Pacific colonisation more recent and rapid than previously thought

Tuesday, December 28, 2010

WELLINGTON - A new research has suggested that East Polynesia was colonised by humans more recently, and faster, than previously thought.

The study indicates the region was settled in two distinct phases hundreds of years later than previously thought, reports

The earliest phase of the region’s colonisation was in the Society Islands (AD 1025-1120, four centuries later than previously assumed) and the colonisation of all remaining islands, including New Zealand, Hawaii and Easter Island, occurred between 70 and 265 years later.

The findings mean existing models of human colonisation, ecological change and historical linguistics for the region now require substantial revision.

More than 1,400 radiocarbon dates from 47 Pacific islands were analysed for the study.

Lead author Dr Janet Wilmshurst, an environmental scientist from Landcare Research, New Zealand, said the results showed an amazing feat of Polynesian discovery at a rate unprecedented in oceanic prehistory.

“It’s even more incredible given that these isolated islands are spread across a vast area of the Pacific Ocean from the subtropics to the subantarctic. Nearly all of the 500 or so islands were discovered, despite being scattered across an area of ocean the size of North America,” she added.

The work resolves longstanding paradoxes and offers a robust explanation for the remarkable uniformity of East Polynesian culture, human biology and language, said Wilmshurst.

The study showed migration into the region began after an 1800-year pause since the first settlement of Samoa around 800 BC, possibly due to rapid population growth, technical innovation in sailing vessels, climate or environmental disaster, she said.

It shortened the timeframe in which humans are thought to have impacted on island ecosystems, particularly by way of deforestation and plant and animal extinctions, and that environmental transformations may have occurred over decades rather than centuries.

Previous research suggesting there was a long period of relatively benign interaction between humans, rats, dogs and indigenous vertebrates now needed to be revised as the impacts had to have been immediate, severe and continuous, said Wilmshurst.

Another co-author Dr Carl Lipo said short-lived plant remains, such as seeds or small twigs, were analysed because these were most likely to date an event accurately.

“The results showed than none of the radiocarbon dates on reliable short-lived plant materials were older than AD 1000. This contrasts with dates on other material types that extend back to 350 BC,” he said.

The findings are published in the journal Proceedings of the National Academy of Sciences. (ANI)

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