Anthropologist and explorer, who made his reputation in 1947 when he sailed the primitive balsa-wood raft KON-TIKI from Peru to an island in the Tahiti chain. The Kon-Tiki expedition proved that pre-Columbian South American Indians could have reached and settled islands in the South Pacific. It also won the anthropologist a worldwide reputation and brought him justification for his views. Since that time, Heyerdahl has participated in many additional expeditions, ranging from trying to cross the South Atlantic in an African reed boat to researching and excavating sites on the Maidive Islands in the Indian Ocean.
Heyerdahl, a diffusionist, believes that different cultures only rarely develop similar ideas and artifacts. In all his expeditions, he seeks to show that people usually thought to be isolated from other cultures were in fact open to contact. His 1955 expedition to Easter Island, Aku-Aku, showed that the lonely island had been inhabited from at least 380 C.E. and had experienced at least three waves of migration. In the 1960s, Heyerdahl con¬ structed papyrus reed rafts in Africa and sailed them 3,270 nautical miles across the South Atlantic in what became known as the Ra Expeditions, showing that ancient Egyptians could have traveled to the Americas.