More ancient DNA evidence of Indo-European mass migrations

Population genomics of Bronze Age Eurasia (figures; supplementary information):

The Bronze Age of Eurasia (around 3000–1000 BC) was a period of major cultural changes. However, there is debate about whether these changes resulted from the circulation of ideas or from human migrations, potentially also facilitating the spread of languages and certain phenotypic traits. We investigated this by using new, improved methods to sequence low-coverage genomes from 101 ancient humans from across Eurasia. We show that the Bronze Age was a highly dynamic period involving large-scale population migrations and replacements, responsible for shaping major parts of present-day demographic structure in both Europe and Asia. Our findings are consistent with the hypothesized spread of Indo-European languages during the Early Bronze Age. We also demonstrate that light skin pigmentation in Europeans was already present at high frequency in the Bronze Age, but not lactose tolerance, indicating a more recent onset of positive selection on lactose tolerance than previously thought.

Dienekes links to the raw data:

Investigation of Bronze Age in Eurasia by sequencing from 101 ancient human remains.

The Bronze Age (BA) of Eurasia (c. 3,000-1,000 years BC, 3-1 ka BC) was a period of major cultural changes. Earlier hunter-gathering and farming cultures in Europe and Asia were replaced by cultures associated with completely new perceptions and technologies inspired by early urban civilization. It remains debated if these cultural shifts simply represented the circulation of ideas or resulted from large-scale human migrations, potentially also facilitating the spread of Indo-European languages and certain phenotypic traits. To investigate this and the role of BA in the formation of Eurasian genetic structure, we used new methodological improvements to sequence low coverage genomes from 101 ancient humans (19 > 1X average depth) covering 3 ka BC to 600 AD from across Eurasia. We show that around 3 ka BC, Central and Northern Europe and Central Asia receive genetic input through people related to the Yamnaya Culture from the Pontic-Caspian Steppe, resulting in the formation of the Corded Ware Culture in Europe and the Afanasievo Culture in Central Asia. A thousand years later, genetic input from North-Central Europe into Central Asia gives rise to the Sintashta and Andronovo Cultures. During the late BA and Iron Age, the European-derived populations in Asia are gradually replaced by multi-ethnic cultures, of which some relate to contemporary Asian groups, while others share recent ancestry with Native Americans. Our findings are consistent with the hypothesised spread of Indo-European languages during early BA and reveal that major parts of the demographic structure of present-day Eurasian populations were shaped during this period. We also demonstrate that light skin pigmentation in Europeans was already present at high frequency during the BA, contrary to lactose tolerance, indicating a more recent onset of positive selection in the latter than previously believed.

DNA Deciphers Roots of Modern Europeans (NYT):

About 4,500 years ago, the final piece of Europe’s genetic puzzle fell into place. A new infusion of DNA arrived — one that is still very common in living Europeans, especially in central and northern Europe.

The closest match to this new DNA, both teams of scientists found, comes from skeletons found in Yamnaya graves in western Russia and Ukraine.

Archaeologists have long been fascinated by the Yamnaya, who left behind artifacts on the steppes of western Russia and Ukraine dating from 5,300 to 4,600 years ago. The Yamnaya used horses to manage huge herds of sheep, and followed their livestock across the steppes with wagons full of food and water.

It was an immensely successful way of life, allowing the Yamnaya to build huge funeral mounds for their dead, which they filled with jewelry, weapons and even entire chariots. [. . .]

The Copenhagen team’s study suggests that the Yamnaya didn’t just expand west into Europe, however. The scientists examined DNA from 4,700-year-old skeletons from a Siberian culture called the Afanasievo. It turns out that they inherited Yamnaya DNA, too.

Related: Massive migration from the steppe is a source for Indo-European languages in Europe; Penny starting to drop for academics

Individual identity signaling in humans

Interesting-looking poster title:

Michael Sheehan Morphological and population genomic evidence of selection for individual identity signaling in human faces

There's no abstract, but one area where I suspect selection of this sort may turn out to be relevant (at least more relevant than Peter Frost-style sexual selection) is in explaining European hair and eye color variation.

"Traits signaling identity should be highly variable, often display polymodal distributions, not be condition dependent (i.e., be cheap to produce and/or maintain), not be associated with fitness differences, exhibit independent assortment of component characters, and often occur as fixed phenotypes with a high degree of genetic determination."

