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.
Their model *kind* of looks like a pulse before Neolithic from I’d guess inland NW *within* East Asia, with more persistence of Basal Asian D related ancestry in coastal NE (Japan Jomon / Sakhalin), SW (Tibetan High Altitude Adapted) and SE (Fujian Early Neolithic samples), and then among Hoabinhian in MSEA (who contribute very slightly to some groups today). Then post agricultural movements overlain to this (somewhat different to models that suggested *all* displacement was agriculture related, and South China Hoabinhian like until expansion of agriculture).
Slight tangent, their qpadm table (Extended 5) on the Basal Asian D related ancestry (Andamanese proxy) gives:
ShandongEn = 14%
Liangdao2En = 43%
Han_Shandong (Present) = 22% – e.g. present day Shandong would have about 27% Liangdao2En like, 63% Shandong_En like.
Han_Guangdong (Present) 28% – e.g. 48% Liangdao2En and 52% Shandong_En.
Agrees pretty well with previous estimate North Han about 1/3 derived from Southern China Early Neolithic and Northern China En 2/3, and 50:50 in South Han, with median probably closer to North China (e.g. probably 40:60, 35:65, 37:63).
Miao, Zhuang and Lahu about 30% “D-related” so slight dominance of Southern China Early Neolithic (>50%).
If Fujian EN is a proxy for Yangtze EN with proportions intermediate (but leaning to Fujian), then more contribution of early Yangtze population to present day East Asians.
Their model presents that Jomon and the Fujian En (Liangdao) would have not too different proportion of D related (57 v 48).
Devils Cave N estimated to have 11% while present day Ulchi only 1%, interesting given Ulchi presented as direct descendents of early Amur Basin people. Maybe some difference.
This all contrasts a bit with Melinda Yang paper suggesting no link between Jomon and Hoabinhians/Onge… But the D link does seem to make sense.
Obvs that Han cline seems predominantly pointed away from Shandong En towards Austronesians (more so that other groups/Fujian En samples) would suggest that Austronesians = Eastern Yangtze Early Neolithic and the main southern China side contributors to present day Han.
One other comment:
“Finally, an admixture between Tibeto-Burman incomers and indigenous Austroasiatic speakers formed the Tibeto-Burman speakers in Southeast Asia by ∼2,000 BP.”
However, to repeat as I always do, Lipson published the Oakaie sample from Myanmar dated 3000BP that showed a Sino-Tibetan genetic structure…
If the sample’s contaminated or wrongly dated and shouldn’t be admitted for use, that’s OK reason to not use, but not using it with no explanation gives the impression that some authors just “don’t like” the idea of Sino-Tibetans in today’s Myanmar by 3000BP and “want them” to be a later layer. If sample is OK, bizarre to ignore it as direct evidence in favour of indirectly inferring a later population movement.
Probably not the case that authors are just ignoring it and may have their reasons, but authors please explain why addressing this sample!
Can anyone explain how a supposed genetically closed population to the Basal East Eurasians “aka Australo-Melanesians” were able to reach as far north of the Asian continent, as the archipelago of Japan, in order to contribute massively to the Jomon hunter-gatherer gene pool?
It looks to me that this “ghost population” and their genetically closed relatives inhabited all the East Eurasian landmass before the Neolithic period.
Australians and Papuans are overwhelming K-lineage, this “Austo-Melanesian” label doesn’t make sense for D lineage. Both of them are also ‘Early East Eurasians’ genomeically. Andaman_HG is better term here like they are proposing in the paper but the whole picture is likely very complicated and not simply D-lineage as you’re suggesting.
Nothing is really ideal, certainly not Andamanese_HG; the population wasn’t co-evolving with Andamanese for much longer than the East Asian strand (low single digit thousands of years) and never did so in the Andaman Islands. That term is terrible as it would imply both of those things.
But the structure is important, not the label that’s hung on it.