While Thor Heyerdahl's theories on ancient seafarers spreading civilization were initially ridiculed by scientists, a younger generation is studying his ideas from five decades ago as the basis for new ideas about early cultural exchanges.
Robson Bonnichsen, who studies how the American continent became populated, calls Heyerdahl "a visionary ahead of his time."
Bonnichsen, director of the Center for the Study of the First Americans at Oregon State University, told The Associated Press that many experts now give serious consideration to the idea that people in boats sailed along the Pacific Rim.
"Our perception of the peopling of the Americas is changing" and encompasses more than one colonization, including an early population from Southeast Asia, he said.
"A lot of new ideas are on the table -- and Thor Heyerdahl led the way years ago," he said.
The new theories suggest that American settlement was much more complex than first thought and that migrants arrived more than once and from different parts of the world.
Dennis Stanford, an anthropologist at the Smithsonian Institution's National Museum of Natural History in Washington, has even suggested some American ancestors could have come from Spain during the Ice Age, arriving in Maine after skirting the ice of the North Atlantic in boats.
Walter Neves of the University of Sao Paulo is gathering evidence suggesting that early South Americans originated in Australia or South Asia and possibly crossed the Pacific.