Out of Africa scenario depends on a bias in protein coding loci
Another criticism of the “out-of-Africa” scenario for human ancestry in today’s Molecular Biology and Evolution:
Previous studies have found that at most human loci, ancestral alleles are “African,” in the sense that they reach their highest frequency there. Conventional wisdom holds that this reflects a recent African origin of modern humans.
This paper challenges that view by showing that the empirical pattern (of elevated allele frequencies within Africa) is not as pervasive as has been thought. We confirm this African bias in a set of mainly protein-coding loci, but find a smaller bias in Alu insertion polymorphisms, and an even smaller bias in noncoding loci. Thus, the strong bias that was originally observed must reflect some factor that varies among data sets—something other than population history. This factor may be the per-locus mutation rate: the African bias is most pronounced in loci where this rate is high.
Abstract at MBE Online