"Is human facial distinctiveness an adaptive signal of individual identity? From a sociobiological perspective, humans seem to have the ‘perfect storm’ of selection pressures that might favor recognizability. We are extremely social, interacting repeatedly with large numbers of individuals, each with varying roles in our lives. We are extremely cooperative, and we make complex decisions about whether and how much to cooperate based on kinship, friendship and social reputation [39,78]."

Evidence both purifying selection and positive selection act on MC1R in S. Europe

Mol Biol Evol (2013) doi: 10.1093/molbev/mst158 First published online: September 17, 2013

Simultaneous purifying selection on the ancestral MC1R allele and positive selection on the melanoma-risk allele V60L in South Europeans

Martínez-Cadenas et al.

In humans, the geographical apportionment of the coding diversity of the pigmentary locus MC1R is, unusually, higher in Eurasians than in Africans. This atypical observation has been interpreted as the result of purifying selection due to functional constraint on MC1R in high UVB radiation environments. By analyzing 3,142 human MC1R alleles from different regions of Spain in the context of additional haplotypic information from the 1000 Genomes (1000G) Project data, we show that purifying selection is also strong in Southern Europe, but not so in Northern Europe. Furthermore, we show that purifying and positive selection act simultaneously on MC1R. Thus, at least in Spain, regions at opposite ends of the incident UV-B radiation distribution show significantly different frequencies for the melanoma-risk allele V60L (a mutation also associated to red hair and fair skin and even blonde hair), with higher frequency of V60L at those regions of lower incident UV-B radiation. Besides, using the 1000G South-European data, we show that the V60L haplogroup is also characterized by an EHH pattern indicative of positive selection. We, thus, provide evidence for an adaptive value of human skin depigmentation in Europe and illustrate how an adaptive process can simultaneously help maintain a disease-risk allele. In addition, our data support the hypothesis proposed by Jablonski and Chaplin (2010), which posits that habitation of middle latitudes involved the evolution of partially depigmented phenotypes that are still capable of suitable tanning.

More excerpts from Chris Stringer's "The Origin of Our Species"

I read this a few months ago, but never got around to posting anything on it.

On group selection:

However, more recently, biologists and anthropologists such as Paul Bingham and Samuel Bowles have returned to the issue by recruiting weaponry and genes to the cause of group selection. The argument goes that by joining together to use effective projectile weaponry, individual risks were reduced, and thus coalitions of warriors would have been advantageous for group defence and offence. Bingham proposed that this development would also have been important within societies by deterring free-riders who tried to reap the rewards of group membership without contributing their fair share of commitment to the associated costs or risks. However strong individually, they could soon be brought into line when faced with a coalition of spear-armed peers, who could act as general enforcers of within-group rules and solidarity. Bowles posited the idea that if Palaeolithic groups were relatively inbred and genetically distinct from each other, and warfare between groups was prevalent, then group selection via collaborative defence and attack could evolve and be maintained. Without warfare, a gene with a self-sacrificial cost of only 3 per cent would disappear in a few millennia, but with warfare, Bowles's model showed that even levels of self-sacrifice of up to 13 per cent could be sustained. He used archaeological data (although mainly post-Palaeolithic) to argue that lethal warfare was indeed widespread in prehistory, and that altruistic group-beneficial behaviours that damaged the survival chances of individuals but improved the group's chances of winning a conflict could emerge and even thrive by group selection. Moreover, the model could work whether the behaviour in question was genetically based or was a cultural trait such as a shared belief system. As mentioned above, Bowles's archaeological data do not come from the Palaeolithic, but there is one observation that does resonate with his views: the French archaeologist Nicolas Teyssandier has noted that the period of overlap of the last Neanderthals and first moderns in Europe was characterized by a profusion of different styles of stone points. This might reflect a sort of arms race to perfect the tips of spears, perhaps to hunt more efficiently, but equally, this could suggest heightened intergroup conflict.

On modern behavior:

In terms of innovation, we saw in chapter 1 that the apparently sudden florescence of the rich Upper Palaeolithic societies of Europe seduced many in the last century to consider that this period marked the real arrival of fully modern humans, even if areas like the Middle East or Africa had been rehearsal grounds for the revolution that was to be finally expressed in the caves of France. But as we have also seen, this Eurocentric viewpoint that the Cro-Magnons were the first "modern" people has been largely abandoned, although that is not to deny that something special did happen in the Upper Palaeolithic of Europe. If Africa was actually at the forefront of Palaeolithic innovations more than 40,000 years ago, why was that? As anthropologist Rob Foley has pointed out, the sheer size of Africa (one could easily fit China, India and Europe into its surface area), and its position straddling the tropics, certainly gave it advantages over any other area inhabited by early humans. The rapidity and repetition of climatic oscillations outside of Africa probably continually disrupted long-term adaptations by human populations in those regions. Thus Neanderthals in Europe and the descendants of Homo erectus in northern China were constantly faced with sudden range contractions and the extinction of large parts of their populations every time temperatures sank rapidly, as they often did. [. . .]

