DNA from ancient skeletons reveals the Polynesians may have come from Taiwan 5,000 years ago

Scattered across the Pacific Ocean, they were some of the last places on Earth to be populated by humans around 3,000 years ago.

Now a genetic study has raised intriguing new insights into who the pioneering sea-going people who first arrived on the remote South Pacific Islands were.

The findings suggest that the first inhabitants on the Polynesian islands did not come from New Guinea as originally thought.

Instead they appear to have come from another mysterious Neolithic East Asian population that is thought to have originated in Taiwan.

Researchers have sequenced the genomes of four individuals of the Lapita culture who lived between 2,300 and 3,100 years ago on the islands of Vanuatu and Tonga.

They compared these to DNA from 778 people who currently live on the islands as well as elsewhere in East Asia and Oceania.

They found that Pacific islanders have a mix of ancestry from Papuan people of New Guinea and the ancient East Asian population.

The scientists say there was almost no Papuan ancestry in the genomes of the four ancient remains they analysed.

This suggests that the Papuan people must have arrived on the islands at a later date and mixed with the people who were already living there around 500 to 1,100 years ago.

Writing in the journal Nature, Dr David Reich, a geneticist at Harvard Medical School, said: “Our study has shown that many of the first humans in remote Oceania had little, if any, Papuan ancestry, in stark contrast to the situation today.

“The scenario emerging from ancient DNA analysis is radically different from that suggested by previous genetic studies, which have generally posited that the first people in Remote Oceania and Polynesia had substantial Papuan ancestry.” 

The first modern humans who are thought to have spread from southeast Asia to the islands of Indonesia, New Guinea and then onto Australia around 40,000 years ago.

However, outlying islands in the Pacific remained uninhabited until around 3,000 years ago. These people are thought to have used the first boats capable of long distance sea travel.

They also brought several species of domesticated animals and plants to the islands. Distinctive earthenware pottery has been found at many sites inhabited by these pioneers.

It has been previously assumed that these people who formed the Lapita culture were part of the Papuan people of New Guinea – who are descendants of the first wave of humans who spread from southeast Asia 40,000 years ago.

But modern people living in the Pacific islands owe just 25 per cent of their genetic heritage to the Papuans of New Guinea. 

Dr Reich and his colleagues analysed DNA from the remains of three skeletons found in a large cemetery on Efate Island in Vanuatu and one from the Talasiu site on Tongatapu island, Tonga.

They found that the ancient skeletons were not have any ancestry from the Papuans and instead appear to descend from another unknown group from East Asia.

Traces of these people can still be found today in the genomes of nearly all Pacific Islanders today - from Vanuatu to Hawaii..

Professor Matthew Spriggs, an archaeologist at the Australian National University who was one of the co-authors of the research, said it provides new insights into these people’s ancestry.

He told MailOnline: “In this new paper we have basically cracked the problem of the origin of Pacific Islanders, often posed as the 'origin of the Polynesians”.

“Some archaeologists such as myself have argued that the Lapita culture of the Western Pacific is primarily the easterly expansion of the Island SE Asian Neolithic that originates in Taiwan perhaps 5500 years ago as pottery using farmers.

“It then spreads through the Philippines and Eastern Indonesia shortly after 4000 years ago, and just over 3000 years ago appears in the Western Pacific as the Lapita culture.

“This spreads from the islands off New Guinea's eastern end through Solomons, Vanuatu, New Caledonia, Fiji and on to Tonga and Samoa.

There is then a major pause until just over 1000 years ago in Western Polynesia before descendant groups spread to places such as Hawaii, Easter Island and finally to New Zealand about 700 years ago.”

The research also suggests some members of the Lapita people formed colonies along the coasts of New Guinea and nearby islands where they began intermingling with long settled Papuans.

It was then these people who formed the second wave and began intermarrying with the original Asian Pacific islanders in places like Vanuatu and Tonga.

The new study also highlights that the majority of the Lapita East Asian ancestry appears to come from female rather than male ancestors.

This suggests the Papuans who arrived on the islands were mainly men who mixed with females from the Lapita culture who were already living there.

Professor Spriggs said the findings may also lead to some changing ideas about the ancestry of other groups living in the Pacific Ocean.

He said: “In fact the difference between a 'Polynesian' and a 'Melanesian' is simply a question of the percentage of Asian as opposed to Papuan genes.

“If you have 26 per cent Papuan then you are called a Polynesian, when it gets up towards 50 per cent or more you are called a Melanesian. 

“I think it is time to abandon these terms and just talk about 'Pasifika' people and their origins from two great gene pools - the Papuan and the Asian First Remote Oceans.”....

 

DNA was extracted from this 3,000 year old skull and mandible from Vanuatu

Supplied: Frederique Valentin