Stuff

i. “Jesus said to his disciples: “Things that cause people to stumble are bound to come, but woe to anyone through whom they come. It would be better for them to be thrown into the sea with a millstone tied around their neck than to cause one of these little ones to stumble.” (Luke 17, quote found here).

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ii. Dimetrodon. Image from the article:

“a predatory synapsid genus that flourished during the Permian period, living between 280–265 million years ago (during the Artinskian to Capitanian stages).

As a synapsid it was more closely related to mammals than to true reptiles such as lizards and snakes. It is classified as a pelycosaur. Fossils of Dimetrodon have been found in North America and Europe. Dimetrodon had a sail on its back, which is known to have been used for regulating body temperature. [...]

Dimetrodon has two types of teeth, shearing teeth and sharp canine teeth. Its name, in fact, means “two-measures of teeth”. Dimetrodon was one of the first animals with differentiated teeth and the teeth were suitable for killing animals then tearing them to pieces. [...]

The spines of Dimetrodon have grooves on the base that were presumably ingested by blood vessels and thus ensured good bloodflow through the skin of the sail. The theory is that Dimetrodon was active in the early morning when the sun rose. The sail would be pointed towards the sun and would absorb heat allowing rapid warming. This allowed Dimetrodon to hunt at a time when other animals were not sufficiently warmed up and were slow. The sail increased body surface area by 50%. According to calculations by Bramwell Fellgett, it took a 200 kg (440 lb) Dimetrodon approximately one and a half hours for its body temperature to go from 26 to 32 °C (79 to 90 °F) [13] A study by Haack concluded that warming was slower than previously thought and that the process probably took four hours.[14] In order to cool its body in the hot midday sun, Dimetrodon turned its sail away from the sun, causing the heat to drain. The rapid warming using the sail give Dimetrodon an edge over larger animals, weighing over 55 kg. Smaller animals had higher body surface-to-mass ratio, making them hotter than Dimetrodon. The prey of Dimetrodon would therefore have been mostly large animals like Diadectes, Eryops and Ophiacodon. The changing climate during the Permian period, when the temperature increased, is a possible reason for the extinction of Dimetrodon since the sail meant no benefit over other animals and was rather a disadvantage due to its fragility.”

Even though in most Western cultures there seem to be quite a bit of focus on dinosaurs and the Mesozoic and a lot less focus on what came before that, it’s worth remembering that there was a lot of stuff going on before life ever got to the dinosaurs.

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iii. A quote:

“My model of this situation is less sanguine than others here, though Yvain and Tetronian hinted at it: it’s identity politics. Humans very naturally associate themselves with many different groups, some of them arbitrarily defined, and often without any conscious thought. Religion, favorite sports teams, the street/neighborhood/city/state/country you live in, and many other things can be the focal point of these groups. The more you associate with one of these groups, the more its part of your identity – i.e. how you see yourself. If you associate with one of these groups particularly strongly, any action which appears to make a rival group look better will personally offend you and elicit a response.”

In general, on a related note I think that the likelihood that an argument will escalate (conflict level will increase) is increasing in n in most naturally occuring settings. When two people argue nobody else is watching – which means that there are nobody else there to impress/defend. The more people are watching, the more people will witness a status loss or a status gain resulting from the argument. Also, once several people are involved coalitions will start to form naturally and you’ll start to not only be defending yourself but also feel that you have a duty (due to implicit community norms ect.) to defend the tribe. Gender also matters; in my (admittedly limited) experience, a male with a female partner arguing with another male will argue ‘more strongly’ for X if the partner is present than if she is not (unless the female makes clear that she considers the argument irrelevant; if she does and the male picks up on that signal, he’ll be likely to ‘fold’ whether or not he ‘was winning’ (…which of course he was)). Also, males are probably likely to a) be more aggresive (conflict-prone) if there are women present, and b) be more -ll- if the gender ratio is skewed ‘against them’ (# males >> # females) and less likely to be -ll- if the gender ratio is skewed ‘in their favour’ (# males << # females).

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iv. Square/Cube Law. (see also wikipedia)

“When an object undergoes a proportional increase in size, its new volume is proportional to the cube of the multiplier and its new surface area is proportional to the square of the multiplier.