The complex climates of Africa may also explain why there seems to be no single centre of origin for the earliest signals of behavioural modernity. Perhaps North Africa (and the Middle East?) led the way 120,000 years ago, but as conditions deteriorated, populations there shrank back or even became extinct, as favoured environments rapidly vanished. Perhaps the torch of modernity was then kept alive further south at sites like Blombos and Klasies River Mouth, as conditions favoured that region for a while (give or take the interruption of events like the Toba eruption).Waves of population expansion and contraction could explain the brief but extensive florescence of the Still Bay culture with its rich symbolism, and the subsequent rise and fall of the Howieson's Poort with its innovative tiny hafted blades and engraved ostrich eggshells (recently described from Diepkloof rock shelter) more than 5,000 years later. And it is my guess (though we lack much data to support it) that East Africa became one of the next centres for behavioural evolution, about 60,000 years ago, as it was from there that modern humans (and their developing suite of modern behaviours) made their way out of Africa. [. . .]

The big picture is that we are predominantly of recent African origin, so is there a special reason for this? Overall, I think that the pre-eminence of Africa in the story of modern human origins was a question of its larger geographical and human population size, which gave greater opportunities for morphological and behavioural variations, and for innovations to develop and be conserved, rather than the result of a special evolutionary pathway. "Modernity" was not a package that had a unique African origin in one time, place and population, but was a composite whose elements appeared at different times and places, and were then gradually assembled to assume the form we recognize today.

On genetic evidence for archaic admixture:

Up to now, the big picture, from our autosomal, mitochondrial and Y-chromosome DNA, has generally lacked signs of introgression from other human species, although scientists such as John Relethford, Vinayak Eswaran, Henry Harpending and Alan Templeton have argued that indications were indeed there. Short branches in our gene trees, particularly in Y and mtDNA, have pointed to a simple, recent African origin, and simulations from mtDNA data of the level of possible Neanderthal and Cro-Magnon admixture had suggested that it was either zero or very close to zero. However, despite the fact that mtDNA and Y-DNA provide such clear genealogical signals, they constitute only about 1 per cent of our total DNA, and signs of hybridization were clearly lurking in the rest of our genome. [. . .]

A recent example of such work is the study by Jeffrey Wall and colleagues of 222 SNPs (see chapters 7 and 8) in the genes of people from West Africa (Yoruba), China and Europe. Many of the SNPs were tightly clustered, and so deviations from the expectation of them all sharing the same pattern of inheritance from a single recent African ancestral population should have shown up clearly. The majority met Out of Africa expectations, but analysis suggested that the populations did display unusual mutations in some genes, and these had different histories from each other, and when compared between the geographical samples. Wall argued that the most likely explanation was that there was not a single ancestral population for all the SNPs -- most fitted the bill, but some were apparently descended from ancestral groups that had been isolated from each other long enough to develop separate SNP mutational patterns, which had then been bequeathed in slightly different ways to the modern regional populations. Interestingly, although each showed a signal of some "archaic" (rather than recent African) genetic contribution, the strongest pattern was not in Europe (where the Neanderthals might have been the source), nor in China (where it might have come from Denisovans), but in West Africa -- a puzzling result. The work has been criticized because some of the anomalous genes might have developed via recent drift or strong selection, if the mutations were regionally advantageous, but enough have been found to convince sceptics like me that there probably was ancient admixture in Africa as well.

On Iwo Eleru:

