A little less brown and not necessarily blue-eyed

 

 

The skin color is about right. Not so sure about the eyes (source: Spanish National Research Council (CSIC)). There seems to have been a succession of changes to hair, eye, and skin color within a relatively restricted area of Europe. These changes then spread outward, the changes to eye color being apparently the earliest.

Ancient DNA has been retrieved from another Mesolithic hunter-gatherer, who is dated to 7,000 years ago and comes from La Braña-Arintero, Spain. We again see a strange combination of dark skin and light eyes. If we look at the three genes that produce white skin, only one of them, TYRP1, had the derived ‘European’ allele. The other two had the ancestral allele. So this Mesolithic individual was a bit lighter-skinned than the one from Luxembourg, dated to 8,000 BP, who had ancestral alleles at all three loci:

 

Of the ten variants, the Mesolithic genome carried the ancestral and non-selected allele as a homozygote in three regions: C12orf29 (a gene with unknown function), SLC45A2 (rs16891982) and SLC24A5 (rs1426654). The latter two variants are the two strongest known loci affecting light skin pigmentation in Europeans and their ancestral alleles and associated haplotypes are either absent or segregate at very low frequencies in extant Europeans (3% and 0% for SLC45A2 and SLC24A5, respectively). We subsequently examined all genes known to be associated with pigmentation in Europeans, and found ancestral alleles in MC1R, TYR and KITLG, and derived alleles in TYRP1, ASIP and IRF4. (Olalde et al., 2014)

Media reports describe the two Mesolithic individuals from Spain and Luxembourg as blue-eyed, although this is not what either study actually found. All we know is that their eyes were not brown. They had blue, gray, hazel, or green eyes:

 

[The individual had] the associated homozygous haplotype spanning the HERC2–OCA2 locus that is strongly associated with blue eye colour. Moreover, a prediction of eye colour based on genotypes at additional loci using HIrisPlex24 produced a 0.823 maximal and 0.672 minimal probability for being non-brown-eyed (Supplementary Information). The genotypic combination leading to a predicted phenotype of dark skin and non-brown eyes is unique and no longer present in contemporary European populations. Our results indicate that the adaptive spread of light skin pigmentation alleles was not complete in some European populations by the Mesolithic, and that the spread of alleles associated with light/blue eye colour may have preceded changes in skin pigmentation. (Olalde et al., 2014)

These findings seem to conflict with previous estimates of the time frame when European skin became white: 11,000 to 19,000 years ago according to Beleza et al. (2013) and 7,600 to 19,200 years ago according to Canfield et al. (2014). I would argue that this was indeed the time frame when European skin became white; however, white skin was initially confined to a geographic area that covered only part of Europe, essentially the plains of the north and east.

It also appears that the changes to hair, eye, and skin color did not happen simultaneously. First came the diversification of eye color and then the diversification of hair color. Parallel to these changes, and extending over a longer time, was the whitening of skin color. 

The most surprising—though least commented on—finding is that this Mesolithic hunter-gatherer had the ancestral allele for KITLG. According to Beleza et al. (2013), this gene was involved in the first stage of skin lightening that affected the common ancestors of Europeans and East Asians some 30,000 years ago. It looks like this first stage, like the second stage over 10,000 years later, affected Europeans only within part of Europe. The Mesolithic hunter-gatherers from Spain and Luxembourg thus seem to have belonged to a population that was peripheral to the evolution of white skin and multi-hued hair and eyes.

References

 

Beleza, S., Murias dos Santos, A., McEvoy, B., Alves, I., Martinho, C., Cameron, E., Shriver, M.D., Parra E.J., and Rocha, J. (2013). The timing of pigmentation lightening in Europeans. Molecular Biology and Evolution, 30, 24-35.

http://mbe.oxfordjournals.org/content/30/1/24.short 

Canfield, V.A., A. Berg, S. Peckins, S.M. Wentzel, K.C. Ang, S. Oppenheimer, and K.C. Cheng. (2014). Molecular phylogeography of a human autosomal skin color locus under natural selection, G3, 3, 2059-2067.
http://www.g3journal.org/content/3/11/2059.full 

Lazaridis, I., Patterson, N., Mittnik, A., Renaud, G., Mallick, S., et al. (2013). Ancient human genomes suggest three ancestral populations for present-day Europeans, BioRxiv, December 23.

http://biorxiv.org/content/early/2013/12/23/001552.full-text.pdf+html

Olalde, I., M.E. Allentoft, F. Sanchez-Quinto, G. Saintpere, C.W.K. Chiang, et al. (2014).  Derived immune and ancestral pigmentation alleles in a 7,000-year-old Mesolithic European, Nature, early view

http://www.nature.com/nature/journal/vaop/ncurrent/full/nature12960.html

SLC24A5: Reply to Greg Cochran

 

Ethiopian manuscript paintings (source: A. Davey). Ethiopians have a self-image that is lighter-skinned than their actual selves. If the prevalence of SLC24A5 is higher in Ethiopia than the degree of admixture from lighter-skinned peoples across the Red Sea, this discrepancy may be explained by social selection for lighter skin.

 

Greg Cochran has been asking why the “European” allele for SLC24A5 has been so successful, not only in Europe but also elsewhere. He seems to be hinting that this allele has a selective advantage that is unrelated to skin color.

I posted the following comments at his website. References have been inserted for this post.

