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 (2012 film) the ropes." Thor Heyerdahl, Jr., who worked with Watzinger, concurred in the criticism of the film's portrayal of Watzinger. Other minor alterations from Heyerdahl's book include the ship's parrot being eaten by a shark in the film (its real-life counterpart was simply washed overboard by a large wave). The film also shows the crew only getting access to valuable US military equipment once they have arrived in Peru and are building the raft, whereas Heyerdahl in fact arranged for the equipment at a visit to the Pentagon before traveling to Peru. The film premiered on 18 August 2012 at the