West Africa, where the oldest known fossil, from the Iwo Eleru rock shelter in Nigeria, is thought to be less than 15,000 years old. This poorly preserved skeleton was excavated from basal sediments at Iwo Eleru in 1965 by archaeologist Thurstan Shaw and his team, and was associated with Later Stone Age tools. That latter fact alone would suggest a relatively young age, and a radiocarbon date on a piece of charcoal suggested an age of about 13,000 years. The skeleton, and particularly the skull and jaw, was studied in 1971 by Don Brothwell, my predecessor at the Natural History Museum, and he argued that while the specimen could be related to recent populations in West Africa, it actually looked rather different from them. I studied the skull for my Ph.D., with surprising results. I also found that it did not closely resemble recent African populations, but in its long and low shape it was actually closer to early moderns such as those from Skhul, and even to more primitive specimens such as Omo 2. This was decidedly odd for such a young skeleton, and so I recently collaborated in a new study of the specimen with archaeologist Philip Allsworth-Jones, dating expert Rainer Gruen and anthropologist Katerina Harvati. We first checked with Thurstan Shaw whether there were any hints that the skull could have been much older than previously suggested, and there were none. With the help of Nigerian archaeologist Philip Oyelaran, I obtained a fragment of bone from the skeleton and passed it to Gruen in order to check its age directly. His determination from a direct uranium-series age estimate is that the bone is unlikely to be older than 20,000 years, consistent with the stratigraphy, and associated archaeology and radiocarbon date. Finally, could Brothwell and I have been wrong about the unusual shape of the skull? Harvati used state-of-the-art geometric morphometric scanning techniques on an exact replica of the skull (which is now in Nigeria), and found, as we did, that it was quite distinct from recent African crania, and indeed from any modern specimen in her comparative sample. Her results placed the skull closest to late archaic African fossils such as Ngaloba, Jebel Irhoud and Omo 2 -- all thought to be at least 140,000 years old. So what does this mean? Because of the poor preservation of Pleistocene bones in West Africa, we have no other data on the physical form of the inhabitants of the region during the whole of the Pleistocene, so we have to be careful in interpreting an isolated specimen such as Iwo Eleru. But it does not seem to be diseased or distorted, and does indeed seem to indicate that Africa contained archaic-looking people in some areas when, and even long after, the first modern-looking humans had appeared. Support for this view comes from the work of anthropologist Isabelle Crevecoeur. Her restudy of the numerous Ishango fossils from the Congo has shown that these Later Stone Age humans were not only similar to Iwo Eleru in age, but also in the surprisingly archaic features found in their skulls, jaws and skeletons. [. . .]

Africa today has the greatest internal genetic variation of any inhabited continent, and its skull shapes show the highest variation. This is usually attributed to its greater size, larger ancient populations and deepest timelines for humanity. But could those timelines go back even further than we thought? Did the early modern morphology evolve gradually, and then spread outwards from a region like East Africa, completely replacing archaic forms within Africa, and then outside (as mtDNA data would suggest)? Or, could there have been a version of assimilation or multiregional evolution within Africa, with modern genes, morphology and behaviour coalescing from partly isolated populations across the continent? Given its huge size, complex climates and patchworks of environments, Africa could have secreted distinct human populations just as easily as the rest of the inhabited world. So was the origin of modern humans there characterized by long periods of fission and fusion between populations, rather than representing a sudden single event? And was the replacement of the preceding late archaic peoples not absolute, so that they were partly absorbed by the evolving moderns rather than completely dying out? In which case, did early Homo sapiens forms, and even the preceding species, Homo heidelbergensis, survive alongside descendant modern humans?

Possible reason we don't have pigmentation genes from Neanderthals:

If the interbreeding actually happened earlier, in a warmer region or a warmer period, maybe the Neanderthals involved were not light-skinned and cold-adapted European examples? In fact, the interbreeding might even have happened when people like those from Skhul-Qafzeh and Tabun were in the Middle East 120,000 years ago. If a thousand of those early moderns mixed with just fifty Neanderthals and then survived somewhere in Arabia or North Africa, could they have subsequently interbred with the Out of Africa emigrants 60,000 years later, and passed on their hidden component of Neanderthal genes?

Y haplogroup R1b and light hair in Italy

Via Italian Wikipedia.

 

Update addressing some questions/comments:

(1) The map specifically shows the frequency of blond hair; so yes the frequency of light hair in general will be higher.

(2) The map is adapted from Biasutti's Razze e popoli della Terra. The data was originally collected by Ridolfo Livi in 1859-1863.

(3) The Biasutti/Livi map shows a higher frequency of blond hair in Corsica than in Sardinia. In keeping with the apparent pattern elsewhere in Italy, the frequency of R1b appears to be markedly higher in Corsicans than in Sardinians (in this paper, "HG 1" in combination with "HG 22" roughly corresponds to R1b).

