A new study has teased out the voyages that Pacific peoples took by studying present-day genomes.
The study estimates that voyagers from Samoa, Fiji, and Tonga first migrated to Rarotonga around the year 830.
Two hundred years later, one group went further east to Papa Nui, or Easter Island.
The researchers identified rare genetic traits present on only some Pacific Islands in order to trace ancestry and migration routes.
Lead author Alexander Ioannidis, a research fellow at Stanford Medical School, says that medical researchers should use similar ancestry genetic analysis to provide more personalised patient care.
He says that the category of "Pacific Islander" may paint too broad of a brush on a medical chart, because some genetic risk factors occur only among those from particular nations.
Ioannidis spoke to Susie Ferguson.