The sweet potato kumara, which is native to the Americas, was widespread in Polynesia when Europeans first reached the Pacific. Kumara has been radiocarbon-dated in the Cook Islands to 1000 CE, and current thinking is that it was brought to central Polynesia circa 700 CE and spread across Polynesia from there, possibly by Polynesians who had traveled to South America and back. It is possible, however, that South Americans brought it to the Pacific or that this plant or its seed-bearing parts simply floated across the Pacific without human contact ever occurring. The traditional name for the Haida homeland of Queen Charlotte Island is Haida’gwai’i, very similar linguistically to Hawai’i (homeland). Names such as Tonga’s (southern) Strait and Hakai’i Channel appear to also be relic names suggesting an Austronesian past to this area.
Irving Goldman, author of Ancient Polynesian Society, has this to say on the comparison between Kwakiutl and the Polynesians. "For reasons that remain to be discovered, the Indian tribes of this area [NW Coast] share formal principles of rank, lineage, and kinship with Pacific islanders. The Kwakiutl, seem very close to what I have designated as the "traditional" Polynesian society. They share with Polynesians a status system of graded hereditary ranking of individuals and of lineages; a social class system of chiefs ("nobles"), commoners, and slaves; concepts of primogeniture and seniority of descent lines; a concept of abstract supernatural powers as special attributes of chiefs; and a lineage system that leans toward patriliny, but acknowledges the maternal lines as well. Finally, Kwakiutl and eastern Polynesians, especially, associate ambiguity of lineage membership with "Hawaiian" type kinship, a fully classificatory system that does not distinguish between maternal and paternal sides, or between siblings and cousins."
Thor Heyerdahl proposed in the mid-twentieth century that the Polynesians had migrated from South America on balsa-log boats.