(4) "Does R1b necessarily correlate with light hair?" In Italy it pretty clearly does. If you mean am I suggesting a strict correspondence between light hair and haplogroup R1b, obviously I am not. Looking at Europe as a whole, I doubt much of a correlation exists. But the evidence is consistent with the bearers of R1b (or more specifically subclades of R-L11) being lighter than the previous inhabitants of Italy. This doesn't mean the original carriers of R-M417 and some subclades of I weren't probably also lighter-haired, or that as R1b spread throughout Europe and mixing occurred, R1b always remained associated with light hair. It does tend to add yet more weight against attempts to link R1b in Europe to migration of Neolithic farmers from Anatolia, but dispensing with that question for good awaits large, high-resolution studies of ancient and modern DNA.

"haplogroup R1b is found in some of it's highest concentrations among European peoples in Spain and Portugal -- two countries hardly known for blondes."

Within Iberia, though, it's certainly possible the pattern will hold. Among Iberians, Basques have some of the highest frequencies of both R1b and blondism. According to Coon: 'The French Basques are by no means all brunet; Collignon finds 22 per cent of blue eyes, 44 per cent of "medium," and 34 per cent of dark. Black hair is found in 7 per cent of the group, brown in 77 per cent, and light brown to blond in 16 per cent. Among the Spanish Basques the incidence of blondism is somewhat lower, but the Basques are still light when compared to most other inhabitants of Spain.'

The beautiful woman in medieval Iberia: Rhetoric, cosmetics, and evolution

From a 2005 Ph.D. thesis by an Italian:

Literary portraits of the beautiful woman in medieval Iberia tend to emphasize several physical features, such as long, blond hair, or light-colored and hairless skin. This study examines the specific features of the beautiful woman in several major works and genres from medieval Iberia. It also traces the rhetorical sources of these portraits to the Classical and medieval Latin traditions, whose influence is evident in other early vernacular literatures of Europe. It then analyzes several medieval cosmetic treatises in Latin and in vernacular languages that attest to medieval women's beautifying practices, such as the use of hair-dyes, depilatories, and skin-whitening creams.

The comparison of the literary and cosmetic evidence shows a canonical view of feminine beauty that encompasses different cultural areas in medieval Iberia. This view is also consistent with ancient as well as with twenty-first century conceptions of beauty. The findings suggest that the ideal of feminine beauty in medieval Iberia is not unique, but rather a manifestation of near-universal male preferences shaped by sexual selection in the course of human evolution. [. . .]

Most cosmetic treatises devote considerable space to the maintenance of well-groomed, long, and healthy hair. They also include many recipes for hair-dyes (blond and black). In Spanish literature, blond hair appears to be more typical of learned poetry and appears to be associated with nobility: "rruvios, largos cabellos / segund doncellas d’estado" (Marqués de Santillana 11-12). In the cantigas it is not mentioned, and in the Andalusian and Arabic tradition hair is black, not without exceptions (see Chapter Three).

[Claudio Da Soller. The beautiful woman in medieval Iberia: Rhetoric, cosmetics, and evolution. University of Missouri - Columbia, 2005.]

Light-skinned black women rated more attractive

Shocking, perhaps, but here are interviewer ratings of black womens' attractiveness vs. skin color from wave 3 of Add health:

Variables:
Row H3IR1 S35Q1 PHYSICAL ATTRACTIVENESS OF R-W3
Column H3IR17 S35Q17 RESPONDENT SKIN COLOR-W3
Control BIO_SEX3 BIOLOGICAL SEX-W3
Filter H3OD4B(1) S1Q4B RACE-BLACK/AFRICAN AM-W3(=Marked)

Please make no unkind inferences concerning a possible relationship between degree of European admixture and attractiveness. The obvious conclusion is Kanazawa's critics were right: biased raters downgrade the beauty of African American women owing to their racism and brainwashed adherence to Eurocentric beauty standards. This insidious form of racism apparently extends to more literal sexual marketplaces:

Gwen and Alicia were especially coveted because of their skin color. In a rigid hierarchy that clinical psychologist Melissa Farley—founder of Prostitution Research & Education, a San Francisco–based think tank—calls “eroticized racism,” the “snow bunnies” (white girls) outclass the “ducks” (black girls). “Maybe one out of 50 callers would request a black or Latina,” says Caroline. “Most asked for ‘the girl next door’—a blonde, thin teenager with big breasts. That’s candy to ants.” [Sex Trafficking of Americans: The Girls Next Door]

I'll sheepishly admit I'm a longtime regular at strip clubs. I'll often get black strippers with slightly desperate looks on their faces sitting at my table trying really hard to be friendly to me hoping they can sell me a lap dance. Meanwhile the blonde strippers in the club don't even have to approach anyone; the male customers swarm the stage when they get up to dance. In a strip club it's kind of obvious who men find the most attractive. I admit this is not a scientific study, just my personal observation. [A comment at Mangan's]

