Article

Genome-wide Analysis Indicates More Asian than Melanesian Ancestry of Polynesians

Department of Forensic Molecular Biology, Erasmus University Medical Center Rotterdam, PO Box 2040, 3000 CA Rotterdam, The Netherlands.
The American Journal of Human Genetics (Impact Factor: 10.93). 02/2008; 82(1):194-8. DOI: 10.1016/j.ajhg.2007.09.010
Source: PubMed

ABSTRACT

Analyses of mitochondrial DNA (mtDNA) and nonrecombining Y chromosome (NRY) variation in the same populations are sometimes concordant but sometimes discordant. Perhaps the most dramatic example known of the latter concerns Polynesians, in which about 94% of Polynesian mtDNAs are of East Asian origin, while about 66% of Polynesian Y chromosomes are of Melanesian origin. Here we analyze on a genome-wide scale, to our knowledge for the first time, the origins of the autosomal gene pool of Polynesians by screening 377 autosomal short tandem repeat (STR) loci in 47 Pacific Islanders and compare the results with those obtained from 44 Chinese and 24 individuals from Papua New Guinea. Our data indicate that on average about 79% of the Polynesian autosomal gene pool is of East Asian origin and 21% is of Melanesian origin. The genetic data thus suggest a dual origin of Polynesians with a high East Asian but also considerable Melanesian component, reflecting sex-biased admixture in Polynesian history in agreement with the Slow Boat model. More generally, these results also demonstrate that conclusions based solely on uniparental markers, which are frequently used in population history studies, may not accurately reflect the history of the autosomal gene pool of a population.

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    • "It is important to fully specify the models and which components are being tested - for example, there are at least seven independent components to the ‘express train’ model including three related to Taiwan (language, associated culture, and the maternal genetics from mitochondrial DNA), three related to the rate of movement (including a relatively rapid movement, no significant breaks after leaving Taiwan until reaching Western Polynesia, little displacement of existing peoples), and finally the question of ongoing genetic contact with other peoples in the region – including differences between introgression of males and females [12]. Also, different models can have the same name; an example being the ‘slow boat’ models of Kayser et al. [13] and of Oppenheimer and Richards [14]. While we do not attempt to formally evaluate the main models here (but see Hurles et al, 2003 [2]), it is important to be aware that most models have several compon that can be evaluated independently, and by using data from a range of disciplines. "
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