 

***************************************************

SLC24A5 is one of three genes involved in the whitening of European skin, the other two being SLC45A2 and TYRP1. This whitening occurred over a relatively short time and long after the entry of modern humans into Europe some 40,000 years ago. Sandra Beleza’s team estimates that all three genes “went white” between 11,000 and 19,000 years ago (Beleza et al, 2013). Victor Canfield’s team, working only with SLC24A5, estimates between 7,600 and 19,200 years ago (Canfield et al., 2014).

So, yes, white European skin is not an adaptation to weaker sunlight; otherwise, it would have evolved much earlier. Are we looking at some pleiotropic effect then? In that case, this effect would involve not only SLC24A5 but the other two genes as well. Perhaps, but I’d like to see the evidence.

No, I’m not going to invoke sexual selection to explain the apparent success of the “European” allele for SLC24A5. Sexual selection, especially sexual selection of women, occurs under very limited circumstances.  I believe that there was an episode of very intense sexual selection of women, but this episode was confined to northern and eastern Europe during the time frame of 10,000 to 20,000 years ago, i.e., the last ice age (Frost, 2006; Frost, 2008).

How then do we explain the much greater geographic and historical success of this allele? The answer is part of the larger one of why lighter-skinned folks have done better than darker-skinned folks. Mean temperature is inversely correlated with technological complexity, even going back to the hunter-gatherer stage of cultural evolution. This is partly because colder environments created a greater need for heat conservation (by means of tailored clothing and insulated shelters) and partly because their food resources were more dispersed and typically available for short periods of time. There was thus strong selection in such environments for time budgeting, forward planning, and the ability to manage storage technologies (ice cellars) and untended facilities (traps, snares). Northern hunters were pre-adapted for technological complexity and thus better able to exploit the sort of complex cultural environments that developed much later in time (Hoffecker, 2002, pp. 6-12).

Is this the whole story? You point to Ethiopians as an example where SLC24A5 seems to be present at a higher frequency than Caucasian admixture. This discrepancy can probably be explained by social selection for lighter skin, as indicated by an Israeli study that found light-skin preference among Falasha children (Munitz et al., 1987).  This preference may be learned, although there is evidence that people are predisposed to associate lighter skin with certain good qualities (as a result of a mental algorithm that uses skin tone for identification of women and young infants) (Frost, 2011). For whatever reason, social selection for lighter skin is a reality in Ethiopia, and it probably has had some impact on the prevalence of SLC24A5.

 

Question from ‘RS’: Sexual selection, especially sexual selection of women, occurs under very limited circumstances. So you are equally attracted to all women?

 

Sexual selection is not the same thing as sexual preference. In other words, what you prefer is not necessarily what you will get. It all comes down to the law of supply and demand.

Sexual selection occurs when too many of one sex have to compete for too few of the other. Normally, the males have to compete for the females. The reverse is rare in nature. It happens when (1) males die much earlier than females do and (2) the costs of providing for a second mate are too high for almost all males. In human hunter-gatherers, the ratio of men to women on the mate market declines as one moves away from the equator. It reaches its lowest point in open steppe-tundra environments, where almost all food is obtained by men through hunting and where male mortality is high because men have to pursue mobile herds of game over long distances in a cold environment that offers few alternate sources of food.

Steppe-tundra covered most of northern and eastern Europe during the Late Pleniglacial (25,000 to 10,000 BP). I use the term “last ice age” in order to be better understood. There was a series of ice ages during the Pleniglacial (70,000 to 10,000 BP), but modern humans had to adapt only to the last one. To date, it looks like the most visible features of Europeans (white skin, multi-hued hair and eyes) evolved during the time window of the Late Pleniglacial. If the estimates by Beleza and Canfield are to be believed, the time window is somewhere between 20,000 and 10,000 BP.

These estimates seem to conflict with the recent findings of brown-skinned Mesolithic Europeans from Spain (7,000 BP) and Luxembourg (8,000 BP). I would argue that the changes to hair, eye, and skin color took place within a relatively restricted geographic area (essentially the plains of northern and eastern Europe) and later spread outward. It’s silly to argue that these changes must have originated in the Middle East, since the Middle East was inhabited by an African-like population until at least 12,000 BP. This population (the Natufians) shows no biological continuity with later Middle Easterners.

 

References

 

Beleza, S., Murias dos Santos, A., McEvoy, B., Alves, I., Martinho, C., Cameron, E., Shriver, M.D., Parra E.J., and Rocha, J. (2013). The timing of pigmentation lightening in Europeans. Molecular Biology and Evolution, 30, 24-35.

http://mbe.oxfordjournals.org/content/30/1/24.short 

Canfield, V.A., A. Berg, S. Peckins, S.M. Wentzel, K.C. Ang, S. Oppenheimer, and K.C. Cheng. (2014). Molecular phylogeography of a human autosomal skin color locus under natural selection, G3, 3, 2059-2067.

http://www.g3journal.org/content/3/11/2059.full 

Cochran, G. (2014). Shades of pale, January 27, West Hunter

http://westhunt.wordpress.com/2014/01/27/shades-of-pale/

Frost, P. (2011). Hue and luminosity of human skin: a visual cue for gender recognition and other mental tasks, Human Ethology Bulletin, 26(2), 25-34. http://media.anthro.univie.ac.at/ISHE/index.php/bulletin/bulletin-contents 

Frost, P. (2008). Sexual selection and human geographic variation, Special Issue: Proceedings of the 2nd Annual Meeting of the NorthEastern Evolutionary Psychology Society. Journal of Social, Evolutionary, and Cultural Psychology, 2(4), pp. 169-191.

http://www.jsecjournal.com/articles/volume2/issue4/NEEPSfrost.pdf

Frost, P. (2006). European hair and eye color - A case of frequency-dependent sexual selection? Evolution and Human Behavior, 27, 85-103.

