WASHINGTON: A genetic study helps confirm the theory that Polynesians, who settled islands across a vast swathe of ocean, started out in Taiwan, researchers reported on Monday.

Mitochondrial DNA, which is passed along virtually unchanged from mothers to their children, provides a kind of genetic clock linking present-day Polynesians to the descendants of aboriginal residents of Taiwan.

Samples taken from nine indigenous Taiwanese tribes — who are different ethnically and genetically from the now-dominant Han Chinese — show clear similarities between the Taiwan groups and ethnic Polynesians, Jean Trejaut and Marie Lin of Mackay Memorial Hospital in Taipei and colleagues reported.

Indigenous Taiwanese, Melanesian and Polynesian populations share three specific mutations in their mitochondrial DNA that are not found in mainland east Asian populations, they report in the journal Public Library of Science Biology.

Their findings suggest that Taiwanese aboriginal populations have been genetically isolated from mainland Chinese for between 10,000 and 20,000 years, and that the original Polynesian migrants originated from people identical to the aboriginal Taiwanese.

Earlier studies have looked at the Y chromosome, which men pass along from father to son.

No Y chromosome link has been found between the early residents of the island of Formosa and the Polynesians, which could suggest early Oceanic societies organized around wives and mothers, the researchers, who included a team at Estonian Biocentrein Tartu, Estonia, said.—Reuters