Pacific Islanders’ Ancestry Emerges in Genetic Study

New light is shed of how the pacific islands were populated in a study published in the journal of the Public Library of Science – Genetics. The new study shows that the pacific islanders share very little genetic traits with those from Melanesia (the region encompassing Maluku to the east and Fiji to the west) and have much more in common with the aboriginies in Taiwan and East Asia. This in turn infers that a human migration from Taiwan eastwards had little interaction with Melanesia, and that the colonization of the pacific islands were not a result of Melanesians moving east.

Pacific Islanders’ Ancestry Emerges in Genetic Study
New York Times, 18 January 2008

The abstract of the study, “The Genetic Structure of Pacific Islanders”

Human genetic diversity in the Pacific has not been adequately sampled, particularly in Melanesia. As a result, population relationships there have been open to debate. A genome scan of autosomal markers (687 microsatellites and 203 insertions/deletions) on 952 individuals from 41 Pacific populations now provides the basis for understanding the remarkable nature of Melanesian variation, and for a more accurate comparison of these Pacific populations with previously studied groups from other regions. It also shows how textured human population variation can be in particular circumstances. Genetic diversity within individual Pacific populations is shown to be very low, while differentiation among Melanesian groups is high. Melanesian differentiation varies not only between islands, but also by island size and topographical complexity. The greatest distinctions are among the isolated groups in large island interiors, which are also the most internally homogeneous. The pattern loosely tracks language distinctions. Papuan-speaking groups are the most differentiated, and Austronesian or Oceanic-speaking groups, which tend to live along the coastlines, are more intermixed. A small “Austronesian” genetic signature (always <20%) was detected in less than half the Melanesian groups that speak Austronesian languages, and is entirely lacking in Papuan-speaking groups. Although the Polynesians are also distinctive, they tend to cluster with Micronesians, Taiwan Aborigines, and East Asians, and not Melanesians. These findings contribute to a resolution to the debates over Polynesian origins and their past interactions with Melanesians. With regard to genetics, the earlier studies had heavily relied on the evidence from single locus mitochondrial DNA or Y chromosome variation. Neither of these provided an unequivocal signal of phylogenetic relations or population intermixture proportions in the Pacific. Our analysis indicates the ancestors of Polynesians moved through Melanesia relatively rapidly and only intermixed to a very modest degree with the indigenous populations there.

You can download the open access article here.

Related Books:
Man’s conquest of the Pacific: The prehistory of Southeast Asia and Oceania by P. Bellwood
Indo-Pacific Prehistory 1990. Proceedings of the 14th Congress Held at Yogyakarta. Vol 1 & 2. by P. Bellwood (Ed)
East of Wallace’s Line : Studies of Past and Present Maritime Cultures of the Indo-Pacific Region (Modern Quaternary Research in Southeast Asia, V. 16)
Prehistory of the Indo-Malaysian Archipelago by P. Bellwood

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Author: Noel Tan

Dr Noel Hidalgo Tan is the Senior Specialist in Archaeology at SEAMEO-SPAFA, the Southeast Asian Regional Centre for Archaelogy and Fine Arts.

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