Hoffecker, J.F. (2002). Desolate Landscapes. Ice-Age Settlement in Eastern Europe. New Brunswick: Rutgers University Press.

Munitz, S., B. Priel, and A. Henik. (1987). Color, skin color preferences and self color identification among Ethiopian and Israeli born children, in M. Ashkenazi and A. Weingrod (eds.), Ethiopian Jews and Israel. (pp. 74-84). New Brunswick (U.S.A.): Transaction Books.

The new European phenotype: expansion into the Middle East

Natufian sites (15,000 – 12,000 BP). These semi-sedentary hunter-gatherers are widely seen as precursors to the early civilizations of the Middle East. Yet biological continuity between the two seems doubtful. Physically, they looked more like present-day sub-Saharan Africans. (source: Phirosiberia)

 

Humans look “European” not only in Europe but also to varying degrees in North Africa, the Middle East, and South Asia. This phenotype was thought to have begun to differentiate from an older African phenotype not long after modern humans entered Europe some 40,000 years ago. The timing of this change now seems much later, however, probably during the last ice age between 20,000 and 10,000 years ago. The new phenotype was not an adaptive response to weaker sunlight. Rather, it seems to have resulted from a selection pressure that acted primarily on women. This is particularly so for the most visible features—white skin, the diverse palette of hair and eye colors, and the more childlike face. As I have argued elsewhere, the most likely cause is sexual selection—too many women competing for too few men—due to a low polygyny rate and a high death rate among men who had to hunt over long distances on the steppe-tundra (Frost, 2006; Frost, 2008).

If this new phenotype arose on the former steppe-tundra of northern and eastern Europe, why did it later spread to the rest of Europe, not to mention North Africa, the Middle East, and South Asia? The reason probably had less to do with physical appearance and more to do with the mental toolkit that humans had developed in this unique environment. These northern hunting peoples were pre-adapted to technological complexity and thus better able to exploit the opportunities of later cultural environments (see previous post).

As late as the early Holocene, the old phenotype persisted to varying degrees in the more peripheral parts of Europe. In the Middle East, it seems to have persisted as late as the Natufians (15,000 – 12,000 BP). On the basis of skeletal remains, Brace et al. (2006) found them to be more like present-day West Africans than present-day Middle Easterners:
 

Interestingly enough, however, the small Natufian sample falls between the Niger-Congo group and the other samples used. […] This placement suggests that there may have been a Sub-Saharan African element in the make-up of the Natufians. (Brace et al., 2006)

Angel (1972) similarly found that “one can identify Negroid (Ethiopic or Bushmanoid?) traits of nose and prognathism appearing in Natufian latest hunters […] and in Anatolian and Macedonian first farmers.”

Both descriptions are consistent with a much earlier one made when the Natufians were first discovered:
 

Skulls and thighbones of this race were unearthed within the last four years, first at Shukbah near Jerusalem and later in caves at Mount Carmel, and because they puzzled the excavators who found them they received the new name “Natufians.”

Today the first authoritative account of them was given by Sir Arthur Keith to the congress of Prehistoric and Protohistoric Sciences and showed them to be one of the greatest riddles of archaeology.

They were clearly a Negroid people, said Sir Arthur, with wide faces flat-noses and long large heads.

They were short of stature 5 feet 3 or 4 inches tall-and their thighs and legs were remarkably strong. While their arms and shoulders were weak. (New York Times, 1932)

This is not to say that the Natufians were of recent sub-Saharan origin, but rather that they still retained many of the physical characteristics of early modern humans. This older phenotype later gave way to the new European phenotype that was expanding both within Europe and outside.

This lack of biological continuity argues against the widespread belief that the Natufians were ancestral to the sedentary farmers who created proto-cities in the Middle East like Çatalhöyük (9500 – 7700 BP). Yes, the Natufians were semi-sedentary and harvested wild cereals. Some of them may have even made the transition to true farming. But they were nobody’s ancestors. The earliest civilizations did not result from slow cultural change going back to Natufian times. The change was faster-paced, with most of it taking less than two thousand years. This was not a case of immigrants moving in from the north and applying what they already knew to a strange environment. Instead, they created a whole new world from scratch … and very quickly.

There is a second point to consider as well. This demographic expansion into the Middle East must have occurred while the new European phenotype was still evolving on the steppe-tundra. In particular, it must have predated the diversification of hair and eye color and the whitening of the skin up to the physiological limit. Thus, the “full” European phenotype could not have arisen until the final two to three thousand years of the last ice age. 

 

References

Angel, J.L. (1972). Biological relations of Egyptian and eastern Mediterranean populations during Pre-dynastic and Dynastic times, Journal of Human Evolution, 1, 307-313.

