Mitochondrial DNA variation is an indicator of Austronesian influence in Island Melanesia

Abstract

Past studies have shown a consistent association of a specific set of mitochondrial DNA 9 base pair (bp) deletion haplotypes with Polynesians and their Austronesian-speaking relatives, and the total lack of the deletion in a short series of New Guinea Highlanders. Utilizing plasma and DNA samples from various old laboratory collections, we have extended population screening for the 9-bp deletion into "Island Melanesia," an area notorious for its extreme population variation. While the 9-bp deletion is present in all Austronesian, and many non-Austronesian-speaking groups, it is absent in the more remote non-Austronesian populations in Bougainville and New Britain. These results are consistent with the hypothesis that this deletion was first introduced to this region about 3,500 years ago with the arrival of Austronesian-speaking peoples from the west, but has not yet diffused through all populations there. The pattern cannot be reconciled with the competing hypothesis of a primarily indigenous Melanesian origin for the ancestors of the Polynesians. Although selection clearly has operated on some other genetic systems in this region, both migration and random genetic drift primarily account for the remarkable degree of biological diversity in these small Southwest Pacific populations.

Maori origins, Y-chromosome haplotypes and implications for human history in the Pacific

“…In addition, there may have been a dis-proportionate amount of non-Polynesian male mediated gene flow, compared to females, from Melanesian related populations following initial settlement. Thus, in contrast to most of mtDNA and linguistic data [Merriwether et al, 1999;Gray and Jordan, 2000], the scenario suggested here by Y-chromosome variation is more consistent with a deep genetic contribution of Melanesian ancestry to the Polynesian gene pool than with the "Express Train to Polynesia" model.…”

“…These migrations are a part of the overall colonization of Austronesian Polynesia that started from Southeast Asia about 3,000-4,000 years ago. While much of the evidence pertaining to the origins of Polynesians is archeological and linguistic [Bellwood, 1978;Gray and Jordan, 2000], mitochondrial DNA evidence has provided an independent assessment that is consistent with a Southeast Asian Austronesian influence [Hertzberg et al, 1989;Murray-McIntosh et al, 1998;Merriwether et al, 1999]. A different scenario, recently suggested by Y-chromosome markers, indicates that Melanesian populations strongly influenced the Polynesian gene pool [Kayser et al, 2000;Capelli et al, 2001].…”

Genetic characterization of four Austronesian-speaking populations

“…Melton et al (1998) further suggested that since the origin of the ''Polynesian motif'' can be traced to Taiwan, the island of Formosa may be the origin of the expansion. The genetic influence of these aboriginal groups from Formosa in Melanesia has also been supported by other mtDNA investigations (Merriwether et al 1999). Other mtDNA studies have suggested that the Indonesian archipelago may be the origin of the expansion some 17,000 years ago (Richards et al 1998).…”

Mitochondrial DNA analysis reveals diverse histories of tribal populations from India

“…The mitochondrial DNA (mtDNA) intergenic COII/tRNA Lys 9-bp deletion marker, present at high frequency in some Asian 15 and African 16 populations, is found at low frequencies in India and arose multiple times independently. [17][18][19] Based on a study of autosomal and mtDNA markers in eight Indian tribes speaking Austro-Asiatic, Dravidian or Tibeto-Burman languages, it was concluded that these different language groups represented distinct founding groups, with AustroAsiatic speakers being the most ancient inhabitants of the region.…”