Showing posts with label Natufians. Show all posts
Showing posts with label Natufians. Show all posts

Saturday, January 25, 2014

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