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 The crew once used a hand-cranked emergency transmitter to send out an "all well, all well" message "just in time to head off a massive rescue attempt". The call sign LI2B was used by Heyerdahl again in 1969–70, when he built a papyrus reed raft and sailed from Morocco to Barbados in an attempt to show a possible link between the civilization of ancient Egypt and the New World. "Kon-Tiki" left Callao, Peru, on the afternoon of April 28, 1947. To avoid coastal traffic it was initially towed out by the Fleet Tug "Guardian Rios" of the Peruvian Navy, then