For example, if you double the size (measured by edge length) of a cube, its surface area is quadrupled, and its volume is increased by eight times.

The point of this law is that with living beings, muscle strength is (more or less) a function of surface area, but weight is a function of volume. And Newton’s famous Second Law (the “force = mass * acceleration” one) means that if you double a critter’s size, you end up with four times the muscle power moving eight times the mass, so instead of having the same relative agility as the original, the double-sized creature actually has only half.

This applies to flyers as well: Double the size, and you get four times the wingpower attempting to keep eight times the weight airborne, so the creature’s ability to fly has actually been cut by half.”

Part of why dung beetles can roll up to 50 times their own weight (/and why we can’t).

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v. “The ancient Greeks and Romans used torture for interrogation. Until the 2nd century AD, torture was used only on slaves (with a few exceptions). After this point it began to be extended to all members of the lower classes. A slave’s testimony was admissible only if extracted by torture, on the assumption that slaves could not be trusted to reveal the truth voluntarily.[12]” (wikipedia)

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vi. Swaziland

“Swaziland, officially the Kingdom of Swaziland (Umbuso weSwatini), and sometimes called Ngwane or Swatini, is a landlocked country in Southern Africa, bordered to the north, south and west by South Africa, and to the east by Mozambique. The nation, as well as its people, are named after the 19th century king Mswati II.

Swaziland is a small country, no more than 200 kilometres (120 mi) north to south and 130 kilometres (81 mi) east to west. [...]

Some 75% of the population are employed in subsistence farming, and 60% of the population live on less than the equivalent of US$1.25 per day. [...]

Swaziland’s economic growth and societal integrity is highly endangered by its disastrous HIV epidemic, to an extent where the United Nations Development Program has written that if it continues unabated, the “longer term existence of Swaziland as a country will be seriously threatened.”[5] The infection rate in the country is unprecedented and the highest in the world at 26.1% of adults[6] and over 50% of adults in their 20s.[5] [...]

…Swaziland has the highest HIV infection rate in the world [...] and also the lowest life expectancy at 32 years, which is 6 years lower than the next lowest average of Angola. From another perspective, the last available World Health Organization data in 2002 shows that 64% of all deaths in the country were caused by HIV/AIDS.[11] [...]

In 2004, Swaziland acknowledged for the first time that it suffered an AIDS crisis, with 38.8% of tested pregnant women infected with HIV [...] Life expectancy has fallen from 61 years in 2000 to 32 years in 2009.[15]“

The Human Past (ii)

Second post in the series about the book, the first is here. I’ll complete my treatment of chapter two in this post:

i. “A rich fossil record documenting the earliest hominins has now been discovered on the African continent, with perhaps a dozen hominin species identified as existing prior to 1.5 million years ago [...] The fossil finds were initially concentrated in South Africa, but in more recent years significant discoveries have extended to eastern Africa, and even further afield, in central Africa and the Sahara [...] New discoveries have also expanded the known time depth of the hominin lineage, to perhaps as much as 6 million years. [...]
Identification of early hominins that branched off since the last common ancestor of humans and African apes is usually based on one of two criteria: either (1) postcranial (referring to the skeleton below the skull) evidence of bipedality; or (2) derived dental characteristics that are shared with later hominins but not with apes. Prior to 4 million years ago, there is tantalizing evidence of this early stage of proto-human evolution in the discovery of pre-Australopithecus (“southern ape man”) fossils in East Africa and the Sahara.
The fossil finds from Chad, Sahelanthropus tchadensis, include a nearly complete cranium dating to between 7 and 6 million years ago, as well as fragments of lower jaws and some teeth. [...] Between 6 and 4 million years ago, new fossil forms that have been designated as early hominins (as they show a number of hominin features even while retaining ape-like characteristics), have been found in East Africa and the Middle Awash region of Ethiopia.”

ii. “The hominin fossil record becomes much better represented from around 4 million years ago, with the appearance of early australopithecines. A number of australopithecine species then appear over the ensuing 3 million years, with fossils attributed to the genus Homo appearing fairly late on the African scene, around 2 million years ago or slightly earlier.”

