Kostenki
Man, reconstructed by Mikhail Gerasimov (1907-1970). An early European who was
not yet phenotypically European.
Who
were the first Europeans? We now have a better idea, thanks to a new paper about
DNA from a man who lived some 38,700 to 36,200 years ago. His remains
were found at Kostenki, a well-known Upper Paleolithic site in central European
Russia (Seguin-Orlando et al., 2014).
Kostenki
Man tells us several things about the first Europeans and, more broadly, the
first non-African humans:
The Neanderthal
encounter
Modern
humans received their Neanderthal admixture when they were just spreading out
of Africa some 54,000 years ago. At that time, they had not yet encountered the
Neanderthals and were entering the territory of the Skhul/Qafzeh hominids, a
semi-archaic people of the Middle East. So we may have got our Neanderthal
admixture indirectly. The Skhul/Qafzeh hominids had probably interbred with
their Neanderthal neighbors to the north, and our ancestors may have then
picked up this admixture while in the Middle East.
When
our ancestors spread farther north into Europe, some 45,000 to 42,000 years
ago, they could have interbred directly with Neanderthals, but they didn't.
Perhaps the two groups were just too different. They seem to have intermixed
only via a third party that was neither fully modern nor fully archaic.
A strange detour
... and then another!
There
was initially a large continuous population across northern Eurasia, perhaps
composed of nomads who pursued wandering herds of reindeer across the European
Plain and its eastward extension into central and northern Asia.
Not
long before the time of Kostenki Man, these Northern Eurasians began to split
into three regional groups: Western Eurasians, Eastern Eurasians, and the
ancestors of Middle Eastern farmers. The degree of reproductive isolation is
unclear, however, and gene flow may have continued between all three groups
until the onset of the last ice age some 25,000 years ago. This may be why
Kostenki Man does not fit perfectly into any of the three groups, although he
is genetically closest to Western Eurasians.
Yes,
Northern Eurasians were ancestral to the early farming peoples of the Middle
East. It seems that early modern humans had to head north, learn to hunt reindeer,
and then head south again before they could start farming. Sounds like a
strange detour. Wouldn't it have been easier to stay put and do it locally? You
know, Middle-Eastern hunter-gatherers becoming Middle Eastern farmers?
Apparently not.
It
gets even more convoluted. After some of those Northern Eurasians had gone
south to the Middle East, some of their farming descendants
"returned" to Europe and partially replaced its hunter-gatherers,
particularly in southern and central Europe. This second detour has been
greeted with disbelief. Dienekes (2014), for instance, has written: "I
don't think many archaeologists would derive European farmers from Russia
(Russia is actually one of the last places in Europe that became
agricultural)."
True,
but farming requires a mindset that may have come from those northern hunters
(Frost, 2014). When Piffer (2013) looked at human variation in alleles at COMT, a gene linked to executive
function, working memory, and intelligence, he found that northern hunting
peoples had more in common with farming peoples than with other
hunter-gatherers, "possibly due to the higher pressure on technological
skills and planning abilities posed by the adverse climatic conditions."
That
mindset made farming possible, but the first steps toward farming could not be
taken in a cold climate. They had to be taken in a place with a long growing
season and a wide variety of domesticable plants and animals, such as in the
Middle East. Once farming had developed there, it could move back north, while
taking along its technologies, its food crops, and its livestock species.
Farming
can develop in the tropics with a "tropical" mindset, but it looks
very different. The farming that arose in West Africa is overwhelmingly women's
work and seems to have wholly developed out of female plant gathering. The
guinea fowl is the only animal that has been domesticated for food consumption
in sub-Saharan Africa.
The Ice Age was
not so bad
The
Upper Paleolithic humans of northern and eastern Europe did not die out during
the last ice age, as was commonly thought. They survived the glacial maximum
intact.
