Human dispersal in eastern Polynesia

A study suggests that humans arrived in eastern Polynesia in 900 AD, earlier than thought and coinciding with a prolonged regional drought. Colonization of the southern Cook Islands in eastern Polynesia did not take place until almost two millennia after human dispersal in Tonga and Samoa, but the underlying reasons are unclear. David A. Sear and colleagues investigated the timing and effect of climatic changes on the settlement of eastern Polynesia by combining lake core samples with archaeological records. Analyzing freshwater lake core samples from Vanuatu, Samoa and the southern Cook Islands, the authors found evidence of human and pig fecal biomarkers traced to around 900 AD. Evidence of soil erosion proxies in the catchment, which would suggest colonization rather than periodic visits, appeared 200 years later. To reconstruct the precipitation record, the authors analyzed lipid hydrogen isotope content in algae and terrestrial leaves found in the lake cores. The results showed that a dry period, which would have experienced rainfall well below current averages, coincided with human arrival. According to the authors, the regional drought, combined with political factors, may have helped drive an incremental, multiphased expansion into eastern Polynesia.

ARTICLE #19-20975: “Human settlement of East Polynesia earlier, incremental, and coincident with prolonged South Pacific drought,” by David A. Sear et al.

MEDIA CONTACT: David A. Sear, University of Southampton, Southampton, UNITED KINGDOM; e-mail:

[email protected]

; Melinda S. Allen, University of Auckland, Auckland, NEW ZEALAND; tel: +64 9 923 4645; e-mail:

[email protected]

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