One thing I took away from the book was that Polynesian colonization follows a pattern that looks deliberate. Specifically that they would depart on a voyage against the winds and currents, the hard way, so that they could make a swift return if they couldn't find the destination. Or at least that's what some computer modelling of the spread of Polynesian culture says. That finding is a bit at odds with this NYT article, not sure what that means.
Some other links for this NYT article:
The PNAS page (abstract only, paywall) http://www.pnas.org/content/early/2016/10/18/1612426113
Another summary with more details https://around.uoregon.edu/content/study-finds-climate-helpe...
https://www.amazon.ca/Vaka-Moana-Voyages-Ancestors-Settlemen...