The past is another country


 
Male figurine, pottery, c. 7,000–5,000 years ago, Greece, Archaeological Museum of Heraklion, Wikicommons

 

A very important recent finding is the recovery of the entire genomes of three prehistoric farmers who lived in northern Greece 7500-5500 years BP. The data have been analyzed and are expected to shed light on the ancestral relationships of the first Europeans and provide a wealth of information about functional and morphological characteristics. Already it is known that some of our Neolithic ancestors could not digest milk, i.e., they were intolerant to lactose, and had brown eyes and dark skin. (Anon, 2015)

This is one of several findings with a common theme: the farther back in time we go, the less familiar people look. And we don't have to go very far.

This fact came up in a column I wrote about the Americas. If we turn back the clock, Amerindians look more and more European, yet their genes say they're still Amerindian. We're just getting closer to the time when both groups were the same people. If we turn back the clock even farther, those "proto-Amerindians" give way to a very different sort of human, much like the inhabitants of Papua New Guinea (Frost, 2015).

What happened to those first Americans? They were "replaced." If you're looking for family entertainment, don't study history or prehistory.

Ironically, one of the comments on that column argued that European settlers had stolen this land from the Native Americans and had thus forfeited any moral right to complain about immigration. Well, one genocide doesn’t justify another. I would also venture to say that the universe cares little about our notions of morality. There is only survival or extinction. Everything else is sophistry.

Early and not-so-early Europeans

Ancient DNA is telling a similar story about early Europeans. As late as 8,000 years ago, only the hunting peoples of northern and eastern Europe had white skin and a diverse palette of hair and eye colors. Farther west and south, in Spain, Luxembourg, and Hungary, we find hunter-gatherers with a strange mix of brown skin and eyes of blue, green, or grey. Central Europe was also home to early farmers with white skin, dark hair, and brown eyes. If we go still farther south, beyond the Alps, we see faces and bodies that seem to evoke another continent (Gibbons, 2015; Olalde and Lalueza-Fox, 2015).

This is in line with earlier work on skeletal remains. Angel (1972) 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." In the Middle East, the Natufians (15,000-12,000 BP) were anatomically more similar to present-day West Africans than to present-day Middle Easterners (Brace et al., 2006).

Many African-looking skulls and skeletons have been found in an arc of territory stretching from Brittany, through Switzerland and northern Italy, and into the Balkans. Most are from the Neolithic, but some are as recent as the Bronze Age and the early Iron Age (Boule and Vallois, 1957, pp. 291-292)

Does this mean that prehistoric Greek farmers were more closely related to sub-Saharan Africans than to present-day Greeks? The genome analysis isn't complete, but I think not. They may have looked un-European, but their genomes would probably place them a lot closer to present-day Europeans than to anyone else. We saw the same thing with Kennewick Man. His skull looked European, yet genetically he was closer to Amerindians.

Those prehistoric Greeks were descended from a wave of modern humans that entered Europe some 40,000 years ago. In the north and east, the new settlers encountered selection pressures that recolored and reshaped their most visible features, making them look very different from their African-like relatives to the south and west. Yet this new look came about through changes to just a tiny subset of the genome.

This is not to argue that "we're all pretty much the same under the skin." One could just as well say that humans and chimps are pretty much the same under the skin. They are, actually, if one looks only at flesh and blood. Nonetheless, a human is not a chimp with a body shave.

A second look at the spread of farming

This portrait of early Europeans is still incomplete, and some findings seem contradictory. For instance, why did those Greek farmers lack the alleles for white skin and lactose tolerance when the same alleles were present in Central European farmers from the same time period? In fact, it now seems that both traits evolved in Europe (Gibbons, 2015). A year ago, almost everyone pointed to those Central Europeans as proof that white skin and lactose tolerance must have come from the Middle East, along with farming itself.

It has become popular to argue that farming spread out of the Middle East and into Central Europe through a process of population replacement. The argument seems logical. Because farming supports a larger population per unit of land area, immigrants from the Middle East should have overwhelmed the native hunter-gatherers of Europe by force of numbers. Apparently, things weren’t so simple. Early European farmers were a mixed bunch, and their relationship to the Middle East looks just as problematic. Farming did spread out of the Middle East, but the extent to which this diffusion was genetic or cultural is far from clear. Even the hard evidence looks soft when given a second look.

For instance, we know that a sharp genetic boundary separates late hunter-gatherers from early farmers in Europe. That's good evidence for population replacement. But when a Danish team used a more complete time series of ancient DNA samples, they found that the genetic boundary actually separated early farmers from somewhat later farmers. Haplogroup U, the supposed genetic signature of Europe's ancient hunter-gatherers, reached its current low level after the Neolithic, according to that time series (Melchior et al., 2010). The genetic boundary must therefore be partly due to something else than population replacement, perhaps new selection pressures.

Another piece of hard evidence is the cultural conservatism of hunter-gatherers, who generally prefer to die out than embrace farming and who especially dislike having to plan their lives over a yearly cycle. But that finding is based on tropical hunter-gatherers. Northern hunter-gatherers plan ahead over the coming year and are better able to make the leap. If we take the Mississippian culture of the American Midwest and Southeast (c. 800 -1600), we find that small groups of hunter-gatherers had little trouble making the shift not only to large-scale intensive maize farming but also to life in large towns of up to 40,000 people—all this in half a millennium.

Indeed, if we look at pre-Columbian America, we see that farming first developed in Mesoamerica and then spread north through cultural diffusion. There were very few cases of farmers demographically replacing hunter-gatherers. Why would the situation have been so different in prehistoric Europe? As a general rule, it seems that population replacement occurs only when there is a profound difference in mental makeup that cannot be easily changed.

A final question

Southern Europe and the Middle East were initially home to dark African-like people, who were then replaced by European-like people, apparently from the north, beginning around 12,000 ago. The process of replacement was still incomplete, however, during the time of those northern Greek farmers 7,500 to 5,500 years ago. That last date is very close to the dawn of history. Only a millennium and a half later, the Minoans were building the palace of Knossos. Are those African-like people remembered in European myths, legends, and folk tales?

h/t to Dienekes

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. 

Anon. (2015). The Archeological Museum of Thessaloniki. Report on ancient DNA -Learn what eye color your ancestor had and what he ate in the Neolithic! Iefimerida
http://www.iefimerida.gr/news/219751/ekthesi-gia-arhaio-dna-mathe-ti-hroma-matia-eihe-kai-ti-etroge-o-neolithikos-progonos

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

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, 242-247
http://www.pnas.org/content/103/1/242.full 

Dienekes. (2015). Prehistoric farmers from northern Greece had lactose intolerance, brown eyes, dark skin, Dienekes' Anthropology Blog, August 7
http://dienekes.blogspot.ca/2015/08/prehistoric-farmers-from-northern.html 

Frost, P. (2015). Guess who first came to America? The Unz Review
http://www.unz.com/pfrost/guess-who-first-came-to-america/ 

Gibbons, A. (2015). How Europeans evolved white skin, Science, Latest News, April 2
http://news.sciencemag.org/archaeology/2015/04/how-europeans-evolved-white-skin 

Melchior, L., N. Lynnerup, H.R. Siegismund, T. Kivisild, J. Dissing. (2010). Genetic diversity among ancient Nordic populations, PLoS ONE, 5(7): e11898
http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0011898#pone-0011898-g002 

Olalde, I. and C. Lalueza-Fox. (2015). Modern humans' paleogenomics and the new evidences on the European prehistory, Science and Technology of Archaeology Research, 1
http://www.maneyonline.com/doi/pdfplus/10.1179/2054892315Y.0000000002

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