Brace, C.L., N. Seguchi, C.B. Quintyn, S.C. Fox, A.R. Nelson, S.K. Manolis, and P. Qifeng. (2006). The questionable contribution of the Neolithic and the Bronze Age to European craniofacial form, Proceedings of the National Academy of Sciences U.S.A., 103, 242-247http://www.pnas.org/content/103/1/242.full

Frost, P. (2008). Sexual selection and human geographic variation, Special Issue: Proceedings of the 2nd Annual Meeting of the NorthEastern Evolutionary Psychology Society. Journal of Social, Evolutionary, and Cultural Psychology, 2(4), pp. 169-191.

http://www.jsecjournal.com/articles/volume2/issue4/NEEPSfrost.pdf

Frost, P. (2006). European hair and eye color - A case of frequency-dependent sexual selection? Evolution and Human Behavior, 27, 85-103.

New York Times (1932). Bones of cannibals: a Palestine riddle, August 4, 1932; p. 21

http://select.nytimes.com/gst/abstract.html?res=FA0917F63E5416738DDDAD0894D0405B828FF1D3

 

The first industrial revolution

 

Eyed sewing needles from Ice Age Europe (17,000 to 10,000 BP). (source: Didier Descouens)

As early modern humans spread farther north, they entered more challenging environments. This was particularly so when they left the boreal forests and entered the open steppe-tundra that covered much of northern Eurasia. Food was plentiful but largely took the form of meat—herds of reindeer and other herbivores. With few plant foods to gather, women took on other tasks: meat processing, shelter building, and garment making. Men also had to make the most of their hunting successes, since no other food was available during lean times.

Necessity is the mother of invention. Northern hunting peoples had to create a wider range of new and complex tools, as well as mental simulations of how their actions would play out in the future:

The technology of recent hunter-gatherers is also influenced by temperature and diet. Both the diversity of tool types and the complexity of individual tools and weapons […] increase as effective temperature and the percentage of plant foods in the diet decline […]. This apparently reflects the need for greater foraging efficiency in habitats where resources are available for limited periods of time. Recent hunter-gatherers in cold environments also tend to make increased use of storage technologies and untended facilities (e.g., traps and snares). The former represent another adaptive response to seasonal variations in resource availability, while the latter reflect an efficient approach (i.e., reduced mobility) to collecting unpredictable and widely dispersed resources […]. Finally, modern hunter-gatherers in northern environments produce relatively complex technology for heat conservation and cold protection (e.g., tailored fur clothing). (Hoffecker, 2002, p. 10).

On the frozen steppe-tundra, each base camp became a center of activity for production, processing, and storage. Deep storage pits were dug into the permafrost for meat refrigeration. Hand-powered rotary drills made their appearance. We find “traces of fired ceramic technology, including remains of kilns heated to as much as 800 degrees C.” There is also evidence of woven textiles, as well as eyed sewing needles and other fine instruments for the making of tailored clothing (Hoffecker, 2002, p. 161, 107).

Much of this activity was driven by the need to do a lot in a short time:

 

In such [non-tropical] areas, one or two seasonally abundant resources may be relied on to produce the critical storable surplus for the lean seasons. This would require short periods of intensive harvest and precise scheduling during those times of the year when these resources were available. In such ‘time-stressed environments’, time was at a premium and hunter-gatherer societies responded by developing time-saving devices: by budgeting their time and by preparing in advance more sophisticated, but also more complicated tools designed for the specific tasks involved. The development of capture facilities, such as pits, traps, weirs, and nets can be also seen as time-saving devices. Another technological requirement for effective exploitation of seasonal resources consists of storage. […] These technological developments, combined with the development of the microlithic industry, could be called, with some justification, the original industrial revolution. (Zvelebil, 2009, p. 170)

 

Did these new cognitive demands have an evolutionary impact? Did they select for certain mental capacities over others? Piffer (2013) has addressed these questions by seeing how hunter-gatherers differ from farming peoples in alleles at COMT, a gene linked to executive function, working memory, and intelligence:

Ethnic groups whose economy is based on farming have higher frequencies of the Met allele (symbol: A), whereas societies based on a hunter-gatherer economy have very low frequencies of the Met allele and a disproportionate predominance of the Val allele. Moreover, the frequency of the Met allele was positively correlated to the populations’ IQ (r = 0.57).

Northern hunting peoples, however, differ from other hunter-gatherers and resemble more advanced farming populations:

[…] hunter-gatherers living at high latitudes (Inuit) show high frequencies of the Met allele, possibly due to the higher pressure on technological skills and planning abilities posed by the adverse climatic conditions near the North Pole.

 

Conclusion

Modern humans arose in Africa, and founded the first civilizations in the Middle East. These two milestones are separated by the development of a new mental toolkit, i.e., an improved ability to imagine how resources can be used collectively not only in the present but also over long periods of time in the future. Surely, then, this mental toolkit must have arisen in the same geographic area. Wouldn’t that be the simplest answer? 

Sometimes the simplest answer is not the right one. Evolution can appear unnecessarily complicated at times, and this is a fine example. Although the new mental toolkit was initially an adaptation to harsh semi-Arctic conditions, it would later prove useful in warmer climes. We see this in an apparent series of demographic expansions out of the northern tier of Eurasia, beginning as early as 15,000 years ago, as indicated by the existence of the Eurasiatic language macrofamily and the more hypothetical Borean macrofamily. Today, most of the human gene pool has its origins in people who once roamed the northern wastes of Eurasia.

References 

Hoffecker, J.F. (2002). Desolate Landscapes. Ice-Age Settlement in Eastern Europe. New Brunswick: Rutgers University Press.

