Chicken bones tell story of early Pacific migration

Why did the chicken cross the Pacific? To help modern-day scientists retrace the path of early Polynesians from islands of Southeast Asia to the Pacific islands to South America. Although it's debatable whether the chickens had much say in the matter, that's exactly what scientists have done. By matching a genetic signature of the original Polynesian chickens with DNA collected from modern chickens, scientists have been able to better understand the dispersal of these ancient chicken breeds and as a result, make more educated inferences about the migration of Polynesian peoples. "We have identified genetic signatures of the original Polynesian chickens, and used these to track early movements and trading patterns across the Pacific," explained lead author Dr. Vicki Thomson, a researcher at University of Adelaide's Australian Center for Ancient DNA. "We were also able to trace the origins of these lineages back into the Philippines, providing clues about the source of the original Polynesian chicken populations." The earliest European explorers could not believe that the Polynesians had managed to settle the remote Pacific islands they were found inhabiting on their own. Wild theories were offered on how they came to live on islands like Fiji, Tahiti, Tonga and Samoa. Although historians now understand the Polynesians to have deliberately traveled to these remote islands via canoe, tracing their exact origins has been difficult. Thomson and her colleagues at ACAD were assisted by researchers from Australian National University, University of Sydney, and Durham and Aberdeen Universities in the U.K. The researchers sourced the original DNA signature from chicken bones unearthed during archaeological digs on the islands of Hawaii, Rapa Nui (Easter Island) and Niue. Their findings were published today in the Proceedings of the National Academy of Sciences USA. While the original migration of the Asian peoples to Polynesia is murky, the scientists say their new analysis does disprove earlier research that suggested the Polynesians may have beaten Columbus to South American. That theory, researchers say, was likely based on contaminated results. "There are still many theories about where the early human colonists of the remote Pacific came from, which routes they followed and whether they made contact with the South American mainland," said Associate Professor Jeremy Austin, deputy director of ACAD. "Domestic animals, such as chickens, carried on these early voyages have left behind a genetic record that can solve some of these long standing mysteries." But even if more research is necessary to piece together the exact path of the earliest Polynesians, the new findings may have some more immediate and commercial value. "Remarkably, our study also shows that the original Polynesian lineages appear to have survived on some isolated Pacific islands, despite the introduction of European domestic animals across the Pacific in the last couple of hundred years," said Professor Alan Cooper, director of ACAD. "These original lineages could be of considerable importance to the poultry industry which is concerned about the lack of genetic diversity in commercial stocks."