Some aboriginal Australians can trace as much as 11% of their genomes to migrants who reached the island around 4,000 years ago from India, a study suggests. Along with their genes, the migrants brought different tool-making techniques and the ancestors of the dingo, researchers say.
This scenario is the result of a large genetic analysis outlined today in the Proceedings of the National Academy of Sciences1. It contradicts a commonly held view that Australia had no contact with the rest of the world between the arrival of the first humans around 45,000 years ago and the coming of Europeans in the eighteenth century.
“Australia is thought to represent one of the earliest migrations for humans after they left Africa, but it seemed pretty isolated after that,” says Mark Stoneking, a geneticist at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, who led the study.
Irina Pugach, a postdoctoral researcher in Stoneking’s laboratory, discovered signs of the Indian migration by comparing genetic variation across the entire genomes of 344 individuals, including aboriginal Australians from the Northern Territory, highlanders from Papua New Guinea, several populations from Southeast Asian and India and a handful of people from the United States and China.
Pugach confirmed an ancient association between the genomes of Australians, New Guineans and the Mamanwa — a Negrito group from the Philippines. These populations diverged around 36,000 years ago, suggesting that they all descended from an early southward migration out of Africa.
But Pugach also found evidence of more recent genetic mixing, or gene flow, between the Indian and northern Australian populations — taking place around 141 generations ago.
( via nature.com )