Topo model of Sahul
Original Published Date: 
Wednesday, May 26, 2021

Full article issued by the ARC Centre of Excellence for Biodiversity and Heritage.

New research from the ARC Centre of Excellence for Biodiversity and Heritage (CABAH) advances our knowledge about the most likely routes that early Australians travelled as they peopled this giant continent.

Sea levels were much lower at the time of their arrival, meaning that Australia was connected to New Guinea and Tasmania in a land known as Sahul, that was 30% bigger than Australia is today. Evidence is scarce as there are only a few archaeological sites that date to such early times.

It is assumed that early Australians navigated in new territories by focusing on prominent land features protruding above the relative flatness of the Australian continent. The researchers then used four pieces of information to build a computer model of paths travelled: (1) topography; (2) the visibility of tall landscape features; (3) the presence of freshwater; and (4) demographics of the travellers. To map these features, they built the most complete digital elevation model for Sahul ever constructed, including areas now underwater.

The pathways chosen by the computer model were then compared with the distribution of the oldest known archaeological sites in Sahul, which provided a weighting of probabilities for each path, providing a scale going from the 'most likely' to the 'least likely' chosen paths. This generated a map of most likely pathways, what the group dubbed the 'super-highways' of Indigenous movement. The next most likely paths are marked by dotted lines.

The researchers note that the paths shown on the map echo well-documented Aboriginal trade routes criss-crossing the country. There are also striking similarities between the 'super-highways' and the most common trading and stock routes used by early Europeans, who followed already well-known routes established by Aboriginal peoples.

Australian Laureate Fellow Professor Lynette Russell notes that the new modelling establishes the infrastructure for detailed local and regional studies to engage respectfully with Indigenous knowledges, ethnographies, historical records, oral histories, and archives.

Photo credit: 

How the Sahul landmass would have looked more than 50,000 years ago. Credit: CABAH.