Piffer, D. (2013). Correlation of the COMT Val158Met polymorphism with latitude and a hunter-gather lifestyle suggests culture–gene coevolution and selective pressure on cognition genes due to climate, Anthropological Science, 121, 161-171.

https://lesacreduprintemps19.files.wordpress.com/2014/01/correlation-of-the-comt-val158met-polymorphism-with-latitude-and-a-hunter-gather-lifestyle-suggests-culturee28093gene-coevolution-and-selective-pressure-on-cognition-genes-due-to-climate.pdf

Zvelebil, M. (2009). Hunters in Transition: Mesolithic Societies of Temperate Eurasia and Their Transition to Farming, Cambridge University Press. 

The brown man with blue eyes

Venus of Willendorf (30,000 – 27,000 BP). Is that a special headdress … or peppercorn hair? (source: Matthias Kabel)

Europeans already had blue eyes while still hunter-gatherers. This is what we’ve learned after retrieving ancient DNA from two Mesolithic individuals, one from Luxembourg, dated to 8,000 years ago, and another from Spain, dated to 7,000 years ago (Dienekes, 2013; Lazaridis et al.,2013). These are late hunter-gatherers, so there is always the possibility of gene flow from early European farmers. Nonetheless, the time of origin now seems earlier for the palette of European eye colors and probably for the palette of European hair colors. How much earlier? Probably within the same time frame when European skin turned white: somewhere between 11,000 and 19,000 years ago according to Beleza et al. (2013) or between 7,600 and 19,200 years according to Canfield et al. (2014). Although different genes are responsible for eye, hair, and skin color, there was probably a single selection pressure that seems to have acted primarily on early European women (Frost, 2006; Frost, 2008).

Interestingly, although the Luxembourg man was blue-eyed, he also had brown skin. He lacked the ‘European’ alleles at all three genes involved in the whitening of European skin. Such a genotype is extremely rare today in unadmixed Europeans (Khan, 2014). Equally odd is the fact that this brown-skinned European lived long after (Beleza et al., 2013) or probably after (Canfield et al., 2014) the time period when European skin turned white. How could that be? Well, these estimates apply only to the ancestors of living Europeans. This individual may not have been so lucky.

When the last ice age ended some 10,000 years ago, it may be that only some European populations had acquired a fully ‘European’ phenotype, i.e., white skin, multi-hued eyes and hair, a more childlike face, and longer, straighter hair. This phenotype would have been most predominant on the former steppe-tundra of northern and eastern Europe. Moving outward from this region, one would have seen humans with more and more of the evolutionarily older traits, i.e., brown skin, uniformly brown eyes and black hair, a more robust face, and short, frizzy hair.

This older phenotype might have persisted well into the Holocene in peripheral and isolated parts of Europe.  As Fleure (1945) notes:

In a few places in Sweden, Britain, and France, people have been noticed who show characteristics of the skull and face that remind one of late-Paleolithic man: these people are usually darker, in hair and eyes, than their neighbors; sometimes they even have swarthy skins.

Even in Scandinavia, we find references in folklore and mythology to an ancient dark-skinned population. A Norse poem, the Rigsthula, describes how the god Rig created a class of thralls who were black-haired, swarthy, and flat-nosed (Jonassen, 1951). This theme comes up elsewhere in Old Norse literature (Karras, 1988).

This leads us to the debate over the discovery of so-called ‘Negroid’ skeletal remains in Europe. Clearly, these individuals were not African, but nor were they like present-day Europeans. They seem to represent an older phenotype that had already lost predominance by Holocene times. The skeletal evidence is reviewed by Boule and Vallois (1957, pp. pp. 291-292):

‘In Brittany, as well as in Switzerland and in the north of Italy, there lived in the Polished Stone period, in the Bronze Age and during the early Iron Age, a certain number of individuals who differed in certain characters from their contemporaries’, in particular in the dolichocephalic character of their skull, in possessing a prognathism that was sometimes extreme, and a large grooved nose. This is a matter of partial atavism which in certain cases, as in the Neolithic Breton skull from Conguel, may attain to complete atavism. Two Neolithic individuals from Chamblandes in Switzerland are Negroid not only as regards their skulls but also in the proportions of their limbs. Several Ligurian and Lombard tombs of the Metal Ages have also yielded evidences of a Negroid element.

Since the publication of Verneau’s memoir, discoveries of other Negroid skeletons in Neolithic levels in Illyria and the Balkans have been announced. The prehistoric statues, dating from the Copper Age, from Sultan Selo in Bulgaria are also thought to portray Negroids. In 1928 René Bailly found in one of the caverns of Moniat, near Dinant in Belgium, a human skeleton of whose age it is difficult to be certain, but which seems definitely prehistoric. It is remarkable for its Negroid characters, which give it a resemblance to the skeletons from both Grimaldi and Asselar.

It is not only in prehistoric times that the Grimaldi race seems to have made its influence felt. Verneau has been able to see, now in modern skulls and now in living subjects, in the Italian areas of Piedmont, Lombardy, Emilia, Tuscany, and the Rhone Valley, numerous characters of the old fossil race.

This older phenotype must have gradually disappeared as the newer phenotype spread outwards from the plains of northern and eastern Europe. Why did one replace the other? What sort of selective advantage did the newer phenotype confer? The reason probably had less to do with physical appearance and more to do with the mental toolkit that humans had developed on the steppe-tundra of the last ice age. These northern hunting peoples were pre-adapted to technological complexity and thus better able to exploit the opportunities of later cultural environments (Frost, 2010). Some of them, specifically the semi-sedentary hunter-fisher-gatherers around the North Sea and the Baltic, would become pre-adapted not only to technological complexity but also to social and economic complexity (Frost, 2013).

