New DNA research suggests a genetic relationship between Australia's Indigenous people and more recently arrived Indian migrants, which blended together long after Asiatic populations also descended to the continent.
The German study, published today, genetically sampled populations from across the region and concluded that there was a “substantial gene flow between Indian and Australia populations”, occurring 141 generations ago or about 4,230 years ago.
This challenges the prevailing view that Australia's Indigenous population was genetically isolated from the rest of the world prior to European contact.
Professor Alan Cooper is the director of the Australian Centre for Ancient DNA at the University of Adelaide.
He says the research, conducted by the Max Planck Institute for Evolutionary Anthropology, confirms theories about the close connection between Indigenous peoples, particularly of the Northern Territory, and other hunter-gatherer populations in South East Asia.
“But this connection with India was completed unexpected,” he said.
The study suggests that in addition to an earlier northern route of migration out of Africa, into Asia, and then South East Asia about 60,000 to 70,000 years ago, the second wave occurred much later, arriving during the Holocene period about 4,230 years ago.
“About that point in the archaeological record, there were significant changes in the use of stone tools, in hunting techniques and significantly, the introduction of the dingo,” Professor Cooper said.
There are other theories that may support the evidence of a more recent influx of migrants from India, including that they brought with them a disease of epidemic proportions that wiped out earlier Aboriginal populations.
Peter Sutton is an Aboriginal ethnologist and linguist with the South Australian Museum, who says that about the same time, the linguistic diversity of Aboriginal Australia “collapsed.”
“It's my hypothesis that the reason why the range of language groups dramatically dropped about four to six thousand years ago was due to an epidemic, which would have had to have come from outside,” he said.
These findings may provide new understandings about the ebb and flow of ancient migration patterns.
“What it confirms is our lack of knowledge about human history in Australia, we have an incredibly long and rich human history that we know nothing about,” Professor Cooper said.
“It could be that Australia represents one of the longest continuous occupations of human culture anywhere in the world.”
The study says that the genetic information was obtained 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.
The Aboriginal Australian samples were obtained in the early 1990s by forensic scientists from individuals throughout the Northern Territory, who gave oral consent for their samples to be used in studies of population history, and have been used in previous such studies.
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