Norwegian explorer and ethnographer. In a diffusionist tradition, Heyerdahl postulated that the Polynesians had come to the islands of the Pacific from South America, rather than as is more commonly supposed, from South-East Asia. In 1947, along with an international team, he sailed on a balsa raft - the Kon Tiki - constructed on the basis of local, South-American models, from the Peruvian coast to the Tuamotu Islands - proving that the voyage was possible (and, in the post-war years, proving that international cooperation in spectacular ventures was possible). Later, Heyerdahl attempted a similar voyage across the Atlantic, to demonstrate that migration from Egypt to South America was possible. He also conducted archaeological and other research in support of his theory. Though Heyerdahl's migratory thesis is generally frowned on by Polynesianists and others, the sheer adventure of his expeditions retains - of course - its attraction.