Ancient genomes reveal distinct human dispersals and social stratification in the settlement history of western...

The settlement of western Remote Oceania involved interactions among deeply divergent populations. Initial settlement ∼3,000 years ago by Lapita-associated, Southeast Asian-related groups was followed by Papuan-related expansions and later sea voyages from Polynesia. We present genome-wide data spanning the past three millennia from the eastern Solomon Islands, Vanuatu, Fiji, and Tonga. We find that the Papuan-related expansion proceeded at a slower pace than the earlier Lapita-associated expansion and reached Fiji through at least two distinct human dispersals, centuries earlier than previously suggested. We provide direct evidence of Polynesian-related gene flow at around 1,000 years ago, giving rise to Polynesian Outlier communities in southern Vanuatu. Finally, we examine an early Fijian community, revealing social practices that preserved wealth/status within a biological kin group with elevated Southeast Asian-related ancestry. Our findings refine the settlement model of western Remote Oceania and highlight the complex interplay of past migrations and community structure.