I've been blogging a fair bit on the relationship between history & genetics (see here, here and here), both as a parameter in shaping the course of events (e.g., immunological profiles, or through gene-culture coevolution), and as a tool in tracing out phylogenetic relationships between peoples and fleshing out demographic details. It so happens that an excellent paper which focuses upon the latter came out this week, The Genetic Structure of Pacific Islanders, in PLoS Genetics. It is so good and I'm so busy that I'll simply encourage you to read the paper in the original, and then read the popular press summaries. Below the fold are bullet points from their conclusion if that's all you care about....
1) To whom are these Melanesian populations most closely related outside the Pacific? Outside the Pacific, East Asian populations are apparently the closest (but still very distant) relatives of Melanesians. Africans and Europeans are the most distant. 2) How does the genetic diversity of Near Oceanic populations compare with groups in other regions? The within-group diversity in Melanesian populations is consistently very low, which acts to exaggerate the considerable among-group distinctions there. This great diversity in such a small region makes comparisons of human population structure from continent to continent problematic. 3) Is there a clear organization of the variation among Melanesian groups? The diversity among groups is primarily organized by island size and topographic complexity, with the inland Papuan-speaking groups the most isolated and differentiated. Shore-dwelling Oceanic-speaking groups are more intermixed (dispersal along the shorelines was easier). 4) Is there an identifiable genetic signature of Taiwanese/Southeast Asian or Polynesian influence in Near Oceanic populations, especially in the Bismarcks, where the Lapita Cultural Complex developed? There is a weak ''Austronesian'' genetic signature in only a portion of Oceanic-speaking populations in Melanesia, and none at all in Papuan-speaking groups (contradicting the results of mtDNA, but in accord with the NRY results). 5) Are Polynesians more closely related to Asian/Taiwanese populations or to Melanesians? Polynesians are closely related to Asian/Taiwanese Aboriginal populations, while they are very weakly associated with any Melanesian groups (the closest association there appears to be with New Ireland populations). This is in accord with mtDNA interpretations, but differs from the usual interpretation of the NRY results. The sailing capabilities of the ancestors of the Polynesians transformed the nature of their Diaspora and kept them relatively homogeneous.
