John Derbyshire has made the point that Republican women are generally better looking than their Democratic counterparts. I have yet to be impressed by the photos of Anne Coulter that he has offered in support of his argument.

But the other day, one of my apolitical coworkers happened to be near the city convention center when Bush stopped for a campaign visit. His one impression? How hot Republican women are.

My theory is that maybe the females on the Democrat side are hot too, but they just don’t know how to show it. A recent post by Palooka supports my argument: 1, 2, and 3.

Posted by Thrasymachus at 07:26 PM

The publication This is London screamed this hysterical headline today;

Doctor has cloned cells from dead baby

Gasp! Shock! (naive readers will ask “did he kill the baby?” “did he steal it’s corpse?”)

Then the first line read;

Controversial fertility specialist Panos Zavos today revealed plans to clone a dead baby.

What?!?!? he’s trying to clone a cute little baby

but then we learn;

One involved a child of a one-and-a-half who had died during surgery. For an undisclosed fee from the parents, Dr Zavos and his Kentucky team inserted genetic material from the child’s skin cells into a cow egg, where they continued to grow. The resulting embryos were then terminated.

Uh? What? he’s got the parents consent and he’s terminating the embryos? But you said he wanted to clone a cute widdle baby.

Then we get to this line at the end;
“This was not about created a pregnancy, we are using cow eggs to refine our techniques. This is pure experimentation.”

Ah crap, you just contradicted your opening line.

The hysterical attitude that inspired the reporting slant in this article reminds me of the attitude that early anatomy students had to endure as they studied their discipline, forcing them to running around in the middle of the night stealing corpses.

Finally, do you think China would have problems with a researcher “refining his technique” by using donated cells of dead persons?

Posted by scottm at 03:57 PM

It’s a basic assumption among GNXP posters that the study of human biodiversity is an important contributing factor to the study of humanity in general. At the same time, though, it’s important to keep in mind that human biodiversity isn’t the only factor involved in the construction of early 21st century societies.

Take South Africa, for instance. The topic of South Africa has been frequently debated on GNXP. The main thing to remember about modern South Africa is that it’s a fundamentally unequal society. Even a decade after South Africa’s formally ended the policies of apartheid, many observers–for instance, Bryan Rostron in The New Statesman–have observed that South Africa remains a society where wealth and status continue to correlate strongly with the country’s racial divisions:

In his book A History of Inequality in South Africa, the economist Sampie Terreblanche acknowledges the growth of a new “colour-blind” middle class, but argues that the country has simply shifted from race-based to class-based disparities.

South Africa’s population of 45 million, he suggests, can be divided into three socio-economic classes of about 15 million each. The first group, an affluent middle class, comprises four million whites (that is, all but roughly 500,000 of South Africa’s whites), along with 11 million blacks, Indians and mixed-race “coloureds”. The second group is a struggling working class, mostly black. The bottom 15 million is almost entirely black: an underclass in dire poverty, property-less, mostly uneducated and still “voiceless, pathetically powerless” in Terreblanche’s words.

According to the UN Development Program’s 1994 report, South Africa’s HDI was 0.650–for whites 0.878 and for blacks 0.462 (compared to 0.881 for American blacks and 0.986 for American whites). If white South Africa had been a separate country, it would have ranked 24th in the world in income per capita rankings, just below Italy and Spain and above Portugal in per capita income rankings (6500 US dollars at market exchange rates, 14920 US dollars at PPP). Black South Africa, in contrast would rank 123rd, below Botswana, Gabon, Swaziland, Lesotho, and Zimbabwe (670 US dollars at market exchange rates, 1710 US dollars at PPP).

The question that many at GNXP have asked is whether or not this remarkable division of South African society, strongly correlated with race, reflects innate differences between the different racial groups of South Africa. You can argue this, I suppose, if you wanted. I’d argue that history, though, is a much more potent explanatory force; indeed, history is so dominant a force that arguing in favour of lower or higher IQs for people of different races based on genetics is nonsensical.

Consider that South Africa compares in many ways to Russia, or even Brazil. These three countries both have middle-income economies marked by extreme inequality, while they have recently emerged to establish democratic regimes (with varying levels of success) and are currently coping with a wide array of social pathologies, including exceptionally high rates of violent crime, serious income inequality, and deteriorating health standards. All three countries are marked by very serious social divisions, by extreme inequalities of wealth and health and political power.

