbolic ingroup instinct to delimit a quite diverse array of culturally defined subgroups, within which a good deal of cooperation is routinely achieved. […] Many problems and conflicts revolve around symbolically marked groups in complex societies. Official dogmas often stultify desirable innovations and lead to bitter conflicts with heretics. Marked subgroups often have enough tribal cohesion to organize at the expense of the larger social system. […] Wherever groups of people interact routinely, they are liable to develop a tribal ethos. In stratified societies, powerful groups readily evolve self-justifying ideologies that buttress treatment of subordinate groups ranging from neglectful to atrocious.”

“Many individuals in modern societies feel themselves part of culturally labeled tribal-scale groups, such as local political party organizations, that have influence on the remotest leaders. In older complex societies, village councils, local notables, tribal chieftains, or religious leaders often hold courts open to humble petitioners. These local leaders in turn represent their communities to higher authorities. To obtain low-cost compliance with management decisions, ruling elites have to convince citizens that these decisions are in the interests of the larger community. As long as most individuals trust that existing institutions are reasonably legitimate and that any felt needs for reform are achievable by means of ordinary political activities, there is considerable scope for large scale collective social action. However, legitimate institutions, and trust of them, are the result of an evolutionary history and are neither easy to manage nor engineer. […] Without trust in institutions, conflict replaces cooperation along fault lines where trust breaks down. Empirically, the limits of the trusting community define the universe of easy cooperation […] At worst, trust does not extend outside family […] and potential for cooperation on a larger scale is almost entirely foregone.”

If I were the kind of person who were interested in political stuff, I might have decided to talk a bit about how the above remarks may relate to how to set up optimal policies aimed at maintaining cooperation and trust (perhaps subject to a few relevant constraints). Some ideas spring to mind, perhaps in relation to immigration policy in particular. But I’m not that kind of person, so I won’t talk about that here.

I figured it might be a good idea to cover some ‘related’ topics here, as I can’t be sure how much the people reading along here has read about this kind of stuff and what kind of background people have. Many of the remarks below are only tangentially related to the coverage above, but they’re arguably important if you want ‘a bigger picture’.

One thing to note is that in the context of this part:

“only about 10,000 years ago, the origins of agricultural subsistence systems laid the economic basis for revolutionary changes in the scale of social systems. The evidence suggests that genetic changes in the social instincts over the last 10,000 years are insignificant.”

…there are at least two important points to mention. One is that the 10.000 years number is ‘just a number’, and that there is no ‘one true number’ here – that number depends on geography and a lot of other stuff. The origins of agriculture are still somewhat murky, though we do know a lot. There are lots of problems archaeologists need to deal with when analyzing these sorts of things, like for instance the issue that locally the date for first observed/established case of agricultural adoption may not correlate well with the first actual adoption date, because we have this tendency to overlook the sort of evidence that has already evaded attention for thousands of years. Another problem is that the switch was often gradual and took a lot of time, and involved some trial and error. A related point is that switches in food procurement strategies likely happened at local levels in the far past – in some areas of the world it would seem likely that a strategy of mostly relying on a few select crops (‘agriculture’) in ‘good periods’ (perhaps lasting hundreds of years) and then relying more on a more diversified set of different crops as well as other complementary food sources (‘hunter-gathering’) in ‘bad periods’ may have been superior to a strategy of relying exclusively on one or the other, especially around the ‘border areas’ where people almost couldn’t make agriculture work at all due to climatic factors. It’s incidentally worth noting that “no single plant can provide the mix of amino acids that primates need for growth, so primates must either eat a variety of different plants to achieve an adequate amino-acid balance, or have a regular supplement of animal foods in their diet”, so the ‘rely-on-only-one-plant agricultural model and nothing else’ is not workable in practice and never was (quote from Sponheimer et al., p.361. Less extreme versions of dependence on a single crop is feasible if you can get the other stuff elsewhere, but it’s highly risky – ask e.g. the Irish. Despite how far we’ve come in other areas, we humans incidentally rely on quite few crops to supply a substantial part of the calories we need, making us somewhat vulnerable; for example more than one-fifth of all calories consumed by humans are derived from rice). Yet another problem is that ‘agriculture’ isn’t just ‘agriculture’ – people got better at this stuff over time and things like intensification and yield improvements were important, yet often difficult or frankly impossible to estimate, especially at the intensive margin. This means that ‘we think agriculture started here in 8900 BC’ may in some contexts not mean quite what you could be tempted to think it means.

But the above, and many related, issues aside, of course the main problem with a statement including words like ‘about 10,000 years ago’ is that the variation in when different people living different places ‘adopted agriculture’ (whatever that may mean) is astonishingly huge. Here are two illustrative passages from Scarre et al. – exhibit 1: “The site of Ohalo II in northern Israel, dated around 20,000 BC, provides a remarkable snapshot of lifeways in the Levant during the Last Glacial Maximum […] At Ohalo II […] we have evidence for the exploitation of a broad spectrum of plants and animals, the extensive use of storable plant foods, and the year-round occupation of a settlement. The starch traces found on the surfaces of grinding stones confirm that they were indeed used in the preparation of hard-seeded plant foods.” The site is a hunter-gatherer site, but these guys belonged to a sedentary hunter-gatherer settlement inhabited by people who were doing many, though not all, of the things we usually only associate with traditional farmers, illustrating how these sorts of categorizations sometimes get slightly complicated if you’re not very careful when you define your terms (and sometimes even if you do) – and perhaps illustrating that it makes sense to be cautious about which mental models of our hunter-gatherer forebears we apply. Either way more ‘proper’ farming communities, such as these, which started to pop up during the early Neolithic were themselves likely at least in part ‘the result’ of gradual changes that humans which came before them had had on their surrounding environments (especially local flora and fauna – in terms of the latter probably especially our impact on local megafauna) – the processes which eventually lead us to agriculture probably took a lot of time, though just how long into the past you need to look to get the full picture is an open question, and probably will remain so as the amount of evidence available to us is sparse (which impact had human activities taking place during the late Pleistocene had on the range and distribution of potential domesticables at the beginning of the Holocene? Such questions do not to me seem easy to answer, and they’re part of the story). Although agriculture in some areas of the world by now has a ‘shelf life’ of 10.000 years or more, in other areas of the world that ‘shelf life’ is much, much shorter – exhibit 2: “no agricultural colonization of Australia, the last completely hunter-gatherer continent to survive until European contact, ever occurred.”

Agriculture provided the economic foundation for achieving the scale of social complexity which humans have achieved. This is true, but an important point/caveat here is that the evolution of ‘(relatively) advanced cultural and societal complexity’ in prehistoric times was not always contingent upon agriculture; agriculture often did lead to societal complexity, but humans could rise in societal complexity and experience significant cultural evolution without it – there were sedentary populations of some size and organizational complexity living in communities without what we usually conceptualize as agriculture (viz farming or pastoralism), e.g. in areas well-endowed with natural resources such as those near major lakes or coasts full of fish. To take one example (again from Scarre et al.), “agriculture was not a necessary prerequisite for the emergence of chiefdoms in the Southeast [North America]” – another example would be the “longstanding “Maritime Hypothesis” […] which proposes […] that maritime resources sustained population growth and the rise of sedentary earthwork-building communities” along the Pacific coast of South America during prehistoric times. There were mound builders in pre-agricultural North America as well, see e.g. this and this.

It’s worth remembering when thinking about human societies which existed especially during transitional phases – which may include many different time periods, depending on which part of the world you’re looking at – where people were starting to use agriculture but perhaps hadn’t really gotten the hang of it yet, that hunter-gatherer groups occasionally simply outcompeted farmers at the local level because some places just plain aren’t very good places to engage in agriculture, meaning that the ‘cultural victory’ of agriculturalists was by no means universal or a given at the local level, even if it’s very easy to convince yourself otherwise if you don’t know very much about these aspects of human development. Sometimes new (‘cultural’) inventions, like irrigation systems, could turn the tide in situations and geographic localities where agricultural food procurement strategies were at a disadvantage, but occasionally even that wasn’t enough.

Food production practices are/were key to societal complexity, because in order to get complexity you need to produce enough ‘excess food’ for some people to be free to engage themselves in non-food-production/procuring-activities, but another related point is that how to actually categorize and delineate various prehistoric food production practices is not always completely obvious. Food production undertaken by humans can take on multiple forms, and sometimes an ‘agriculture’ vs ‘hunter-gatherers’ dichotomic conceptualization of the issues may make you overlook important details due to ‘misclassification’ or similar problems; to take a couple of examples, some prehistoric sedentary societies based on fishing were as mentioned more or less stable food producing societies, and on a different note the cultural practices of (mobile) pastoralist societies often shared some social dimensions with hunter-gatherer societies that e.g. sedentary rice farming societies did not. Worth keeping in mind in this context is also that present-day hunter-gatherer societies still in existence often do not well reflect the cultural aspects of hunter-gatherer societies which existed in the far past, meaning that you need to be very careful about which inferences you make and what you base them on.

An aspect really important to keep in mind in general when thinking about the Holocene ‘post-agricultural period’ of human development is that the cultural development which took place in agricultural societies did not take place in a vacuum. Agriculturalists interacted with hunter-gatherers, farmers interacted with pastoralists, different e.g. geographic (mountains, seas) and biological constraints (malaria, horses) shaped human development in all kinds of ways. Boyd and Richerson do talk about this in the book, but I figured I should as well in this post. One thing to note is that in some areas agricultural practices spread much faster than in others for reasons having nothing to do with ‘the type’ of people who were doing these things, for example due to reasons of physical geography or other environmental constraints or the lack of such, and both the speed and manner of adoption likely had important (and varied) cultural ramifications. These things had genetic ramifications as well; areas where agricultural spread was particularly easy saw population growth other areas did not. Climate and climatic variation post-adoption incidentally naturally had important cultural ramifications as well – for example looking over the (pre)history of pre-colonial South America, it’s obvious that climate here was a key parameter with a huge impact on ‘the rise and fall of civilizations’.

There were multiple ways for agriculture to spread, from pure displacement to pure local adoption, as well as any combination in between, and how it proceeded varied with geography and probably a lot of other stuff as well. Some places and times the optimal type of agriculture was variable over time; which didn’t just mean that it made sense for farming societies to diversify and rely on more than one crop with different responses to e.g. drought, but also that climate change sometimes caused people to switch away from farming and towards pastoralism in bad periods – a good example of the latter is Peru during the Late Intermediate Period, where it is clear that “intensification of pastoralism was an important respone to drought” (see Moseley, p.246). Aspects such as climate have certainly had various important cultural as well as genetic impacts around the globe, e.g. on cultural transmission patterns at the regional level even during the ‘post-agricultural’ period. I mentioned interaction patterns – themselves a result of cultural dynamics, but also a driver of them – between sedentary farming societies and more mobile hunter-gatherers or pastoralists above, and perhaps I should say a little more about this kind of stuff because people may not be clear on precisely what I’m getting at there. It seems clear that in some areas division of labour dynamics played an important role in explaining and shaping cultural evolution; for a great account of these aspects of cultural dynamics and evolution in mountainous terrains and their surrounding areas, I again refer to Moseley’s account here. Inhabitants of sedentary farming societies didn’t move around very much, so things which were far away from them were things they’d often be willing to trade with more mobile human groupings. From one point of view you have a type of (modified) core-periphery model where the people from the core produced ‘excess’ food, and/or things which the people living in the core area who did not have to work on food procurement could come up with, which they then traded for other stuff, e.g. various natural resources located elsewhere (metals and wood are classic examples), with people who lived on the periphery. People looking at these things today without knowing anything about how such interaction patterns looked like may, I think, have a tendency to think of mobile hunter-gatherer groups as the morons who were left behind in this story and the pastoralists as more ‘primitive’ than the farmers, but I don’t really think that’s necessarily how it was – sometimes quite neat systems of exchange benefited both groups and were arguably by themselves important drivers of ‘cultural progress’, in the sense that they enabled and facilitated increased social complexity in the societies engaged in such systems. Of course peaceful interaction patterns were not the only ones which were explored.

May 28, 2014 Posted by | Anthropology, Archaeology, Books, culture, Evolutionary biology, Religion | Leave a comment

Wikipedia articles of interest

i. Great Fire of London (featured).


