13 Aug 2015

Tracking the Lapita Expansion Across the Pacific

From Our Changing World, 9:06 pm on 13 August 2015

by Veronika Meduna

Detail of the intricate pottery designs on Lapita ceremonial pots.

Detail of the intricate pottery designs on Lapita ceremonial pots. Photo: RNZ / Veronika Meduna

The whole Lapita story is an extraordinary chapter of human history. These are the first people that get beyond the main Solomons chain.
Stuart Bedford, Australian National University, Vanuatu Cultural Centre

Stuart Bedford has spent many years scouring Vanuatu’s volcanic soil for evidence of the archipelago’s first inhabitants, but one of his best discoveries came when he wasn’t looking. A digger driver who was excavating soil for a prawn farm on Vanuatu’s main island Efate discovered a richly decorated shard of pottery – and recognised it as something unusual.

Bedford and his colleague Matthew Spriggs, both archaeologists at the Australian National University in Canberra, were called in and immediately identified it as Lapita.

The serendipitous discovery soon led to a major project which unearthed not just more pottery but human remains. More than a decade later, the site at Teouma is now famous among Pacific archaeologists as the oldest Lapita cemetery, reaching back three millennia to the very beginning of an epic voyage of discovery.

Archaeological excavations at Teouma.

Archaeological excavations at Teouma. Photo: Stuart Bedford / Vanuatu Cultural Centre

The Lapita are ancestors of modern Polynesians, who later went on to explore all corners of the Polynesian triangle, from Hawaii to Easter Island and ultimately New Zealand. But 3000 years ago it was Lapita seafarers who heralded the last major prehistoric wave of migration by sailing to Vanuatu and from there out into an area known as Remote Oceania.

In July, Vanuatu’s capital Port Vila hosted the 8th Lapita conference, which brought together scientists from disciplines as far apart as archaeology, linguistics and genetics to discuss the latest findings about the Lapita, from the techniques they used to produce their unique, elaborately decorated pottery, to their burial practices, their health, their impact on the archipelago’s ecology - and of course their Pacific sailing itinerary.

The Prime Minister of Vanuatu, Sato Kilman, left, with Stuart Bedford and Matthew Spriggs, right, at a kava ceremony to mark the opening of the Lapita conference and an exhibition at the Vanuatu Cultural Centre and national museum, in Port Vila.

The Prime Minister of Vanuatu, Sato Kilman, left, with Stuart Bedford and Matthew Spriggs, right, at a kava ceremony to mark the opening of the Lapita conference and an exhibition at the Vanuatu Cultural Centre and national museum, in Port Vila. Photo: RNZ / Veronika Meduna

"Teouma is the first kind of really core Lapita site … so it’s given us unique insights into who the Lapita people were," says Matthew Spriggs.

From the bones and teeth, the team gleaned information about their diet and health, but most importantly perhaps, the Teouma bones confirm the Polynesian link.

We can compare the skull shape of the Lapita people and see who they resemble most among living populations today and they fit very neatly within the Polynesian/Asian mode rather than the Australian, Aboriginal and Melanesian mode.
Matthew Spriggs, Australian National University, Vanuatu Cultural Centre

Spriggs says that it was during the relatively short period of Lapita expansion that change happened and, while the people at Teouma are ancestors of Polynesians, later Lapita site are more closely linked with modern Melanesians.

“It’s only during Lapita that we have evidence of extensive interactions between all the archipelagos, so from New Guinea, the Bismarck Archipelago, through to the Solomons, Vanuatu, New Caledonia and out to Fiji. There’s extensive exchange networks, contact between these areas.”

French archaeologist Frederique Valentin is measuring up one of the 3000-year-old skulls from the Teouma cemetery, at the museum collection in Port Vila.

French archaeologist Frederique Valentin is measuring up one of the 3000-year-old skulls from the Teouma cemetery, at the museum collection in Port Vila. Photo: RNZ / Veronika Meduna

At the Teouma cemetery, archaeologists also discovered 68 burial sites, and the bleached bones almost certainly belong to the first people to make landfall in Vanuatu. They unearthed clear evidence that the Lapita used their highly decorated pottery for ceremonies and rituals, but for Frederique Valentin, an archaeologist at the National Centre for Scientific Research in Paris, the bones tell a fascinating story of ritual burial practices – with headless skeletons and deliberately rearranged bones.

Hallie Buckley, a biological anthropologist at the University of Otago, has coordinated the excavation of the bones and has studied them for signs of disease.

These same bones also tell a story of hard work, and of people suffering from gout and what we now know as metabolic disease. But Anna Gosling, also at the University of Otago, says the gout may be an evolutionary consequence of protection against malaria.