References 

Beleza, S., Murias dos Santos, A., McEvoy, B., Alves, I., Martinho, C., Cameron, E., Shriver, M.D., Parra E.J., and Rocha, J. (2013). The timing of pigmentation lightening in Europeans. Molecular Biology and Evolution, 30, 24-35.

http://mbe.oxfordjournals.org/content/30/1/24.short

Boule, M. and H.V. Vallois. (1957). Fossil Men. New York: Dryden Press. 

Canfield, V.A., A. Berg, S. Peckins, S.M. Wentzel, K.C. Ang, S. Oppenheimer, and K.C. Cheng. (2014). Molecular phylogeography of a human autosomal skin color locus under natural selection, G3, 3, 2059-2067.

http://www.g3journal.org/content/3/11/2059.full 

Dienekes (2013).  Mesolithic Iberians (La Braña-Arintero) not ancestors of modern ones,

Dienekes’ Anthropology Blog
http://dienekes.blogspot.ca/2013/12/europeans-neolithic-farmers-mesolithic.html

Fleure, H.J. (1945). The distribution of types of skin color, Geographical Review, 35, 580-595. 

Frost, P. (2013). Origins of Northwest European guilt culture. Part II, Evo and Proud, December 14

http://evoandproud.blogspot.ca/2013/12/origins-of-northwest-european-guilt.html

Frost, P. (2010). Out of North Eurasia, Evo and Proud, May 27

http://evoandproud.blogspot.ca/2010/05/out-of-north-eurasia.html 

Frost, P. (2008). Sexual selection and human geographic variation, Special Issue: Proceedings of the 2nd Annual Meeting of the NorthEastern Evolutionary Psychology Society. Journal of Social, Evolutionary, and Cultural Psychology, 2(4), pp. 169-191.

http://www.jsecjournal.com/articles/volume2/issue4/NEEPSfrost.pdf

Frost, P. (2006). European hair and eye color - A case of frequency-dependent sexual selection? Evolution and Human Behavior, 27, 85-103.

Jonassen, C.T. (1951). Some historical and theoretical bases of racism in northwestern Europe, Social Forces, 30, 155-161.

Karras, R.M. (1988). Slavery and Society in Medieval Scandinavia. New Haven. 

Khan, R. (2014). Phenotypic Whiteness as an Outcome of Neolithic Admixture, The Unz Review: An Alternative Media Selection, January 3.

http://www.unz.com/gnxp/phenotypic-whiteness-as-an-outcome-of-neolithic-admixture/ 

Lazaridis, I., Patterson, N., Mittnik, A., Renaud, G., Mallick, S., et al. (2013). Ancient human genomes suggest three ancestral populations for present-day Europeans, BioRxiv, December 23.

http://biorxiv.org/content/early/2013/12/23/001552.full-text.pdf+html 

Looking ahead to 2014

 

When did early Europeans acquire their palette of eye colors? And their palette of hair colors? That question may soon be answered with retrieval of ancient DNA. (source: Dipoar)

 

As the new year begins, I’m particularly interested in the following topics.

 

When did Europeans begin to look European?

It seems that this evolution took place between 20,000 and 10,000 years ago—long after modern humans had arrived in Europe some 40,000 years ago. This is when Europeans acquired their most visible features: white skin, multi-hued eyes and hair, and a more childlike face shape. In my opinion, such features were an adaptation not to weak sunlight but to a competitive mate market where men were scarce because they were less polygynous and more at risk of early death. This situation prevailed on the European steppe-tundra of the last ice age, whose high bio-productivity made possible a relatively large human population at the cost of a chronic oversupply of mateable women. The result was an unusually intense degree of sexual selection.

If we look at European hair color, eye color, skin color, and face shape, all of these visible features seem to have assumed their current appearance through a selection pressure that acted primarily on women. It is European women who have pushed these evolutionary changes to their farthest extent:

- Hair color varies more in women than in men. Redheads are especially more frequent among women (Shekar et al., 2008).

- Eye color varies more in women than in men when both copies of the so-called blue-eye allele are present. There is thus a greater diversity of female eye colors in regions where blue eyes are the single most common phenotype, i.e., northern and eastern Europe (Martinez-Cadenas, et al., 2013).

- Blue eyes are associated in men with a more feminine face shape (Kleisner et al., 2010; Kleisner et al., 2013).

- In all human populations, women are paler than men after puberty. This post-pubescent lightening is due to sexual maturation and not to differences in sun exposure (Edwards and Duntley, 1939; Edwards and Duntley, 1949; Edwards et al., 1941; van den Berghe and Frost, 1986). In women, lightness of skin correlates with thickness of subcutaneous fat and with 2nd to 4th digit ratio—a marker of prenatal estrogenization (Manning et al., 2004; Mazess, 1967). Admittedly, this sex difference is not greater in Europeans than in other populations, although it could not easily be otherwise, since Europeans of both sexes are so close to the physiological limit of depigmentation.

- European facial features seem to have assumed their present form through a selective force that acted primarily on women (Liberton et al., 2009). 

