Forget a chunk of what you think you know about how Maori got to New Zealand. Bruce Munro talks to Prof Atholl Anderson about his startling conclusion that the first colonists were exiles with no way of returning home.
Over the din of chattering voices, a hissing espresso machine and clinking cups, Prof Atholl Anderson is explaining what he has discovered about early Polynesian sailing technology.
''Here, let me draw it for you,'' he says, taking pen and notebook.
Sitting at a small table in the Otago Museum cafe, the former University of Otago anthropologist sketches a vessel with a sail stretched between V-shaped spars.
Unseen but almost directly above him, on the top side of a thick concrete slab, is a display wall of model canoes marking the entrance to the museum's Pacific Cultures gallery.
Opposite, on the far side of the mezzanine floor, is the dark entrance to the Tangata Whenua gallery.
The two galleries are natural complements to each other, Maori having arrived in New Zealand as part of a continuous, extensive and systematic exploration of the South Pacific during a period of up to 2000 years.
Or so the story goes, says Prof Anderson, who is rocking the proverbial waka with an alternative argument that redefines the linkages between New Zealand and East Polynesia.
Prof Anderson, FRSNZ, is of Kai Tahu descent.
He was head of anthropology at Otago before spending the last 17 years of his academic career at Australian National University, in Canberra.
The final three years before retiring, and the four years since, have been focused on producing the first comprehensive history of Maori, spanning 5000 years and more than twice as many kilometres, from the migration out of Asia across the Pacific to their place in New Zealand today.
Published late last year, Tangata Whenua: An Illustrated History, was co-written with the late-Dame Judith Binney and Dr Aroha Harris.
This week, the book was named one of five titles shortlisted for the 2015 Royal Society of New Zealand Science Book Prize.
Prof Anderson's contribution - a third of the scholarly yet accessible history, covering developments from 3000BC to 1830AD - includes the latest findings by researchers across a broad swathe of academic disciplines.
It presents a fascinating picture, with several new pieces of research expanding or challenging the accepted, traditional narrative of New Zealand's first people. None more so than Prof Anderson's own research into the impact of climate change on waka migration to Aotearoa.
The story of this country's first colonisation, as most New Zealanders have been told it, is one of large, fast, double-hulled canoes making return voyages between East Polynesia and these bountiful, mountainous southern islands, followed by growing isolation as skills and knowledge progressively declined.
But there is a significant problem with that story, Prof Anderson believes.
The traditional history is based on sail technology which allows seafarers to travel downwind and upwind.
But Prof Anderson's research suggests that technology did not exist in East Polynesia when New Zealand was colonised around the mid-to-late-13th century.
Certainly lateen sails, of the type often associated with Arab dhows and eastern Mediterranean water craft, which can be sailed into the wind, were seen by James Cook and Joseph Banks in Tonga, Samoa and Fiji.
But the lateen sail is not known in the Indian Ocean until the 16th century and is unlikely to have been invented independently in two places, Prof Anderson argues.
It most likely did not reach the Pacific until at least the 16th century, hundreds of years after it would have been needed for return voyages between the Cook Islands and Tahiti in the north and New Zealand in the south.
''That's how it started for me,'' Prof Anderson says.
''I thought the technology being argued here is without any historical foundation.''
Adding weight to that view are two facts.
The only sail recorded in New Zealand before the 1800s was the double spritsail, a V-shaped sail lashed to spars on each side, which cannot sail to windward.
And, if there were return voyages, archaeologists could reasonably expect to find at least some evidence.
''If people went back to the Cook Islands or Tahiti for example, you would have assumed they would have carried things like obsidian and pounamu, rock types that were highly valued and which they did not have in Tahiti or the Cooks,'' he says.
''But there is no evidence that that happened. We don't have any finds from early sites of that kind of material. Whereas, we do have a few instances of material from tropical Polynesia which ended up in early New Zealand.''
If the technology did not allow windward sailing, how did the first Pacific settlers get here, given that the prevailing wind is in the wrong direction for anyone in East Polynesia with a rudimentary sail and a hankering to head south?
It could not have been a result of the occasional fecund adventurer catching a freak breeze.
The evidence of oral histories and genetics points to 15 to 20 canoes carrying a total of about 200 men and an equal number of women to these shores within a period of a few decades.
''So if there's a large migration to New Zealand, either they have to have a windward capacity or the sailing conditions have to be different,'' he says.
''So, it was the sailing conditions which we investigated.''
Prof Anderson had the help of climate scientists who analysed oxygen isotopes from stalagmites and stalactites hundreds of years old, scattered across the Pacific.