Gout is a result, usually, of high serum urate levels. Pacific Island people, throughout the Pacific, have been found to have quite high levels of this particular chemical in their blood compared to most other populations worldwide, which is suggesting that there is some sort of genetic link. 
Anna Gosling, University of Otago

Urate has several important function: it helps maintain blood pressure, it is an anti-oxidant, and it plays a role in the body's innate immune response. During a Malaria infection, urate levels increase to stimulates an immune response.

"The argument we're trying to make here is that if you already have slightly higher urate levels in your blood, you need less red blood cells to ... burst apart before your immune system kicks in and tries to resolve the infection, which would give you quite an advantage."

This map shows the areas known as Near and Remote Oceania.

This map shows the areas known as Near and Remote Oceania. Photo: Supplied

The human settlement of the Pacific and the origins of the Polynesian people have been topics of intense debate for decades, and scientists have sought to chart the path of the Lapita expansion. Collectively they have accumulated evidence that points to an origin in island Southeast Asia, but with more clarity in some of the detail comes increasing complexity of the total picture.

The first wave of colonisation in the Pacific region began when people fanned out across an area known as Near Oceania, sometime around 40,000 years ago. Sea levels were lower then – New Guinea, Australia and the island of Tasmania were still one landmass – and these first explorers had to navigate smaller gaps of ocean. They spread as far as the Bismarck Archipelago north of Papua New Guinea and the Solomon Islands in the Pacific.

Patrick Kirch, an anthropologist at the University of California at Berkeley and an expert in Pacific prehistory, says for 30,000 years, the sea gap between the main chain of the Solomon Islands and Vanuatu was an invisible boundary. But then, around 3000 years ago, the Lapita, breached this voyaging barrier. Their unmistakable comb-toothed pottery is the most distinctive cultural signature they left behind, and it now helps to reconstruct their journey.

You can use the pottery and other material culture to trace the movement very clearly and with the assistance of radio carbon dating we’ve put a timeframe on that.
Patrick Kirch, University of California at Berkeley

This Lapita “bursting out into this part of the Pacific that had never been occupied by humans” ended at about 800BC in Tonga and Samoa, but just what motivated the rapid expansion is still a point of debate.

Population pressure is often discussed as one option, but Kirch thinks people were pulled rather than pushed. “By pull I mean things like new resources. We know in Vanuatu they had these tortoises and pigeons, they were great food items.”

Also, he says, there could be social factors such as a hierarchical clan structure in which younger sons may have wanted to establish elsewhere.

Some of the complete pots that have been unearthed at the Teouma cemetery.

More than 350 Lapita pots have been unearthed at the Teouma cemetery, but only few were complete, still showing the elaborate stamped motifs. Photo: RNZ / Veronika Meduna

Although the dentate pottery – edged with toothlike projections – is the most consistent Lapita identifier, it’s clear that the people carried with them a suite of other skills, including open-ocean navigation, boat-building, fishing and agriculture. Archaeologists prefer to use the term Lapita Cultural Complex, rather than implying that Lapita was a homogenous group of people defined largely by their pottery design style.

Linguistically, the origins are clear. Lapita is just one chapter in the Austronesian diaspora.

Austronesian is unusual among language families: it’s extremely large, with more than a thousand modern languages, and it’s the most widely dispersed in the world (until the post-Columbus expansion of Indo-European languages). It extends from Madagascar to Rapa Nui, or Easter Island, and spans over 70 degrees of latitude, from Hawaii to the southern tip of New Zealand. All modern Polynesian languages are daughters of this family.

Like drawing up an evolutionary tree from the genetic diversity found in living organisms, modern languages can also be used to reconstruct ancestral proto languages and their relationships to each other. When this is done, Taiwan emerges as the most likely origin of Austronesian.

The archaeological record supports the notion that the Lapita journeys were a deliberate effort to colonise new land. Lapita sites discovered so far are close to the beach and, in Near Oceania they are mostly on small off-shore islands. The choice of coastal sites also suggests a dual subsistence economy, relying on both fishing and agriculture. Excavations have also revealed that the Lapita toolbox included a range of fish hooks made from shell, nets, spears and different types of stone adzes.

Intriguingly, the most complex patterns of decoration are associated with the oldest sites, and plain ware and more simply decorated pots make up a growing proportion of assemblages found in later settlements.

Why the Lapita might have abandoned the rituals and practices they had so treasured remains a mystery. Matthew Spriggs says once you move beyond Samoa and Tonga, the area of sea compared to the area of land “increases massively and there was probably a threshold of relatively easy travel back and forth”.