Jamie Morton is the NZ Herald's science reporter.

Wairau Bar surrenders our nation's history

Scientists have renewed their focus on the Wairau Bar off Marlborough's Cloudy Bay, which bears the secrets of our earliest settlers and their paths to Aotearoa. Jamie Morton meets Professor Lisa Matisoo-Smith.
Wairau Bar was once a scrub-covered island. Photo / Luka Zappula
Wairau Bar was once a scrub-covered island. Photo / Luka Zappula

One day in 1939, a young schoolboy named Jim Eyles was walking along a windswept, porkchop-shaped wedge of grass and gravel off the Marlborough coastline when something caught his eye.

His curiosity piqued by a cavity in the ground, the 13-year-old used the best tool for the job at the time, number eight wire, and dug himself into the history books.

What he found on the now-famous Wairau Bar turned out to be perhaps the greatest discovery in New Zealand archaeology - a large necklace, a sperm whale tooth, a 20cm moa egg and the remains of what scientists maintain were this land's first settlers.

Successive studies have put their arrival at the bar, which at that point would have been a scrub-covered island, at some point between 1288 and 1300 - a time in history when Marco Polo was journeying through Asia and William Wallace leading a Scottish revolt.

Flash forward to June 2016, and interest with the site is perhaps more intense.

Last week, delegates attending the New Zealand Archaeological Association's annual conference visited ancient hangi pits at the site that Otago University researchers and members of Rangitane iwi have been excavating.

At the same time, a major new research programme is trying to tackle the most puzzling questions surrounding the landmark that science still hasn't resolved.

Where exactly did our first human inhabitants come from? What brought them here and how many came ashore?

Near Oceania

What we assume today is this: voyagers settled Near Oceania sometime between 50,000BC and 25,000BC, before Austronesians left Taiwan around 2000BC and spread through the islands of Southeast Asia.

Centuries later, around 1500BC, Austronesian seafarers who entered Near Oceania mixed with diverse groups already there, eventually giving birth to the distinct Lapita people, from which arose Polynesian cultures.

It is this sheer amount of genetic diversity that destroyed any perception that the Pacific was inhabited only by unrelated pockets of humanity that had forever stayed stuck on their islands, says biological anthropologist Professor Lisa Matisoo-Smith, of Otago University.

"We often tend to just gloss migration back to a single point in the past and a point today, whereas I think most human history is much more complicated than that."

The fact there's no evidence of occupation in this country before the settlement around 1300 means Maori were almost indisputably the first people to arrive here. Less clear is the exact place they'd previously called home.

"Was their homeland Hawaiki a single island? My guess, and from the data that we have, I would suggest that's unlikely."

It was, however, a region somewhere in Central East Polynesia, an area that matched up with artefacts found at the Wairau Bar.

The nature of the settlement itself remains a point of debate among researchers.

Professor Lisa Matisoo-Smith. Photo / University of Otago
Professor Lisa Matisoo-Smith. Photo / University of Otago

Matisoo-Smith believes the colonisation wasn't a single event but multiple arrivals that took place rapidly, over a short space. Further, she rejects lingering theories that the migration was a forced one.

"I don't think there were starving people on these canoes when they arrived," she said.

"These people knew what they were doing and they were very purposeful voyagers, as opposed to a bunch of people who were pushed out into a boat and sent into exile."

The great expanses of ocean they traversed, and the speed at which they settled new lands, was something anthropologists with eurocentric views often failed to comprehend or appreciate.

"These were Oceanic people. The ocean was their lifeblood, their source of food. It wasn't like they lived on a continent and then decided they were going to conquer the ocean."

For tangata whenua, she felt it had been positive to see that their oral traditions aligned with what the latest technology could show.

"Everybody is interested in their origins. Maori of course have whakapapa that provide that link in their identity, but when that goes together nicely with the scientific evidence, there's almost a relief."

Power of DNA

Matisoo-Smith hopes the best tool for the job today - cutting-edge DNA technology - untangles the complex web that is ancient migration across the Pacific.

Over her career, she has followed the clues left by centuries-old DNA of dogs, pigs, rats and chickens, all carried by Polynesian explorers in their canoes.

