A new model of human dispersal
Analysis of previously unpublished allele counts obtained from the French-San-Neanderthal-Chimpanzee alignment of the high quality DNA sequence of a Neanderthal from the Altai Mountains raises significant questions about the currently accepted phylogenetic model of the origins of Europeans. Previous estimates of the proportion of Neanderthal ancestry in present-day Europeans ranged between 1.3% and 2.7% supporting a recent Out-of Africa dispersal model followed by a low level of admixture with Neanderthals. However, analysis of the allele counts indicates the existence of an unidentified third archaic ancestor of Europeans, which diverged from its common ancestor with sub-Saharan Africans around 900 thousand years ago. This analysis shows that the relative proportions of derived alleles in the 0.0826% of the European genome that is not shared with the common ancestor of humans and chimpanzee are 13.6% Neanderthal, 32.3% sub-Saharan African and 54.2% third archaic ancestor. This analysis together with anthropological and archaeological evidence suggests a new model of human dispersal based on a Eurasian lineage in the Levant, which admixed with Neanderthals and descendants of African mtDNA haplogroup L3, followed by radiation from a basal admixed population around 55-50 Kya, with no subsequent major contribution to the European genome.