A new preprint has appeared in the American Journal of Human Genetics site about the mtDNA origins of island SE Asians.
American Journal of Human Genetics (preprint)
A mitochondrial stratigraphy for Island Southeast Asia
Catherine Hill et al.
Island Southeast Asia (ISEA) was first colonized by modern humans at least 45,000 years ago, but the extent to which the modern inhabitants trace their ancestry to the first settlers is a matter of debate. It is widely held in both archaeology and linguistics that they are largely descended from a second wave of dispersal, proto-Austronesian-speaking agriculturalists who originated in China and spread to Taiwan ~5,500 years ago. From there they are thought to have dispersed into Island Southeast Asia ~4,000 years ago, assimilating the indigenous populations. Here, we demonstrate that mtDNA diversity in the region is extremely high and includes a large number of indigenous clades. Only a fraction of these date back to the time of first settlement, and the majority appear to mark dispersals in the late Pleistocene or early
Holocene most likely triggered by post-glacial flooding. There are much closer genetic links to Taiwan than to the mainland, but most of these probably pre-dated the mid-Holocene ‘out of Taiwan’ event as traditionally envisioned. Only ~20% at most of modern mtDNAs in ISEA could be linked to such an event, suggesting that if an agriculturalist migration did take place it was demographically minor, at least as regards the involvement of women.