“The Great Fire of London was a major conflagration that swept through the central parts of the English city of London, from Sunday, 2 September to Wednesday, 5 September 1666.[1] The fire gutted the medieval City of London inside the old Roman city wall. It threatened, but did not reach, the aristocratic district of Westminster, Charles II‘s Palace of Whitehall, and most of the suburban slums.[2] It consumed 13,200 houses, 87 parish churches, St. Paul’s Cathedral and most of the buildings of the City authorities. It is estimated to have destroyed the homes of 70,000 of the City’s 80,000 inhabitants.”

Do note that even though this fire was a really big deal the ‘70,000 out of 80,000’ number can be misleading as many Londoners didn’t actually live in the City proper:

“By the late 17th century, the City proper—the area bounded by the City wall and the River Thames—was only a part of London, covering some 700.0 acres (2.833 km2; 1.0938 sq mi),[7] and home to about 80,000 people, or one sixth of London’s inhabitants. The City was surrounded by a ring of inner suburbs, where most Londoners lived.”

I thought I should include a few observations related to how well people behaved in this terrible situation – humans are really wonderful sometimes, and of course the people affected by the fire did everything they could to stick together and help each other out:

“Order in the streets broke down as rumours arose of suspicious foreigners setting fires. The fears of the homeless focused on the French and Dutch, England‘s enemies in the ongoing Second Anglo-Dutch War; these substantial immigrant groups became victims of lynchings and street violence.” […] [no, wait…]

“Suspicion soon arose in the threatened city that the fire was no accident. The swirling winds carried sparks and burning flakes long distances to lodge on thatched roofs and in wooden gutters, causing seemingly unrelated house fires to break out far from their source and giving rise to rumours that fresh fires were being set on purpose. Foreigners were immediately suspects because of the current Second Anglo-Dutch War. As fear and suspicion hardened into certainty on the Monday, reports circulated of imminent invasion, and of foreign undercover agents seen casting “fireballs” into houses, or caught with hand grenades or matches.[37] There was a wave of street violence.[38] William Taswell saw a mob loot the shop of a French painter and level it to the ground, and watched in horror as a blacksmith walked up to a Frenchman in the street and hit him over the head with an iron bar.

The fears of terrorism received an extra boost from the disruption of communications and news as facilities were devoured by the fire. The General Letter Office in Threadneedle Street, through which post for the entire country passed, burned down early on Monday morning. The London Gazette just managed to put out its Monday issue before the printer’s premises went up in flames (this issue contained mainly society gossip, with a small note about a fire that had broken out on Sunday morning and “which continues still with great violence”). The whole nation depended on these communications, and the void they left filled up with rumours. There were also religious alarms of renewed Gunpowder Plots. As suspicions rose to panic and collective paranoia on the Monday, both the Trained Bands and the Coldstream Guards focused less on fire fighting and more on rounding up foreigners, Catholics, and any odd-looking people, and arresting them or rescuing them from mobs, or both together.”

I didn’t really know what to think about this part:

“An example of the urge to identify scapegoats for the fire is the acceptance of the confession of a simple-minded French watchmaker, Robert Hubert, who claimed he was an agent of the Pope and had started the Great Fire in Westminster.[55] He later changed his story to say that he had started the fire at the bakery in Pudding Lane. Hubert was convicted, despite some misgivings about his fitness to plead, and hanged at Tyburn on 28 September 1666. After his death, it became apparent that he had not arrived in London until two days after the fire started.”

Just one year before the fire, London had incidentally been hit by a plague outbreak which “is believed to have killed a sixth of London’s inhabitants, or 80,000 people”. Being a Londoner during the 1660s probably wasn’t a great deal of fun. On the other hand this disaster was actually not that big of a deal when compared to e.g. the 1556 Shaanxi earthquake.

ii. Sea (featured). I was considering reading an oceanography textbook a while back, but I decided against it and I read this article ‘instead’. Some interesting stuff in there. A few observations from the article:

“About 97.2 percent of the Earth’s water is found in the sea, some 1,360,000,000 cubic kilometres (330,000,000 cu mi) of salty water.[12] Of the rest, 2.15 percent is accounted for by ice in glaciers, surface deposits and sea ice, and 0.65 percent by vapour and liquid fresh water in lakes, rivers, the ground and the air.[12]

“The water in the sea was once thought to come from the Earth’s volcanoes, starting 4 billion years ago, released by degassing from molten rock.[3](pp24–25) More recent work suggests that much of the Earth’s water may have come from comets.[16]” (This stuff covers 70 percent of the planet and we still are not completely sure how it got to be here. I’m often amazed at how much stuff we know about the world, but very occasionally I also get amazed at the things we don’t know. This seems like the sort of thing we somehow ‘ought to know’..)

“An important characteristic of seawater is that it is salty. Salinity is usually measured in parts per thousand (expressed with the ‰ sign or “per mil”), and the open ocean has about 35 grams (1.2 oz) of solids per litre, a salinity of 35‰ (about 90% of the water in the ocean has between 34‰ and 35‰ salinity[17]). […] The constituents of table salt, sodium and chloride, make up about 85 percent of the solids in solution. […] The salinity of a body of water varies with evaporation from its surface (increased by high temperatures, wind and wave motion), precipitation, the freezing or melting of sea ice, the melting of glaciers, the influx of fresh river water, and the mixing of bodies of water of different salinities.”

“Sea temperature depends on the amount of solar radiation falling on its surface. In the tropics, with the sun nearly overhead, the temperature of the surface layers can rise to over 30 °C (86 °F) while near the poles the temperature in equilibrium with the sea ice is about −2 °C (28 °F). There is a continuous circulation of water in the oceans. Warm surface currents cool as they move away from the tropics, and the water becomes denser and sinks. The cold water moves back towards the equator as a deep sea current, driven by changes in the temperature and density of the water, before eventually welling up again towards the surface. Deep seawater has a temperature between −2 °C (28 °F) and 5 °C (41 °F) in all parts of the globe.[23]

“The amount of light that penetrates the sea depends on the angle of the sun, the weather conditions and the turbidity of the water. Much light gets reflected at the surface, and red light gets absorbed in the top few metres. […] There is insufficient light for photosynthesis and plant growth beyond a depth of about 200 metres (660 ft).[27]

“Over most of geologic time, the sea level has been higher than it is today.[3](p74) The main factor affecting sea level over time is the result of changes in the oceanic crust, with a downward trend expected to continue in the very long term.[73] At the last glacial maximum, some 20,000 years ago, the sea level was 120 metres (390 ft) below its present-day level.” (this of course had some very interesting ecological effects – van der Geer et al. had some interesting observations on that topic)

“On her 68,890-nautical-mile (127,580 km) journey round the globe, HMS Challenger discovered about 4,700 new marine species, and made 492 deep sea soundings, 133 bottom dredges, 151 open water trawls and 263 serial water temperature observations.[115]

“Seaborne trade carries more than US $4 trillion worth of goods each year.[139]

“Many substances enter the sea as a result of human activities. Combustion products are transported in the air and deposited into the sea by precipitation. Industrial outflows and sewage contribute heavy metals, pesticides, PCBs, disinfectants, household cleaning products and other synthetic chemicals. These become concentrated in the surface film and in marine sediment, especially estuarine mud. The result of all this contamination is largely unknown because of the large number of substances involved and the lack of information on their biological effects.[199] The heavy metals of greatest concern are copper, lead, mercury, cadmium and zinc which may be bio-accumulated by marine invertebrates. They are cumulative toxins and are passed up the food chain.[200]

Much floating plastic rubbish does not biodegrade, instead disintegrating over time and eventually breaking down to the molecular level. Rigid plastics may float for years.[201] In the centre of the Pacific gyre there is a permanent floating accumulation of mostly plastic waste[202] and there is a similar garbage patch in the Atlantic.[203] […] Run-off of fertilisers from agricultural land is a major source of pollution in some areas and the discharge of raw sewage has a similar effect. The extra nutrients provided by these sources can cause excessive plant growth. Nitrogen is often the limiting factor in marine systems, and with added nitrogen, algal blooms and red tides can lower the oxygen level of the water and kill marine animals. Such events have created dead zones in the Baltic Sea and the Gulf of Mexico.[205]

iii. List of chemical compounds with unusual names. Technically this is not an article, but I decided to include it here anyway. A few examples from the list:

“Ranasmurfin: A blue protein from the foam nests of a tropical frog, named after the Smurfs.”

“Sonic hedgehog: A protein named after Sonic the Hedgehog.”

Arsole: (C4H5As), an analogue of pyrrole in which an arsenic atom replaces the nitrogen atom.[16]

“DAMN: Diaminomaleonitrile, a cyanocarbon that contains two amine groups and two nitrile groups bound to an ethylene backbone.”

fucK: The name of the gene that encodes L-fuculokinase, an enzyme that catalyzes a chemical reaction between L-fuculose, ADP, and L-fuculose-1-phosphate.[3]

Moronic acid: Moronic acid [3-oxoolean-18-en-28-oic acid], a natural triterpene

Draculin: An anticoagulant found in the saliva of vampire bats.[27]

iv. Operation Proboi. When trying to make sense of e.g. the reactions of people living in the Baltic countries to Russia’s ‘current activities’ in the Ukraine, it probably helps to know stuff like this. 1949 isn’t that long ago – if my father had been born in Latvia he might have been one of the people in the photo.

v. Schrödinger equation. I recently started reading  A. C. Phillips’ Introduction to Quantum Mechanics – chapter 2 deals with this topic. Due to the technical nature of the book I’m incidentally not sure to which extent I’ll cover the book here (or for that matter whether I’ll be able to finish it..) – if I do decide to cover it in some detail I’ll probably include relevant links to wikipedia along the way. The wiki has a lot of stuff on these topics, but textbooks are really helpful in terms of figuring out the order in which you should proceed.

vi. Happisburgh footprints. ‘A small step for man, …’

“The Happisburgh footprints were a set of fossilized hominin footprints that date to the early Pleistocene. They were discovered in May 2013 in a newly uncovered sediment layer on a beach at Happisburgh […] in Norfolk, England, and were destroyed by the tide shortly afterwards.  Results of research on the footprints were announced on 7 February 2014, and identified them as dating to more than 800,000 years ago, making them the oldest known hominin footprints outside Africa.[1][2][3] Before the Happisburgh discovery, the oldest known footprints in Britain were at Uskmouth in South Wales, from the Mesolithic and carbon-dated to 4,600 BC.[4]”

The fact that we found these footprints is awesome. The fact that we can tell that they are as old as they are is awesome. There’s a lot of awesome stuff going on here – Happisburg also simply seems to be a gift that keeps on giving:

“Happisburgh has produced a number of significant archaeological finds over many years. As the shoreline is subject to severe coastal erosion, new material is constantly being exposed along the cliffs and on the beach. Prehistoric discoveries have been noted since 1820, when fishermen trawling oyster beds offshore found their nets had brought up teeth, bones, horns and antlers from elephants, rhinos, giant deer and other extinct species. […]

In 2000, a black flint handaxe dating to between 600,000 and 800,000 years ago was found by a man walking on the beach. In 2012, for the television documentary Britain’s Secret Treasures, the handaxe was selected by a panel of experts from the British Museum and the Council for British Archaeology as the most important item on a list of fifty archaeological discoveries made by members of the public.[14][15] Since its discovery, the palaeolithic history of Happisburgh has been the subject of the Ancient Human Occupation of Britain (AHOB) and Pathways to Ancient Britain (PAB) projects […] Between 2005 and 2010 eighty palaeolithic flint tools, mostly cores, flakes and flake tools were excavated from the foreshore in sediment dating back to up to 950,000 years ago.”

vii. Keep (‘good article’).


“A keep (from the Middle English kype) is a type of fortified tower built within castles during the Middle Ages by European nobility. Scholars have debated the scope of the word keep, but usually consider it to refer to large towers in castles that were fortified residences, used as a refuge of last resort should the rest of the castle fall to an adversary. The first keeps were made of timber and formed a key part of the motte and bailey castles that emerged in Normandy and Anjou during the 10th century; the design spread to England as a result of the Norman invasion of 1066, and in turn spread into Wales during the second half of the 11th century and into Ireland in the 1170s. The Anglo-Normans and French rulers began to build stone keeps during the 10th and 11th centuries; these included Norman keeps, with a square or rectangular design, and circular shell keeps. Stone keeps carried considerable political as well as military importance and could take up to a decade to build.

