CALLA WAHLQUIST | The Guardian
SYDNEY - The first people to arrive in Australia are likely to have sailed east from Borneo to Sulawesi and island-hopped to New Guinea, according to research.
A study led by Australian National University PhD candidate Shimona Kealy and published in the Journal of Human Evolution has modelled the most likely route from south-east Asia to the Australian mainland based on which pathway would have required the least expenditure of energy and resources.
Kealy said she hoped the research would help answer the question of why archaeological sites in Australia — which show human occupation around 65,000 years ago — are so much older than sites that have been discovered in the countries that were long suspected to be en route.
Her modelling identified the least-cost route as going from Borneo to Sulawesi and through a series of smaller islands to Misool Island off the coast of West Papua. New Guinea was connected by land to Australia until about 10,000 years ago, meaning the first people could walk down through what is now Cape York to the rest of the continent.
“The visibility and the shorter distances between the islands is what really makes [this route] much more feasible for travel,” she told Guardian Australia. “Most of the time that visibility is shore-to-shore visibility.”
Kealy also tracked other factors, like whether a particular route would involve going over or around a hill, in order to determine the most likely path of travel.
“We are looking at the first sea journey of our species,” she said.
The route follows roughly the same path as the northern route described by US anthropologist Joseph Birdsell in 1977, who theorised two likely paths that have been largely accepted and used as a model for researchers.
Birdsell’s northern route goes through Sulawesi to West Papua and the southern route goes through Timor and ends with a significant sea crossing to the Northern Territory or Kimberley coastline.
Archeologists have since found a number of sites in East Timor that show proof of human occupation, but none are older than 45,000 years old.
Artefacts from the oldest known site in Australia, a rock shelter at Madjedbebe in the Jabiluka mining lease within the Kakadu national park, on Mirarr country, have been dated at 65,000 years old.
A site on Barrow Island off the coast of Western Australia has been dated at 50,000 years old.
“Obviously people had to travel through these islands somehow to get to Australia so presumably the dates that we found in Australia should be younger or around the same age as the dates that we are getting from these East Timor sites,” Kealy said.
The fact that those sites are significantly younger, she said, suggests that maybe the first peoples took a different path.
Islands along Birdsell’s northern route have received comparatively little archeological attention due to isolation, expense, and political conflict in West Papua.
Kealy and co-author Prof Sue O’Connor, are applying for research grants to investigate some likely sites along the northern route next year.
“If we can find something that’s older than 60,000 years old, I would be super-dooper happy,” she said.
The timeframe of 65,000 plus years is not universally accepted in the academic community. Another recent study asserted 50,000 to 55,000 years was the most likely timeframe but Kealy said her modelling tracked changes in both coastline and sea level from 45,000 to 70,000 years ago.
The sea level was at its lowest point 65,000 years ago and highest 70,000 years ago.