In my opinion, it will slowly become apparent that the way to harmonize our picture of human origins is to accept a substantial degree of archaic admixture in Africa. Such admixture cannot be detected directly, because there are no archaic genomes from Africa, and the hot climate throughout much of the continent may make preservation of DNA more difficult than in northern parts of Eurasia (where Neandertal and Denisovan individuals were from). Nor can it always be detected with LD-based methods, since LD decays exponentially and really old admixture is indistinguishable from an excess of mutation in a large population size. But, its acceptance will simultaneously solve the riddle of excess polymorphism in Africans, remove the need for an Out-of-Africa bottleneck of biblical proportions, and resolve the discrepancy between autosomal and uniparental evidence.
Sunday, September 16, 2012
Africa and multiregionalism
Dienekes discusses the origins of the human species: