Polynesian Ancestors May have Migrated Through Indonesia, not Taiwan
Previous research had suggested Polynesian origins were in Taiwan or the southwestern Pacific islands of Melanesia.
But a new study led by Bing Su of the University of Texas Health Science Center in Houston fails to support the older theory, suggesting the South Asian migration route. The findings are being published in Tuesday's issue of Proceedings of the National Academy of Science.
The team studied the Y chromosomes of 551 men from across the Pacific and Southeast Asia, comparing the distribution of 15 specific genetic markers on those chromosomes.
The Y chromosome is specific to males and is passed from father to son.
They found that the Taiwanese aboriginal peoples carried a different set of these markers than either the Polynesians of the eastern Pacific or the Micronesians of the northwestern Pacific.
Indeed, the study concluded that "the divergence between the Taiwanese and the Micronesian/Polynesian populations is twice as great as the divergence of either population group from Southeast Asians."
The researchers concluded that the most likely explanation for their findings is that both the original Taiwanese and the Polynesians originated in Southeast Asia, but that they dispersed independently of one another.
The researchers also noted that there has been controversy over the extent to which the Melanesians of the southwestern Pacific contributed to the populations of Micronesia, to their north, and Polynesia, to their east.
They found one marker, H17, common in Melanesians was completely missing in Polynesians, suggesting the Melanesian contribution was "very low or negligible."
They also found no significant European contribution to Polynesian ancestry. While the Y chromosome study does not unequivocally point to a center of origin for the Polynesians, the islands of Southeast Asia, such as the Indonesian group, emerge as a probable migration route, the researchers said.
The earlier theory of Polynesian origins, suggesting dispersal via Taiwan, had been based on studies of mitochondrial DNA. That is a type of DNA inherited only from the mother.
Some questions about the earlier studies have been raised in recent years, but the researchers said the reason for the different findings using the male-only Y chromosome is unclear. One possibility, they suggested, might have been differences in male and female migration patterns.
Polynesia is the group of Pacific Islands east of the International Date Line, including Hawaii, Samoa, Tonga, the Society Islands and others. Melanesia is generally south of the Equator and west of the date line, including the islands from the New Guinea to Fiji, the Solomon Islands and Vanuatu. Micronesia is north of the Equator and west of the date line, including the Mariana, Marshall and Caroline islands.
More