While women are more diverse than men in both hair color and eye color, this greater diversity came about differently in each case. With hair color, women have more of the intermediate hues because the darkest hue (black) is less easily expressed (Shekar et al., 2008). With eye color, women have more of the intermediate hues because the lightest hue (blue) is less easily expressed (Martinez-Cadenas et al., 2013).

Some of these sex linkages may nonetheless share a common developmental cause, such as the prenatal surge of estrogen that feminizes the developing female fetus. Thus, eye color is linked to face shape only in males, perhaps because female face shape is hormonally overdetermined, i.e., all girls are exposed to enough estrogen in the womb to feminize their faces, but only blue-eyed boys reach this level of exposure.

We see a similar pattern with eye color and shyness. In preschool boys, shyness is more strongly associated with blue eyes than with brown eyes, but this association is absent in preschool girls (Coplan et al., 1997). 

An 8,000 year-old hunter-gatherer from Luxembourg

The latest estimates place the whitening of European skin between 19,000 and 11,000 years ago (Beleza et al., 2013). We have no estimates at all for the diversification of European hair color. For diversification of European eye color, we used to have only an educated guess of 6,000 to 10,000 years ago (Eiberg et al., 2008).

A recent study has pushed the origin of blue eyes farther back in time. When ancient DNA was retrieved from the remains of a hunter-gatherer who lived 8,000 years ago in present-day Luxembourg, the reconstituted genome revealed that this individual probably had blue eyes (Lazaridis et al., 2013).

This finding shows that blue eyes already existed when early Europeans were still hunter-gatherers. It thus undermines a rival theory that Gregory Cochran put forward to explain the diverse palette of European hair and eye colors.

Greg’s theory is a mirror image of my own. I argue that shyness in blue-eyed boys is a side effect of sexual selection for women with novel hair and eye colors (Frost, 2006; Frost, 2008). He argues that these new colors are a side effect of natural selection for male submissiveness. This alternate theory is presented in The 10,000 Year Explosion:

[...] selection on genes affecting skin color, eye color, and hair color somehow created lots of variety in Europeans: redheads and blondes, blue eyes and green eyes. Nowhere else in the world is that sort of variety common. In most parts of the world, even in temperate regions, everyone has dark eyes and dark hair. (Cochran and Harpending, 2009, p. 94)

With the introduction of farming to Europe, and a resulting rise in population density and sedentary living, people had to become more socially wary. This self-domestication thus favored blue eyes (and presumably other eye and hair colors) as an evolutionary side effect:

Selection for submission to authority sounds unnervingly like domestication. In fact, there are parallels between the domestication in animals and the changes that have occurred in humans during the Holocene period. In both humans and domesticated animals, we see a reduction in brain size, broader skulls, changes in hair color or coat color, and smaller teeth. (Cochran and Harpending, 2009, p. 112)

Can this theory accommodate the recent discovery of a blue-eyed hunter-gatherer? One might argue that this individual was a fluke, perhaps a result of gene flow from farming communities. To settle this debate, we really need ancient DNA from pre-Holocene Europe, particularly from the critical period of 10,000 to 20,000 BP.

 

My ebook collection

I've decided to begin writing a collection of ebooks on subjects that have come up several times on this blog. This is partly in response to requests from different people and partly because I feel I should be exploiting this niche. 

For now, I am trying to educate myself about the mechanics of it all. PDF seems to be the best format but consumes a lot of space. There is also the question of whether I should self-publish or go through a publishing house. Getting published, especially in the English-language market, inevitably means finding a literary agent and tolerating a lot of questionable schmoozing, not to mention delays.

 

Why the minimum wage matters (even on an anthropology blog)

I've never understood why conservatives are so hostile to a higher minimum wage. At present, minimum wage earners take more from the public purse than they put back in. They are tax consumers, not tax payers. As a result, the taxpayer is subsidizing employers who cannot or will not pay a wage that is at least fiscally neutral.

This situation is especially toxic at a time when the business community is seeking to cut labor costs through globalization. If a job cannot be outsourced, as is often the case with employment in services, construction, and food processing, the answer is to “insource” labor at a lower rate of pay ... with the costs of public services being passed on to a shrinking base of taxpayers.

The irony of it all is pointed out by Ron Unz:

The most doctrinaire libertarians, notably Prof. Bryan Caplan of George Mason University, have held fast to their principles and denounced the very notion of a minimum wage as a violation of basic human liberty. If a desperately impoverished Congolese is willing to come to America and work for a dollar a day, then that is his fundamental moral right, at least if he is willing to forego any access to medical care or other normal social benefits as part of the deal. (Unz, 2013)

That part of the deal won't be happening any time soon. Perhaps libertarians know this but think they can bankrupt the welfare state through mass immigration. Or perhaps they haven’t thought this idea all the way through. Or perhaps they're just shills.

Hostility to the minimum wage isn’t just a libertarian thing. Mainstream conservatives feel the same way:

Harvard economist and former Reagan Advisor Martin Feldstein recently took to the editorial pages of The Wall Street Journal to explicitly call for the creation of a new economic system that would fully integrate welfare payments and work into a seamless system of government support aimed at ensuring a basic standard of living for everyone in the country.