What they found was that between roughly 1170AD and the late-13th century the prevailing winds were from the east and northeast, but that by the new century they had turned southwesterly again.
During that window, East Polynesian canoes, with only downwind sails, would have been blown towards New Zealand.
Who, then, were those first colonists?
If they were not deliberately setting out for islands from which other intrepid adventurers had returned with glowing reports, why were they voyaging into the unknown?Prof Anderson's answer is startling.
Traditional and historical accounts in Polynesia and oral traditions in New Zealand all point to conflict as a strong motivation, he says.
He cites a traditional account of the exile of about 100 people from the Polynesian island of Tikopia.
''The women and children were in the canoes; many of the men swam alongside . . . Wailing, the fold of Nga Faea abandoned the land, some of them supporting their chief on the deck of his vessel . . . So they went from sight, to be lost forever from the knowledge of men.''
Maori traditions talk of disputes over land between the high chief of Hawaiki, Uenuku, and the captains of the Tainui and Aotea canoes, Tamatekapua and Turi.
Other Maori traditions emphasis the killing of priests in their accounts of leaving ancestral homes.
Hunger, disputes over land, population pressures, feuds and warfare could all have played a significant part in the first settlement of New Zealand, Prof Anderson says.
It is likely they were not willing colonists but desperate exiles and refugees, strong enough to survive the arduous open-sea journey, fortunate enough to hit land as they were blown south, but without any hope of returning home.
Prof Anderson admits his views are controversial and that the evidence on both sides is still a matter of contention.
''You can't say with certainty that anything is right or wrong. All you can do is deal with probabilities. The probability, based on the data we have, is that they did not have a means of sailing against the wind.''
And even if his retelling of the story proves to have the stronger evidence, it could be some time before it is widely accepted.
''It's been an argument that I've been involved in since about 2008. Actually, I began it about 2000,'' Prof Anderson says.
''Some people agree with me, and some don't . . . Because most people still prefer the traditional view, and Maori strongly prefer the traditional view, on the whole. Backed up, of course, by the small industry of building and sailing supposed Polynesian water craft.
''To most people it seems that kind of view is incontrovertible. But it's not.''
NEW NOTATIONS
The first third of Tangata Whenua: An Illustrated History covers the period from 3000BC to early Maori and European contact. Written by Prof Atholl Anderson, part one of the first comprehensive history of Maori draws on his own findings and the latest research across a range of disciplines including oral history, archaeology, genetics, linguistics, ethnography, historical observations, palaeoecology and climate science.
Key points from the new research included in the book are:
• Points of origin: The earliest Polynesian ancestors originated in south China about 5000 years ago and migrated into the Pacific through Taiwan and Indonesia, joining with people already resident in the islands of the west Pacific to form a distinctive population and culture. Recent research in historical linguistics and genetics indicates the ancestors of Maori came from a broad region of south China, rather than specifically Taiwan.
• Traditions, science and history: There is a link between Maori oral traditions and the evidence of scientific and archival sources. It is apparent that whakapapa recorded in the oral traditions throughout New Zealand were interlinked and consistent in their content and in their recording of large-scale events. The oral traditions, therefore, are a legitimate and valuable source of history for the period from initial colonisation to the 19th century.
• Time of Polynesian arrival: Analysis of 150 whakapapa from the main voyaging traditions shows there is a reliable record of canoes arriving in New Zealand around 1300AD. Archaeological and other scientific investigations also now agree on a date of about 1300AD. For the first time, all sources of evidence agree about the age of Maori colonisation.
• The impact of climate change on waka migration to New Zealand: Maori canoes seen by the first European visitors had limited sailing technology. However, research that reconstructs the wind patterns of the past 1200 years in the Pacific Ocean shows there were windows of opportunity for relatively easy sailing downwind from tropical Polynesia, especially in the period 1170AD to 1300AD. The notion of an early voyaging period, and then lengthy isolation until the arrival of Pakeha, is also found in oral traditions.
• Climate change over time: Changes in climate may have had a substantial influence on early Maori history. A century or so after colonisation, the New Zealand climate entered a cool, wet phase that impacted on Maori agriculture. Early cultivation had extended to Canterbury, but by about 1500AD kumara was hardly grown at all in the South Island and its distribution was restricted in the lower North Island. Agricultural decline and rising population density in northern New Zealand created competition and warfare. As a result, many groups moved away. Archaeology and climate records provide evidence for this. Oral traditions also record numerous long-distance migrations in New Zealand at this time, most of them towards the southern North Island and the South Island.