Are Indians related to Native Australians

Australia: Indians as Stone Age Immigrants

Australia's natives developed less isolated than previously thought: Instead of living tens of thousands of years without contact with the outside world, they received visitors around 3,200 years ago - from India. This is what an international team of researchers found out using genetic analyzes. The Indian immigrants not only left their traces in the genes of the Aborigines, their presence also explains why the culture of the indigenous people changed significantly at that time, as the researchers report in the journal “Proceedings of the National Academy of Sciences”.

The history of the native people of Australia goes back a good 45,000 years. At that time, their ancestors immigrated from Africa via Asia to what is now Indonesia and Australia. This first wave of immigration to Australia was, according to current assumptions, also the last before the arrival of the Europeans. The Aborigines, it is believed, remained to themselves for tens of thousands of years and developed their culture largely isolated from the outside world. "The prevailing view was that there was little, if any, contact between Australia and the rest of the world until the first Europeans came in the 18th century," explain Irina Pugach from the Max Planck Institute for Evolutionary Anthropology in Leipzig and her colleagues.

Dingoes and a puzzling cultural change

But one was not quite sure. Because at least in the animal world there was a clear indication of external contact: dingoes first appeared in Australia around 4,000 years ago. These predators, descended from domestic dogs, were real exotic species in the otherwise marsupial-dominated fauna - and therefore had to have immigrated. And also in the culture of the ancestors of today's Aborigines there was a clear change around 4,200 years ago: They suddenly began to make other stone tools. Instead of coarse wedges, they now also made fine micro-blades. And now they also prepared their plant food differently than before. But why?

Pugach and her colleagues have now looked in the genes of the Aborigines for a possible explanation for this sudden change. Because maybe, so their guess, there was contact with the outside world after all. In order to clarify this, the researchers examined the genome of the Aborigines again specifically for traces of foreign genes. To do this, they compared the pattern of point mutations - changes in individual letters in the genetic code - of Aborigines with that of people from other parts of the world. Residents of New Guinea, various islands in Southeast Asia and India as well as Chinese, Europeans and an African tribe served as comparison groups.

Conspicuous genetic matches

The surprising result: between Aborigines and Indians there were noticeable similarities in part of the mutation pattern, as the analyzes showed. In other population groups, however, this pattern did not appear. “This indicates a gene flow from India to Australia,” the researchers state. People of Indian descent must have come to the fifth continent and then mixed with native Aborigines. This find contradicts the previous assumption that Australia's indigenous people developed completely isolated from the outside world for tens of thousands of years.

The scientists were also able to read from their mutation data when the Indians arrived in Australia after their long journey via Indonesia. Because the speed with which the genetic material changes due to copying errors and other mutations is relatively stable and known. Using small differences in the mutation pattern of the Indians and Australians, the researchers calculated that immigration must have occurred around 141 generations ago. "Assuming a generation time of around 30 years, the gene exchange between India and Australia therefore occurred around 4,230 years ago," report Pugach and her colleagues.

This coincides pretty much with the time when the Aboriginal culture changed significantly. According to the researchers, this is no coincidence. At that time, the immigrants obviously brought not only their genes, but also their knowledge and culture to their new homeland - and shared both with their new neighbors. (Proceedings of the National Academy of Sciences (PNAS), doi: 10.1073 / pnas.1211927110)

(PNAS, January 15, 2013 - NPO)

January 15, 2013