[...] Indeed, Feldstein argued that once the eligibility of various welfare programs were widened, the minimum wage could reasonably be cut, allowing American workers to take jobs paying just four, five or six dollars per hour, with the ordinary taxpayer making up the difference. The logical endpoint to such proposals would be for businesses to pay their workers absolutely nothing at all, with all employee living expenses and spending money coming from governmental anti-poverty programs. (Unz, 2013)

This kind of income support (earned income tax credit) already exists and cost the American taxpayer $56 billion in 2012. Feldstein’s proposal would not only expand it but also extend it to a range of wages that is currently illegal and found only outside the Western world. It would thus greatly facilitate the ongoing influx of low-wage labor.

Not such a great idea

When the concept of "globalization" first became popular, we were told it would create so much more wealth that we would all be better off. The reality has been less wonderful. Median wages have stagnated throughout the Western world since the mid-1970s, despite a doubling of worker productivity. And the trend is now downwards. In a globalized world where businesses can move about capital and labor as they please, there is nothing to stop our wages from being leveled down to the current global mean. 

And that's the best scenario. By dissolving those cultures that have historically produced the most wealth—because of their peaceful social relations, future time orientation, and high level of trust—globalization may cause an overall contraction of economic activity. History will go into reverse. We will lose the market economy and return to the old marketplace economy, where most monetary transactions take place in gated high-security enclosures.

 

References

Beleza, S., Murias dos Santos, A., McEvoy, B., Alves, I., Martinho, C., Cameron, E., Shriver, M.D., Parra E.J., and Rocha, J. (2013). The timing of pigmentation lightening in Europeans. Molecular Biology and Evolution, 30, 24-35.

http://mbe.oxfordjournals.org/content/30/1/24.short

Cochran, G.M. and H. Harpending. (2009). The 10,000 Year Explosion, Basic Books.

Coplan, R., B. Coleman, and K. Rubin. (1998). Shyness and little boy blue: Iris pigmentation, gender, and social wariness in preschoolers. Developmental Psychobiology, 32, 37-44.

Edwards, E.A., and Duntley, S.Q. (1939). The pigments and color of living human skin. American Journal of Anatomy, 65, 1-33. 

Edwards, E.A., and Duntley, S.Q. (1949). Cutaneous vascular changes in women in reference to the menstrual cycle and ovariectomy. American Journal of Obstetrics & Gynecology, 57, 501-509.

Edwards, E.A., Hamilton, J.B., Duntley, S.Q., and Hubert, G. (1941). Cutaneous vascular and pigmentary changes in castrate and eunuchoid men. Endocrinology, 28, 119-128.

Eiberg, H., Troelsen, J., Nielsen, M., Mikkelsen, A., Mengel-From, J., Kjaer, K.W., and Hansen, L. (2008). Blue eye color in humans may be caused by a perfectly associated founder mutation in a regulatory element located within the HERC2 gene inhibiting OCA2 expression. Human Genetics, 123, 177-187.

Frost, P. (2006). European hair and eye color - A case of frequency-dependent sexual selection? Evolution and Human Behavior, 27, 85-103. 

Frost, P. (2008). Sexual selection and human geographic variation, Special Issue: Proceedings of the 2nd Annual Meeting of the NorthEastern Evolutionary Psychology Society. Journal of Social, Evolutionary, and Cultural Psychology, 2(4),169-191.

http://137.140.1.71/jsec/articles/volume2/issue4/NEEPSfrost.pdf 

Lazaridis, I., Patterson, N., Mittnik, A., Renaud, G., Mallick, S., et al. (2013). Ancient human genomes suggest three ancestral populations for present-day Europeans, BioRxiv, December 23.

http://biorxiv.org/content/early/2013/12/23/001552.full-text.pdf+html

Kleisner, K., Kocnar, T., Rubešova, A., and Flegr, J. (2010). Eye color predicts but does not directly influence perceived dominance in men. Personality and Individual Differences, 49, 59-64.

Kleisner, K., Priplatova, L., Frost, P., and Flegr, J. (2013). Trustworthy-looking face meets brown eyes. PLoS One, 8(1): e53285.

Liberton, D.K., Matthes, K.A., Pereira, R., Frudakis, T., Puts, D.A., & Shriver, M.D. (2009). Patterns of correlation between genetic ancestry and facial features suggest selection on females is driving differentiation, Poster #326. American Society of Human Genetics, 59th annual meeting, October 20-24, 2009. Honolulu, Hawaii.

Manning, J.T., Bundred, P.E., and Mather, F.M. (2004). Second to fourth digit ratio, sexual selection, and skin colour. Evolution and Human Behavior, 25, 38-50.

Martinez-Cadenas, C., Pena-Chilet, M., Ibarrola-Villava, M., & Ribas, G. (2013). Gender is a major factor explaining discrepancies in eye colour prediction based on HERC2/OCA2 genotype and the IrisPlex model. Forensic Science International: Genetics, 7, 453-460.

Mazess, R.B. (1967). Skin color in Bahamian Negroes. Human Biology, 39, 145-154.

Shekar, S.N., Duffy, D.L., Frudakis, T., Montgomery, G.W., James, M.R., Sturm, R.A., and Martin, N.G. (2008). Spectrophotometric methods for quantifying pigmentation in human hair-Influence of MC1R genotype and environment. Photochemistry and Photobiology, 84, 719-726. 

Unz, R. (2013). Conservatives for more welfare, The Unz Review, December 30.

http://www.unz.com/runz/conservatives-for-more-welfare/

van den Berghe, P.L., and Frost, P. (1986). Skin color preference, sexual dimorphism and sexual selection: A case of gene-culture co-evolution? Ethnic and Racial Studies, 9, 87-113.