Does this paper, completely overturn the Out-of-Africa model?
Posted 16 December 2012 - 10:04 PM
"Global genetic variation at OAS1 provides evidence of archaic admixture in Melanesian populations.
Mendez FL, Watkins JC, Hammer MF.
Department of Ecology and Evolutionary Biology, University of Arizona, USA.
Recent analysis of DNA extracted from two Eurasian forms of archaic human shows that more genetic variants are shared with humans currently living in Eurasia than with anatomically modern humans in sub-Saharan Africa. Although these genome-wide average measures of genetic similarity are consistent with the hypothesis of archaic admixture in Eurasia, analyses of individual loci exhibiting the signal of archaic introgression are needed to test alternative hypotheses and investigate the admixture process. Here, we provide a detailed sequence analysis of the innate immune gene OAS1, a locus with a divergent Melanesian haplotype that is very similar to the Denisova sequence from the Altai region of Siberia. We resequenced a 7-kb region encompassing the OAS1 gene in 88 individuals from six Old World populations (San, Biaka, Mandenka, French Basque, Han Chinese, and Papua New Guineans) and discovered previously unknown and ancient genetic variation. The 5' region of this gene has unusual patterns of diversity, including 1) higher levels of nucleotide diversity in Papuans than in sub-Saharan Africans, 2) very deep ancestry with an estimated time to the most recent common ancestor of >3 myr, and 3) a basal branching pattern with Papuan individuals on either side of the rooted network. A global geographic survey of >1,500 individuals showed that the divergent Papuan haplotype is nearly restricted to populations from eastern Indonesia and Melanesia. Polymorphic sites within this haplotype are shared with the draft Denisova genome over a span of ∼90 kb and are associated with an extended block of linkage disequilibrium, supporting the hypothesis that this haplotype introgressed from an archaic source that likely lived in Eurasia."
Posted 17 December 2012 - 11:55 AM
Posted 18 December 2012 - 09:19 AM
Not at all - I would interpret this (only read the abstract) as saying that the Melanesian populations have some roots in Asia, which makes sense given the linkage of islands down from Asia towards Melanesia. It doesn't state that anything about the origins of the H. sapiens species at all.
Do you think that this lends credibility to the Multiregional hypothesis?
Posted 19 December 2012 - 10:39 AM
No, not really.
Really, why is that? If you don't mind me asking?
Posted 19 December 2012 - 11:44 AM