Anthroplogy
razib | January 24, 2010Changes in human diet driven by cultural evolution seem to be at the root of many relatively recently emerged patterns of genetic variation. In particular, lactase persistence and varied production of amylase are two well known cases. Both of these new evolutionary genetic developments are responses to the shift toward carbohydrates over the last 10,000 years as mainstays of caloric intake. Rice and wheat serve as the foundations of much of human civilization. It is notable that both China and India are divided into rice and wheat (or millet) belts, so essential are modes of agriculture in…
razib | January 21, 2010Modern civilization has extremely deleterious consequences in regards to species richness, primarily through destruction of habitat. Because of these negative aspects of modernity hunter-gatherers have been idealized as a model of humanity at equilibrium with their ecology. 1491: New Revelations of the Americas Before Columbus lays out the revisionist, and to some extent now mainstream, argument that the American wilderness which European settlers encountered was actually an instance of "re-wilding" in the wake of native demographic collapse due to disease. But setting this case aside, what…
razib | January 21, 2010A western Eurasian male is found in 2000-year-old elite Xiongnu cemetery in Northeast Mongolia:
We analyzed mitochondrial DNA (mtDNA), Y-chromosome single nucleotide polymorphisms (Y-SNP), and autosomal short tandem repeats (STR) of three skeletons found in a 2,000-year-old Xiongnu elite cemetery in Duurlig Nars of Northeast Mongolia. This study is one of the first reports of the detailed genetic analysis of ancient human remains using the three types of genetic markers. The DNA analyses revealed that one subject was an ancient male skeleton with maternal U2e1 and paternal R1a1 haplogroups.…
razib | January 21, 2010Creation, the Charles Darwin biopic, is opening in a few large cities tomorrow.
razib | January 19, 2010At least that was my take home message from a new paper in PLoS One, Language Structure Is Partly Determined by Social Structure:
Background: Languages differ greatly both in their syntactic and morphological systems and in the social environments in which they exist. We challenge the view that language grammars are unrelated to social environments in which they are learned and used.
Methodology/Principal Findings: We conducted a statistical analysis of .2,000 languages using a combination of demographic sources and the World Atlas of Language Structures— a database of structural…
razib | January 19, 2010For the past few decades there has been a long standing debate as to the origins of modern Europeans. The two alternative hypotheses are:
* Europeans are descended from Middle Eastern farmers, who brought their Neolithic cultural toolkit less than 10,000 years ago.
* Europeans are descended from Paleolithic hunter-gatherers, who acculturated to the farming way of life through diffusion of ideas.
The two extreme positions are not really accepted in such stark forms by anyone. Rather, the debate is over the effect size of #1 vs. #2. Bryan Sykes, a geneticist at Oxford, has been arguing for the…
razib | January 13, 2010The changing height of Homo erectus:
Today, I think it's fair to say that the variation of stature in Homo erectus was more or less like the variation within living people. There are short and tall populations today, varied in ecology and latitude. The average stature of young men in the Netherlands today is 184 cm. Adult women in the Philippines average only 150 cm. So the best way to compare statures is to illustrate the range.
That being said, I don't think we know how stature has evolved over time. We do have some data points -- the Neandertals were shorter than Upper Paleolithic…
razib | January 10, 2010The New Republic has published a review of the book The Invention of the Jewish People. There is a genetic aspect to the story:
But in fact we can go far back in time, with the help of historical DNA studies, which have burgeoned in the last twenty years, and the most disgraceful pages in Sand's book are those in which he displays an ignorant disdain for the work that has been done in this field by serious investigators. Without the least apparent understanding of how historical genetics works or what it can tell us, he attacks some of its most distinguished practitioners, such as Batsheva…
razib | December 23, 2009I referenced a paper in PNAS yesterday, and I thought it might be good to actually point to it today. There's nothing that new in the paper. It confirms the finding that ~20% of the ancestry of African Americans is European, and, that African ancestry seems to be much more dominant when it comes to components of the genome presumably disproportionately contributed by females (2/3 of X chromosomes). In any case, the paper, Genome-wide patterns of population structure and admixture in West Africans and African Americans:
Quantifying patterns of population structure in Africans and African…
razib | December 21, 2009Spatial Organization of Hominin Activities at Gesher Benot Ya'aqov, Israel:
The spatial designation of discrete areas for different activities reflects formalized conceptualization of a living space. The results of spatial analyses of a Middle Pleistocene Acheulian archaeological horizon (about 750,000 years ago) at Gesher Benot Ya'aqov, Israel, indicate that hominins differentiated their activities (stone knapping, tool use, floral and faunal processing and consumption) across space. These were organized in two main areas, including multiple activities around a hearth. The diversity of human…
razib | December 17, 2009Megan McArdle has a post up where she follows up on her disgust with home owners who "walk away" from their mortgage obligations when they can continue to pay them. In California, and many other states, the bank can't come after you if you walk away, so if your home is "underwater" then it is often a "rational" decision.