The European
phenotype came later
Kostenki
Man was dark-skinned, dark-eyed, and rather short. These details, curiously
enough, appear not in the paper but in a review of the paper, published by the
same journal, as well as in an interview with one of the authors (Associated Press, 2014; Gibbons, 2014).
So
we now have an upper bound for the emergence of the European phenotype, i.e.,
light skin and a diverse palette of hair and eye colors. The lower bound has
been set by the remains of a Swedish hunter-gatherer, dated to 8,000 years ago,
who had the "European" allele for light skin at the gene SLC24A5 (Skoglund et al., 2014).
Conclusion
My
main criticism centers on the dating to 38,700 - 36,200 years ago. At the
Kostenki site, the radiocarbon dating used to be some 10,000 years younger. It
was then recalibrated to an older range of dates when a layer of volcanic ash
at the site was attributed to a volcano that had erupted in southern Italy some
39,000 years ago. This recalibration was initially controversial, but the
controversy has since subsided (Sinitsyn and Hoffecker, 2006). I would not rule
out a subsequent re-recalibration.
By
retrieving ancient DNA from an early modern human, we have made a key advance
in human paleogenetics, perhaps more so than by sequencing the Neanderthal
genome. We again see that evolution did not slow down with the emergence of
anatomically and behaviorally modern humans some 60,000 years ago. It actually
began to speed up, as humans began to enter not only new natural environments
but also new cultural environments of their own making.
References
Associated
Press (2014). DNA study dates Eurasian split from East Asians, The Columbus Dispatch, November 6
http://hosted2.ap.org/OHCOL/07e34bb59e064cedb7e2776e8db4b4f7/Article_2014-11-06-EU--Eurasian%20Split/id-ae36fa368c634c7383d807942bd5fe67
Dienekes
(2014). Genome of Kostenki-14, an Upper Paleolithic European (Seguin-Orlando,
Korneliussen, Sikora, et al. 2014), Dienekes'
Anthropology Blog, November 7
http://dienekes.blogspot.ca/2014/11/genome-of-kostenki-14-upper-paleolithic.html
Frost,
P. (2014). The first industrial revolution, Evo
and Proud, January 18
http://evoandproud.blogspot.ca/2014/01/the-first-industrial-revolution.html
Gibbons,
A. (2014). European genetic identity may stretch back 36,000 years, Science, News, November 6
http://news.sciencemag.org/archaeology/2014/11/european-genetic-identity-may-stretch-back-36000-years
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
Seguin-Orlando,
A., T.S. Korneliussen, M. Sikora, A.-S. Malaspinas, A. Manica, I. Moltke, A.
Albrechtsen, A. Ko, A. Margaryan, V. Moiseyev, T. Goebel, M. Westaway, D.
Lambert, V. Khartanovich, J.D. Wall, P.R. Nigst, R.A. Foley, M.M. Lahr, R.
Nielsen, L. Orlando, and E. Willerslev. (2014). Genomic structure in Europeans
dating back at least 36,200 years, Science,
Published online 6 November 2014
http://www.sciencemag.org/content/early/2014/11/05/science.aaa0114 http://www2.zoo.cam.ac.uk/manica/ms/2014_Seguin_Orlando_et_al_Science.pdf
Sinitsyn,
A.A., and J.F. Hoffecker. (2006). Radiocarbon dating and chronology of the
Early Upper Paleolithic at Kostenki, Quaternary
International, 152-153, 164-174.
http://www.sciencedirect.com/science/article/pii/S1040618206000206
Skoglund,
P., H. Malmstrom, A. Omrak, M. Raghavan, C. Valdiosera, T. Gunther, P. Hall, K.
Tambets, J. Parik, K-G. Sjogren, J. Apel, E. Willersley, J. Stora, A.
Gotherstrom, and M. Jakobsson. (2014). Genomic diversity and admixture differs
for stone-age Scandinavian foragers and farmers, Science, 344 (6185),
747-750.
http://www.sciencemag.org/content/344/6185/747.short
