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
Kon-Tiki expedition sailed roughly west carried along on the Humboldt Current. The crew's first sight of land was the atoll of Puka-Puka on July 30. On August 4, the 97th day after departure, "Kon-Tiki" reached the Angatau atoll. The crew made brief contact with the inhabitants of Angatau Island, but were unable to land safely. Calculations made by Heyerdahl before the trip had indicated that 97 days was the minimum amount of time required to reach the Tuamotu islands, so the encounter with Angatau showed that they had made good time. On August 7, the voyage came to an end when the