Take violence, for instance. South Africa has, unfortunately, one of the highest rates of violent crime in the world, ranking alongside (again) Russia and Brazil. Violence, though, has a long history in South Africa. Balicki’s study of the Netsilik Eskimo and Chagnon’s study of the Yanomamo, among many other anthropological studies, have demonstrated that not only are Iron Age cultures not natively peaceable, but that they are actually prone to exceptional levels of violence by the standards of early 21st century industrial and post-industrial societies, with pervasive assault and murder. In South Africa’s case, the 19th century was particularly traumatic thanks to the mfecane, which radically transformed society in the modern Zulu homeland of KwaZulu-Natal by establishing the ancestral state to the modern-day Zulu monarchy. It also devastated African societies throughout the interior of the modern-day Republic of South Africa at a cost of hundreds of thousands of dead, sent sizable contingents of refugees at least as far as Zimbabwe (the Ndebele). Unsurprisingly, this degree of devastation allowed Afrikaner migrants armed with superior weapons technologies to enter the affected areas and create the Boer republics of Transvaal and Orange Free State.

Of course, the South African state under apartheid was quite willing to use violence in order to maintain the racial hierarchies. It’s not many governments which manage to get their own agents listed in databases of serial killers like CrimeLibrary.com. (Wouter Basson, incidentally, was responsible for the murder through biological and chemical warfare of some two hundred prisoners.) Not everything was as spectacular as Basson’s crimes, although the broad scope of the apartheid regime’s destabilization campaigns–wars against the Lusophone Marxist states of Angola and Mozambique at the cost of hundreds of thousands of civilian dead, an ongoing campaign against the Namibians protesting their colonization, support of the Rhodesian dictatorship, terrorist campaigns waged against South African refugees in neighbouring countries–comes close in a different area.

The maintenance, at every level of society, of an intrusive police state which regulated what jobs people could perform, what people they could relate to socially, what ideologies they could profess, what places they could live–in short, which sought to determine for people their proper place in life–and felt entirely justified in using massive amounts of violence to make people obey, was quite an endeavour. That it also delegitimized the police as a legitimate force was another, secondary, consequence of note mainly now that the police is needed for non-repressive activities.

Differences essentially political have caused rapid divergences between closely related populations. In Weimar Germany, for instance, East Germany contained in Saxony and Berlin some of the most advanced industrial areas in Germany. In the 1930s, Estonian living standards were in advance of Finland’s, and Czechoslovakia had a more sophisticated industrial economy than Austria. Poland, with a relatively buoyant economy and a not-inconsiderable military, was certainly on the same level as Spain, and arguably not much behind Italy. And now? How things have changed, for the worse. If politics in the form of prolonged and destructive Soviet occupation hadn’t interfered, the economic gap between western and central Europe would be substantially smaller if it existed at all.

The grand scheme of apartheid made economic progress difficult to impossible for non-whites. These policies made it impossible for non-whites to enter modern society on equal terms. The 1913 Natives’ Land Act, for instance, marked the first stage in a general dispossession of non-white lands. Residential segregation laws made it impossible for non-whites to securely own residential property:

District 6, established circa 1867 on the fringes of downtown Cape Town, was a community of character and characters. Bars and brothels competed for space with two-story homes
and shops and theaters. Dance halls were packed on weekends, and the busy cobblestone streets were used as cricket grounds and soccer fields. A boisterous carnival snaked through the hilly streets to mark each new year.

By the 1950s, shortly before the removals began, “District 6 was an exuberant and vibrant place despite its deliberate neglect by the authorities,” notes a display at Cape Town’s District 6 museum. “It was a place of warmth and gaiety, struggle and sadness, of respectability and rascality, of despair and creativity. It hummed with a zest for life.”

The passage of the 1959 Promotion of Bantu Self-Government Act not only created hierarchies of local governments for Blacks and assigned them specific national territories, but it artificially froze distinctions between groups, dividing the Sotho and Nguni groups into subtribes which could supposedly be better managed and were more natural. The Group Areas Act made it impossible for non-whites to access white-dominated segments of the economy (or vice versa).

