Pre-Columbian rafts voyaged as far as Mexico and introduced metallurgy to the civilizations of that country. Some scholars and adventurers of the 20th and 21st century have asserted that the rafts and their crews journeyed thousands of miles across the Pacific to Polynesia, most notably Thor Heyerdahl who reached Polynesia on the Kon-Tiki raft. Several other people and groups have also built rafts based on prehistoric models and undertaken trans-Pacific voyages. Balsa is the Spanish word for raft. The use of rafts for commerce on the coasts of Peru and Ecuador, from northern Chile to southern Colombia, continued until the late 19th
Thor Heyerdahl the late 1990s, genetic testing found that the mitochondrial DNA of the Polynesians is more similar to people from Southeast Asia than to people from South America, showing that their ancestors most likely came from Asia. Anthropologist Robert Carl Suggs included a chapter titled "The Kon-Tiki Myth" in his 1960 book on Polynesia, concluding that "The "Kon-Tiki" theory is about as plausible as the tales of Atlantis, Mu, and 'Children of the Sun.' Like most such theories, it makes exciting light reading, but as an example of scientific method it fares quite poorly." Anthropologist and National Geographic Explorer-in-Residence Wade Davis