Scientists have revealed intriguing new insights into the earliest ancestors of Maori, confirming that the first people to settle in the Pacific were from Asian farming groups.
The revelations, published today in Nature and co-authored by Massey University computational biologist Professor Murray Cox, may hold the key to future health improvements for Maori and Pasifika populations.
The research is the first to sequence ancient DNA from 3000-year-old skeletons to identify who were the first people to reach the Pacific Islands.
By examining skeletal remains from the first people to settle in Vanuatu and Tonga, the research was able to put a 40-year-debate to rest, showing the ancient settlers had little to no Papuan ancestry, contrary to what had previously been suggested.
This proved that the first people to reach remote Oceania were from Asian farming groups, with later movements bringing Papuan genes into the region.
Before this work, no ancient genomic DNA had ever been obtained from any tropical region, including the Pacific. This resulted in two opposing scenarios to explain why Maori and Pasifika have Papuan and Asian ancestry - the other stating that farming groups moving out of Asia mixed with Papuans near New Guinea and created a mixed group with both ancestries and the mixed group settling in the Pacific.
"This paper gives us the first basic picture of the genomic make-up of Pacific Islanders," Cox said. "Unlike European New Zealanders, where we can leverage off research done in the UK and US, we knew very little about the genomes of Pasifika and Maori."
Otago University anthropologist Professor Lisa Matisoo-Smith said the findings were very exciting and showed how difficult it was to model population histories based on modern population sampling alone.
• The study examined ancient DNA from three individuals who were among the earliest to settle in Vanuatu up to 3100 years ago and one who was among the earliest to settle in Tonga up to 2700 years ago.
• The Vanuatu skeletal samples were extracted from a 3000-year-old burial site, where 60 skeletons, whose skulls had been taken away by mourners, were discovered by construction workers on Efate Island in 2003.
• The Tongan skeletal samples, found at a site on Tongatapu Island, were the oldest securely dated skeletal assemblage from Polynesia around 2500 years ago. The data was then compared to DNA samples from 356 present-day humans from 38 Southeast Asian and Oceanian populations.