UCSC Paleogenomics Lab, Department of Anthropology, University of California, Santa Cruz, 1156 High Street, Santa Cruz, CA 95064, USA; UCSC Genomics Institute, University of California, Santa Cruz, 1156 High Street, Santa Cruz, CA 95064, USA.
Department of Archaeology and Anthropology, University of Bristol, 43 Woodland Road, Bristol BS8 1UU, UK.
Curr Biol. 2017 Oct 23;27(20):3209-3215.e6. doi: 10.1016/j.cub.2017.09.029. Epub 2017 Oct 12.
The origins and lifeways of the inhabitants of Rapa Nui (Easter Island), a remote island in the southeast Pacific Ocean, have been debated for generations. Archaeological evidence substantiates the widely accepted view that the island was first settled by people of Polynesian origin, as late as 1200 CE [1-4]. What remains controversial, however, is the nature of events in the island's population history prior to the first historic contact with Europeans in 1722 CE. Purported contact between Rapa Nui and South America is particularly contentious, and recent studies have reported genetic evidence for Native American admixture in present-day indigenous inhabitants of Rapa Nui [5-8]. Statistical modeling has suggested that this genetic contribution might have occurred prior to European contact [6]. Here we directly test the hypothesis that the Native American admixture of the current Rapa Nui population predates the arrival of Europeans with a paleogenomic analysis of five individual samples excavated from Ahu Nau Nau, Anakena, dating to pre- and post-European contact, respectively. Complete mitochondrial genomes and low-coverage autosomal genomes show that the analyzed individuals fall within the genetic diversity of present-day and ancient Polynesians, and we can reject the hypothesis that any of these individuals had substantial Native American ancestry. Our data thus suggest that the Native American ancestry in contemporary Easter Islanders was not present on the island prior to European contact and may thus be due to events in more recent history.
拉帕努伊岛（复活节岛）位于东南太平洋，其居民的起源和生活方式已争论了几代人。考古证据证实了一个广泛被接受的观点，即该岛最初是由波利尼西亚人于公元 1200 年左右定居的[1-4]。然而，在公元 1722 年与欧洲人首次有历史记载的接触之前，该岛人口历史上的事件性质仍存在争议。拉帕努伊岛与南美洲之间据称有过接触，这一点尤其有争议，最近的研究报告称，在拉帕努伊岛的现代土著居民中存在美洲原住民的混血[5-8]。统计模型表明，这种遗传贡献可能发生在与欧洲人接触之前[6]。在这里，我们通过对分别来自阿胡 Nau Nau和阿纳凯纳的五个个体样本的古基因组分析，直接检验了当前拉帕努伊岛人口的美洲原住民混血发生在欧洲人到来之前的假设。对完整的线粒体基因组和低覆盖率的常染色体基因组的分析表明，所分析的个体属于现代和古代波利尼西亚人的遗传多样性范围，我们可以拒绝这些个体中有大量美洲原住民祖先的假设。因此，我们的数据表明，当代复活节岛民的美洲原住民血统在欧洲人接触之前并未出现在该岛上，可能是由于更近的历史事件所致。
