Based on archaeology, linguistics, and, most recently, genetics, it is traditionally thought that Polynesia was inhabited by mariners originating in Taiwan or south China beginning about 3,500 years ago (in fact, our departmental reading, Relethford’s “Reflections of Our Past,” has an interesting chapter on this issue).
A recently published study modifies this story somewhat. This study looked at the largest mtDNA (which is only passed through the maternal line) sample to date in order to determine which populations were most similar to modern Polynesians. From an interview with Martin Richards, one of the members of the research team, in the ScienceDaily summary:
“Most previous studies looked at a small piece of mtDNA, but for this research we studied 157 complete mitochondrial genomes in addition to smaller samples from over 4,750 people from across Southeast Asia and Polynesia. We also reworked our dating techniques to significantly reduce the margin of error. This means we can be confident that the Polynesian population — at least on the female side — came from people who arrived in the Bismarck Archipelago of Papua New Guinea thousands of years before the supposed migration from Taiwan took place.”
What is especially interesting here is that the linguistic and archaeological evidence still strongly suggest some sort of connection with Taiwan. For one, modern Polynesian languages are thought to belong to the Austronesian language family, which is a group of languages spoken from Madagascar to Easter Island, but differ from the native languages of Australia and New Guinea. Archaeologists maintain that the earliest Polynesian pottery (called the “Lapita Culture”) shares many similarities to earlier pottery found on Taiwan and in south China. So, how do we reconcile these findings with the genetics? Again, Dr. Richards:
“Although our results throw out the likelihood of any maternal ancestry in Taiwan for the Polynesians, they don’t preclude the possibility of a Taiwanese linguistic or cultural influence on the Bismarck Archipelago at that time,” explains Professor Richards. “In fact, some minor mitochondrial lineages back up this idea. It seems likely there was a ‘voyaging corridor’ between the islands of Southeast Asia and the Bismarck Archipelago carrying maritime traders who brought their language and artefacts and perhaps helped to create the impetus for the migration into the Pacific.
“Our study of the mtDNA evidence shows the interactions between the islands of Southeast Asia and the Pacific was far more complex than previous accounts tended to suggest and it paves the way for new theories of the spread of Austronesian languages.”
This implies that later populations were moving through the area with their language and culture, but they were not necessarily bringing their genes (i.e., interbreeding), at least on the female side.