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 ancestors with no descendants

Venus of Mal’ta, a figurine from a site in eastern Siberia (source). She comes from a population that was related to modern Europeans and Amerindians but not to modern native Siberians. The Mal’ta Siberians died out at the height of the last ice age and were replaced by people spreading north from East Asia and west from Beringia.

On the eve of the last ice age, Siberia was home to a people who were related to modern Europeans and Amerindians but not to modern native Siberians. So concludes an analysis of DNA from the remains of a boy who lived 24,000 years ago at Mal’ta near Lake Baikal, Siberia.

They found that a portion of the boy's genome is shared only by today's Native Americans and no other groups, showing a close relationship. Yet the child's Y chromosome belongs to a genetic group called Y haplogroup R, and its mitochondrial DNA to a haplogroup U. Today, those haplogroups are found almost exclusively in people living in Europe and regions of Asia west of the Altai Mountains, which are near the borders of Russia, China, and Mongolia.

One expected relationship was missing from the picture: The boy's genome showed no connection to modern East Asians. DNA studies of living people strongly suggest that East Asians—perhaps Siberians, Chinese, or Japanese—make up the major part of Native American ancestors (Balter, 2013).

These findings are consistent with earlier ones. Strong dental and cranial affinities exist between remains from the same site and those of Upper Paleolithic Europeans (Alexeyev and Gokhman, 1994). Also, when we compare the Clovis sites of early Amerindians (13,000 BP) with early European and Siberian sites (20,000-15,000 BP), we find many features in common: characteristic lithic technology, grave goods with red ocher, and sites with small shallow basins (Goebel, 1999; Haynes, 1980; Haynes, 1982).

What do these findings tell us? I would propose the following:

1. When the last ice age began some 25,000 years ago, a single population of nomadic hunters occupied the steppe-tundra that stretched from southwestern France to Beringia.

2. Ancestral East Asians had already split away from this proto-Eurasian population. They had probably adapted to life farther south in the more temperate environments of what is now north China. The Ainu may be an evolutionarily conservative branch of these East Asians.

3. At the height of the last ice age some 20,000 to 17,000 years ago, Siberia became virtually devoid of human life (Graf, 2009a; Graf, 2009b). Proto-Eurasians survived in refugia in parts of Europe to the west and in coastal regions of northeast Asia, Beringia and northwest North America to the east. Kennewick Man (c. 9,000-10,000 BP) may have been an example of this refuge population.

4. Siberia was then repeopled by two streams of settlement. One was composed of ‘Kennewickians’ spreading westward and inland from coastal refugia. The other stream was composed of early East Asians spreading northward.

5. This new mixed population of eastern Siberia and Beringia would later spread eastward into the interior of post-glacial North America around 13,000 years ago. These people were the early Amerindians of the Clovis culture.

It would be interesting to know what the reconstructed Mal’ta genome tells us about the skin, hair, and eye color of the proto-Eurasians. Were they pale-skinned with a diverse palette of hair and eye colors, like modern Europeans? Or were they brown-skinned with black hair and brown eyes, like modern Amerindians?  Probably the second possibility, given that the European color scheme seems to be a later evolutionary development—11,000 to 19,000 years ago for white skin and probably the same time frame for diversification of hair and eye color (Beleza et al., 2013). The Mal’ta people might have gone on to develop the same characteristics during this time frame, but they all died out at the height of the last ice age. 

In short, the Mal’ta people probably looked very much like native Indians with a more European skull shape, perhaps like the Ainu of northern Japan or the Kennewick humans of North America. 

References

Alexeyev, V.P., and I.I. Gokhman. (1994). Skeletal remains of infants from a burial on the Mal'ta Upper Paleolithic site, Homo, 45, 119‑126. 

Balter, M. (2013). Ancient DNA links Native Americans with Europe, Science, 342, 409-410.

http://www.sciencemag.org/content/342/6157/409.full

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

http://www.utm.utoronto.ca/~parraest/profile/PDF%20files/Beleza-2012(Mol.Biol.Evol.).pdf 

Goebel, T. (1999). Pleistocene human colonization of Siberia and peopling of the Americas: An ecological approach, Evolutionary Anthropology, 8, 208‑227.

http://onlinelibrary.wiley.com/doi/10.1002/(SICI)1520-6505(1999)8:6%3C208::AID-EVAN2%3E3.0.CO;2-M/abstract

Graf, K.E. (2009a). “The Good, the Bad, and the Ugly”: evaluating the radiocarbon chronology of the middle and late Upper Paleolithic in the Enisei River valley, south-central Siberia. Journal of Archaeological Science, 36, 694–707.

http://www.centerfirstamericans.com/cfsa-publications/Graf-JAS2009-36-694.pdf

Graf, K.E. (2009b). Modern human colonization of the Siberian Mammoth Steppe: A view from South-Central Siberia. In M. Camps, P. Chauhan (eds.), Sourcebook of Paleolithic transitions (pp. 484-496), Springer Science & Business Media.

Haynes, C.V. (1982). Were Clovis progenitors in Beringia? In D.M. Hopkins (ed). Paleoecology of Beringia, (pp. 383‑398), New York: Academic Press. 

Haynes, C.V. (1980). The Clovis culture, Canadian Journal of Anthropology, 1, 115‑121.