During the 12th century new designs began to be introduced – in France, quatrefoil-shaped keeps were introduced, while in England polygonal towers were built. By the end of the century, French and English keep designs began to diverge: Philip II of France built a sequence of circular keeps as part of his bid to stamp his royal authority on his new territories, while in England castles were built that abandoned the use of keeps altogether. In Spain, keeps were increasingly incorporated into both Christian and Islamic castles, although in Germany tall towers called Bergfriede were preferred to keeps in the western fashion. In the second half of the 14th century there was a resurgence in the building of keeps. In France, the keep at Vincennes began a fashion for tall, heavily machicolated designs, a trend adopted in Spain most prominently through the Valladolid school of Spanish castle design. Meanwhile, in England tower keeps became popular amongst the most wealthy nobles: these large keeps, each uniquely designed, formed part of the grandest castles built during the period.

By the 16th century, however, keeps were slowly falling out of fashion as fortifications and residences. Many were destroyed between the 17th and 18th centuries in civil wars, or incorporated into gardens as an alternative to follies. During the 19th century, keeps became fashionable once again and in England and France a number were restored or redesigned by Gothic architects. Despite further damage to many French and Spanish keeps during the wars of the 20th century, keeps now form an important part of the tourist and heritage industry in Europe. […]

“By the 15th century it was increasingly unusual for a lord to build both a keep and a large gatehouse at the same castle, and by the early 16th century the gatehouse had easily overtaken the keep as the more fashionable feature: indeed, almost no new keeps were built in England after this period.[99] The classical Palladian style began to dominate European architecture during the 17th century, causing a further move away from the use of keeps. […] From the 17th century onwards, some keeps were deliberately destroyed. In England, many were destroyed after the end of the Second English Civil War in 1649, when Parliament took steps to prevent another royalist uprising by slighting, or damaging, castles so as to prevent them from having any further military utility. Slighting was quite expensive and took considerable effort to carry out, so damage was usually done in the most cost efficient fashion with only selected walls being destroyed.[103] Keeps were singled out for particular attention in this process because of their continuing political and cultural importance, and the prestige they lent their former royalist owners […] There were some equivalent destruction of keeps in France in the 17th and 18th centuries […] The Spanish Civil War and First and Second World Wars in the 20th century caused damage to many castle keeps across Europe; in particular, the famous keep at Coucy was destroyed by the German Army in 1917.[111] By the late 20th century, however, the conservation of castle keeps formed part of government policy across France, England, Ireland and Spain.[112] In the 21st century in England, most keeps are ruined and form part of the tourism and heritage industries, rather than being used as functioning buildings – the keep of Windsor Castle being a rare exception. This is contrast to the fate of bergfried towers in Germany, large numbers of which were restored as functional buildings in the late 19th and early 20th century, often as government offices or youth hostels, or the modern conversion of tower houses, which in many cases have become modernised domestic homes.[113]

viii. Battles of Khalkhin Gol. I decided to look up that stuff because of some of the comments in this thread.

“The Battles of Khalkhyn Gol […] constituted the decisive engagement of the undeclared Soviet–Japanese border conflicts fought among the Soviet Union, Mongolia and the Empire of Japan in 1939. The conflict was named after the river Khalkhyn Gol, which passes through the battlefield. In Japan, the decisive battle of the conflict is known as the Nomonhan Incident […] after a nearby village on the border between Mongolia and Manchuria. The battles resulted in the defeat of the Japanese Sixth Army. […]

While this engagement is little-known in the West, it played an important part in subsequent Japanese conduct in World War II. This defeat, together with other factors, moved the Imperial General Staff in Tokyo away from the policy of the North Strike Group favored by the Army, which wanted to seize Siberia as far as Lake Baikal for its resources. […] Other factors included the signing of the Nazi-Soviet non-aggression pact, which deprived the Army of the basis of its war policy against the USSR. Nomonhan earned the Kwantung Army the displeasure of officials in Tokyo, not so much due to its defeat, but because it was initiated and escalated without direct authorization from the Japanese government. Politically, the defeat also shifted support to the South Strike Group, favored by the Navy, which wanted to seize the resources of Southeast Asia, especially the petroleum and mineral-rich Dutch East Indies. Two days after the Eastern Front of World War II broke out, the Japanese army and navy leaders adopted on 24 June 1941 a resolution “not intervening in German Soviet war for the time being”. In August 1941, Japan and the Soviet Union reaffirmed their neutrality pact.[38] Since the European colonial powers were weakening and suffering early defeats in the war with Germany, coupled with their embargoes on Japan (especially of vital oil) in the second half of 1941, Japan’s focus was ultimately focused on the south, and led to its decision to launch the attack on Pearl Harbor, on 7 December that year.”

Note that there’s some disagreement in the reddit thread as to how important Khalkhin Gol really was – one commenter e.g. argues that: “Khalkhin Gol is overhyped as a factor in the Japanese decision for the southern plan.”

ix. Medical aspects, Hiroshima, Japan, 1946. Technically this is also not a wikipedia article, but multiple wikipedia articles link to it and it is a wikipedia link. The link is to a video featuring multiple people who were harmed by the first nuclear weapon used by humans in warfare. Extensive tissue damage, severe burns, scars – it’s worth having in mind that dying from cancer is not the only concern facing people who survive a nuclear blast. A few related links: a) How did cleanup in Nagasaki and Hiroshima proceed following the atom bombs? b) Minutes of the second meeting of the Target Committee Los Alamos, May 10-11, 1945. c) Keloid. d) Japan in the 1950s (pictures).

April 11, 2014 Posted by | Archaeology, Engineering, History, Medicine, Physics, Wikipedia | Leave a comment

The Roman Invasion of Britain

By Graham Webster.

I liked the first half much better than the second half. I ended up at two stars on goodreads. He spends a lot of time in the second half of the book talking about where various roads/routes and forts may have been located 2000 years ago, and unless you actually happen to live near one of the areas described you’re probably going to get bored at some point; he just keeps going and going about those roads and that little pottery shard which may indicate that perhaps there was a fort nearby, etc. I got bored towards the end, and I do not bore easily. The first half had some quite interesting stuff though.

In general the book could be easier to navigate and it was downright infuriating a few times; there were a lot of placenames I didn’t know (I didn’t grow up in Sussex), and I was thinking to myself while reading this: Why the hell not present a map with that kind of stuff at the beginning to make the book easier to read for people who happen not to have grown up in Eastern Essex (…or wherever)? I should note that there were plenty of maps in the book, with depictions of where various different types of coins have been found and where military routes and forts are assumed to have been located, among other things – so it’s probably not that the idea did not occur to him. But for some reason the author decided that the first 15 maps in the book (or whatever, I didn’t count) should contain close to zero information about place-names, etc. You could probably add placenames to the maps included by deducing where all those places he’s talking about must be located given the locations of the dots on the early maps (each dot representing a coin which has been found at that location), but the first map with a significant number of place-names was on page 117; much, much too late. I at one point gave up figuring out precisely where one of the places he talks about in the book was, because pretty much the only google hits I got from looking up the term were quotes from the book; wikipedia had no clue where it was. Later on I realized where it was, but that kind of stuff just can’t happen – I thought up some not very nice terms which I might have been tempted to use to describe the author while I was confused about these things, and I don’t often finish books which start making me think along those lines.

I did finish it though, and it actually isn’t as bad as I might have made it out to be – there was good stuff as well. I’ve previously read some stuff about the European bronze age, and some stuff about the history of the Roman Empire – from more than one angle – but although Robin Lane Fox did talk a bit about this stuff in his book this was definitely a topic about which I did not know much and about which I wanted to know more. And I did learn quite a bit although it’s not a very exciting book. The book is not just about the Romans; a substantial number of pages are devoted to telling you about the British people inhabiting the islands at the time of the invasion (and before), and about the various tribal leaders and their relationships with each others and with Rome. Some cultural (e.g. the Romans didn’t like the Druids, and the feeling was mutual) and economic (some parts of South England were for various reasons trading much more with Rome than were other parts, see also below) factors of importance are covered. Great emphasis is often placed on the problems confronted by the archaeologist when he’s to decide what can and cannot be deduced from the evidence at hand, and although there’s a lot of speculation in the book (given so limited evidence there arguably has to be in a book like this, for it to be at all readable) it’s clear where the evidence ends and the speculation starts.

I should perhaps emphasize that my relatively low rating of the book has nothing to do with it being ‘poorly documented’ or ‘unscientific’. It’s a solid piece of work, almost surely based on the best evidence available at the time of publication. Nope, it’s got nothing to do with that. It’s rather that the author somehow manages to make this exciting stuff quite boring, and he also managed to make me borderline angry at him while I was reading his book because of the things he chose not to include in his work. At the time where he was talking about the 28th route on his map, I really didn’t give a crap whether there was a fort near Baldock or not. You need to be more autistic than I am to find that stuff interesting.

A few quotes from the book below – I’ve added links to wiki articles to provide context where I assumed context was needed:

“Taking a broad view of the country, one could say that the most backward peoples were living in the hill country of the north and west, while the most sophisticated, in terms of social organization and knowledge of the crafts, especially in metallurgy, occupied the lowlands of the south and east, and in those parts nearest the Continent dwelt the very latest newcomers.
But such statements should be treated with caution” […]

“The first Iron Age culture to make inroads in Britain is known as the Hallstatt […] So great had been the influx of new settlers, that there are signs of land hunger and a struggle for possession. This is seen in the growth of defended enclosures in strong positions, the first hill-forts. […] it would seem that by c. 700 BC the newcomers had spread across Britain, taking possession of lands and setting up their hill-forts to protect themselves from others coming along in their wake or, of course, against the people whose lands had been taken over. […] the distribution of the Hallstatt type of defences and artefacts was confined to the south and east of a line from the Bristol Channel to the Humber, apart from settlements in east Yorkshire. This important geological division was to remain, […] a cultural divide in the organization of the Province of Roman Britain. […] the people of Britain, at the time of the Roman conquest, were an amalgam of those who had been here for thousands of years and of the spasmodic succession of migrants more recently from Europe seeking refuge and lands for settlement. The most important ethnic groups which came to dominate much of Britain were the Celts. These peoples originated in central Europe in the valleys of the Upper Danube and Rhine.” […]

“The most important effect of Caesar’s appearance on the British scene was to divide the south-eastern tribes into pro- and anti-Roman groups. Those who had suffered defeat, i.e. the tribes on the north bank of the Thames and in Kent were forced to pay an annual tribute which sustained a festering hatred of Rome. Those who benefited, the Trinovantes, the Catuvellauni if, as logic demands, are the people of the Verulamion and Braughing areas and their allies, would have been rewarded by political alliances and access to trade with Rome […] As far as Rome was concerned, south-eastern Britain had been conquered and treaty relationships had been established with a powerful group of tribes. The next stage would have been to allow the effects of trade and cultural contacts to prepare the way for full occupation with all the apparatus of government and law.” [But then the Romans had trouble with Gallic tribes, and then there was a civil war.] “The 97 years between the two Roman invasions can thus be divided into two parts; the first, when Rome was preoccupied by her own internal troubles and when there are no historical references to Britain; the second, when Augustus began to consider the problems of his Empire, and Britain was placed on the diplomatic agenda and references begin to appear. One has to rely heavily on the archaeological evidence to supply the missing parts in the story of these changes.” […] One can reasonably assume that a trading connection had been well established by c. 10 BC following the wine route. Fine Roman wines needed fine vessels to grace the tables of the richer Britons […] we know now that the trade extended far beyond this range of goods. A rescue excavation at Skeleton Green, not far from Braughing, has produced a large assemblage of pottery, which included nearly a hundred vessels from the well-known factory at modern Arezzo, halfway between Florence and Perugia.” […] very little imported wine reached Kent, nor is there evidence of any imported metalwares or pottery […] The pottery from the Kent cemeteries seems to bear out the evidence, or lack of it, in the absence of early amphorae and the very small quantity of fine metalware, all of which points to the lands south of the Thames being in a cultural backwater.” […]

