razib | October 2, 2007My ideas about skin color & diet aren't original. I am pretty sure that I originally read them in Great Human Diasporas by L.L. Cavalli-Sforza. Here's the extract:
In Europe the development of agriculture has lead to the spread of cereals as the primary foodstuff over the last ten thousand years. Unlike meat, particular fish liver, cereals contain no vitamin D. They do, however, contain a precursor taht becomes vitamin D if exposed to the ultraviolet light from the sun's rays absorbed through the skin. Cereal eaters can produce enough vitamin D to survive and grow normally if they are…
razib | October 1, 2007Archaeology: Sharp shift in diet at onset of Neolithic:
The introduction of domesticated plants and animals into Britain during the Neolithic cultural period between 5,200 and 4,500 years ago is viewed either as a rapid event or as a gradual process that lasted for more than a millennium. Here we measure stable carbon isotopes present in bone to investigate the dietary habits of Britons over the Neolithic period and the preceding 3,800 years (the Mesolithic period). We find that there was a rapid and complete change from a marine- to a terrestrial-based diet among both coastal and inland…
razib | October 1, 2007 It's that time of the year again! I'm getting involved in Donors Choose for the month of October, check out projects I'm trying to raise money for at the link.
There are other ScienceBloggers involved of course. Below the fold are further details from Janet:
This year, the challenge runs for the entire month of October. A number of ScienceBloggers have already put together challenges, but I suspect a few more may arrive fashionably late. Here's who's in so far:
A Blog Around the Clock (challenge here)
Adventures in Ethics and Science (challenge here)
Aetiology (challenge here)…
razib | October 1, 2007Vitamin D deficiency and skin color are two biological topics I've focused on a lot. The latter may have a relationship to the former insofar as light skin is better at synthesizing Vitamin D at low radiation levels (i.e., at high latitudes). Additionally, some of the genes that are under recent natural selection (within the last 10,000 years), such as OCA2 & SLC24A5, are related to pigmentation (specifically, the lightening of skin or eye color). At my other blog I've reproduced some ethnographic data which shows deviation from expectation of skin color in various populations assuming…
razib | September 30, 2007I don't know if we should believe Svante Pääbo anymore, but his lab has some new findings re: Neandertal mtDNA:
Neanderthals in central Asia and Siberia
Nature advance online publication 30 September 2007. doi:10.1038/nature06193
Authors: Johannes Krause, Ludovic Orlando, David Serre, Bence Viola, Kay Prüfer, Michael P. Richards, Jean-Jacques Hublin, Catherine Hänni, Anatoly P. Derevianko & Svante Pääbo
Morphological traits typical of Neanderthals began to appear in European hominids at least 400,000 years ago and about 150,000 years ago in western Asia. After their initial…
razib | September 30, 2007I have to say, this Ian Buruma op-ed, Religion as a force for good, read my mind in relation to the events of the past few days. Another rebellion civil society against an autocracy coalescing around the predominant religion of a society. What's surprising? The Iranian revolution against the Shah, the Christian led protests against the dictatorship of Syngman Rhee (himself a Christian) in South Korea, Buddhist protests against the persecution of the government of Ngo Dinh Diem in South Vietnam, the role of liberation theology across Latin America. The list goes on. Of course, religion…
razib | September 29, 2007
Pew has a new survey out, Public Expresses Mixed Views of Islam, Mormonism. The table to the left summarizes the most important points in the survey: Americans dislike Islam somewhat more than Mormonism, and they think Mormonism is a pretty weird religion (and on the whole, barely Christian). And of course atheists are the gold-standard in terms of being disliked. There are a few points which I think are important to keep in mind. First, many Americans have vague understandings of their own religion, asking them about Mormonism or Islam is pretty humorous. What you're gauging here are…
razib | September 28, 2007This post is more of a personal note...here are three papers that are really cool must reads:
Williamson SH, Hubisz MJ, Clark AG, Payseur BA, Bustamante CD, et al. (2007) Localizing Recent Adaptive Evolution in the Human Genome. PLoS Genet 3(6): e90 doi:10.1371/journal.pgen.0030090
Voight BF, Kudaravalli S, Wen X, Pritchard JK (2006) A Map of Recent Positive Selection in the Human Genome. PLoS Biol 4(3): e72 doi:10.1371/journal.pbio.0040072
Tang K, Thornton KR, Stoneking M (2007) A New Approach for Using Genome Scans to Detect Recent Positive Selection in the Human Genome. PLoS Biol 5(7):…
razib | September 28, 2007
OK, someone got his foot run over by a car, and had to have a few toes removed. He's fine, though he'll go crazy staying in....
