Genomic insights into the peopling of the Southwest Pacific

Abstract

The appearance of people associated with the Lapita culture in the South Pacific ~3,000 years ago1 marked the beginning of the last major human dispersal to unpopulated lands. However, the relationship of these pioneers to the long established Papuans of the New Guinea region is unclear. We report genome-wide ancient DNA data from four individuals from Vanuatu (~3100-2700 years before present) and Tonga (~2700-2300 years before present), and co-analyze them with 778 present-day East Asians and Oceanians. Today, indigenous peoples of the South Pacific harbor a mixture of ancestry from Papuans and a population of East Asian origin that does not exist in unmixed form today, but is a match to the ancient individuals. Most analyses have interpreted the minimum of twenty-five percent Papuan ancestry in the region today as evidence that the first humans to reach Remote Oceania, including Polynesia, were derived from population mixtures near New Guinea, prior to the further expansion into Remote Oceania2–5. However, our finding that the ancient individuals had little to no Papuan ancestry implies later human population movements that spread Papuan ancestry through the South Pacific after the islands’ first peopling.

Tracing the peopling of the world through genomics

“…The Melanesian ancestry was added to the original East Asian ancestry after the initial Polynesian expansion had begun 80 . Whether Polynesians reached the Americas and admixed with Native Americans during their eastward expansion that ended about 1 kyr ago remains controversial.…”

Multi-isotopic analysis of first Polynesian diet (Talasiu, Tongatapu, Kingdom of Tonga)

“…BP (Valentin and Clark, 2013;Clark et al, 2015;Skoglund et al, 2016) (Table 1). Calibrated charcoal and bone 14 C ages between 2600 and 2300 BP are strongly influenced by curve flattening resulting in multiple curve intercepts and a substantial widening in the calibrated age range of determinations.…”

“…Originating from South-East Asia, the first settlers of the Pacific region east of the Solomon archipelago are associated with the Lapita culture that appeared about 3300 years ago in north Melanesia (Summerhayes et al, 2010;Skoglund et al, 2016;Valentin et al, 2016). These original colonizers are generally regarded as people with a mixed subsistence economy that combined the exploitation of marine resources with a low level of terrestrial resource production based on chicken or pig husbandry and taro cultivation (Groube, 1971;Burley, 1999;Kirch, 2002;Kennett et al, 2006).…”

A Minimally-Invasive Method for Sampling Human Petrous Bones from the Cranial Base for Ancient DNA Analysis

“…Additional recent developments in aDNA analysis have focused on increasing DNA yields through optimized extraction protocols (11), improved library preparation (12,13), and the addition of enrichment techniques prior to sequencing (14,15). These developments have led to the first publications of genome-wide data on prehistoric human specimens from non-temperate regions, including Africa, the Near East, and the Southwest Pacific (2,7,1619). Nevertheless, an equally important potential area of improvement is bone sampling methods.…”