Investigating the origins of eastern Polynesians using genome-wide data from Leeward Society Isles

Genetic evidence from the Leeward Society Isles supports inter-connectivity models of Polynesian originsThe settlement of Polynesia represents the last major episode of human pioneering settlement, and is one of the most intensively studied subject areas in post-war anthropology. To date, research into the origins of Polynesians has been focused on the Lapita era settlement of western Polynesia, with a tendency to treat the settlement of eastern Polynesia as an inevitable consequence of people arriving in Tonga and Samoa during the early 3rd millennium BP. To investigate the settlement history of eastern Polynesia, we generated novel multi-locus genetic data from the Leeward Society Isles, located at the centre of this region. The results of our analyses are consistent with archaeological dates for the late settlement of eastern Polynesia commencing ~1,000 BP, and indicate that the ancestors of the Leeward Society Islanders were predominantly Island Southeast Asian in origin whose genomes display evidence for multiple episodes of admixture with people of northern Melanesian ancestry. The multi-locus data sets suggest a complex demographic history, involving the Solomon Islands, and provide potentially important insights into putative sources in Island Southeast Asia contributing to the ancestry of the peoples of the Leeward Society Isles.