Pacific migration
tracked by rat DNA
The origins of Polynesian people and their ancestors in the Western Pacific, a topic of debate for more than 200 years, may be uncovered through the analysis of rat DNA, says a new study in the online journal Proceedings of the National Academy of Sciences.
The research implies that the ancient Lapita people, a seafaring culture that appeared in the Western Pacific about 3,500 years ago, migrated to the region in a slower, more complex manner than prior theories suggest. They are widely believed to be ancestors of the Polynesians.
Instead of quick movement from Southeast Asia to Polynesia, with little or no contact with native people along the way, Lapita people moved more slowly, with significant interactions among populations, according to the new study, led by Elizabeth Matisoo-Smith at the University of Auckland in New Zealand.
To trace the migration pattern within Oceania, a large group of islands in the Western Pacific, the researchers examined DNA of ancient and modern rats throughout the Pacific and Island Southeast Asia. The Lapita colonists are thought to have introduced rats and other animal and plant species to the area. Rats are especially useful in the study of Lapita migration because, since they don't swim, humans were solely responsible for their dispersal throughout the Pacific.
Further prehistory of the region will be learned when the study's results are combined with data from archaeology, comparative linguistics and molecular biology of human populations, the researchers said.