There was the remarkable case of pre-Columbian chicken bones found in South America which matched the same DNA as chickens in the Pacific - the first evidence of probable Polynesian introduction of something from the Pacific to the Americas. This led to her a collection of human remains in a South American museum, and the skulls instantly struck her as Polynesian. She then travelled to Isla Mocha, 30km off the coast of Chile, to investigate whether the bones belonged to an exploratory or even migratory group, or had simply been taken there on a European ship.

In 2012, she was on the team that sequenced the first complete mitochondrial genomes of the bar's famed voyagers.

Mitochondrial DNA (mtDNA) is a powerful asset to anthropology, because it's inherited through the mother's side and can be used to trace maternal lineages back many generations.

We found out that our earliest inhabitants carried among them a surprising degree of genetic diversity. This was exciting as it threw up more fascinating leads to follow, but was also frustrating as it clouded the picture further.

The findings proved in line with other DNA-based studies led by Matisoo-Smith over the past decade, which have shown that the lineages of Polynesian peoples are far more variable than we have ever assumed.

Jim Eyles (right) and Roger Duff dig at the bar site in the 1940s. Photo / Canterbury Museum
Jim Eyles (right) and Roger Duff dig at the bar site in the 1940s. Photo / Canterbury Museum

While archaeological research has refined the timeframe that the first waka might have landed on Aotearoa sands, from 1000 years ago to 750, we can thank mtDNA evidence for transforming our understanding of the number of colonists that came.

The figure has jumped dramatically from between 70 and 90 women to many hundreds, and perhaps even more than 1000.

At the centre of a new study by Matisoo-Smith, awarded a $767,000 grant by the Marsden Fund, are 42 individual samples of koiwi tangata, or human remains, that came from the bar.

This time, there's the hope of extracting from them nuclear DNA, which makes up the entire human jigsaw and should provide a much deeper insight into the settlers and their own points of origin.

We can expect the stories they'll tell us will span millennia and thousands of kilometres of ocean, reaching back to that place in East Polynesia which Maori know as Hawaiki, and hopefully beyond.

After a century of research, we might now be on the cusp of accurately reconstructing the population history of Aotearoa right from its beginnings.

Population moves

Matisoo-Smith says our understanding has come a long way since the first days of physical anthropology when there was little to work with but oral histories and noticeable linguistic similarities between Polynesian communities.

Still, by the early to mid-20th century, researchers had enough clues to roughly piece together Polynesian expansion across the Pacific. They were also able to draw links between Polynesian culture and that of the Lapita people, the ancient ancestors of settlers across Polynesia, Micronesia, and some coastal areas of Melanesia.

"There was also linguistic evidence recognising the Polynesian language as belonging to the Austronesian language, so this was the very earliest evidence that really started looking in the right direction," she says.

It wasn't until the late 1980s that this was backed up by DNA evidence, with markers in haemoglobin genes showing how Polynesians carried mutations that had obvious origins in the region known as Near Oceania, comprising Papua New Guinea, the Solomon Islands and the Bismarck Archipelago.

The giveaway was a genetic link with malaria - something found nowhere else in wider Oceania, and indicating that they must have travelled through it, or from it, at some point. Later, in the early 1990s, researchers first used mtDNA to link Polynesian people back to East-Asian origins.

"That nailed down the likely homeland regions for Polynesians, but then in the early 2000s, we started getting Y-chromosome data that was telling quite a different story," Matisoo-Smith says.

While mtDNA evidence pointed back to East Asia, Y-chromosome markers, tracing paternal ancestry, suggested their roots lay further to the south in New Oceania.

"We still had a general picture of populations moving through both these areas, but how much contribution each of them had made to Polynesian populations today is difficult to tell, as there's clearly a mixed heritage and there's no such thing as a pure population anywhere."

It's only been in recent years that archaeologists have worked with iwi to return the 800-year-old koiwi tangata and other artefacts from Canterbury Museum to their resting place.

Matisoo-Smith says only time will tell whether the fresh DNA analysis will give her the information she seeks.

"I'd love to better understand who the Polynesians' ancestors were - was it just Lapita and if so, what was their genetic make-up? Or were there continuous movements of people into the Polynesian triangle?

"Those are the big questions that are still outstanding, and which I guess we'll always be debating."

- NZ Herald

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