Of interest is that the racial ancestry of Polynesians as evidenced by genomic analysis is different from the expected one based on uniparentally transmitted markers (on mtDNA and the Y chromosome). Nonetheless, the discrepancy is small enough to validate the use of such markers as a first-order approximation of a people's racial ancestry.
The American Journal of Human Genetics, Volume 82, Issue 1, 194-198, 10 January 2008
Genome-wide Analysis Indicates More Asian than Melanesian Ancestry of Polynesians
Manfred Kayser et al.
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.