Study shows ‘gene flow’ from India to Australia 4000 years ago

Indian people may have arrived on Australian shores about 4000 years before Europeans colonised the continent, scientists report.

Modern humans are thought to have arrived down under about 40,000 years ago, having made their way out of Africa around the coast of the Arabian Peninsula and India to Australia.

Most scientists believed these ancestors of modern Aborigines remained isolated from other populations until Europeans appeared in the late 18th century.

But a genetic analysis of more than 300 Aborigines, Indians and people from Papua New Guinea and islands of south-east Asia has found a “significant gene flow” from India to Australia about 4230 years, or 141 generations, ago.

The study’s lead researcher, Irina Pugach, from the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, said the arrival of these people during the Holocene coincided with many changes in Australia’s archaeological record.

“[There was] a sudden change in plant processing and stone tool technologies, with microliths appearing for the first time, and the first appearance of the dingo in the fossil record,” said Dr Pugach.

“Since we detect inflow of genes from India into Australia at around the same time, it is likely that these changes were related to this migration,” she said.

The researchers said it was possible Indian ancestry came to Australia indirectly, through south-east Asian populations who had trade links with northern Australia and Indonesia.

But the analysis found no evidence of this scenario in the genes of the south-east Asian populations.

The study also found a common origin between Aboriginal Australians, New Guinea populations and the Mamanwa – a Negrito group from the Philippines. The researchers estimate these groups split from each other about 36,000 years ago.

A study co-author, Mark Stoneking, said this finding supported the view that these populations were the descendants of an early “southern route” migration out of Africa.

The findings are published in the Proceedings of the National Academy of Sciences journal.