Is anyone surprised that living standards and economic output are so poor for those South Africans who aren’t white? The planners of grand apartheid could hardly have done a better job of wrecking the South Africa economy. Fortunately, things are changing.

What could have been? Well, the 1996 UN Human Development Report (drawing on 1993 data) gave South Africa a HDI ranking of 0.649, 100th place. Botswana scored 0.741, 71st place. Since then, the collapse in life expectancies caused by the HIV/AIDS epidemic has pushed HDI levels down for both countries, Botswana more than South Africa.

The Botswanan economic miracle is, admittedly, fragile, based on a single commodity, manifesting in a middle-income economy with sharp income inequality. Even so: If Botswana, with sparse human resources and a natural-resource bonanza of questionable value, was able in the space of a generation to match and exceed South African levels of human development, then what might a South Africa freed of apartheid have accomplished? Absent Communism, Czechoslovakia (or its components) would have remained in the top rank of European economies alongside Austria. Might not an apartheid-less South Africa have done a rather better job at catching up to the First World? In 1950, after all, South Africa was richer per capita than Portugal, Greece, Japan, and South Korea. Cutting out three-quarters and more of your population from any but the most menial segments of your economy is deadly.

Oh, there’s the HIV/AIDS epidemic. It’s worth noting that in the early 1990s, Thailand and South Africa were at roughly the same stages of the epidemic, driven in both countries by migrant labour and by heterosexual sex. Thailand had the benefit of abundant economic resources in the middle of a political structure which (particularly after 1992) was recognized as basically legitimate. South Africa did not. Had the transition from apartheid taken place a decade earlier, South Africa would at least have had the benefit of a legitimate government unconcerned with regime transition. Perhaps it might even have had the economic boom.

It comes down to Occam’s razor, in the end. Could human biodiversity explain South Africa’s difficult history? Perhaps. It’s much simpler, though, to recognize that, in fact, South Africa’s problems were produced by a racially-motivated pattern of systematic mismanagement that lasted for generations before its dissolution, not even having the courtesy to clean up its horrible messes for the post-apartheid regime.

Can human biodiversity explain the race-associated divergences in the South African economy? History–a simple legacy of consistent harsh neglect and oppression–does a much better job than the former. People shouldn’t turn to race to explain purely cultural phenomena.

Posted by randymac at 08:50 PM

Supermodel/Oxford PhD Olivia Judson

Godless Capitalist generously invited me to post something on GNXP, as my blog, Beautiful Atrocities is very similar, since I’m primarily concerned with soap operas, innuendo, Ann Wilson, low-rent pop culture, septicemic humor, & asthmatic prose. Here then is what I learned from the delightful Dr. Tatiana’s Sex Advice to All Creation, by Olivia Judson, the world’s most pneumatic Oxford Phd.

• Hyena scats are white because they’re mostly bone powder; unlike most carnivores, hyenas can digest bone.

• Lionesses have a clinical sex mania, requiring so much stimulation – hundreds of romps – to become fertile that, by some estimates, less that 1% of copulations produce litters. Why such inefficiency? If the males of a pride are defeated, the new males kill all the cubs, which stops lactation, which brings the females back into heat. It’s possible that the uber-virility required of males is a test to make sure they’re strong enough to defend the pride.

• Male redback spiders have a unique fetish for being cannibalized: a male will snatch rivals from the jaws of death and leap into the meat grinder, during which process he slips her his pedipalp, thus fertilizing more eggs than if he’d survived. This curious ritual does not seem to have caught on in evolutionary circles.

• Contrary to John Derbyshire, sex is not congruent with reproduction, but refers to any process by which individuals exchange genes. Bacteria reproduce by cloning, but have sex to swap genes. Viruses can’t reproduce, but still have sex & swap genes, which is why we need a new flu vaccine every year.

• A human male typically has enough sperm for 1½ ejaculations; a ram has enough for 95.

• Female sagebrush crickets drink the blood of their mates, who have evolved a pair of useless fleshy hindwings for this purpose. The female climbs on the male’s back & chews on them while copulating. But since females don’t like used goods, males have evolved a brutal countermeasure: when a female climbs onto a male cricket to check out his hot wings, an extra set of teeth on the male’s back stabs her in the belly & holds her fast, whether she wants it or not.

