Genetic study uncovers new path to Polynesia

Surprising new evidence which overturns current theories of how humans colonised the Pacific has been discovered by scientists at the University of Leeds.

The islands of Polynesia were first inhabited around 3,000 years ago, but where these people came from has long been a hot topic of debate amongst scientists.

The most commonly accepted view, based on archaeological and linguistic evidence as well as genetic studies, is that Pacific islanders were the latter part of a migration south and eastwards from Taiwan which began around 4,000 years ago.

But the Leeds research - published today in The American Journal of Human Genetics - has found that the link to Taiwan does not stand up to scrutiny. In fact, the DNA of current Polynesians can be traced back to migrants from the Asian mainland who had already settled in islands close to New Guinea some 6-8,000 years ago.

The type of DNA extracted and analysed in this kind of study is that stored in the cell's mitochondria.

Mitochondrial DNA (mtDNA) is passed down the maternal line, providing a record of inheritance which goes back thousands of years. The scientists look for genetic signatures which enable them to classify the DNA into different lineages and then use a 'molecular clock' to date when these lineages moved into different parts of the world.