In the book the author of the chapter makes a distinction between ‘gracile australopithecines’ and ‘robust -ll-’. In fact it seems that there is some disagreement whether the two ‘types’ of australopithecines even belong to the same genus, but that a branching process took place in this timeframe (3-1.8 mya) is beyond doubt. Applying the gracile/robust framework, it seems likely that we, Homo Sapiens, are descendants of some form(/s) of the gracile australopithecines, whereas on the other hand the robust australopithecine branch went extinct about 1 million years ago. The early homo species didn’t really have ‘huge brains’ or anything like that, the brains were somewhat/significantly larger than that of the robust australopithecines but compared to our huge brains they are quite similar. Brain development was a gradual process and it is a very wrong way to think about the evolutionary process eventually leading to us, Homo Sapiens, as some sort of narrative about how much smarter species of apes outcompeted the ‘slow’ ones very fast and took over for a while, until some even smarter ones turned up and outcompeted the new dullards – or worse, like a process where a single species just got smarter and smarter over time. Many species of honinins lived simultaneously, and some of the species that eventually died out were around for a very long time – A. boisei were around for almost a million years, half of that time contemporaneously with the early homo species. Also, there were lots of different species around at the same time: “Between 2.5 and 1.5 million years [ago], a number of hominin species (perhaps eight) are found in Africa, including the “robust” large, cheek-toothed australopithecines, as well as more “gracile” forms, and Homo Habilis, H. rudolfensis and H. ergaster/erectus.” When it comes to brain size, robust australopithecines like A. boisei (2.3-1.4 mya) and A. robustus (1.8 to perhaps 1 mya) had cranial capacities of 500-550 cc, whereas “the cranial capacity of homo habilis [an early homo species] ranges between 510 and 687 cc.” – to compare, “the average for modern humans is about 1350 cc and around 450 for chimpanzees and gorillas”. There was still a long way to go when the first Homo species showed up. The book sums some of all this up like this:

“To recapitulate: the earliest bipedal hominins [2.10] appear to emerge in the fossil record by 6 million years ago. During the Plio-Pleistocene, a major bifurcation in the hominin lineage led to the robust australopithecines as one evolutionary branch, or clade, and to the genus Homo as the other. In addition to bipedality, other hominin traits that emerged included longer legs, shorter arms, more dextrous hands with a longer thumb, reduced canines and incisors (and in early Homo, reduced molars and premolars), and brain expansion, again especially in early Homo. In the Homo lineage, body size tends to increase and sexual dimorphism appears to decrease through time.”

iii. Tools! When it comes to tools, we have found quite a bit more than just a broken axe-head and a couple of bones lying next to it a few places:

“The Zinjanthropus site (FLK Zinj) is one of the richest Oldowan sites ever excavated, containing well over 2000 stone artifacts and over 3500 fossil animal bone specimens, with over 1000 of the bones identifiable to taxon (unit of zoological classification, such as species, genus, or family) or body part; more than 90 percent of these belong to larger mammals.” And it’s not the only one of its kind: “At one site FJ-1 [Fejej, Ethiopia], almost 2000 artifacts have been excavated from two major layers”. The Nyabusosi (Site NY 18) site in Uganda, “dated to 1.5 million years ago, contains an assemblage of approximately 600 artifacts”. Excavations at Senga 5A in DR Congo “have yielded hundreds of artifacts, along with many fossil animal bones.”

More generally,

“The earliest archaeological sites found have been assigned to the Oldowan Industry, a term coined by Louis Leakey (1903-1972) and Mary Leakey (1913-1996), based on their work at Olduvai Gorge in Tanzania [...] The Oldowan is characterized by simple core forms (the parent piece of rock from which flakes are detached), created from river-worn cobbles and angular blocks of stone; the sharp-edged, angular flakes and fragments detached from such cores (debitage); often battered hammerstones; and occasional retouched pieces (usually flakes, the edges of which were further modified by striking off tiny chips to reshape or sharpen the edge) [...] Most archaeologists now group the Oldowan and Developed Oldowan into the “Oldowan industrial complex” (Isaac 1976)” – yeah, you got that right, ‘industrial complex’. These were toolmaking complexes.

