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 Raft Across the South Seas", later reprinted as "Kon-Tiki: Across the Pacific in a Raft". It appeared with great success in English in 1950, also in many other languages. A documentary motion picture about the expedition, also called "Kon-Tiki", was produced from a write-up and expansion of the crew's filmstrip notes and won an Academy Award in 1951. It was directed by Thor Heyerdahl and edited by Olle Nordemar. The voyage was also chronicled in the documentary TV-series "The Kon-Tiki Man: The Life and Adventures of Thor Heyerdahl", directed by Bengt Jonson. The original "Kon-Tiki" raft is now on display