Human genome-wide variations in the Massim region

The Massim, a cultural region encompassing the southeastern tip of mainland Papua New
Guinea (PNG) and nearby islands, is famous for the Kula trading network, in which
different valuables circulate in different directions among the islands. To explore Massim
genetic history, we generated genome-wide data from across the region and found variable
levels of Papuan-related (indigenous) ancestry, including a novel ancestry associated with
Rossel Island, and Austronesian-related ancestry that arrived later. We find genetic
evidence for different patterns of contact across PNG, the Massim, and the Bismarck and
Solomon Archipelagoes for Austronesian-related vs. Papuan-related ancestry, with more
geographic restriction for the latter. Moreover, Kula-practicing groups share more genetic
similarity than do other groups, and this likely predates the origin of Kula, suggesting that
high between-group contact facilitated the formation of Kula. Our study provides the first
comprehensive genome-wide assessment of Massim inhabitants and new insights into the
fascinating Kula system.EGA study EGAS00001006010