• Banana slugs are hermaphrodites whose gigantic phalluses sometimes get stuck during the deed. The organ is then gnawed off, & doesn’t grow back, making the slug a female. Foreplay for the European giant garden slug consists of sitting on a branch oozing mucus for an hour. Then they wrap themselves together and bungee jump, hanging by a mucus rope, unfurl their penises (from the side of their heads, who knew?), and dangle.

• Black vultures are not just faithful, they’re prudes, & won’t tolerate sex anywhere but the privacy of the nest. If a young randy tries to get laid at a roost, the others will flame him.

• Male scorpionflies are scavengers who present females with dead insects as a bribe. If they can’t find any, they’ll steal from a spider, which is dangerous to say the least. Fortunately they have a huge member with which they whack! the spider if caught. (If they’re such a loser that even spider-filching doesn’t work, they secrete a large gelatinous blob of saliva, which is better than nothing.)

• Spotted hyenas live in matriarchal packs led by a dominant female. Females have an enormous clitoris, capable of erection. The lips of the vagina are fused shut in a sort of pseudo-scrotum, so that urination, copulation, & birth occur via the clitoris. Thus 10% of females die in birth when the clitoris rips. How could this be an advantage?

Possible explanation: High exposure to androgens in the womb makes hyenas extremely aggressive (& in humans, gives females a huge clitoris). Hyenas are usually born in litters of 2, upon which one will immediately kill the other. Such siblicide is most common among pairs of females. The offspring of dominant females survive at twice the rate of their less aggressive peers, possibly offsetting the lethal cost of the phallic clitoris.

Posted by jeff at 06:53 PM

From National Geographic:

Michael Phelps stands 6 feet 4 inches (193 centimeters) and weighs 195 pounds (88.5 kilograms), with the broad shoulders and slim waist common to the elite swimmer. But consider his body measurements a little closer and it becomes clearer why Phelps is dominating these Olympic Games.

He has an extended trunk and relatively short legs, a distinct advantage in the water. The inseam of his pants is reportedly 32 inches (81 centimeters), shorter than that of Hicham El Guerrouj, the great Moroccan runner, who is 5 feet 9 inches (175 centimeters) but all legs. Phelps has double-jointed elbows, knees, and ankles, which allows him to bend himself like few swimmers can. His size-14 (European-size 48.5) feet are like giant fins. Add to that the extraordinary work rate of his lungs and heart and Phelps appears almost superhuman—a different species from the rest of us.

Of course, he also trains extraordinarily hard. But so do others. To be an Olympic champion, a person’s genes must first be preset for maximal athletic performance. After all, great athletes are born, then made better.

“The best athletes in the world are a result of good genes and optimal training,” said Phillip B. Sparling, who is a professor of applied physiology at the Georgia Institute of Technology in Atlanta. “A person who has great dedication, motivation, and excellent training will not rise to the world-class level unless he or she has inherited a supercharged physiological system for the sport.”

A refreshing change from the usual. See also this piece on Kenyan runners. More clips inside:

The speed of a sprinter is determined in large part by physiology. Muscle proteins, including key energy-producing enzymes, are dictated by genes, as is muscle-fiber composition. Great sprinters, like Maurice Greene and Marion Jones, have a high percentage of fast-twitch muscle fibers—fibers that contract quickly but tire quickly too.

A cyclist, in contrast, needs great lung capacity, for superior endurance, and strives for a high “VO2 max,” the maximum amount of oxygen the lungs can consume. Lance Armstrong, not surprisingly, has an amazingly high VO2 max.

Great cyclists generally have an extraordinary heart capacity. The average resting heart rate is 66 to 72 beats per minute (bpm). A well-trained endurance athlete has a resting heart rate of 40 bpm. Miguel Indurain, a five-time Tour de France winner and Olympic gold medalist in 1996, recorded a resting heart rate of 28 bpm. In the mountain stages of the Tour de France, Indurain could take his pulse rate up to 190 beats per minute and drop it back to 60 on the descent within half a minute.

