Ancient DNA reveals sources of migration to Micronesia and female household-centered social structure, showing Micronesia distinct from nearby southwest Pacific

AMERICAN ASSOCIATION FOR THE ADVANCEMENT OF SCIENCE (AAAS)—An analysis of ancient and modern DNA from Micronesia – a scattering of nearly 2,000 islands in the western Pacific Ocean – has revealed unique migration and population patterns in the region unlike those in the nearby southwest Pacific. The findings indicate that Micronesia was populated by 5 successive migration streams from Southeast Asian islands. Moreover, these early settlements were matrilocal, characterized by a female household-centered social structure where men migrated to find their mates, settling with the female’s family and community. Archaeological evidence suggests that people first arrived and began settling the vast region of Micronesia roughly 3,500 years ago. However, due to sparse genomic data, where these people migrated from isn’t well understood. Despite this, Micronesia’s genetic history is often assumed to be similar to that of the southwest Pacific and Polynesia. Here, Yue-Chen Lui, David Reich and colleagues present an analysis of 164 ancient human genomes from five different archeological sites across Micronesia, representing several prehistoric periods ranging from 2,800-500 years ago, as well as 112 genomes from present-day individuals from the same area. Lui et al. discovered five separate migrations into Micronesia – three likely originating in East Asia, one from Polynesia and another from a Papuan source related to mainland New Guineans. According to the findings, people of the Mariana Archipelago may be the only population in Remote Oceania without Papuan ancestry. While the genomic ancestry of Micronesia differs from that in the southwest Pacific, the authors noted that female-inherited mitochondrial DNA was highly differentiated among Island communities, yet similar within them across many Pacific Islands. These findings indicate that many of the earliest groups to settle the region were matrilocal.

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Micronesian sunset. Pixabay

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Summary author: Walter Beckwith

Article Source: AAAS news release