Megan makes the point that our economic and social system does not rely purely on rational self-interest, but also on an accumulated capital of norms which lead to virtuous cycles. My family is from Bangladesh, and I have seen this first hand. Corruption & nepotism in…
razib | December 17, 2009Apropos of my skepticism of Census projections of 2050 demographic balances, there's a new paper out on Argentina which is relevant. Here's Wikipedia on Argentina's self-conception:
As with other areas of new settlement such as Canada, Australia and the United States, Argentina is considered a country of immigrants. Most Argentines are descended from colonial-era settlers and of the 19th and 20th century immigrants from Europe, and 86.4% of Argentina's population self-identify as European descent. An estimated 8% of the population is mestizo, and a further 4% of Argentines were of Arab or…
razib | December 15, 2009That's probably the big takeaway of a new paper on the genetics of Asians, a set which includes South Asians, but in the new research mostly focuses on the people of East Asia. In a global context this work is important. The backstory is that there are disagreements about the exact process of the "Out of Africa" migration. Most researchers would agree that the vast majority, perhaps all, of the distinctive genetic content of the human species derives from a migration from the African continent between 50 and 100 thousand years ago (closer to the former date than the latter likely). Note that…
razib | December 5, 2009About six months ago I had a post up on the Cape Coloureds of South Africa. As a reminder, the Cape Coloureds are a mixed-race population who are the plural majority in the southwestern Cape region of South Africa. Like the white Boers they are a mostly Afrikaans speaking population who are adherents of Reformed Christianity. After the collapse of white racial supremacy many white Afrikaners have argued that it is natural and logical to form a cultural alliance with the Cape Coloureds because of the affinity of language and faith (Afrikaans speaking Coloureds outnumber Afrikaans speaking…
razib | December 2, 2009For the past few months I've been following The Givewell Blog. Here's a recent post, Why are we always criticizing charities?:
Recently, we've criticized (in one way or another) many well-known, presumably well-intentioned charities (Smile Train, Acumen Fund, UNICEF, Kiva), which might lead to some to ask: should GiveWell focus on the bad (which may discourage donors from giving) as opposed to the good (which would encourage them to give more)? Why so much negativity and not more optimism?
The fact is, we are very optimistic about what a donor can accomplish with their charity. Donor's can…
razib | December 1, 2009We May Be Born With an Urge to Help:
What is the essence of human nature? Flawed, say many theologians. Vicious and addicted to warfare, wrote Hobbes. Selfish and in need of considerable improvement, think many parents.
But biologists are beginning to form a generally sunnier view of humankind. Their conclusions are derived in part from testing very young children, and partly from comparing human children with those of chimpanzees, hoping that the differences will point to what is distinctively human.
The somewhat surprising answer at which some biologists have arrived is that babies are…
razib | November 23, 2009
In medical news which won't be surprising to anyone, Ethnic Variation in Fat and Lean Body Mass and the Association with Insulin Resistance:
Objective: Our objective was to compare total body fat to lean mass ratio (F:LM) in Aboriginal, Chinese, European, and South Asian individuals with differences in insulin resistance.
...
Results: After adjustment for confounders and at a given body fat, South Asian men had less lean mass than Aboriginal [3.42 kg less; 95% confidence interval (CI) = 1.55-5.29], Chinese (3.01 kg less; 95% CI = 1.33-4.70), and European (3.57 kg less; 95% CI = 1.82-5.33)…
razib | November 23, 2009FuturePundit points me to a new paper on the Toba explosion, Environmental impact of the 73 ka Toba super-eruption in South Asia:
The cooling effects of historic volcanic eruptions on world climate are well known but the impacts of even bigger prehistoric eruptions are still shrouded in mystery. The eruption of Toba volcano in northern Sumatra some 73,000 years ago was the largest explosive eruption of the past two million years, with a Volcanic Explosivity Index of magnitude 8, but its impact on climate has been controversial. In order to resolve this issue, we have analysed pollen from a…
razib | November 23, 2009Cannibalism is a controversial topic. It is routine for particular societies to accuse "barbarians", enemies, or evil mythological figures, of cannibalism. When it comes to the archaeological record some skeptics have claimed that like "sacred objects" too often human remains found in peculiar circumstances are ascribed to human sacrifice or cannibalism. In Did Adam and Eve Have Navels? Martin Gardner lays out the skeptical case for why cannibalism is rare to non-existent, and rather something which emerges from the imaginations of ethnographers and archaeologists, or is rooted in…