Just as I finish reading (or rather, re-reading) chapters concerning the fate of Easter Island (Rapanui) and of Henderson and Pitcairn Islands in Collapse: How Societies Choose to Fail or Survive by Jared Diamond, the 23rd January issue of Science arrives, bearing two articles on the spread of humans (Austronesians) from Taiwan and onwards across Micronesia to Polynesia. One of these papers, by Gray and colleagues, presents a linguistic analysis of langauages across this region. The second, by Moodley et al looks at the variation of the human pathogen Helicobacter pylori in these same peoples. Both strands of evidence documenting this population spread are in striking agreement.
I have no experience in the kind of linguistic analysis carried out by Gray and colleagues, so my understanding is informed by Colin Renfrew's Perspectives article in this issue of Science.There are over 1000 polynesian languages, making it one of the largest language families. Ultimately, the populations that eventually colonised even the most remote islands such as Easter were ultimately derived from a migration that can (at least in one theory) be traced back to origins in Taiwan (upper panel in the figure below). Other possibilities include origins in island Southeast Asia. Genetic evidence (such as that provided by mitochondrial DNA sequences) has been ahrd to interpret, and may not support the Taiwan origin of the Austronesian speaking people. On the other hand, such evidence may be complicated by post-colonial gene flow.