The uniqueness of Australian Aboriginal people and their long association with the continent has been revealed in a landmark genetic study

Deborah Smith:

Researchers analysed the DNA of more than 120 Aboriginal people and compared it with the DNA of indigenous people in the region, including Papua New Guinea, Malaysia and the Andaman Islands off the coast of India.

A Sydney scientist, Sheila van Holst Pellekaan, said her team found the Aboriginal people could be grouped into five genetic haplogroups, or super families, that were very distinct from their regional neighbours.

"Australian super families are unique. This confirms they have been here a very long time," said Dr van Holst Pellekaan, formerly of the University of Sydney and now at the University of NSW.

The researchers calculated that Aboriginal people were spread widely across the continent by at least 40,000 years ago.

This fits with archaeological evidence that the first people arrived here between 45,000 and 60,000 years ago.

Identification of one of the Aboriginal haplogroups also supported a genetic study last year that concluded a group of modern humans who left Africa more than 65,000 years ago and eventually populated the globe were beachcombers, moving very rapidly around the coast of India and down to Australia, long before Europe was colonised.

However, the presence of the other four haplogroups could indicate a different dispersal history for these people's ancestors, Dr van Holst Pellekaan said.

Her team studied DNA in the mitochondria, or energy producing parts of the cell, which is inherited maternally. The amount of variation in the mitochondrial DNA sequence between different groups reflects the amount of time since they diverged from each other.

Wiimpatja people from the Darling River area of western NSW and Walbiri people from Yuendumu in central Australia were the main participants in the study, which is published in the American Journal of Physical Anthropology.

The most ancient lineages, two super families dubbed A and B, were widespread across Australia. People living in western NSW and the north of the country belonged to super family C, while people in central Australia belonged to the D and E groups.

As expected, very ancient connections with people in India, South-East Asia and PNG were evident in the DNA of the Aboriginal people.

The C and E groups, for example, shared a genetic similarity with a super family in PNG known as P.

Dr van Holst Pellekaan said this was probably because they had all descended from one original population that moved into both countries long ago.

The study also supported research published last year suggesting a super family known as Q had evolved in PNG in isolation from Australia.

"On current evidence, genetic exchange across the Torres Strait subsequent to initial colonisation appears to have been surprisingly limited," she said.

It found no evidence for a recent scientific claim that Indian people had migrated to Australia about 10,000 years ago.

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