[LINK] "Non-zero sum transitions in the human past"

[rfmcdonald]

Science blogger Razib Khan at his Discover-based blog GNXP makes an argument similar to the one I made in my post this afternoon, suggesting that culture more about the replacement of the Neanderthals and other hominins than biology does. This, Razib concludes, makes the population changes of distant prehistory much more comprehensible via analogies with our documented history.

[W]e have many cases of more recent replacements and assimilations on the scale of that of the Neandertals. In the New World Europeans and Africans have replaced and assimilated the indigenous population in many regions which were ecologically suitable. In places like the Dominican Republic indigenous ancestry does persist at low levels, especially in the mtDNA, but it is not longer salient or culturally relevant in a concrete (as opposed to symbolic) sense. There were major biological differences between these Old World populations and the indigenous ones, mostly having to do with susceptibility to disease. Still, we can not separate biological advantages of the new populations from their cultural context. Malaria resistance amongst Africans became prevalent only with the rise of agriculture, as broad swaths of wilderness were cleared and transformed into farmland which was a superior environment for the mosquitoes which transmitted the pathogen. Similarly, the various infectious agents to which Europeans were inured spread via long distance contacts, which could exhibit a scale in Eurasia unmatched in the New World thanks to the emergence of a genuine ecumene.

The Columbian Exchange looms large in part because it is well documented and concerns Europeans, but genetic, linguistic, and archaeological data from Southeast Asia strongly implies that the ancient hunter-gatherers of both the mainland and the maritime zones have been assimilated by successive waves of agriculturalists issuing from the margins of southern China. There is also now evidence of massive population shifts in Europe and India due to the spread of agriculturalists. If an alien archaeologist examined the data I do think they might posit that were a biological speciation events which might explain this, as new traits arose which allowed the farming population to expand and replace the hunter-gatherers. Some of this is actually straightforwardly plausible. Consider the spread of lactase persistence or the ability of farming populations to digest amylose.

[. . .]

If there was a great leap forward to behavioral modernity ~40,000 years ago, then I think one should logically assert that there was another “great leap forward” ~10,000 years ago in the Middle East with the first farmers. There was also another “great leap forward” ~5,000 years ago ago with the invention of writing. There was another “great leap forward” ~300 years ago in Western Europea with the crystallization of a genuine scientific community.

I’m not actually suggesting that what happened 10,000 years ago was a speciation event. What I’m suggesting is that the near past may be more similar to the distant past than we imagine. This makes the near past more exotic, and the distant past less exotic.