28 Dec 2010

Pacific colonisation more recent than thought

9:51 pm on 28 December 2010

New research shows New Zealand, and East Polynesia, was colonised by humans more recently - and faster - than previously thought. The findings show New Zealand was settled in the fourteenth century.

Research using radiocarbon dating, published in an American academic journal, Proceedings of the National Academy of Sciences, suggests settlers arrived in the French Polynesian Society Islands 400 years later than previously accepted.

The findings show the earliest dispersal happened between AD1025 and AD1120 in the central Society Islands, which now form part of French Polynesia. The second wave, including to New Zealand, took place from AD1210 to AD1385.

Previous estimates of when New Zealand was first settled, go back 1,000 years.

More than 1,400 radiocarbon dates from 47 Pacific islands were analysed in the study. Dr Janet Wilmshurst says the results show an amazing feat of Polynesian discovery at a rate unprecedented in Oceanic prehistory.

The timing of the events has been disputed, with some Maori claiming oral histories of 1,000 years. But one of the authors, Dr Terry Hunt, says their research in the disputed area ties in with the writings of the 20th century Maori anthropologist Peter Buck.

A Professor of Prehistory at the Australian National University, Atholl Anderson, who is a co-author of the study, says similarities in artefacts across the Pacific explain the rapid colonisation.

He says the study sorted all radiocarbon-dated materials into sample type, including categories of short-lived plant remains (such as seeds or small twigs), unidentified wood charcoal, bone and marine shells.

Another co-author, Dr Carl Lipo, said short-lived plant remains are the least likely sample material to suffer from contamination or calibration issues, and most likely to date an event accurately and precisely.

Because of this, these were selected as a subset of reliable dates from which estimates for the age of initial colonisation were made.

"The results showed that none of the radiocarbon dates on reliable short-lived plant materials were older than AD1000. This contrasts with dates on other material types that extend back to about 350BC," Dr Lipo said.