Spencer Wells
Spencer Wells

@spwells

7 Tweets 14 reads Nov 08, 2021
Ancient genomes from the last three millennia support multiple human dispersals into Wallacea ๐Ÿงฌ๐Ÿ‡ฎ๐Ÿ‡ฉ๐ŸŒ Cool paper - well worth a threadโ€ฆ (1/n)
biorxiv.org
16 genomes were sampled in Wallacea, spanning a temporal range of ~2600 to ~250 years before present (YBP). The oldest sample is from Liang Bua on Flores, the same cave where H. floresiensis was discovered. Samples came from NTT, Sulawesi and the North Moluccas. (2/n)
The Austronesian admixture in Wallacea is estimated to have begun ~3,000 YBP, consistent w/ archaeology, though the data suggest successive waves of migration & admixture that complicates estimates from newer samples. Perhaps older samples might yield even earlier datesโ€ฆ? (3/n)
The authors suggest most of the Denisovan admixture in Wallacea arrived via back-migration from New Guinea, and show that itโ€™s correlated with the level of Papuan ancestry. Very interesting, and more evidence to support the notion that PNG was the Denisovansโ€™ final refuge. (4/n)
Finally - this was especially fascinating - even the earliest sample from NTT (the 2,600 YBP Liang Bua individual) had substantial admixture with mainland Southeast Asia, suggesting a very old migration from the mainland to the Sundas, but not to the Moluccas. (5/n)
The oldest evidence of contact between these regions prior to this was was from the Dong Son drums (like the ones at the Mataram museum earlier this week), dating from nearly a millennium later than the Liang Bua sample. (6/n)
One final interesting finding is that the individuals studied were genetically more similar to present-day Papuans than to the mid-Holocene Wallacean genome published in August, despite being from the same region. The identity of these more ancient Wallaceans remains an enigma.

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