razib | September 28, 2007Yesterday I put up a post where I attempted to use a visual analogy for what I believe might be evolutionary forces operative over short periods of time that result in phenotypic diversification across populations with recent common ancestry. But what about the flip side? In the case yesterday the basic genetic substratum, the preponderance of the genome, was not subject to powerful diversifying forces because only drift was presumably operating over short periods of time. It was on selectively salient slices of the genome where differences came into sharp focus quickly. But there is an…
razib | September 27, 2007In my post The new races of man I tried to offer a verbal exposition of my current thinking as to how and why human physical variation shows the patterns we see around us. In short, I believe that powerful selective forces have reshaped a subset of the human genome in similar and different ways across a range of populations over the past 10,000 years. Empirically, I would predict that the physical appearance we denote as stereotypically "Chinese" or "Swedish" or "West African" might be rather recent ecotypes, adapted to new circumstances, both environmental and cultural. The types we see…
razib | September 26, 2007Here are the rankings for this year according to Transparency International.
razib | September 26, 2007Regular readers know that I often check in on the results from The Barna Group, an evangelical Christian polling outfit. On the one hand I think The Barna Group tends to be a bit alarmist (they have a very narrow definition for a "Biblically based Christian," e.g., Catholics don't count), but on the other hand you can be sure that they aren't going to be pushing atheist wishful thinking. So I was really interested when I saw that a new study had come out, A New Generation Expresses its Skepticism and Frustration with Christianity. In short, the authors find that a growing number of young…
razib | September 24, 2007The New Republic has a piece titled The Greatest Dying by Jerry Coyne & Hopi E. Hoekstra (see below the fold for how to read it for free if you don't have a TNR subscription). The piece covers the a) general parameters of the mass extinction and b) the reasons why we should care. Coyne and Hoekstra immediately start out making the humanistic utilitarian case, i.e., "How does this help humanity be healthy, wealthy and secure?" But, they proceed to add near the end:
Our arguments so far have tacitly assumed that species are worth saving only in proportion to their economic value and…
razib | September 24, 2007The Boston Globe has a long piece titled DNA unraveled. With the subtitle like "A 'scientific revolution' is taking place, as researchers explore the genomic jungle" you know what to except, lots of adjectives and a healthy dollop of hyperbole. I guess I lean toward the side of the conservatives in the article, but ultimately it doesn't matter, nature always has the last laugh.
Update: Eye on DNA has a more thorough comment on this article and many others in the latest round up. Always worth checking out!
razib | September 22, 2007The Inducivist is always digging into the GSS and coming back with interesting stuff. For example, he reports:
Percent who believe astrology is very or sort of scientific
43.3% Extremely liberal
32.2% Liberal
31.4% Slightly liberal
25.9% Moderate
25.9% Slightly conservative
26.1% Conservative
25.0% Extremely conservative
What's going on here? I think what's showing up isn't really ideology, but the fact that political ideology has a strong correlation with adherence to theologically conservative Christianity. The Christian church has spent 2,000 years fighting magic, which it often…
razib | September 22, 2007Well, you may not have blue eyes, but many people do. The post below suggests that there is still a lot of confusion on how eye color is inherited, but now in 2007 we are coming close to clearing up many issues. A paper which came out early this year, A Three-Single-Nucleotide Polymorphism Haplotype in Intron 1 of OCA2 Explains Most Human Eye-Color Variation (Open Access), suggests that about 3/4 of the eye color variation in Europeans (from pale blue to dark brown) can be explained by polymorphism around the OCA2 gene. In other words, eye color comes close to being a monogenic Mendelian…
razib | September 21, 2007Do any readers know of work which tracks the correlation between characteristics such as blonde hair and blue eyes (within population where these are extant at high frequencies, but not fixed)? I am also interested in geographic distributions. In part I'm interested in exotic combinations, for example, look below the fold....