Note: Kanazawa's methods may well be flawed. I personally wouldn't be comfortable drawing the conclusion he did based on the data he did. I actually expect racial differences (or similarities) in average rated physical attractiveness have little to do with actual sexual attraction/behavior. To the extent that ratings of physical attractiveness reflect subconscious judgments of youth, health, symmetry, and so on, we should be able to meaningfully rank attractiveness across races; but this does not make even an "attractive" black woman an ideal or preferred sexual partner for a normal white man. Sorry Severn (commenter at Mangan's who is flipping out about Kanazawa's "bad science" and who coincidentally says he has dated black women).

Blonde women earn more, have husbands who earn more

David W. Johnston. Physical Appearance and Wages: Do Blondes Have More Fun? (Economic Letters 108, s. 10-12):

Our data source is the 1979 cohort of the National Longitudinal Survey of Youth (NLSY79). [. . .] We limit our sample to Caucasian women aged 25 and over. [. . .] Regression results indicate that blonde women receive a wage premium equivalent in size to the return for an extra year of schooling. A significant blondeness effect is also evident in the marriage market. Blonde women are no more or less likely to be married; but, their spouse's wages are around 6% higher than the wages of other spouse's.

Masculinity, skin color, and male facial attractiveness

Does Masculinity Matter? The Contribution of Masculine Face Shape to Male Attractiveness in Humans (PLoS ONE):

The proposal [. . .] that masculine men are immunocompetent and attractive – underpins a large literature on facial masculinity preferences. Recently, theoretical models have suggested that current condition may be a better index of mate value than past immunocompetence. This is particularly likely in populations where pathogenic fluctuation is fast relative to host life history. As life history is slow in humans, there is reason to expect that, among humans, condition-dependent traits might contribute more to attractiveness than relatively stable traits such as masculinity. [. . .]

The relationship between masculinity and attractiveness was assessed in two samples of male faces. Most previous research has assessed masculinity either with subjective ratings or with simple anatomical measures. Here, we used geometric morphometric techniques to assess facial masculinity, generating a morphological masculinity measure based on a discriminant function that correctly classified >96% faces as male or female. When assessed using this measure, there was no relationship between morphological masculinity and rated attractiveness. In contrast, skin colour – a fluctuating, condition-dependent cue – was a significant predictor of attractiveness.

The authors point out problems with attempts to assess the affect of masculinity on facial attractiveness that rely on human ratings of perceived masculinity or digital manipulation of photographs: (1) for rated masculinity, "subjective judgments of masculinity are based on factors other than just morphological masculinity"; (2) with morphing techniques, factors potentially more important than masculinity in determining real world attractiveness are not allowed to vary, and a preference for averageness might result in participants systematically preferring more or less masculine morphs even if women are completely indifferent to masculinity. As for the effects of skin color, in this sample:

The regression retained only skin yellowness as a predictor of attractiveness, and the effect of skin yellowness was positive and highly significant (F(1,71) = 10.806, Beta = .366, t = 3.287, p<.002). Skin lightness, redness and morphological masculinity did not significantly predict attractiveness (all p>.114, see Table 1).

Other studies have also found increased skin lightness and redness associated with perceived health and attractiveness. The association of yellowness with attractiveness "may be attributable to dietary carotenoid deposition in the skin. This suggests that carotenoids, which are involved in health signaling (Massaro et al. 2003; Saks et al. 2003) and sexual selection (Eley 1991; MacDougall and Montgomerie 2003; Massaro et al. 2003) in many species of birds and fish, may also affect the appearance of health in humans."

ASHG 2010: Pigmentation genetics

Selected abstracts from the 2010 meeting of the American Society of Human Genetics.

Redhead day 2010

Wikipedia: "Redheadday is the name of a Dutch summer festival that takes place each first weekend of September in the city of Breda, in the Netherlands."

Facts about redheads: "Red hair is seen on the heads of only less than one percent of people.in the world. Most redheads live in the U.K., Ireland, and former colonies of U.K. like Australia.

The highest percentage of natural Redheads in the world is in Scotland (13%), followed closely by Ireland with 10%. In the US, about 2% of the population are natural redheads.

Redheads are becoming rarer and could be extinct in 100 years, according to genetic scientists."

(Photo credit. More photographs.)

