Polynesians settle the Society Islands

East Polynesia — fifteen archipelagos including New Zealand, Hawaiʻi and Rapa Nui — was the last region of the world to be colonised by prehistoric people, but the chronologies proposed for its settlement varied by more than a thousand years. In 2011 Janet Wilmshurst, Terry Hunt, Carl Lipo and Atholl Anderson analysed 1,434 radiocarbon dates from the region, keeping only reliable dates on short-lived materials. They concluded that colonisation happened in two phases: first the Society Islands, about 1025–1120 — four centuries later than previously assumed — and then, after a gap of some 70 to 265 years, all the remaining islands in a single pulse, about 1190–1290.

Later studies have qualified this picture. Lake sediments from Atiu in the southern Cook Islands studied by David Sear and colleagues (2020) show traces of pigs or people on a virgin landscape from about 900, changes around 1000 and clear human disturbance from about 1100; the authors link these first voyages with a prolonged drought in the western source region and suggest that settlement came a century or two after the first exploratory landfalls — East Polynesia, in their view, was reached earlier and settled step by step. A genomic study of present-day islanders by Alexander Ioannidis and colleagues (2021) traced the expansion from Samoa through Rarotonga to the Society Islands in the 11th century, then to the western Austral Islands and the Tuamotus in the 12th, and on, by way of Mangareva, to the Marquesas, Raivavae and Rapa Nui about 1200. The Society Islands thus stood near the beginning of the dispersal that carried Polynesian voyagers across the Pacific, an ocean that covers a third of the Earth.