“The legions were the main fighting force of the army. Although the number varied there were usually about 30 stationed along the frontiers at any one time. […] A legion consisted of ten cohorts, each divided into six centuries of 80 men (i.e. each cohort had 480 men) except the first cohort, which consisted of five double centuries (160×5=800 men), and could be used as an independent tactical unit. […] When Caesar invaded Britain for the second time in 54 BC there is little doubt that he intended a conquest of the south-east. He brought with him five legions and 2000 horses, which represented an army of about 27,000. But this assumes that his legions were up to full strength, although on another occasion, when Caesar hastened to the relief of the beleaguered Cicero, he gives the number of his force of two legions and some cavalry as 7000.[11] The army of Claudius would certainly have been up to strength and fitness. For such an important enterprise, all units would have retired their elderly and unfit, replacing them with younger men in the customary manner. The army, assembled on the Gallic coast, consisted of four legions, some 20,000 crack troops and, unlike Caesar’s army, as many auxiliaries, so the total, excluding the fleet, could have been as many as 40,000.” […]

“One has to appreciate that the stirrup had not yet reached Europe and fighting on a horse required quite a different technique to that of later periods after its introduction. The horse in classical times and earlier, was controlled with the knees and the bit, there was no solid fixed seat and the rider could not stand up to wield his sword or throw his spear; nor could cavalry be used as shock troops in a charge. Nevertheless, there was no lack of skill and fighting ability, much of which depended on the mobility of the rider on the horse. It also meant that there was a much closer relationship between the horseman and the foot-soldier. […] The functions of auxiliary cavalry varied. When the legions were on the march, they acted as a screen at the front and sides, clearing the ground and woods of any enemy lurking there, chasing off small parties and giving warning of any large body advancing or lying in wait. In a set battle they were stationed on the flanks protecting the legions in the centre from sudden attack from the sides and from the rear, but their most important contribution came when the legions broke the enemy line and their warriors began to retreat and to turn and run. This was the moment when the horsemen rode in from the flanks to cut them down from behind” […]

“the Roman invasion was precipitated by the sudden change in the political climate in south-east Britain. The rise of the anti-Roman forces, following the death of Cunobeline, totally changed the balance of power; Rome had now either to abandon any hope of maintaining useful political and trading relationships, or seize the country by force of arms. It could not have been difficult for Claudius and his advisors to reach a decision.”

“[Crassus] came from a long and distinguished line[49] although Seneca considered him stupid enough to be an emperor”

“[The Battle of the Medway] was one of the greatest and most significant battles fought on British soil signalling not merely a great victory for Rome, but the conquest of lowland Britain. Plautius must have realized that the Province was now virtually his, and all that remained were mopping-up operations and a great deal of talking and argument with the tribal leaders to bring them over to Rome. […] it is worth observing that no archaeological trace has ever been found of this momentous event. There is a myth in the minds of many people that battles leave behind masses of skeletons, a debris of armaments and weapons.[20] This remarkable notion is a complete illusion, since all the valuable equipment would have been carefully collected after the fighting, and the bodies removed for proper burial. One could expect ditches of Roman camps, but they have yet to be found.[21] The only possible piece of evidence is a hoard of 34 gold coins found at Bredgar in 1958[22]. The latest of these are four coins — issues of Claudius minted in 41 and 42. The site of this find is on the Downs but almost 11 miles, a day’s march, due east of the Medway, so it could hardly have been buried immediately before the battle, but must have been at a stopping point in the advance. An officer may have buried his savings before being despatched to deal with a minor incident and never returned to collect it[23].”

November 8, 2013 Posted by | Archaeology, Books | Leave a comment

A few papers

i. The Living Dead: Bacterial Community Structure of a Cadaver at the Onset and End of the Bloat Stage of Decomposition. There are a lot of questions one might ask about how the world works. Incidentally I should note that when I die I really wouldn’t mind contributing to a study like this. Here’s the abstract, with a couple of links added to ease understanding:

“Human decomposition is a mosaic system with an intimate association between biotic and abiotic factors. Despite the integral role of bacteria in the decomposition process, few studies have catalogued bacterial biodiversity for terrestrial scenarios. To explore the microbiome of decomposition, two cadavers were placed at the Southeast Texas Applied Forensic Science facility and allowed to decompose under natural conditions. The bloat stage of decomposition, a stage easily identified in taphonomy and readily attributed to microbial physiology, was targeted. Each cadaver was sampled at two time points, at the onset and end of the bloat stage, from various body sites including internal locations. Bacterial samples were analyzed by pyrosequencing of the 16S rRNA gene. Our data show a shift from aerobic bacteria to anaerobic bacteria in all body sites sampled and demonstrate variation in community structure between bodies, between sample sites within a body, and between initial and end points of the bloat stage within a sample site. These data are best not viewed as points of comparison but rather additive data sets. While some species recovered are the same as those observed in culture-based studies, many are novel. Our results are preliminary and add to a larger emerging data set; a more comprehensive study is needed to further dissect the role of bacteria in human decomposition.”

The introduction contains a good description of how decomposition in humans proceed:

“A cadaver is far from dead when viewed as an ecosystem for a suite of bacteria, insects, and fungi, many of which are obligate and documented only in such a context. Decomposition is a mosaic system with an intimate association between biotic factors (i.e., the individuality of the cadaver, intrinsic and extrinsic bacteria and other microbes, and insects) and abiotic factors (i.e., weather, climate, and humidity) and therefore a function of a specific ecological scenario. Slight alteration of the ecosystem, such as exclusion of insects or burial, may lead to a unique trajectory for decomposition and potentially anomalous results; therefore, it is critical to forensics that the interplay of these factors be understood. Bacteria are often credited as a major driving force for the process of decomposition but few studies cataloging the microbiome of decomposition have been published […]

A body passes through several stages as decomposition progresses driven by dehydration and discernible by characteristic gross taphonomic changes. The early stages of decomposition are wet and marked by discoloration of the flesh and the onset and cessation of bacterially-induced bloat. During early decay, intrinsic bacteria begin to digest the intestines from the inside out, eventually digesting away the surrounding tissues [3]. Enzymes from within the dead cells of the cadaver also begin to break down tissues (autolysis). During putrefaction, bacteria undergo anaerobic respiration and produce gases as by-products such as hydrogen sulfide, methane, cadaverine, and putrescine [5]. The buildup of resulting gas creates pressure, inflating the cadaver, and eventually forcing fluids out [3]. This purging event marks the shift from early decomposition to late decomposition and may not be uniform; the head may purge before the trunk, for example. Purge may also last for some period of time in some parts of the body even as other parts of the body enter the most advanced stages of decomposition. In the trunk, purge is associated with an opening of the abdominal cavity to the environment [3]. At this point, the rate of decay is reported by several authors to greatly increase as larval flies remove large portions of tissues; however, mummification may also occur, thus serving to preserve tissues [6][9]. The final stages of decomposition last through to skeletonization and are the driest stages [7], [10][13].”

It’s really quite an interesting paper, but you probably don’t want to read this while you’re having dinner. A few other interesting observations and conclusions:

“Many factors can influence the bacteria detected in and on a cadaver, including the individual’s “starting” microbiome, differences in the decomposition environments of the two cadavers, and differences in the sites sampled at end-bloat. The integrity of organs at end-bloat varied between cadavers (as decomposition varied between cadavers) and did not allow for consistent sampling of sites across cadavers. Specifically, STAFS 2011-016 no longer had a sigmoidal colon at the end-bloat sample time.” […]

“With the exception of the fecal sample from STAFS 2011-006, which was the least rich sample in the study with only 26 unique OTUs [operational taxonomic units – US] detected, fecal samples were the richest of all body sites sampled, with an average of nearly 400 OTUs detected. The stomach sample was the second least rich sample, with small intestine and mouth samples slightly richer. The body cavity, transverse colon, and sigmoidal colon samples were much richer. Overall, these data show that as one moves from the upper gastrointestinal tract (mouth, stomach, and small intestine) to the lower gastrointestinal tract (colon and rectal/fecal), microbiome richness increases.” […]

“It is important to note that while difference in abundance seen in particular species between this study and the others noted above could be due to the discussed constraints of culturing bacteria, differences could also be due to a variety of factors such as individual variability between the cadaver microbiomes, seasonality, climate, and species of colonizing insects. Finally, abundance does not necessarily indicate metabolic significance for decomposition, a point of importance that our study cannot address.” […]

“Our data represent initial insights into the bacteria populating decomposing human cadavers and an early start to discovering successive changes through time. While our data support the findings of previous culture studies, they also demonstrate that bacteria not detected by culture-based methods comprise a large portion of the community. No definitive conclusion regarding a shift in community structure through time can be made with this data set.”

ii. Protein restriction for diabetic renal disease.


Diabetic renal disease (diabetic nephropathy) is a leading cause of end-stage renal failure. Once the process has started, it cannot be reversed by glycaemic control, but progression might be slowed by control of blood pressure and protein restriction.


To assess the effects of dietary protein restriction on the pro gression of diabetic nephropathy in patients with diabetes .

Search methods

We searched The Cochrane Library , MEDLINE, EMBASE, ISI Proceedings, Science Citation Index Expanded and bibliographies of included studies.

Selection criteria

Randomised controlled trials (RCTs) and before and after studies of the effects of a modified or restricted protein diet on diabetic renal function in people with type 1 or type 2 diabetes following diet for at least four months were considered.

Data collection and analysis

Two reviewers performed data extraction and evaluation of quality independently. Pooling of results was done by means of random- effects model.

Main results

Twelve studies were included, nine RCTs and three before and after studies. Only one study explored all-cause mortality and end-stage renal disease (ESRD) as endpoints. The relative risk (RR) of ESRD or death was 0.23 (95% confidence interval (CI) 0.07 to 0.72) for patients assigned to a low protein diet (LPD). Pooling of the seven RCTs in patients with type 1 diabetes resulted in a non-significant reduction in the decline of glomerular filtration rate (GFR) of 0.1 ml/min/month (95% CI -0.1 to 0.3) in the LPD group. For type 2 diabetes, one trial showed a small insignificant improvement in the rate of decline of GFR in the protein-restricted group and a second found a similar decline in both the intervention and control groups. Actual protein intake in the intervention groups ranged from 0.7 to 1.1 g/kg/day. One study noted malnutrition in the LPD group. We found no data on the effects of LPDs on health-related quality of life and costs.

Authors’ conclusions

The results show that reducing protein intake appears to slightly slow progression to renal failure but not statistically significantly so. However, questions concerning the level of protein intake and compliance remain. Further longer-term research on large representative groups of patients with both type 1 and type 2 diabetes mellitus is necessary.”

The paper has a lot more. Do note that due to the link between kidney disease and dietary protein intake, at least one diabetic I know has actually considered the question of whether to adjust protein intake at an even earlier point in the disease process than the one comtemplated in these studies, i.e. before the lab tests show that the kidneys have started to fail – this is hardly an outrageous idea given evidence in related fields. I do think however that the evidence is much too inconclusive in the case of diabetic nephropathy for anything like this to make much sense at this point. Lowering salt intake seems to be far more likely to have positive effects. I’d be curious to know if the (very tentative..) finding that the type of dietary protein (‘chicken and fish vs red meat’) may matter for outcomes, and not just the amount of protein, holds; this seems very unclear at this point, but it’s potentially important as it also relates to the compliance/adherence problem.

iii. Direct evidence of 1,900 years of indigenous silver production in the Lake Titicaca Basin of Southern Peru:

“Archaeological excavations at a U-shaped pyramid in the northern Lake Titicaca Basin of Peru have documented a continuous 5-m-deep stratigraphic sequence of metalworking remains. The sequence begins in the first millennium AD and ends in the Spanish Colonial period ca. AD 1600. The earliest dates associated with silver production are 1960 ± 40 BP (2-sigma cal. 40 BC to AD 120) and 1870 ± 40 BP (2-sigma cal. AD 60 to 240) representing the oldest known silver smelting in South America. Scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) analysis of production debris indicate a complex, multistage, high temperature technology for producing silver throughout the archaeological sequence. These data hold significant theoretical implications including the following: (i) silver production occurred before the development of the first southern Andean state of Tiwanaku, (ii) the location and process of silverworking remained consistent for 1,500 years even though political control of the area cycled between expansionist states and smaller chiefly polities, and (iii) that U-shaped structures were the location of ceremonial, residential, and industrial activities.”

