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
Tangaroa Expedition solar panels, portable computers, and desalination equipment. The crew posted to their website. Tangaroa's six-man crew was led by Norwegian Torgeir Higraff and included Olav Heyerdahl, grandson of Thor Heyerdahl, Bjarne Krekvik (captain), Øyvin Lauten (executive officer), Swedish Anders Berg (photographer) and Peruvian Roberto Sala. Tangaroa was launched on the same day that Kon-Tiki had been—April 28—and it reached its destination on July 7, which was 30 days faster than Heyerdahl's Kon-Tiki which had taken 101 days for the voyage. Tangaroa's speed was credited to the proper use of the quara centerboards in navigation. Heyerdahl had not known how to