Intelligence and pigmentation in Hirsch's sample

Additional results from Nathaniel Hirsch's 1926 study of children of immigrants -- this table further subdividing the sample by degree of hair and eye pigmentation.

In this section of the study, Hirsch is opposing some straw man version of Nordicism:

The Racialists maintain not only that the Nordics are long-headed, tall people with blue eyes and light hair, but more importantly it is claimed that they are mentally superior to all non-Nordic races.

And the results satisfy him:

that intellectual differences although (1) significant, (2) innate and (3) relatively permanent are Natio-Racial in character rather than Racial.

Which definitely shows "the Racialists". I did find the differences between pigmentation morphotypes within some national groups interesting (though I don't put undue weight on these results), considering light hair and light eyes have apparently been reported elsewhere as correlates of IQ. You can read the entire monograph (which includes more information on the tests used and answers to some criticisms) online at Harvard's open collection on immigration.

Reference: Hirsch, Nathaniel D. M. A study of natio-racial mental differences. Worcester, Mass. : Clark University, c1926.

"Mongoloidness" and pigmentation among Finno-Ugric peoples

Heapost, L. INDEX OF MONGOLOIDNESS AND PIGMENTATION IN K. MARK STUDIES. Papers on Anthropology; 2004, Vol. 13, p18-37.

The paper presents an overview of some descriptive anthropological traits of Finno-Ugrians and their neighbouring peoples (133 local ethnic groups, 13,000 individuals). To compare all the ethnic groups between themselves the index of Mongoloidness (MI) was calculated on the basis of eight traits and the index of pigmentation (PI) on the basis of two traits. The results were compared on a correlation field. Here, two tendencies expressing different directions could be discerned: 1) a grouping where the decrease in MI is accompanied by the increase in PI (most Baltic Finns and Erza Mordvinians, Terjuhans and Finnish Swedes); 2) a grouping, which includes most other Finno-Ugric peoples. Here a tendency can be noticed of both indexes increasing in the same direction. A compact grouping that deserves special attention here includes the ethnic groups with the highest values of MI and PI (most Mari, part of Udmurts, northern and Kola Sami, also one group of Chuvash and Tatars). The comparison of ethnic groups on the basis of these indexes provides a graphic overview of the morphological peculiarities of the peoples which are in one way or another connected with the historical developments of the peoples of different regions.

I'm not convinced "Mongoloid" features among western Uralic speakers actually derive from Mongoloid admixture. Certainly if there had been significant recent admixture we'd expect more "Mongoloid" morphology to be associated with darker pigmentation. More excerpts within:

Pigmentation variation in Finno-Ugric peoples

Leiu Heapost. PIGMENTATION VARIATION IN FINNO-UGRIC PEOPLES. Papers on Anthropology; 2008, Vol. 17, p80-102.

The paper presents a short overview of the variability of eye and hair colour of Finno-Ugric and their neighbouring peoples on the basis of Karin Mark's studies (22 ethnic groups, consisting of 133 local ethnic groups, a total of approximately 13,000 individuals). Eye and hair colour in Finno-Ugric peoples varies rather greatly. The percentage of blue and grey eyes (light, 0 points) ranges in different groups from 2 to 80, of mottled (1 point) from 16 to 63, and of brown eyes (dark, 2 points) from 0 to 42. Still, in most groups, light eyes are dominant; dark eyes are rarer. The average point for eye colour (M) varies from 0.24 to 1.39. Regional variability of hair colour in Finno-Ugric peoples is greater than that of eye colour, although the picture is similar. Fair hair (0-2 points or No 9-26 on the Fischer scale) occurs among 2-50%, brown hair (3 points or No 6-8) among 22-71% and black hair (4 points or No 4-5 and 27) among 7-76% of subjects. The average point varies from 2.42 to 3.73. In most Finno-Ugric peoples, red hair is rare, in some groups even non-existent. The percentage of red hair exceeds 1% in Finnish Swedes (average 1.4%), Bessermen (1.6%) and Komi-Permyaks (1.8%). Udmurts form an exception among the peoples studied with a particularly high percentage of red-haired persons (4%, var 1.0-7.3%).

Eye color and perceived dominance

This study ("Eye color predicts but does not directly influence perceived dominance in men") has gotten some attention, having been reported as if the result were universally applicable.

In fact, there's no evidence it applies outside the sampled population (students in Prague). What the researchers actually seem to have "discovered" is the existence of population structure in the Czech Republic that manifests in different frequencies of morphological types among lightly- and heavily-pigmented inhabitants.