A little more from the paper:

“Our data establish an initial date for silverworking that is at least three centuries earlier than previous studies had indicated. […] Three independent lines of evidence establish the chronological integrity of the deposit: 1) a ceramic sequence in uninterrupted stratigraphic layers, 2) absolute radiocarbon dates, and 3) absolute ceramic thermoluminescence (TL) dates (1). […] the two absolute dating methods are internally consistent, and […] these match the relative sequence derived from analyzing the diagnostic pottery or ceramics. The unit excavated at Huajje represents a rare instance of an intact, well-demarcated stratigraphic deposit that allows us to precisely define the material changes through time in silver production. […] The steps required for silver extraction include mining, beneficiation (i.e., crushing of the ore and sorting of metal-bearing mineral), optional roasting to remove sulfur via oxidation, followed by smelting, and cupellation […] Archaeological or ethnographic evidence for most of these steps is extremely scarce, making this a very significant assemblage for our understanding of early silver production. A total of 3,457 (7,215.84 g) smelting-related artifacts were collected.”

November 1, 2013 Posted by | Archaeology, Biology, Diabetes, Medicine, Microbiology, Nephrology, Papers | Leave a comment

The Incas and their Ancestors: The Archaeology of Peru (II)

Here’s my first post about the book. I gave it 3 stars on goodreads. This is my 49th completed book this year.

The last two-thirds or so of the book actually doesn’t have a lot of stuff about the Incas – that part of the book mostly deals with the people who came before them. I knew very little about this part of South American prehistory, so I learned a lot and it was quite interesting.

I should note that in the Epilogue (last three pages) Moseley can’t stop himself from displaying some of that bottled-up hatred he clearly has towards the later colonial rulers and the current “international financial institutions” that ‘indirectly govern’ “a denigrated ethnic underclass”. Just to make clear – if there’d been just two sentences like that in the first 10 pages of the book, I’d have slammed the book shut and given it one star on goodreads. I have zero tolerance for overt politicizing in books like these. But there weren’t any such sentences to be found – the book is about the archaeology of prehistoric Peru and surrounding areas, and he keeps his mouth shut about ‘other stuff’ until the very last few pages, where you can sort of forgive such digressions. In the last couple of pages he incidentally also repeats a problematic claim from the beginning: “The era opened when Tahuantinsuyu was arguably the largest nation on earth”. This sentence really annoyed me. Has he heard about the Ottoman Empire? The Ming Dynasty? The Grand Duchy of Moscow? For those who haven’t, here are a few numbers:

Inca Empire in 1527: 2,000,000 km².
Ottoman Empire in 1520: Roughly 4,000,000 km²
Grand Duchy of Moscow in 1533: Roughly 2,800,000 km².

Wikipedia doesn’t have an area estimate for the Ming Dynasty during the 1500s, but in 1403 it was estimated at 6,500,000 km² and it didn’t lose more than two-thirds of its total area during the intervening 100-150 years (the population doubled during that century). The estimated Ming population around the year 1500 incidentally was 125 million people (Inca empire: 20 million).

Authors of books like this one tend to feel very strongly about the things they write about and sometimes that means they end up exaggerating certain things. The rest of the book is fine and it’s the only place where I’m aware that he does it – but when I see stuff like that, it annoys me a lot. There’s no doubt the Inca state was a major international player, you don’t need to add inaccurate claims to the mix to impress me.

All that said, most of the book is solid (and interesting!) work. In the stuff below I’ve mostly focused on agricultural developments in part because that’s much easier to blog. There’s a lot of stuff about the platform mounds, sunken courts, ceremonial architecture, sanctuaries, etc. in the book, and in order not to completely disregard all that stuff I decided to add some links at the bottom. Here are also a few pictures:


450px-Sechín_Archaeological_site_-_relief_(warrior)(image credit: Wikipedia)


(image credit: Wikipedia)

Anyway, below some stuff from the last five chapters:

“The spread of intensive farming and pottery followed the path of least resistance, moving from low to high and moist to dry environments. In the well-watered tropical north of Colombia and Ecuador, agriculture was adopted well before 3000 BC. However, extension down the arid Cordillera lagged, and only after an episode of dusty, and apparently dry, climatic times did farming take hold in northern and central Peru around 1800 BC. Further south there was again a lag until 1600 BC when rainfall increased in the Titicaca region and supported the rise of agropastoralism. From here it still took many hundreds of years for farm plants and pottery to diffuse into the hyper-arid environments of San Pedro de Atacama and the very dry Chilean coast. […] As mountain populations decreased their dependence on wild resources and increased their reliance on cultivation, they were slowly drawn away from the higher elevations to lower settings where warmer temperatures and milder conditions favoured plant tending in the bottomlands of sierra drainages. A gradual downward shift in the locations of camps and residential sites is well-documented during pre-pottery times […] human colonization of the Andes was a gradual matter of sedentary parental communities giving rise to more mobile daughter colonies seeking new terrain […] Andean people experienced a many-fold increase in their numbers during the Preceramic Period. In the sierra, residential sites became more numerous and scattered, on the coast fisherfolk filled in the littoral around sources of potable water, and large civic-ceremonial complexes arose in the mountains and deserts of northern and central Peru.” […]

“In many valleys it seems that irrigation developed along the path of least resistance, and most canal systems were situated well inland. Developments began in canyons and valley necks where river gradients are relatively steep […] Reclamation then advanced downstream where shallow gradients required greater investments in canal construction. In many valleys land immediately behind the coast was either never irrigated or only reclaimed very late. Because canal irrigation pulls farmers inland, the Initial Period is marked by split patterns of residence, with fisherfolk living along the littoral and farmers settling inland. […] less than 5 percent of the desert that is farmed today could be easily reclaimed by individual effort, and this condition certainly worked against the rise of independent farmers during the Initial Period. Preceramic economies supported the evolution of corporate organizations capable of executing large building projects.” […]

“In the Ayacucho region Initial Period settlements have yielded pottery assemblages, called Andamarca and Wichqana, with limited decoration and few suggestions of tropical influence. The Wichqana site has a ceremonial structure […] associated with the buried skulls of decapitated women. In the nearby Andahuaylas Valley, excavations in the Muyu Moqo sector of the Waywaka site produced a 3,440-year-old stone bowl containing metalworking tools and gold beated into thin foil. This is the earliest evidence of precious metalworking in the Andes.” [Severed heads? Gold? What’s not to like?]

“In the beginning, mountain agropastoralism and desert irrigation fostered economic boom times with people spreading into under-exploited niches, prospering and increasing their numbers. Yet growth inevitably slowed, and by the time of Christ refinements of Arid Montane and Maritime-Oasis adaptions had led to the filling-in of easily exploited habitats and further agrarian expansion required substantial investment. […] now governance was in the hands of an elite class, the kuraka, who claimed special descent from founding figures. This fostered great elaboration of ancestor veneration among commoners in general and elites in particular. […] competition and hostilities increased as easily farmed land was filled in by growing populations and during episodes of drought” […]

“Geoglyphs at Nazca and elsewhere certainly served more than one function. Calendrial significance for the lines has long been suspecteed, but not yet demonstrated. The great concentration of figures on the Nazca pampa represents by far the largest cultural artifacts of the region’s ancient inhabitants. Similar to the many mounds at Cahuachi, they are numerous and impressive, but do not represent great expenditures of energy. Although the geoglyphs are technically similar, each seems to have been created separately, used for a time, and then forgotten. New figures cross old ones in amazing confusion, and the works were obviously not part of a larger, centralized conception planned by one mind at one time.” […]

“Triggered by deep drought, the Middle Horizon was an era of punctuated cultural change as old empires withered and new ones arose. […] Technically the horizon dates between AD 600 and 1000 in the Ica Valley. Yet it was set in motion in AD 562 when rainfall began a 25-30 percent plunge that lasted until AD 594. This was the most pronounced Andean rainfall abnormality of the last 1,500 years […] Famine certainly occured because agrarian systems in many settings stretched beyond their modern limits. We can infer that the productivity of highland rainfall farming declined proportionally by 25-30 percent and that the productivity of desert irrigation declined disproportionally by at least twice as much due to dry mountain soils absorbing scant runoff moisture. Consequently coastal populations were more severely disadvantaged than their sierra counterparts. During drought, however, both populations were ill-equipped to deal with normal disasters, such as large-magnitude earthquakes and El Niño crises […] Huarpa people in the Ayacucho area were among the first to terrace and irrigate inclined terrain. […] Building such a reclamation system required substantially more labor than other communities were investing in agricultural works at the time. Nonetheless, such investment gave Huari distinct economic advantages over its neighbors, and in a sense preadapted it to weather the great drought. […] The demise of Huari remains undated and not understood, but the original spread of its appealing ideology, featuring a resurrected Staff God, was farreaching due to accompanying agrarian innovations. By introducing mountain-slope, terrace farming to many highland regions Huari preadapted sierra populations to drought […] intensification of pastoralism was an important response to drought.” […]

Tiwanaku people considered cranial deformation a mark of beauty and bound the heads of babies to shape their skull growth. Individuals in a cemetery shared the same deformation pattern, and patterns varied from one Omo graveyard to another.” [And you thought foot binding was bad! (okay, foot binding is bad, but…] […]

“beginning around AD 1100, four centuries of climate change saw precipitation decline and reach a 10-15 percent below-normal nadir shortly after AD 1300. Drought endured until AD 1500, and we can see a range of human responses to the waxing and waning of protracted stress. Sierra populations dispersed to higher altitudes where rainfall could still support farming, albeit with large investments in terracin mountain slopes. There was also migration into the wet eastern face of the Cordillera, where tarracing was again essential. Desert farmers fared very poorly […] the pre-Inca altiplano was a landscape of combative señoríos that the lords of Cuzco played off against one another and conquered in piecemeal fashion. […] The Incas conquered the lake region as drought waned and gave way to exceptionally wet conditions that permitted farming to be renewed at lower, less hostile elevations. Consequently, Tahuantinsuyu often moved people out of fortified hilltops and resettled them in low-lying localities that gave better yields, afforded easier political control and were closer to the imperial highway system. […] Pushing north as dry times waned, Cuzco’s forces often encountered little organized opposition. […] In overview, from northern Chile through northern Peru drought prompted mountain people to move higher, as well as eastward where rainfall could still sustain farming and herding. Opening these vast reaches of the Cordillera to intensive production required extensive investments in terracing and agricultural infrastructure, but they sustained significant population growth in spite of dry times. This changed the demographic balance of power in favor of the sierra, as coastal populations wilted in the wake of protracted drought.” […]

“It is doubtful that combat and blood sacrifice permeated everyday life. More likely, iconographic themes expressed ideological rituals that were scheduled and enacted over the course of an annual ceremonial calender, much like the Inca’s sacramental almanac.” [Note that people in power didn’t suddenly start all that human sacrifice stuff when the Inca’s came into power. This stuff was tradition at that point and had been for a while.]

Links: MocheEl Paraíso, Huaca del Sol. Chan ChanChavín de Huántar. Lima Culture. Nazca Lines. Pachacamac. Wari culture, Pikillaqta.

September 14, 2013 Posted by | Anthropology, Archaeology, Books | Leave a comment

The Incas and their Ancestors: The archaeology of Peru (1)

Here’s the link, the average goodreads rating is 3.55. I found the book via the AskAnthropology reading list.

It’s not the first book I read on this specific subject (THP also covers some of this stuff, but in much less detail), however we know a lot more now than we did when Métraux wrote his book (as Moseley puts it in the introduction, “Due to a tremendous escalation in Andean studies, more archaeological, historical, and anthropological research has been carried out during the current generation than during all prior centuries.”) so I’m learning a lot. A really nice thing about the book is that although it deals only with a very specific group of people, it still has some focus on highlighting general principles regarding human development. Of course a book like Boyd and Richerson’s The Origin and Evolution of Cultures (I’m planning on reading this at some point..) presumbly deals with such matters in much more detail, but it’s still nice to have at least some big-picture stuff in a book like this.

Some stuff from the first half or so of the book, as well as a few comments:

“Just as the historical accounts of Tahuantinsuyu are not without prejudice, the archaeological record did not remain unbiased by the Spanish arrival. The conquering forces quickly learned that great stores of precious metal existed in the ground. Much was purely geological in context, but the tombs of past lords and nobles also contained enormous stores of gold and silver. Within a generation of the conquest, looting operations grew so large and financially rewarding that they became legally synonymous with mining. Ancient monuments were divided into claim areas with titles registered in notarial archives. Title holders established chartered corporations to mobilize massive work forces and systematically quarry ruins. As with geological mines, the Castilian king was entitled to a 20 percent tax on all wealth extracted from the ground. Within a short span the Crown established a royal smelter in the Moche valley, not because of any local geological wealth but because the royal mausoleums of Chan Chan had been discovered and looting of the nearby Pyramid of the Sun was underway. […] the Andean Cordillera is probably the most intensively looted ancient center of civilization in the world.”

