Deep ancestry of Bornean hunter-gatherers supports long-term local ancestry dynamics.

Borneo was a crossroad of ancient dispersals, with some of the earliest Southeast Asian human remains and rock art. The island is home to traditionally hunter-gatherer Punan communities, whose origins, whether of subsistence reversion or long-term foraging, are unclear. The connection between its past and present-day agriculturalist inhabitants, who currently speak Austronesian languages and have composite and complex genetic ancestry, is equally opaque. Here, we analyze the genetic ancestry of the northeastern Bornean Punan Batu (who still practice some mobile hunting and gathering), Tubu, and Aput. We find deep ancestry connections, with a shared Asian signal outgrouping modern and ancient Austronesian-ancestry proxies, suggesting a time depth of more than 7,500 years. They also largely lack the mainland Southeast Asian signals of agricultural Borneans, who are themselves genetically heterogeneous. Our results support long-term inhabitation of Borneo by some Punan ancestors and reveal unexpected complexity in the origins and dispersal of Austronesian-expansion-related ancestry.