Polynesia of the plant in the Cook Islands have been radiocarbon-dated to 1000, and current thinking is that it was brought to central Polynesia c. 700 and spread across Polynesia from there, possibly by Polynesians who had traveled to South America and back. Thor Heyerdahl proposed in the mid-20th century that the Polynesians had migrated from the northwest coast of Canada by large whale-hunting dugouts, and from South America on balsa-log boats. Many anthropologists have criticised Heyerdahl's theory, including Wade Davis in his book "The Wayfinders". Davis says that Heyerdahl "ignored the overwhelming body of linguistic, ethnographic, and ethnobotanical evidence, augmented
Thor Heyerdahl Heyerdahl obtained a radiocarbon date of 400 for a charcoal fire located in the pit that was held by the people of Easter Island to have been used as an "oven" by the "Long Ears", which Heyerdahl's Rapa Nui sources, reciting oral tradition, identified as a white race that had ruled the island in the past (Heyerdahl 1958). Heyerdahl further argued in his book "American Indians in the Pacific" that the current inhabitants of Polynesia migrated from an Asian source, but via an alternate route. He proposes that Polynesians travelled with the wind along the North Pacific current. These migrants