“Thanks to the rugged Cordillera, which is characterized by global extremes in environmental conditions, Andean civilization differs from other great civilizations of antiquity. If thriving civilizations had matured atop the Himalayas while simultaneously accomodating a Sahara desert, a coastal fishery richer than the Bering Sea, and a jungle larger than the Congo, then Tahuantinsuyu might seem less alien. Fundamental contrasts in the Andean Cordillera’s habitats confronted humans with radically disparate conditions and dissimilar ressources. […] The mountain, marine, desert and jungle habitats required distinctive adaptive strategies and promoted different evolutionary pathways, called Arid Montane, Maritime-Oasis, and Tropical Forest lifeways. The Incas were a montane society, but the land of the four quarters incorporated people adapted to other conditions.” (Many large civilizations of the past have had huge environmental variation within their borders, so I think Moseley may be overemphasizing here how unique the Inca empire was in this regard (see e.g. here), but it seems beyond argument that environmental factors played a major role in the structure and development of the Inca state.)

“About 90 percent of Andean runoff descends to the Atlantic watershed, while only 10 percent descends to the Pacific.”

“cold and anoxia oblige people to eat more, and highlanders are estimated to need around 11.5 percent more calories than lowlanders. Consequently, it costs measurably more to support life and civilization in mountains than in lowlands. Life is also more precarious because comparable food shortages, caused by drought and other disasters, exert greater nutritional duress at higher elevations than at lower ones. […] [But on the other hand…] High-altitude rainfall farming fluctuates less severely than low-elevation runoff farming and irrigation. Arid mountain soils, like sponges, absorb fixed amounts of moisture and must reach saturation before rainfall will produce runoff. […] if rainfall fluctuates by 10 percent […] then runoff [may] fluctuate on the order of 36 percent. […] the flow of Andean rivers fluctuates dramatically from year to year. […] Normally, runoff farming generates much higher yields than rainfall farming. […] During drought, rainfall farming is depressed less severely than runoff farming and coastal irrigation suffers the most because it is furthest away from mountain precipitation.”

“Seasonal variation increases with elevation, and plant-growth cycles are successively shorter at progressively higher altitudes. In the towering mountains, ecological zones are compressed and stacked atop one another. Andean people can trek 100 km as the crow flies and go from hilly jungle to alpine tundra, crossing counterparts of the major continental life zones. Mountain populations around the world pursue farming, herding, and the exploitation of multiple ecological zones because stacked habitats with different growing seasons are close together and the productivity of different zones fluctuates from year to year. In the Andes, this exploitation pattern moves people and produce up and down the mountains, and it is called ‘verticality’ in contrast to ‘horizontality’ which typifies lowland movement.
Verticality and horizontality are associated with different means of procuring resources. Mountain families typically exploit three or more ecological zones […] Consequently, they directly procure commodities from a series of habitats by moving produce along a vertical or elevational axis […] Alternatively, in desert and tropical lowlands people generally make their living in a single continental life zone. Because major zones are far apart, resources from distant habitats are procured indirectly by trade, barter, or exchange with other people […] In the world’s highest mountains many forces of natural selection are similar, including anoxia, cold temperatures, frost, hail, poor soils, short growing seasons, very limited crop diversity [few crops can survive in very high altitudes – US], rugged topography, and marked fainfall variation over short distances. Consequently, human populations in the Alps, Himalayas, and Andes exhibit many parallel adaptions, including symbiotic integration of agricultural and pastoral production, exploitation of multiple ecological zones, reliance on different crops from different altitudes, sequential timing of work in different ecological tiers, dependence upon dung fertilizer, frequent fallowing of fields, emphasis on long-term storage of food products, relatively little sexual division of labor in subsistence tasks, and a mixture of household and communal control of land use.”

“Mountain political centers, such as Cuzco, Huari, and Tiwanaku, expanded both through the uplands as well as down into the lowlands where resource diversity was greatest. In contrast, coastal centers, such as Chimor and Moche, expanded along the Pacific littoral, with little penetration into the highlands above 2000 m”

“Labor was the coin of the realm and the imperial economy extracted tribute in the form of work. […] [There were] three types of labor for the state that can be called agricultural taxation, mit’a service, and textile taxation. […] Agricultural taxation extracted work from both men and women. Commoners did not own land – it belonged to the ayllu. It was Inca practice to divide conquered agricultural land into three categories, ideally of equal size, all of which the peasantry was obliged to farm. The first category was dedicated to the support of the gods […] These lands were cultivated first, before other categories of fields. Yields went to support religious functionaries, priests, and shrine attendants […] The second category of fields belonged to the emperor […] Imperial fields were tended after religious ones, and yields went to support the imperial court and the needs of government. […] agrarian tribute from both religious and imperial lands was largely under Cuzco’s direct control. […] The third category of land was assigned to the local community for its support, redistributed annually to village members by the local kuraka. This allotment was not in equal parts, but proportional to the size of a family and the number of dependents under each head-of-household. As households grew or shrank, their share of land changed. […] Puna pasture lands and llama and alpaca resources were organized in a similar three-fold manner.”

August 31, 2013 Posted by | Anthropology, Archaeology, Books, Botany, Evolutionary biology | Leave a comment

The Ancestor’s Tale

I’ve read approximately half the book by now (320 pages). As I pointed out in the last post, “It’s pop sci and I have been disappointed a few times by some of the remarks he’s made during the first 200 pages”. A few examples of ‘irritating/disappointing remarks’:

“In practice all intermediates between pure hunter-gatherers and pure agriculturalists or pastoralists are found. But, earlier than about 10,000 years ago, all human populations were hunter-gatherers.”

Naturally the last sentence is what I take issue with, not the first part. It’s not that it’s wrong as such, but it will likely give people who don’t know any better the wrong impression – you can’t really leave it at that, without qualifying the statement a bit. As I’ve pointed out before, the development of farming and husbandry took thousands of years and what we still think of mostly as ‘hunter-gatherers’ did a lot of the work that brought about the changes necessary for human groups to switch to something close to the model of farming we know today. Dawkins speaks out against the widespread tendency to adopt an essentialist mindset in the field of taxonomy later on (‘the tyranny of the discontinuous mind’), but by mentioning a cut-off point like this without any qualifiers he’s in my view close to engaging in exactly the same kind of behaviour as are the people he’s criticizing. 10,000 years ago is an arbitrary cut-off point, and the ‘hunter-gatherers’ living before then were some places well on their way to developing farming as we know it – the distinction between ‘farmers’ and ‘hunter-gatherers’ was a lot more fluid in the far past than it is now. How far into the past the process went and how gradual the process from hunter-gathering to farming was surprised me a great deal when I read THP, but unfortunately I don’t have the book at my place at this point (I’ve borrowed it to a friend) – so wikipedia will have to do for now:

“Archaeologists have conducted an exhaustive study of Hut 1 at Ohalo II; this hut yielded over 90,000 seeds. The seeds account for more than 100 species of wild barley and fruits. Such a high concentration of seeds in the hut makes it highly unlikely that they were accidentally deposited into the hut via natural forces such as wind. In addition, statistical analysis demonstrates that the concentration of plant matter was significantly higher around the walls than the center. Had the seeds been deposited by the collapsed roof, they would have evenly scattered on the ground. Furthermore, just 13 species of fruit and cereal make up about half of the total number of seeds found in the area; these include brome grains (Bromus pseudobrachystachys), wild barley (Hordeum spontaneum) and millet grass grains (Piptatherum holciforme), just to name a few. This suggests a marked preference of certain species of edible plants. A seed of particular interest comes from the Rubus fruit, which was fragile, difficult to transport, and preferably eaten immediately after collection. The presence of Rubus seeds at the Ohalo II site could indicate that the seeds were dried in the sun or by the fire for storage: early evidence for advanced planning of plant food consumption. Most importantly, the extremely high concentration of seeds clustering around the grinding stone in the northern wall of Hut 1 led Ehud Weiss, an archeologist, to believe that humans at Ohalo II processed the grain before consumption. The exact spatial distribution of the seed around a grinding stone further indicates extensive preparation.”

This settlement burned to the ground around 19,400 BP. They may not have been ‘farmers’, but people who don’t know about people like these may get the wrong idea when reading Dawkins’ statement quoted above. Later on he mentions that, “Husbandry was not the overnight brainwave of some genius” and talks about the gradual changes required to get from where we were to where we ended up, both when it comes to husbandry and agriculture; but the unqualified 10.000 year mark is still bugging me a bit, and it’d not be hard to read the book and assume that the gradual changes mentioned later on took place only after 10.000 BP.

Here’s another annoying little quote:

“It [Madagascar] is a natural botanical and zoological garden, which houses about five per cent of all the plant and animal land species in the world, more than 80 per cent of them being found nowhere else.” […] [two pages later:] “If you wiped out Madagascar, you would destroy about a thousandth of the world’s total land area, but fully four per cent of all species of animals and plants.”

So which is it – four or five per cent? An editor ought to have caught that one and asked him to clarify or change one of the sentences. The repetition also really isn’t necessary. I’d expect stuff like that in a blog post, not in a published book. [see info’s comment…] Yet another:

[footnote:] “Carrots are rich in beta-carotene from which vitamin A can be made: hence the rumour – rumours can be true – that carrots improve vision.”

Yeah, well, if you’re going to include a sentence like that you’re gonna have to write a little more than that. Many people today are presumably aware of how the rumour in question came about but it’s likely that far fewer readers are aware of just how severe of a problem vitamin A deficiency still is in many developing countries (“Most common cause of blindness in developing countries […] Approximately 250,000 to 500,000 malnourished children in the developing world go blind each year from a deficiency of vitamin A, approximately half of whom die within a year of becoming blind.”).

I should point out that he talks about different speciation methods/mechanisms throughout the pages, but he doesn’t mention what they are called (see this for an overview) and his coverage is non-systematic and spread out over many pages. This is understandable given that it’s a pop sci book, but stuff like this is part of the reason why I rarely read such books.

Okay, enough with the critical remarks (I could easily include a few more but it’s not worth it) – there’s lots of really good stuff in there as well. I’ll just post a few quotes below with some ‘big picture’ stuff, but do note that most of the book is concerned with the details of how all this stuff happened – it’s a big narrative, going back hundreds of millions of years, a narrative about where we came from; and given that you need to spend some time talking about what the species which came before us were actually like. Did they have the same number of limbs as we do? How big were they? What did they eat? How did they get from A to B? Who else were around back then? And so on…  Anyway, big picture stuff and some other interesting stuff from the book which I couldn’t help including below:

“Biological evolution has no priviliged line of descent and no designated end. Evolution has reached many millions of interim ends (the number of surviving species at the time of observation), and there is no reason other than vanity – human vanity, as it happens, since we are doing the talking – to designate any one as more privileged or climactic than any other. […] A living creature is always in the business of surviving in its own environment. It is never unfinished – or, in another sense, it is always unfinished. So, presumably, are we.”

“for particular genes, you are more closely related to some chimpanzees than to some humans. And I am closer related to some chimpanzees than to you (or to ‘your’ chimpanzees). Humans as a species, as well as humans as individuals, are temporary vessels containing a mix of genes from different sources. Individuals are temporary meeting points on the crisscrossing routes that genes take through history. […]
We normally assume that we can draw a single evolutionary tree for a set of species. But […] different parts of DNA (and thus different parts of an organism) can have different trees. I think this poses an inherent problem with the very idea of species trees. Species are composites of DNA from many different sources. […] each gene, in fact each DNA letter, takes its own path through history. Each piece of DNA, and each aspect of an organism, can have a different evolutionary tree. […] Species trees can be drawn, but they must be considered a simplified summary of a multitude of gene trees.”

“Rodents are one of the great success stories of mammaldom. More than 40 per cent of all mammal species are rodents, and there are said to be more individual rodents in the world than all other mammals combined.”

“Selection drives evolution only to the extent that the alternative types owe their differences to genes: if the differences are not inherited, differential survival has no impact on future generations.”

