The new preprint, Genomic Insights into the Demographic History of Southern Chinese, is somewhat inaccurately titled. It’s really more about the progenitors of the various Southeast Asian language families, whose origins are in South China. Yes, mother southern Han Chinese absorbed local substrate, but that’s been known for a while.

The story here is successive incidents of ‘collapsing structure’ out of the Last Glacial Maximum. The various East Asian populations admixed after diversification 20-40,000 years ago, and there was a later stage of admixture driven by the expansion of the Han out of the north.

An admixture graph is the best way to get at the major features of their model:

The major finding is that the Austro-Asiatic, Hmong-Mien and Austronesian language families emerge from groups distributed west-east in the Yangzi basin, with the Krai-Dai being more of a synthesis. The Tibeto-Burmans were a later push that synthesized mostly with Austro-Asiatic populations. The details are less important than the reality that some sort of separation and then admixture explains a lot of the local differences. Additionally, their genetic results confirm what is obvious with the Kinh: genetically they are very different from Austro-Asiatic groups which they are often linguistically bracketed.

The most interesting finding is an Andaman-like “ghost population” that contributed to the Jomon, and less to other groups. You know where I’m going here: this is clearly the basal East Eurasian group called “Australo-Melanesian” that contributed genes to some Amazonian groups. This group is the one that contributed haplogroup D to Tibetans and Japanese.

With East Asian population structure I feel we have the broad features, but a lot of the details are rickety. We’ll see.