To varying degree, these traits are all hereditary. As the renowned Swedish exercise physiologist Per-Olof Åstrand once said, “The most important thing an aspiring athlete can do is to choose the right parents.” …

The performance gap between men and women in sports is also due to genetics. Androgens—sex hormones such as testosterone—make males taller, heavier, and more muscular than females…

But genetics, particularlya person’s nerve system, also partly determines how well athletes can train and how successfully they can make adjustments and improve their technique…

All in all, a fascinating survey of human biodiversity – without any “racist” smears. It was particularly gratifying to see the mention of the nervous system, as usually the brain is exempted from consideration. But the first law of behavioral genetics says that all traits are heritable:

Such curiosities led Dr. Turkheimer to formulate with colleague I. I. Gottesman the “first law of behavioral genetics.” The law is: 1) All human behavioral traits are heritable. Dr. Turkheimer has since named two other laws. They are:

2) The effect of being raised in the same family is smaller than the effect of genes.
3) A substantial portion of the variation in complex human behavioral traits is not accounted for by the effects of genes or families.

Heritable is used in the technical sense, here. This includes motivation, conscientiousness, and work ethic. Psychometricians have measures for such variables, but I’m not very familiar with that literature (perhaps Beaujean can comment). See here, though.

Posted by godless at 01:40 PM

Interesting article in the new National Geographic about the state of “native” peoples in America (here’s a map which goes along with the article, giving info on native population around the U.S. plus percent of Indian owned businesses).

Here’s a quote that kinda summarizes the article:

If there is strength in numbers, then Indians are gaining might. The number of Americans who identify themselves as at least part Indian grew from a low of about 240,000 in 1900 to more than four million today (including the 2.5 million who claim American Indian or Alaska Native as their only race).

Showing that yes, we have reversed course in this country to a point where “Native” identity is something desirous. Or this from the person on the front of the article:

For Brad and many thousands of other Indians, Native identity is a growing source of strength that helps them cope with the mainstream America that flows all around them. Yet it can also be a source of turmoil. I speak from personal experience: Like many Native Americans today, my heritage is mixed. My mother was Abenaki, my father was Slovak, and it didn’t really dawn on me that I was Indian until I was in my teens. Even then, it took a long time for my own mother to accept that I was the first of my family in three generations to go “public,” to seek out relatives and elders who could teach me the stories and language my Abenaki grandfather never shared with me. For a while my mother referred to me as, “My son, the Indian,” until my younger sister Margaret asked, “But Mom, what does that make you and me?”

I know that many cynical people would see accepting Native identity as a way to get government benefits and privileges, but Natives in this country have a long history of actually being damaged by government “largesse” and many refuse. I see it more as a grasping, by these mixed persons, for something substantial in a society that is increasingly becoming homogenous which fears emphasizing any sort of Western Ethnic or Cultural values.

Just my thoughts.

Posted by scottm at 01:13 PM

The Boston Globe has an article titled Should medicine be colorblind? that addresses the “debate” over the heart medication that seems to be optimal in the case of African Americans. In a pefect world all medicines would be tailored for each individual, but we don’t live in a perfect world, anything that keeps people alive without killing other people is good by me. Wonder how many of the scholars who expressed worries about giving amunition to those who believe in the biological basis of race have very sick relatives of color?

Related: Abiola posts about Vitamin D Deficiency (he links to a piece in Slate, via Brad DeLong).

Posted by razib at 12:56 PM

Christian pollster George Barna has a new report up: Ethnic Groups Differ Substantially On Matters of Faith. Here are some the results:

	White	Black	Hispanic	Asian
Attended religious service in past week	41%	48%	38%	23%
Prayed to God in the past week	81%	91%	86%	46%
Bible is totally accurate (strongly agree)	36%	57%	40%	24%
Born again Christian	41%	47%	29%	12%
Atheist or agnostic	12%	5%	7%	20%
Aligned with a non-christian faith	11%	12%	10%	45%

The data sample isn’t the largest, but tends to agree with the key findings of The Religious Identification Survey. An interesting point is though, as George Barna himself has noted, there has been an upsurge of evangelical activity among Asian Amerians, it starts from such a low base that the impressive growth is not that astounding (similar to the Asian HIV “epidemic”).