So who made the tools? This is still a bit uncertain, but at the moment Australopithecus garhi is high on the list when it comes to the early Oldowan tools. The estimated cranial capacity of A. garhi is just 450 cc, i.e. comparable to gorillas and chimpanzees. “Many paleoanthropologists consider this species to be a probable maker of early Oldowan tools and a potential ancestor for the genus Homo.”

Tomorrow a new country will be born

The southern part of Sudan will obtain independence.

They have a long road ahead of them:

“I visited South Sudan with Unicef earlier this year, and it would be difficult to imagine a country more in need of intensive care. As hundreds of thousands of displaced people flood across the border, wanting to get back to the south before separation, there is nowhere for them to go and no services to support them. Families set up makeshift homes under a tree, with only the branches for shelter.

International agencies like Unicef are working hard to sink boreholes, train teachers, build hospitals, improve immunisation rates, but they are starting from next to nothing: South Sudan has one of the highest infant-mortality rates and lowest education indicators in the world. There is only one children’s hospital in the country, one child in 10 dies before their first birthday, and fewer than 1% of girls finish their primary education.

To make matters so much worse, the insidious Lord’s Resistance Army (LRA), which has been pushed north out of Uganda, regularly carries out raids on South Sudan villages, killing adults and kidnapping children who are then forced to join the marauders or become their slaves, often being made to murder their own family or friends so that escape and return to their villages becomes impossible. The brave South Sudanese have formed themselves into groups of “arrow boys” to defend their villages using homemade bows and arrows, but they have limited effect against the guns and horses of the LRA.” …

Witchcraft in the 21st century

“By some estimates, about 40 percent of the cases in the Central African court system are witchcraft prosecutions. (Drug offenses in the U.S., by contrast, account for just 12 percent of arrests.) In Mbaiki — where Pygmies, who are known for bewitching each other, make up about a tenth of the population — witchcraft prosecutions exceed 50 percent of the case load, meaning that most alleged criminals there are suspected of doing things that Westerners generally regard as impossible.”

[...]

““The problem is that in a witchcraft case, there is usually no evidence,” said Bartolomé Goroth, a lawyer in Bangui, who recently defended (unsuccessfully) a coven of Pygmies who had been accused of murder-by-witchcraft in Mbaiki. Goroth said the trials generally ended with an admission of guilt by an accused witch in exchange for a modest sentence. I asked how one determined guilt in cases where the alleged witches denied the charges. “The judge will look at them and see if they act like witches,” Goroth said, specifying that “acting like a witch” entailed behaving “strangely” or “nervously” in court. His principal advice to clients, he said, was to act normally and refrain from casting any spells in the courtroom.”

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Here’s the link, via MR.

(more) Bad news from Africa

There were an estimated 2.7 million new infections worldwide in 2008; 1.9 million of them were in Sub-Saharan Africa. The number of people added to treatment each year is also increasing rapidly, but not rapidly enough to keep up with new infections. Worldwide in 2008, 1.1 million people were added to treatment; 825,000 of them in Sub-Saharan Africa.

That is, more than 1 million newly diagnosed untreated were added to the pool of HIV/AIDS-infected people living in Sub-Saharan Africa in 2008. If we ignore the growth rates and just look at the levels, less than half of all the people infected are on antiretroviral drugs:

only 44% of people in need of ARV treatment in Sub-Saharan Africa were actually receiving it

Aid Watch. There’s a lot more at the link, if you follow the links in that post. Here’s one of the main links, a big and depressing report on the problem.

How to write about Africa…

This article is way too good not to quote in some detail:

“Never have a picture of a well-adjusted African on the cover of your book, or in it, unless that African has won the Nobel Prize. An AK-47, prominent ribs, naked breasts: use these. If you must include an African, make sure you get one in Masai or Zulu or Dogon dress.

In your text, treat Africa as if it were one country. It is hot and dusty with rolling grasslands and huge herds of animals and tall, thin people who are starving. Or it is hot and steamy with very short people who eat primates. Don’t get bogged down with precise descriptions. Africa is big: fifty-four countries, 900 million people who are too busy starving and dying and warring and emigrating to read your book. The continent is full of deserts, jungles, highlands, savannahs and many other things, but your reader doesn’t care about all that, so keep your descriptions romantic and evocative and unparticular.”