“Carnivora is an irritating name because, after all, it simply means meat-eater, and meat-eating has been invented literally hundreds of times independently in the animal kingdom. Not all carnivores are Carnivora […] and not all Carnivora are carnivores (think of the gentle giant panda, eating almost nothing but bamboo).”

“Geological time is large not only in comparison to the familiar timescales of human life and human history. It is large on the timescale of evolution itself. This would surprise those, from Darwin’s critics on, who have complained of insufficient time for natural selection to wreak the changes the theory requires of it. We now realise that the problem is, if anything, opposite. There has been too much time! If we measure evolutionary rates over a short time, and then extrapolate, say, to a million years, the potential amount of evolutionary change turns out to be hugely greater than the actual amount. […] Darwinian selection, if we impose it artificially as hard as we’re able, can drive evolutionary change at a rate far faster than we ever see in nature. […]

One million years, which is too short to notice in most parts of the fossil record, is 20,000 times as long as it takes to triple the oil content of maize seeds. […] these experiments serve to warn against looking at apparent trends spread over millions of fossil years, and naively interpreting them as responses to steadily sustained selection pressures.
Darwinian selection pressures are out there, for sure. And they are immensely important […] But selection pressures are not sustained and uniform over the sort of timescales that can normally be resolved by fossils, especially in older parts of the fossil record. The lesson of the maize and the fruit flies is that Darwinian selection could meander hither and yon, back and forth, ten thousand times, all within the shortest time we can measure in the record of the rocks. My bet is that this happens.
Yet there are major trends over long timescales, and we have to be aware of them too. To repeat an analogy I have used before, think of a cork, bobbing about off the Atlantic coast of America. The Gulf Stream imposes an overall eastward drift in the average position of the cork, which will eventually be washed up on some European shore. But if you measure its direction of movement during any one minute, buffeted by waves and eddies and whirlpools, it will seem to move west as often as east. You won’t notice any eastward bias unless you sample its position over much longer periods. Yet the eastward bias is real, it is there, and it too deserves an explanation.”

“Why bother to lose the wings? They took a long time to evolve, why not hang on to them in case one day they might come in useful again? Alas (for the dodo) that is not the way evolution thinks. Evolution doesn’t think at all, and certainly not ahead. […] Evolution, or its driving engine natural selection, has no foresight. In every generation within every species, the individuals best equipped to survive and reproduce contribute more than their fair share of genes to the next generation. The consequence, blind as it is, is the nearest approach to foresight that nature permits. Wings might be useful a million years hence when sailors arrive with clubs. But wings will not help a bird contribute offspring and genes to the next generation […in the specific setting in which the ancestors of the dodos found themselves, US. It seems obvious that in the general case wings do help birds get more offspring or they wouldn’t bother with them…], in the immediate here and now. On the contrary wings, and especially the massive breast muscles needed to power them, are an expensive luxury. Shrink them, and the ressources saved can now be spent on something more immediately useful such as eggs: immediately useful for surviving and reproducing the very genes that programmed the shrinkage.
That’s the kind of thing natural selection does all the time. It is always tinkering: here shrinking a bit, there expanding a bit, constantly adjusting, putting on and taking off, optimising immediate reproductive success. Survival in future centuries doesn’t enter into the calculation, for the good reason that it isn’t really a calculation at all. It all happens automatically, as some genes survive in the gene pool and others don’t. […]

Moas are extreme among flightless birds in that they have no trace of wings at all, not even buried vestiges of wing bones. They thrived in both the North and South Islands of New Zealand until the recent invasion by the Maori people, about 1250 AD. They were easy prey […] and the Maoris slaughtered them all, eating the choicer parts and discarding the rest, belying, not for the first time, the wishful myth of the noble savage living in respectful harmony with its environment. […] Perhaps as many as 200 species [of flightless rail] have gone extinct on tropical Pacific islands since human contact.” […other estimates are even higher]

July 9, 2013 Posted by | Archaeology, Biology, Books, Evolutionary biology, Genetics, Geology, Zoology | 3 Comments

European Societies in the Bronze Age (II)

I finished the book. I ended up giving it 3 stars on goodreads, but as I read the last half I mostly moved closer to a 2-star evaluation. Part of the book is great, part of it is very weak. It’s best when it just deals with the facts; what do we find when we look in the different kinds of tombs left behind (and why might we not always find what we’d expect to find?), how big were the dwellings they lived in and what were they made of, how did these guys procure the metals we’ve been talking about, what did they eat, what did they wear and how did they make their clothes – questions like that. It’s much weaker when he’s engaging in various forms of bigger-picture theorizing, or telling me about the theories other people have come up with for this and that; many of those theories are presumably discussed and forwarded by people I’d prefer got fired from the institutions they work at.

Overall there’s much good stuff and I learned a lot – and as I did point out through the goodreads rating, overall I liked the book. Here’s one of the parts from the last half of the book which answered one of the many questions I’d been curious about the answer to before starting out:

“As with most prehistoric populations, people in the Bronze Age did not live long. Disease, whether chronic such as arthritis, or epidemic, such as viral infections, must have been prevalent at all times and places. Mortality studies invariably show a pattern whereby perinatal and infant mortality was extremely high and child mortality high; for those who survived into their teens, the chances of making it into adulthood were quite good, but by the age of 35 the odds against further survival increased dramatically. People older than 45 were unusual. This can be demonstrated from the analysis of El Argar, where a large sample (563 individuals) was studied: life expectancy at birth was 19.9 years, but at age 20 it was still a further 15.9 years;[19] the figures for Grossbrembach and Velika Gruda are not dissimilar.[20] Brothwell estimated an average lifespan for British Bronze Age males of 31.3 years and for females of 29.9 years, with only 3.3% surviving beyond 50.[21] […] Given the incidence of disease, the quality of life must in many cases have been poor. Those with chronic arthritis would have been in constant pain, and dependent on other members of the community for the maintenance of daily life. Even so ‘minor’ an affliction as tooth caries could have caused ongoing pain, while a tooth abscess could even have been life-threatening. Fourteen of the Grossbrembach adults had tooth caries, in some cases extensive.”

Wikipedia does not at present have enough material on the stuff covered in this book for you to be able to learn anywhere near the same amount of stuff about this topic as you would learn from reading this book (and I’m sure reading the book would make retention much easier than reading random wikipedia articles) – for instance see the main article on Bronze Age Europe, there’s not much stuff here. However below a few more links to stuff (‘samples of the kind of stuff’) covered in the book:

Apennine culture.
Wessex culture.
Hill fort.
Lusatian culture.

June 18, 2013 Posted by | Anthropology, Archaeology, Books | Leave a comment

European Societies in the Bronze Age

“The production of charcoal is an aspect of metalworking that is often ignored.62 Charcoal was the ideal fuel for furnaces prior to the advent of coke because it promotes a strongly reducing atmosphere in the furnace, consisting as it does of almost pure carbon, and on burning creates an oxygen-starved atmosphere, essential if oxygen compounds are to be removed from the metal being worked. The forcing of air into an enclosed charcoal-burning furnace raises the temperature rapidly; charcoal has a calorific value about twice that of dried wood. To make charcoal, cut timber is ignited in a sealed heap or pit and allowed to smoulder; only sufficient oxygen is admitted at the start to get the fire going, after which the process continues without the addition of oxygen. By this means combustion is incomplete, no ash results, and almost everything except carbon is removed from the wood. Considerable quantities of timber would have been needed in the most prolific metal-production areas. It has been estimated that to produce 5 kg of copper metal one would need at least 100 kg of charcoal, which would in turn have required some 700 kg of timber, a considerable requirement in terms of labour.”

From European Societies in the Bronze Age (Cambridge World Archaeology), by A. F. Harding. I’ve roughly read the first half of this book today, and so far I like it – if it continues along the same lines, I’ll probably give it three stars on goodreads (where the average rating is currently 3.8). It’s easy to read and it has a lot of interesting stuff about things I do not know much about. Below I’ve added some wikipedia links to stuff related to what’s covered in the first six chapters – they should tell you a bit about what kind of stuff’s covered in this book.

Urnfield culture.
Clearance cairn.
The Thera eruption.
Wattle and daub.
Ard (plough).
Placer mining.

June 17, 2013 Posted by | Anthropology, Archaeology, Books | Leave a comment


i. PLOS ONE: Till Death (Or an Intruder) Do Us Part: Intrasexual-Competition in a Monogamous Primate.

“Polygynous animals are often highly dimorphic, and show large sex-differences in the degree of intra-sexual competition and aggression, which is associated with biased operational sex ratios (OSR). For socially monogamous, sexually monomorphic species, this relationship is less clear. Among mammals, pair-living has sometimes been assumed to imply equal OSR and low frequency, low intensity intra-sexual competition; even when high rates of intra-sexual competition and selection, in both sexes, have been theoretically predicted and described for various taxa. Owl monkeys are one of a few socially monogamous primates. Using long-term demographic and morphological data from 18 groups, we show that male and female owl monkeys experience intense intra-sexual competition and aggression from solitary floaters. Pair-mates are regularly replaced by intruding floaters (27 female and 23 male replacements in 149 group-years), with negative effects on the reproductive success of both partners. Individuals with only one partner during their life produced 25% more offspring per decade of tenure than those with two or more partners. The termination of the pair-bond is initiated by the floater, and sometimes has fatal consequences for the expelled adult. The existence of floaters and the sporadic, but intense aggression between them and residents suggest that it can be misleading to assume an equal OSR in socially monogamous species based solely on group composition. Instead, we suggest that sexual selection models must assume not equal, but flexible, context-specific, OSR in monogamous species.”

You sort of want to extrapolate out of sample (/…out of species?) here, but be careful:

“Our findings differ from those reported for some monogamous birds, where remaining life-time reproductive success (i.e., the expected future gains) of the individual that initiates or tolerates a ‘divorce’ was higher than if it remained with its initial partner. For example, in kittiwakes (Rissa tridactyla) and many other pair-living birds, but also in some human societies, it is sometimes advantageous to ‘divorce’, if partners prove incompatible [25], [27], [35]. In contrast, our data strongly indicate that break-ups were associated with factors extrinsic to the pair, and that partners did not voluntarily leave or “divorce” as it has been reported for birds, gibbons, and (in at least one case) brown titi monkeys (Callicebus brunneus) [25][27], [36], [37]. On the other hand, in some species (oystercatchers, Haematopus ostralegus), the reproductive success of stable pairs is not only higher, but there are also accrued benefits with increased duration of the pair-bond, independent of effects of age or experience [38]. This was not the case for owl monkeys, since the number of offspring produced did not change with increased duration of the pair-bond (Fig. 2).”

ii. Smbc (click to watch in a higher resolution):

2868 societal complexity
Just to remind you that SMBC is still awesome. Here are a couple of related comics from the site.

iii. PNAS: Microstratigraphic evidence of in situ fire in the Acheulean strata of Wonderwerk Cave, Northern Cape province, South Africa:

“The ability to control fire was a crucial turning point in human evolution, but the question when hominins first developed this ability still remains. Here we show that micromorphological and Fourier transform infrared microspectroscopy (mFTIR) analyses of intact sediments at the site of Wonderwerk Cave, Northern Cape province, South Africa, provide unambiguous evidence—in the form of burned bone and ashed plant remains—that burning took place in the cave during the early Acheulean occupation, approximately 1.0 Ma. To the best of our knowledge, this is the earliest secure evidence for burning in an archaeological context.”

[Another reminder that SMBC is awesome: Here’s a recent comic which is very handy here – it explains what a Fourier transform is, in case you don’t know… (If you actually want to know there’s always wikipedia…)]

iv. I never covered this here and though some of you may already have read it I thought I might as well link to Ed Yong’s write-up on replication studies in Nature published last year. A few quotes from the article:

“Positive results in psychology can behave like rumours: easy to release but hard to dispel. They dominate most journals, which strive to present new, exciting research. Meanwhile, attempts to replicate those studies, especially when the findings are negative, go unpublished, languishing in personal file drawers or circulating in conversations around the water cooler. “There are some experiments that everyone knows don’t replicate, but this knowledge doesn’t get into the literature,” says Wagenmakers. The publication barrier can be chilling, he adds. “I’ve seen students spending their entire PhD period trying to replicate a phenomenon, failing, and quitting academia because they had nothing to show for their time.

