'Indigenous Australians most ancient civilisation on Earth'

 Indigenous Australians are the most ancient continuous civilisation on Earth - dating back to more than 50,000 years ago - according to the first extensive study of their DNA by scientists including one of Indian origin.

Scientists traced the journey of these ancient humans by studying the DNA of modern populations in Australia and Papua New Guinea.

The analysis shows that their ancestors were probably the first humans to cross an ocean, and unveils evidence of prehistoric liaisons with an unknown hominin cousin.

"Now we know their relatives are the guys who were the first real human explorers. Our ancestors were sitting being kind of scared of the world while they set out on this exceptional journey across Asia and across the sea," Eske Willerslev of University of Copenhagen in Denmark, who led the study.

The findings, based on a population analysis of 83 Indigenous Australians and 25 Papuans, shows that these groups can trace their origins back to the very first arrivals on the continent about 50,000 years ago and that they remained almost entirely isolated until around 4,000 years ago.

The study adds to the view that Neanderthals and other now extinct hominins, traditionally portrayed as low-browed prehistoric thugs, were "in reality not particularly different" from our own ancestors, the 'Guardian' reported.

Another study found that the advent of modern human behaviours around 100,000 years ago, indicated by cave art and more sophisticated tools, were not accompanied by any notable genetic mutations.

"Your genome contains the history of every ancestor you ever had," said Swapan Mallick, a geneticist at Havard Medical School in the US who led the analysis of the genomes of people from 142 distinct populations.