Bridging near and remote Oceania: mtDNA and NRY variation in the Solomon Islands.

Conectando-se próximo e distante da Oceania: variação de mtDNA e NRY nas Ilhas Salomão.

Delfin F¹, Myles S, Choi Y, Hughes D, Illek R, van Oven M, Pakendorf B, Kayser M, Stoneking M.

Author information

Mol Biol Evol. 2012 Feb;29(2):545-64. doi: 10.1093/molbev/msr186. Epub 2011 Jul 18.

Abstract

Although genetic studies have contributed greatly to our understanding of the colonization of Near and Remote Oceania, important gaps still exist. One such gap is the Solomon Islands, which extend between Bougainville and Vanuatu, thereby bridging Near and Remote Oceania, and include both Austronesian-speaking and Papuan-speaking groups. Here, we describe patterns of mitochondrial DNA (mtDNA) and nonrecombining Y chromosome (NRY) variation in over 700 individuals from 18 populations in the Solomons, including 11 Austronesian-speaking groups, 3 Papuan-speaking groups, and 4 Polynesian Outliers (descended via back migration from Polynesia).

Embora os estudos genéticos tenham contribuído muito para nossa compreensão da colonização da Oceania Própria e Remota, lacunas importantes ainda existem. Uma dessas lacunas são as Ilhas Salomão, que se estendem entre Bougainville e Vanuatu, conectando assim as regiões próximas e remotas da Oceania, e incluem tanto os grupos de língua austronésia quanto os de língua papua. Aqui, descrevemos padrões de DNA mitocondrial (mtDNA) e não-recombinante cromossomo Y (NRY) variação em mais de 700 indivíduos de 18 populações nas Ilhas Salomão, incluindo 11 grupos de língua Austronesian, 3 grupos de língua Papua, e 4 outliers polinésia (descendente via migração de volta da Polinésia).
 
We find evidence for ancient (pre-Lapita) colonization of the Solomons in old NRY paragroups as well as from M2-M353, which probably arose in the Solomons ∼9,200 years ago and is the most frequent NRY haplogroup there. There are no consistent genetic differences between Austronesian-speaking and Papuan-speaking groups, suggesting extensive genetic contact between them. Santa Cruz, which is located in Remote Oceania, shows unusually low frequencies of mtDNA and NRY haplogroups of recent Asian ancestry.

This is in apparent contradiction with expectations based on archaeological and linguistic evidence for an early (∼3,200 years ago), direct colonization of Santa Cruz by Lapita people from the Bismarck Archipelago, via a migration that "leapfrogged" over the rest of the Solomons. Polynesian Outliers show dramatic island-specific founder events involving various NRY haplogroups. We also find that NRY, but not mtDNA, genetic distance is correlated with the geographic distance between Solomons groups and that historically attested spheres of cultural interaction are associated with the recent genetic structure of Solomons groups, as revealed by mtDNA HV1 sequence and Y-STR haplotype diversity. Our results fill an important lacuna in human genetic studies of Oceania and aid in understanding the colonization and genetic history of this region.

PMID:

21771715

DOI:

10.1093/molbev/msr186