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 Islands in 1936, Heyerdahl married his first wife, Liv Coucheron-Torp (1916–1969), whom he had met shortly before enrolling at the university, and who had studied economics there. The couple had two sons: Thor Jr and Bjørn. The marriage ended in divorce. After the Occupation of Norway by Nazi Germany, he served with the Free Norwegian Forces from 1944, in the far north province of Finnmark. In 1949, Heyerdahl married Yvonne Dedekam-Simonsen (1924–2006). They had three daughters: Annette, Marian and Helene Elisabeth. They were divorced in 1969. Heyerdahl blamed their separation on his being away from home and differences in their