Also, Barna reports that African Americans are rather strong Christians, and as everyone knows they are pretty solid Democratic voters. That makes interviews like this with white evangelical Christians illuminating. In answer to questions about John Kerry and his possible victory, Michael Evans offers the following responses:Number one, we’re in a horrendous battle between darkness and light. We began with a distraction of our moral principles We saw it through the 1960s and the 1970s. We saw it through abortion and prayer in school and all these other issues. We saw it in the White House through Clinton.If Kerry wins, we get Clinton all over again because Kerry has already brought in most of Clinton’s holdovers. We’ll get New Age liberals who will have the same Middle East policies that Clinton hadWe’ll get two Sauls in a row. King Saul was rejected by God. We’ll have gone from a Clinton Saul to a Kerry Saul.This is a battle between two books, two kingdoms and two spirits.

I don’t disagree with everything Michael Evans asserts, but his vehemence and demonization (in a close to literal fashion) of his political enemies quite clearly makes him a mirror image of Michael Moore & co. The transformation of religious beliefs into political positions is pretty disturbing, and rather antithetical to the perpetuation of an open and pluralistic society where defeat is accepted as only a temporary set-back in the democratic process. I’m not the only one, National Review Online has published several critical articles by Catholic author Carl Olson about evangelical eschatology. I have criticized this in the past because of the unseemliness of the establishment intellectual Right turning on evangelicals after using them for their ends for so many years, but I think the fact that NRO signed off on these articles indicates that portions of the elite Right (more Catholic and Jewish than grassroots conservatives) are getting nervous about the tiger they’ve been riding since the rise of the Christian Right.

Addenum: Mr. Evans is a somewhat extreme form of evangelical Christian, and if you read the interview you will understand why he is so focused on Middle East politics. But, many of his views could be found in a diluted fashion among my evangelical friends during my youth. Posted by razib at 08:36 PM

An anecdote from :

Learning that a cockerel could have sex dozens of times a day, Mrs. Coolidge said: “Please tell that to the president.” On being told, Mr. Coolidge asked, “Same hen every time?” “Oh, no, Mr. President. A different one each time.” The president continued: “Tell that to Mrs. Coolidge.”

We all know about these sort of truisms, and they are so banal that they can show up in Jay Leno’s monologue. In this vein, I was pointed by Abiola to this new paper, Genetic Evidence for Unequal Effective Population Sizes of Human Females and Males (be sure to check out Carl Zimmer’s excellent review). This isn’t unsuprising, last year another team published Reduced Y-Chromosome, but Not Mitochondrial DNA, Diversity in Human Populations from West New Guinea. About a month back I posted about Bobbie Low’s , which highlights affinal issues from the perspective of behavorial ecology and cross-cultural anthropology, that is, greater male variance in reproductive success seems almost universal. Genetic studies like the one above point toward the historical depth of this pattern, in other words it is not a reflection of current conditions. Human sexual dimorphism and comparative examination of human testicle sizes in the context of homonoids suggests a mild level of polygyny being normative for our species.

But one must also be cautious. When we think of polygyny we often conjure up images of harems ruled by potentates and guarded by enuchs. As Bobbie Low points out, many Western societies that are socially & legally monogamous tend to exhibit more male reproductive variance (skew) than female reproductive variance. Obviously, in a society where a small group of men monopolize sexual access to women through force of arms, the variance differential between the genders will be great and intuitively obvious, yet one may conjecture other scenarios that might result in the same gap.

Imagine a society characterized by endemic warfare where the mean age of death for males is 25. Many men will live past 30, but men will also die before the age of 20. The latter may never have an opportunity to father children. Additionally, high female mortality rates during childbirth might also mean the ancient men who make it past the age of 40 could be de facto serial monogamists (they have had several wives who have eventually died in child-birth). In contrast, imagine a society, such as some of the tribes of central Australia, which practices gerontocratic polygyny, where rather old males are “married” to the nubile females. In these circumstances, it has been attested that the official husbands often look the other way when their young wives have affairs with other men of the tribe. In this situation, you would see lower reproductive skew than one would expect from the official cultural practices.

As for the above study, I am curious as to possible long term differences between different populations because of reproductive skew and lower male effective population size. Low emphasizes the importance of a pathogenically constrained environment is favoring exogamous polygyny, while others have suggested that resource constraints might have imposed long-term monogamy upon certain populations. For example, would Northern Europeans and Inuit show less of a gap between male and female lineages? What about the Highland Ethiopians (who are generally monogamous) vs. the Sub-Saharan Africans in the lowlands around them?

Posted by razib at 01:13 PM

Earlier this year, I presented a post that offered the following data:

From the book , a survey of Jewish school children in Nazi Germany suggested that the following was the hair color breakdown:

10% blonde.
50% “mixed.”
40% black.

