Ancient DNA has revealed the first inhabitants of Vanuatu and Tonga came from Asia, not other Oceanic populations as has long been assumed, a study published Tuesday found.
The study sheds light on the last great human migration into unpopulated lands, when a people called the Lapita fanned out into the South Pacific about 3,000 years ago.
Little is known of the mysterious culture beyond their distinctive dotted pottery and the human remains they left behind.
Scientists had speculated that they were an offshoot of Australo-Papuan populations of Australia, New Guinea and the Solomon Islands, who arrived in the region 40,000-50,000 years ago.
But analysis of three skeletons from Vanuatu's oldest cemetery found they came from Asia, with no trace of DNA from their Pacific neighbours.
"Their original base population is Asian. They were straight out of Taiwan and perhaps the northern Philippines," said Matthew Spriggs, a professor at the Australian National University and one of the researchers involved in the study.
"They travelled past places where people were already living, but when they got to Vanuatu there was nobody there. These are the first people."
Spriggs said another DNA sample from a Lapita skeleton in Tonga returned similar results.
"We know this because testing conducted by two different laboratories in the United States and Germany confirm that the samples are of the same people," he said.
He added that it now appeared the Asiatic Lapita first colonised the South Pacific, then intermingled with a second wave of Australo-Papuan settlers to create the region's modern genetic mix.
Professor Ron Pinhasi from University College Dublin said the study, published in Nature, was made possible by improved methods of extracting material from skeletal remains.
"The unexpected results about Oceanian history highlight the power of ancient DNA to overthrow established models of the human past," he said.
Explore further: Skulls in ancient cemetery on Vanuatu suggest Polynesians as first settlers
Pontus Skoglund et al. Genomic insights into the peopling of the Southwest Pacific, Nature (2016). DOI: 10.1038/nature19844