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 the late 1990s, genetic testing found that the mitochondrial DNA of the Polynesians is more similar to people from Southeast Asia than to people from South America, showing that their ancestors most likely came from Asia. Anthropologist Robert Carl Suggs included a chapter titled "The Kon-Tiki Myth" in his 1960 book on Polynesia, concluding that "The "Kon-Tiki" theory is about as plausible as the tales of Atlantis, Mu, and 'Children of the Sun.' Like most such theories, it makes exciting light reading, but as an example of scientific method it fares quite poorly." Anthropologist and National Geographic Explorer-in-Residence Wade Davis