After decades of contention, New Zealand researchers have provided the first direct evidence that Polynesians sailed across thousands of miles of the Pacific Ocean to reach South America long before the arrival of the Spanish around AD 1500.
Their proof? Chicken bones.
Using genetic analysis and radiocarbon dating of chicken bones found in Chile, the researchers showed that the fowl originated in Polynesia, not Europe as was previously believed, the researchers said Monday.
"The Polynesian contact probably didn't change the course of prehistory, but I think maybe it makes us recognize the ethnocentrism in our long-standing views of the prehistory of the New World," said archeologist Terry L. Jones of Cal Poly San Luis Obispo, who was not involved in the research.
"The basic premise has always been that there was only one civilization capable of crossing the ocean and discovering the New World," he said. The new findings, reported in the Proceedings of the National Academy of Sciences, indicate that "the prehistory of the New World was probably a little bit more complicated than we thought in the past."
The possibility of contact between Polynesia and the New World has been a subject of contention since Norwegian explorer Thor Heyerdahl's famous 1947 voyage aboard his crude raft Kon-Tiki.
Heyerdahl believed that an ancient, fair-haired race originating high in the Andes around Lake Titicaca sailed to the Pacific islands.
He attempted to prove his ideas by setting off on a trip from the west coast of South America on a raft based on Inca designs.
The 4,300-mile trip from Peru to the Tuamotu Islands took 101 days, but subsequent trips were much faster once researchers learned how to steer the boats.
Despite Heyerdahl's demonstration, the idea that Polynesians could have routinely -- or even occasionally -- navigated across the Pacific was considered farfetched, primarily because of the lack of proof.
"Scientists have not been willing to fully accept the idea" of prehistoric contact between Polynesia and South America, Jones said, "but it is hard to understand why."
The most convincing previous evidence of cultural contact was the presence of sweet potatoes -- a native American plant -- at archeological sites throughout Polynesia.
Most notably, sweet potatoes dating from about AD 1000 have been found on the Cook Islands. Equally important, Jones noted, the name of the potato used throughout Polynesia is the same name given it by South Americans.
Heyerdahl's trip and the discovery of the sweet potatoes showed South Americans could have taken the sweet potato to the islands but did not demonstrate that the islanders could have come to South America.
The new findings show that definitively, said the senior author of the new report, archeologist Elizabeth A. Matisoo-Smith of the University of Auckland.
The chicken bones were recovered from a site called El Arenal-1 in south-central Chile, about a mile and a half inland on the southern side of the Arauco Peninsula. Thermoluminescent dating of ceramics from the site indicates it was occupied from AD 700 to 1390.
Analysis of the bones was conducted by graduate student Alice A. Story in Matisoo-Smith's lab.
Matisoo-Smith said she didn't expect much from the study because finding evidence of Polynesian contact would be like "finding a needle in a haystack."
But radiocarbon dating showed the bones were about 622 years old. Even with potential errors, they dated from AD 1321 to 1407 -- before Spaniards first trod the New World.
Genetic analysis of the chickens showed that they were identical to genetic sequences of chicken from that same time period in American Samoa and Tonga, both more than 5,000 miles from Chile.
The sequences were very similar to those of chickens from Hawaii, also about 5,000 miles distant, and Easter Island, about 2,500 miles away.
"I was pretty excited when the dates came back as clearly pre-European," Matisoo-Smith said. "There were no questions. The Europeans didn't pick them up in Polynesia and bring them back" to South America, she said.
Sailing into the wind from the islands to South America "requires significant sailing technology and navigational skills," she said. "But if you look at the winds, leaving from Easter Island, you would actually land [in South America] around the area where El Arenal-1 is located. You could then make the return voyage further north."
Jones of Cal Poly is particularly pleased because the find supports his theory that Polynesians also landed in the Northern Hemisphere. He and linguist Kathryn A. Klar of UC Berkeley have argued that the Chumash Indians of Southern California learned to build their sewn-plank canoes from the Polynesians, in part because the names of the ships are very similar in the two unrelated languages.
Composite bone fishhooks used by the Indians also closely resembled those used in Polynesia.
If we know they landed in Chile, he said, "then why is it so difficult to imagine they couldn't have made it to Southern California from Hawaii?"