These problems occur throughout the sciences, but psychology has a number of deeply entrenched cultural norms that exacerbate them. It has become common practice, for example, to tweak experimental designs in ways that practically guarantee positive results. And once positive results are published, few researchers replicate the experiment exactly, instead carrying out ‘conceptual replications’ that test similar hypotheses using different methods. This practice, say critics, builds a house of cards on potentially shaky foundations.

These problems have been brought into sharp focus by some high-profile fraud cases, which many believe were able to flourish undetected because of the challenges of replication. Now psychologists are trying to fix their field.”

Good luck with that. I don’t see a fix happening anytime soon. A few numbers:

“In a survey of 4,600 studies from across the sciences, Daniele Fanelli, a social scientist at the University of Edinburgh, UK, found that the proportion of positive results rose by more than 22% between 1990 and 2007 (ref. 3). Psychology and psychiatry, according to other work by Fanelli4, are the worst offenders: they are five times more likely to report a positive result than are the space sciences, which are at the other end of the spectrum […]. The situation is not improving. In 1959, statistician Theodore Sterling found that 97% of the studies in four major psychology journals had reported statistically significant positive results5. When he repeated the analysis in 1995, nothing had changed6.”

But maybe other fields are just as bad? Well, as already mentioned the space sciences do better – and that goes for other fields too (though I’d say there seems to be major problems in many areas besides psychology and psychiatry):


A major problem here is that unless you’re actually a researcher in the field or know whom to ask, the file drawer effect can be completely invisible to you.

v. Globalization of Diabetes – The role of diet, lifestyle, and genes. A new publication in Diabetes Care. As usual when they say ‘diabetes’ they mean ‘type 2 diabetes’. Some numbers from the article:

“According to the International Diabetes Federation (1), diabetes affects at least 285 million people worldwide, and that number is expected to reach 438 million by the year 2030, with two-thirds of all diabetes cases occurring in low- to middle-income countries. The number of adults with impaired glucose tolerance will rise from 344 million in 2010 to an estimated 472 million by 2030.
Globally, it was estimated that diabetes accounted for 12% of health expenditures in 2010, or at least $376 billion—a figure expected to hit $490 billion in 2030 (2). […] Asia accounts for 60% of the world’s diabetic population. [Do note that this does not mean that Asian countries are on average overrepresented in the diabetes statistics. Asia also has roughly 60% of the World’s population. – US] […] In 1980, less than 1% of Chinese adults had the disease. By 2008, the prevalence had reached nearly 10% […] in urban areas of south India, the prevalence of diabetes has reached nearly 20% […] Compared with Western populations, Asians develop diabetes at younger ages, at lower degrees of obesity, and at much higher rates given the same amount of weight gain […]

If current worldwide trends continue, the number of overweight people (BMI >25 kg/m^2) is projected to increase from 1.3 billion in 2005 to nearly 2.0 billion by 2030 (6). […] the prevalence of overweight and obesity in Chinese adults increased from 20% in 1992 to 29.9% in 2002 (8) […]

In the NHS (26), each 2-h/day increment of time spent watching television (TV) was associated with a 14% increase in diabetes risk. […] Each 1-h/day increment of brisk walking was associated with a 34% reduction in risk […] Cigarette smoking is an independent risk factor for type 2 diabetes. A meta-analysis found that current smokers had a 45% increased risk of developing diabetes compared with nonsmokers (29). Moreover, there was a dose-response relationship between the number of cigarettes smoked and diabetes risk. [That one I did not know about!] […] Light-to-moderate alcohol consumption is associated with reduced risk of diabetes. A meta-analysis of 370,000 individuals with 12 years of follow-up showed a U-shaped relationship, with a 30–40% reduced risk of the disease among those consuming 1–2 drinks/day compared with heavy drinkers or abstainers (37). […]

common variants of the TCF7L2 gene that are significantly associated with diabetes risk are present in 20–30% of Caucasian populations but only 3–5% of Asians […] Conversely, a variant in the KCNQ1 gene associated with a 20–30% increased risk of diabetes in several Asian populations (43,44) is common in East Asians, but rare in Caucasians […]

Several randomized clinical trials have demonstrated that diabetes is preventable. One of the first diabetes prevention trials was conducted in Daqing, China (58). After 6 years of active intervention, risk was reduced by 31, 46, and 42% in the diet-only, exercise-only, and diet-plus-exercise groups, respectively, compared with the control group. In a subsequent 14-year follow-up study, the intervention groups were combined and compared with control subjects to assess how long the benefits of lifestyle change can extend beyond the period of active intervention (59). Compared with control subjects, individuals in the combined lifestyle intervention group had a 51% lower risk of diabetes during the active intervention period, and a 43% lower risk over a 20-year follow-up.”

vi. Why chess sucks.

vii. If you think your life sucks

February 3, 2013 Posted by | Archaeology, Biology, Data, Diabetes, Genetics, Papers, Psychology, Random stuff, Zoology | 2 Comments


i. Click to view full size:

(link). He probably is going to say something stupid. According to a new paper: The Mere Anticipation of an Interaction with a Woman Can Impair Men’s Cognitive Performance. ‘Further studies needed’ etc., but I’m inclined to believe that they are right and that yes, males are actually that stupid and impressionable. Though effect sizes are important to have in mind too.

ii. I thought this was funny. Then again I’m weird.

iii. I’ve added Guam to my list of ‘places I don’t want to visit anytime in the near future’. Why? Because of this.

“Birds are dominant apex predators in terrestrial systems around the world, yet all studies on their role as predators have come from small-scale experiments; the top-down impact of bird loss on their arthropod prey has yet to be examined at a landscape scale. Here, we use a unique natural experiment, the extirpation of insectivorous birds from nearly all forests on the island of Guam by the invasive brown tree snake, to produce the first assessment of the impacts of bird loss on their prey. We focused on spiders because experimental studies showed a consistent top-down effect of birds on spiders. We conducted spider web surveys in native forest on Guam and three nearby islands with healthy bird populations. Spider web densities on the island of Guam were 40 times greater than densities on islands with birds during the wet season, and 2.3 times greater during the dry season. These results confirm the general trend from manipulative experiments conducted in other systems however, the effect size was much greater in this natural experiment than in most manipulative experiments. […]

We compared the abundance of web-building spiders on Guam to that on Rota, Tinian and Saipan. At each site, we set up 1–3 transects, separated by at least 200 meters. The transects were 20 or 30 meters long, depending on the year. We counted all visible webs within 1 horizontal meter of each transect centerline and up to 2 vertical meters above the ground. Webs lacking a spider were considered abandoned, and not counted. […] Guam, without birds, had a mean of 18.37 spider webs per ten meters in the wet season, compared to 0.45 webs per ten meters on nearby islands with birds […]. In the dry season, Guam had 26.19 spider webs per ten meters compared to 11.37 webs per ten meters on nearby islands with birds”

iv. You Don’t Know Me, But I Know You: The Illusion of Asymmetric Insight, by Pronin, Kruger, Savitsky and Ross. Interesting. The abstract:

“People, it is hypothesized, show an asymmetry in assessing their own interpersonal and intrapersonal knowledge relative to that of their peers. Six studies suggested that people perceive their knowledge of their peers to surpass their peers’ knowledge of them. Several of the studies explored sources of this perceived asymmetry, especially the conviction that while observable behaviors (e.g., interpersonal revelations or idiosyncratic word completions) are more revealing of others than self, private thoughts and feelings are more revealing of self than others. Study 2 also found that college roommates believe they know themselves better than their peers know themselves. Study 6 showed that group members display a similar bias—they believe their groups know and understand relevant out-groups better than vice versa. The relevance of such illusions of asymmetric insight for interpersonal interaction and our understanding of “naive realism” is discussed.”

v. Crunching the data on human brain evolution. Which functional form fits the underlying process better is an interesting discussion but I’d like to note that what I first thought when seeing these (or rather, similar depictions elsewhere) was: ‘hey, look at that standard deviation!’

vi. Social rejection shares somatosensory representations with physical pain. Another fMRI-study. I don’t know enough about this stuff to comment on the validity of the conclusions, but I’ll probably bookmark it and keep it for later so that I’ll be able to use it to justify my decision not to ask out the hypothetical cute girl in class next semester (or whatever).

vii. Quality of Diabetes Care in Italy. I’m glad I don’t live in Italy:

“Of 126,163 diabetic individuals (prevalence of diabetes 5.8%, mean age 71 years), as many as 42% did not have their HbA1c measured for over a year. Even considering only insulin-treated people, this frequency remains disappointingly high (35%). The proportion of people having at least two annual tests for HbA1c was low (32.7%; 43.1% among insulin-treated patients). […] Another disappointing finding is the very low proportion of subjects in whom microalbuminuria was tested (27%) in spite of its role as a strong predictor of cardiovascular diseases and dialysis. Annual testing for plasma total cholesterol (61.2%), creatinine (58.9%), eye examination (11.1%), electrocardiogram (25.1%), and arterial echo-Doppler (15.9%) were low.”

I recently posted some corresponding Danish numbers here, though unfortunately that post is in Danish. In Denmark approximately 95% of diabetics get their HbA1c measured at least once a year. I get my HbA1c tested 3-4 times a year and I’d have no clue what to do without these numbers. 92% of Danish patients cared for by the hospital outpatient clinics (diabetesambulatorier) and 55% of the patients treated by their local GP were tested for microalbuminuria at least once every two years. I’m tested once per year. I frankly found it shocking that the Italic HbA1c numbers were that low but I probably should have known better, given the variation in diabetes care across countries. Not all of the variables mentioned are equally important but Italy fails at the really basic stuff too. For a Danish diabetic to move to a place like (Southern) Italy (I’m almost certain the situation is far worse in the south than in the north) would be a bit like an old and frail person moving to a place where they haven’t heard about penicillin. This stuff is a big part of why I’m not very likely to move away from Denmark when I finish my education – a lot of places I basically consider ‘off limits’ because I’d be gambling with my health by moving there, and even a lot of relatively advanced societies still have diabetes treatment protocols which belong in the (metaphorical) Stone Age.

September 18, 2012 Posted by | Archaeology, Diabetes, Medicine, Papers, Psychology, Random stuff, Studies | Leave a comment

‘Mezoamerican civilization’ and ‘From village to empire in South America’

“…the really significant development in the evolution of any civilization is the increase of societal size and internal heterogeneity, that is, the emergence of class and occupational divisions; and this is a process, not an invention to be diffused from place to place” (Sanders 1972, 152)”

The title of the post is a combination of the titles of chapters 16 and 17 in THP, and the quote above is from the first page of chapter 16 (no, it doesn’t mean that e.g. technological diffusion doesn’t matter – the importance of diffusion was underlined immediately before this quote in the text, and I omitted one word from the quote, the word ‘But’ which was right in front of it). Anyway, I’ve almost finished the book now (one chapter to go), and so this may be my last post about the book – unless I can’t find anything else to write about in the next days, in which case I’ll probably add a post about ‘Complex Societies in North America’ or some other similarly silly subject. I read Métraux a while back so not all of the stuff covered in chapter 17 was new to me – but a lot of it was. Even so, it’s nice to have some context – it makes it easier to remember stuff and to arrange things in the right order. It’s hard to get the big picture from wikipedia articles like the ones below alone, but they’re also rather meant to just spark interest; there’s a huge amount of interesting stuff covered in the book, and if you wanted to I’m sure you could spend years reading about all these things (without even paying much for it, unlike a lot of the people who choose to do just that at universities around the world).

Some articles about stuff covered to some degree in the two chapters:

i. Mesoamerican chronology (also have links to many of the articles below).
ii. Teotihuacan. (this doesn’t have a ‘good article’ rank, but it is a good article)
iii. Olmec.
iv. Lost-wax casting.
v. Maya civilization.
vi. Tikal (‘good article’).
vii. Aztec.
viii. Human sacrifice in Aztec culture.

And from the chapter about South America:
ix. Cultural periods of Peru (not good, but the tables are better than nothing. Only the later preceramic periods are covered in this chapter; a previous chapter dealt with the earlier periods mentioned. The article contains links to some of the articles below).
x. Tiwanaku.
xi. Moche.
xii. Nazca Lines.
xiii. Sican (/Lambayeque) culture.
xiv. Chan Chan.
xv. Inca empire.
xvi. Swidden agriculture.
xvii. Terra preta.

July 24, 2012 Posted by | Anthropology, Archaeology, Books, History | Leave a comment