David B also forwarded me this data on Jews from 19th century London:

English Ashkenazim: Blue 11.1 Grey 30.1 Brown 58.8.
English Sephardim: Blue 21.3 Grey 11.9 Brown 66.8.

My own personal opinion is that these data points can be explained by admixture from the surrounding non-Jewish populations (and likely a non-trivial amount). Some, like researcher Michael Hammer, argue for a predominantly Middle Eastern origin for Ashkenazi Jews (see his paper), often on the basis of NRY data. Seeing as how the Bene Israel Jews of India display a prevalence of the Cohen Modal Haplotype and an Indian physical appearence, it seems that predominant Middle Eastern Y lineages and a high rate of mixture with non-Jews can coexist (through intermarriage with local women).

But what if the admixture level was low? What if Hammer & co. are vindicated by a large number of studies on neutral markers over the next 10 years? What could explain the relatively high frequency of blue eyes and blonde hair among Ashkenazi Jews (in comparison to their putative source population).

Perhaps the introgression of Sub-Saharan genes into Arab populations might have resulted in a decrease in the expression of these phenotypes from their earlier norms. On the other hand, Yemeni Jews, who have not been nearly as heavily impacted by this genetic flow are, to my knowledge, a rather swarthy population. Additionally, the Anatolian population has not been as deeply impacted by Sub-Saharan gene flow, but I am skeptical that the frequency of blue/grey eyes is as high as 10%.

OK, cutting to the chase, I wonder, could the shift in phenotype be the result of selection? Greg & Henry’s paper focused on IQ, but there has been a lot of work done recently on human color variation. One hypothesis holds that when homonids lost their body hair they became heavily pigmented (this Nick Wade article sketches out the interconnected theses). After “sweeps,” where selection operated upon the MC1R locus and forced any given allelic form to fixation, humans spread out of Africa, and the constraint (the negative impact of high levels of radiation on exposed skin) was “relaxed.” Not only did the level of radiation decrease (both latitude and greater cloud cover could be a factor), but the need for clothing in more frigid climes was likely an important factor.

Some have argued that sexual selection played an important role in the prominence of blondism in northern European (sexual selection could play a role if environmental selection was no longer a limiting constraint). Additionally, there is the old theory that light skin facilitates the synthesis of Vitamin D in regions characterized by low levels of sunlight (so, positive environmental selection).

Ashkenazi Jews were predominantly an urban people, and traditionally do not have “outdoors” reputations. One could posit that selective constraints against a expression of fair phenotypes might have been relaxed as Jews made a transition from being farmers in the Levant to merchants in North-Central Europe. Perhaps a “natural” human tendency to prefer fair skin, or, more precisely, for human males to prefer females fairer than the population mean, was given free reign in the context of an urbanized culture living in a region where sunlight was no longer an overabundant danger?

Ultimately, I do think admixture is the primary causative agent for the relative fairness of the Ashkenazi in comparison to Middle Eastern populations. My personal impression is that many Ashkenazi Jews also reflect Central European populations in traits of facial morphology. But, it is something to wonder about.

Addendum: One point people bring up is the relative darkness of Australian Aboriginals even though much of the continent is in the “temperate” zone. It could be fairness (or the genetic variants that result in it) is not in the “genetic” background of this population, but blondeness among Aboriginals of the deep desert seems to falsify this thesis, and one supposes that the original populations that exited northeast Africa were also rather small and lacking in genetic diversity.

But, Australia is mostly dry, and so rather sunny, in comparison to Europe. Only Victoria is really in a temperate maratime climate. And, to my knowledge, no group of Aboriginals wore very much clothing.

A more interesting case is that of Tasmanian Aboriginals. This group, now extinct in an un-admixed state, was very dark skinned, and had been isolated on Tasmania for about 10,000 years. Tasmania does have a cool maratime climate like much of Europe. My impression is that Tasmania aboriginals were not totally naked. For me, this is a strong argument against the idea that relaxed constraint on the MC1R locus always leads depigmentation because of sexual selection, possibly due to sensory bias or sexual dimoprhism and fecundity indicators (that is, lighter skinned women within a population are more fertile).

Posted by razib at 12:23 AM