The composite photographs from the paper show a somewhat foetalized, Slavic-looking "Alpine" blue-eyed morph and a "Dinaric" brown-eyed morph. Or as the authors put it:

In contrast with blue-eyed males, brown-eyed males have statistically broader and rather massive chins, broader (laterally prolonged) mouths, larger noses, and eyes that are closer together with larger eyebrows. In contrast, blue-eyed males show smaller and sharper chins, mouths that are laterally narrower, noses smaller, and a greater span between the eyes.

According to Coon, "Alpine" and "Dinaric" types differ in frequency between regions of what of what is now the Czech Republic:

While Alpines and Norics are commonest in Bohemia, there is a strong concentration of Dinarics in Moravia, especially among the miners, who seem to form a special group with both racial and occupational peculiarities.

To their credit, the authors advance "genetic linkage" as one potential explanation for their results (noting that this hypothesis could be tested by repeating the experiment in different populations), though this seems to be their least favorite of the three possible explanations they lay out. Unfortunately for them, it's also the most likely to be correct.

Why do men find blonde women so very attractive?

"Carole Jahme shines the cold light of evolutionary psychology on everyday life. This week: The allure of blonde women":

Caucasian blondes are usually slightly higher in oestrogen than brunettes and are likely to exhibit other infantile sexually selected traits (indicating low levels of testosterone) that are considered desirable by males, for example finer facial features, smaller nose, smaller jaw, pointed chin, narrow shoulders, smooth skin and less body hair, and infantile behaviour such as higher energy levels and playfulness. [. . .] Blond hair in males does not correlate with oestrogen levels as it does in females

"Police-style sketches" from forensic DNA?

Scientific American article containing little new information, aside from an update on what Mark Shriver is working on:

“The body interprets the DNA to determine the appearance of the face,” says anthropologist Mark Shriver of Morehouse College, who hopes to duplicate that ability within a decade. [. . .] Nevertheless, pinning down the effects of genes that influence body development is the key to predicting a specific individual’s looks. Shriver is studying populations in Europe and mixed-race groups elsewhere in the hope that correlating a Gallic nose or smiling Irish eyes with genes that influence their distinctive shapes may begin to crack the code the body uses to build a specific feature. He is even exposing inch-square patches of volunteers’ skin to ultraviolet light to gauge the range of skin shades and tones possible for people with various racial and ethnic backgrounds.

More loci influencing iris pigmentation discovered

Researchers "quantified continuous eye color variation into hue and saturation values using high-resolution digital full-eye photographs and conducted a genome-wide association study on 5,951 Dutch Europeans", revealing:

that human eye color varies along more dimensions than the one represented by the blue-green-brown categories studied previously. [. . .] We clearly identified 3 new loci, LYST, 17q25.3, TTC3/DSCR9, in contributing to the natural and subtle eye color variation along multiple dimensions

Specific SNPs identified (not all of these associations were replicated):

At the 1q42.3 locus two SNPs, rs3768056 and rs9782955, were associated with S [. . .] but not with H or categorical colors, which is a different phenomenon compared to the other two new loci identified. Three SNPs at 17q25.3 were associated with multiple color traits [rs7219915, rs9894429, and rs12452184] Five SNPs at 21q22.13 were significantly associated with CHS1 [rs1003719, rs2252893, rs2835621, rs2835630, and rs7277820]

Geographic distribution of an allele affecting skin pigmentation

Lucotte et al. A decreasing gradient of 374F allele frequencies in the skin pigmentation gene SLC45A2, from the north of West Europe to North Africa. Biochem Genet. 2010 Feb;48(1-2):26-33.

The 374F isofrequency values in West Europe and North Africa (Fig. 1) decrease regularly with latitude, from the north of West Europe to North Africa. Higher 374F frequency values were observed in Denmark, England, Belgium, the north of France, Germany, Switzerland, and the north of Italy; medium 374F frequency values were observed in the south of France, Portugal, Spain, Corsica, Italy, Sardinia, and Sicily. The lowest 374F frequency values were observed in the south of Spain and North Africa.

Stereotype of Swedish women as promiscuous

More fun with Swedish girls: Functions of a German heterostereotype. SM SCHRÖDER, M DALE Ethnologia Scandinavica 27, 122-137, Royal Gustav Adolf Academy, 1997.

While dealing specifically with the function of the stereotype as held by Germans of a particular era, this paper touches on some issues relevant to this thread. The PDF no longer seems to be available online, so I'm posting the text below (continue reading).