DNA clue to New Zealand's earliest settlers

Professor Lisa Matisoo-Smith uses DNA to trace humankind's migration across the Pacific. Photo / University of Otago

Major study may be able to pinpoint who came here first and how many there were.

It's one of the longest-standing mysteries surrounding our nation's cultural heritage - where exactly did our first settlers arrive from and how many stepped ashore?

A major study being planned by a leading genetic anthropologist aims to apply the latest DNA technology to ancient human remains originally recovered from Marlborough's Wairau Bar, where some of the earliest evidence of New Zealand's settlement has been found.

If Professor Lisa Matisoo-Smith and her colleagues are able to extract enough DNA evidence from the 42 individual samples that were found at the site, what they discover could offer one of the biggest insights yet into our country's history.

Their hope is to sequence as many genomes - the genetic jigsaw puzzle that makes each of us up - from the remains as possible.

They expect to gather many new samples of mitochondrial DNA, which is only inherited through the mother's side and can be used to trace maternal lineages, with hopes of also finding nuclear DNA, which can provide a picture richer in detail.

In 2012, Professor Matisoo-Smith was part of the team that first sequenced complete mitochondrial genomes for members of what was likely to be one of the first groups of Polynesians to settle the country, revealing a surprising degree of genetic variation among these pioneering voyagers.

Her other detective work, using sequencing technology that has been refined only in the last decade, has also shown the lineages of Pacific Island populations were also far more variable than previously thought.

In recent times, archeological research has pulled back the supposed time the first waka came ashore from 1000 years ago to 750 years ago, while the number of settlers, based on different mitochondrial evidence, has also jumped from groups including between 70 and 90 women to around 200.

"Now we have samples suggesting more than 30 mitochondrial lineages, so we are probably talking hundreds if not more than 1000 women."

By comparing freshly profiled DNA with data already completed in Pacific islands, it could be possible to pinpoint the origin of Maori settlers to a place in the Pacific much more specific than the general region of East Polynesia, which Maori later referred to as Hawaiki.

"We know that linguistically and archaeologically, they came from central East Polynesia - but from how many islands, in what numbers, and over what extended period? Was it just one migration?"

There was also the potential to compare those ancient samples with the hundreds of DNA samples just taken from Maori as part of National Geographic's Genographic Project.

Professor Matisoo-Smith said another possibility was being able to map the history of genetic predispositions prevalent in Maori and Pacific Island populations, including diabetes, gout and cardiovascular disease.

It was still largely unclear whether any of these conditions had developed before or after the great migration.

Professor Matisoo-Smith will be holding a talk about her latest work as part of Queenstown Research Week, which kicked off yesterday.