Friday, 23 September 2011

Genetic Evidence Sheds Light On The Origins Of Aboriginal Ancestors

It is well known in the palaeoanthropological world that the oldest human remains outside of Africa are the remains of Mungo Man, found in South East Australia and dating to around 50,000 years old. This continent, despite being more than 28,000 miles away from Africa, the birth place of humans, is home to the oldest remains of the oldest migratory humans. It is almost universally accepted that these humans were the ancestors of the Aboriginals, making these native Australians the oldest culture on Earth.

The hair sample, collected in 1910 from an Aboriginal Australian,
which sheds light upon the origins of  the modern descendants of
the first Aboriginals
However a recent study of Aboriginal genes suggests that this is not the case. An international team of geneticists headed by Professor Eske Willerslev analysed the genome of an Aboriginal Australian, sampled from a lock of hair collected in 1910. The date is important as it drastically reduces the possibility of an ancestry tainted by a non Aboriginal gene pool. The result of the analysis is very surprising. It shows that the colonisation of Australia, like Europe, happened in two waves.

The first of these is represented by the remains of Mungo Man which started around 60,000 years ago until the colonisation of the continent was fully established around 50,000 years ago. However this wave is not represented within the genes of modern Aboriginals. These archaic Aboriginals probably died out, removing their Archaic DNA from the gene pool. Indeed archaic genes do not appear in the direct descendant populations of the original inhabitants of Oceania. 
The remains of Mungo Man, a so called, Archaic Aboriginal 

There was a second wave of colonisation around 24,000 years ago. The Aboriginal Australian, whose DNA was sampled, was shown to be a direct descendent of this second gene pool. While this does not shed any light upon the mystery of the archaic, 60,000 year old invasion, it does add another piece to the story of  early human migration, answering some of the questions about the origins of the original inhabitants of Oceania.