sciencehabit shares a report from Science Magazine: When humans first set foot in Australia more than 65,000 years ago, they faced the perilous task of navigating a landscape they’d never seen. Now, researchers have used supercomputers to simulate 125 billion possible travel routes and reconstruct the most likely “superhighways” these ancient immigrants used as they spread across the continent. The project offers new insight into how landmarks and water supplies shape human migrations, and provides archaeologists with clues for where to look for undiscovered ancient settlements.
It took weeks to run the complex simulations on a supercomputer operated by the U.S. government. But the number crunching ultimately revealed a network of “optimal superhighways” that had the most attractive combinations of easy walking, water, and landmarks. Optimal road map in hand, the researchers faced a fundamental question, says lead author Stefani Crabtree, an archaeologist at Utah State University, Logan, and the Santa Fe Institute: Was there any evidence that real people had once used these computer-identified corridors? To find out, the researchers compared their routes to the locations of the roughly three dozen archaeological sites in Australia known to be at least 35,000 years old. Many sites sat on or near the superhighways. Some corridors also coincided with ancient trade routes known from indigenous oral histories, or aligned with genetic and linguistic studies used to trace early human migrations. “I think all of us were surprised by the goodness of the fit,” says archaeologist Sean Ulm of James Cook University, Cairns.
The map has also highlighted little-studied migration corridors that could yield future archaeological discoveries. For example, some early superhighways sat on coastal lands that are now submerged, giving marine researchers a guide for exploration. Even more intriguing, the authors and others say, are major routes that cut across several arid areas in Australia’s center and in the northeastern state of Queensland. Those paths challenge a “long-standing view that the earliest people avoided the deserts,” Ulm says. The Queensland highway, in particular, presents “an excellent focus point” for future archaeological surveys, says archaeologist Shimona Kealy of the Australian National University. The study has been published in the journal Nature Human Behavior.