An international team of scientists using a Sandia National Laboratories supercomputer in the largest reconstruction ever attempted of prehistoric travel has mapped the probable "superhighways" that led to the first peopling of Australia.

By simulating the physiology and decisions of early way-finders, an international team of archaeologists, geographers, ecologists, and computer scientists has mapped the probable "superhighways" that led to the first peopling of the Australian continent some 50,000-70,000 years ago.

Dating early human middens becomes uncertain beyond 50,000 years, when radiocarbon dating ceases to be useful. Uranium-series dating of marine shells and bone is uncertain by some 10% because of the structure of these materials. A UC Berkeley and Berkeley Geochronology Center team has now improved the method for a more stable discard: ostrich eggshells. The method extends the accuracy and precision of radiocarbon 10 times into the past, to about 500,000 years ago.