martes, 27 de septiembre de 2016

Solving the riddle of Australia's colonisation


Well-watered routes (darker blue) that may have facilitated rapid movement by people into the continental interior.

James Cook University scientists may have solved the riddle of how the vast continent of Australia was colonised more than 47,000 years ago.

JCU’s Professor Michael Bird, Professor Sean Ulm and Dr Damien O’Grady assessed the position and permanency of water bodies to investigate early human migration across the continent.

“Australia is the driest inhabited continent on Earth and there is debate over when and which route it was colonised by its earliest people,” said Professor Bird.

Aboriginal people initially arrived in Australia by 47,000 years ago, but it may have been as early as 50,000 to 55,000 years ago. From an initial entry point in the north-west or north people quickly made their way to south-east Australia with occupation of the Willandra Lakes region by 41,000 to 45,000 years ago. This suggests that people rapidly filled the continent within 5,000 to 10,000 years of initial arrival.

“We thought the distribution of water sources, particularly in the dry interior, may have played an important role in the rapid human colonisation of the continent.”

The scientists mapped 112,786 permanent water bodies. They found high degrees of connectivity during wet periods and a high density of water sources stretching from northern Australia, through semi-arid and arid regions, to south-eastern Australia and into the continent’s arid centre.

Results have been reported this week in the prestigious Proceedings of the National Academy of Sciences of the United States of America.

“Our analysis placed 84% of archaeological sites older than 30,000 years within 20 km of permanent water sources. The findings suggest that a series of well-watered routes across Australia, particularly through the Channel Country in western Queensland, could have made possible the rapid human occupation of the continent’s arid interior,” said Professor Ulm. JCU Australia