Abstract：
The Massim, a cultural region that includes the southeastern tip of mainland Papua New Guinea (PNG) and nearby PNG offshore islands, is renowned for a trading network called Kula, in which different valuable items circulate in different directions among some of the islands. Although the Massim has been a focus of anthropological investigation since the pioneering work of Malinowski in 1922, the genetic background of its inhabitants remains relatively unexplored. To characterize the Massim genomically, we generated genome-wide SNP data from 192 individuals from 15 groups spanning the entire region. Analyzing these together with comparative data, we found that all Massim individuals have variable Papuan-related (indigenous) and Austronesian-related (arriving ∼3,000 years ago) ancestries. Individuals from Rossel Island in southern Massim, speaking an isolate Papuan language, have the highest amount of a distinct Papuan ancestry. We also investigated the recent contact via sharing of identical by descent (IBD) genomic segments and found that Austronesian-related IBD tracts are widely distributed geographically, but Papuan-related tracts are shared exclusively between the PNG mainland and Massim, and between the Bismarck and Solomon Archipelagoes. Moreover, the Kula-practicing groups of the Massim show higher IBD sharing among themselves than do groups that do not participate in Kula. This higher sharing predates the formation of Kula, suggesting that extensive contact between these groups since the Austronesian settlement may have 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.
摘要：
Massim,一个文化区域，包括巴布亚新几内亚大陆（PNG）的东南端和附近的PNG近海岛屿，以一个叫库拉的交易网络而闻名，不同的贵重物品在一些岛屿之间沿不同的方向流通。尽管自1922年Malinowski的开创性工作以来，Massim一直是人类学调查的重点，但其居民的遗传背景仍未被探索。从基因组上描述Massim，我们从整个区域的15组192个个体中产生了全基因组SNP数据.将这些与比较数据一起分析，我们发现，所有Massim个体都有可变的巴布亚相关（土著）和南岛相关（在3000年前到达）祖先。来自Massim南部的Rossel岛的个人，说一种孤立的巴布亚语言，拥有最高数量的独特巴布亚血统。我们还通过共享相同的血统（IBD）基因组片段调查了最近的接触，发现与南岛有关的IBD片段在地理上分布广泛，但是与巴布亚相关的片段完全由PNG大陆和Massim共享，在俾斯麦群岛和所罗门群岛之间。此外，Massim的Kula实践小组与不参加Kula的小组相比，它们之间的IBD共享更高。这种更高的份额早于库拉的形成，这表明自南岛人定居以来，这些群体之间的广泛接触可能促进了库拉的形成。我们的研究提供了对Massim居民的第一个全面的全基因组评估，以及对迷人的Kula系统的新见解。