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“Among your characters you must always include The Starving African, who wanders the refugee camp nearly naked, and waits for the benevolence of the West. Her children have flies on their eyelids and pot bellies, and her breasts are flat and empty. She must look utterly helpless. She can have no past, no history; such diversions ruin the dramatic moment. Moans are good. She must never say anything about herself in the dialogue except to speak of her (unspeakable) suffering. Also be sure to include a warm and motherly woman who has a rolling laugh and who is concerned for your well-being. Just call her Mama.”

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“Broad brushstrokes throughout are good. Avoid having the African characters laugh, or struggle to educate their kids, or just make do in mundane circumstances. Have them illuminate something about Europe or America in Africa. African characters should be colourful, exotic, larger than life—but empty inside, with no dialogue, no conflicts or resolutions in their stories, no depth or quirks to confuse the cause.

Describe, in detail, naked breasts (young, old, conservative, recently raped, big, small) or mutilated genitals, or enhanced genitals. Or any kind of genitals. And dead bodies. Or, better, naked dead bodies. And especially rotting naked dead bodies. Remember, any work you submit in which people look filthy and miserable will be referred to as the ‘real Africa’, and you want that on your dust jacket. Do not feel queasy about this: you are trying to help them to get aid from the West. The biggest taboo in writing about Africa is to describe or show dead or suffering white people.”

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The link has more. Via Kids Prefer Cheese.

Urban obesity in Africa

Descriptive results showed that the prevalence of urban overweight/obesity increased by nearly 35% during the period covered. The increase was higher among the poorest (+50%) than among the richest (+7%). Importantly, there was an increase of 45-50% among the non-educated and primary-educated women, compared to a drop of 10% among women with secondary education or higher.

The study covers results from the period 1992 to 2005, so it’s not a new development but something that has been going on for a while. These are results from the US, you say? In that case, you’d be wrong; they are from Kenya, Niger, Malawi ect. I was very surprised to learn this, but apparently the urban (poor) population of Africa is getting fatter too.

Of course the link is to Razib Khan’s great blog on scienceblogs.

Why culture matters…

Jewkes and her colleagues interviewed a representative sample of 1,738 men in South Africa’s Eastern Cape and KwaZulu-Natal provinces.

Of those surveyed, 28% said they had raped a woman or girl, and 3% said they had raped a man or boy. Almost half who said they had carried out a rape admitted they had done so more than once, with 73% saying they had carried out their first assault before the age of 20.

The study, which had British funding, also found that men who are physically violent towards women are twice as likely to be HIV-positive. They are also more likely to pay for sex and to not use condoms.

Any woman raped by a man over the age of 25 has a one in four chance of her attacker being HIV-positive.

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Here’s the link, via MR.

Stuff like this is also one of the reasons why I’m not an anarchist. I’m not inviting to a long discussion here, I’m just saying that things like these certainly do not in my mind disprove that Hobbes had a point.

Zimbabwe year on year inflation reaches 355.000%

YEAR on year inflation for the month of March surged to 355 000% from the February figure of 165 000% as prices rose on the back of increased money supply to finance the 2008 harmonised elections.

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the CSO [Central Statistical Office] projection, sources said, has placed inflation for May at over 1 200 000% if the trend continues.

The figures come at a time the RBZ has introduced higher denomination bearer cheques notes to counter the adverse effects of inflation.

The central bank introduced the $500 million bearer cheques for the public and the $5 billion, $25 billion, $50 billion agro-cheques for farmers. The new notes come hardly two weeks after the introduction of the $250 million bearer cheques.

Here’s the link, via Greg Mankiw who also links to this report from the Reserve Bank of Zimbabwe. An excerpt:

1.24: Our economy is and has been in trouble for over ten years and our extraordinary interventions by whatever name have helped to keep the wheels of this economy moving. [my emphasis]

1.25: Even though our efforts have been criticized and derided clearly for undisguised political reasons, we are proud that we had the courage to do something that made a positive difference when it would have been far too easy for us to appear reasonable by doing nothing and thereby make the situation worse.

Make the situation worse? How could things possibly get worse than they are now? How could any other course of action not have improved matters relative to the way they are now? No – don’t answer those questions. The last thing Mugabe needs right now is new ideas on how to make the lives of his countrymen even more miserable than they already are.