Evrim Yazgin
Cosmos science journalist
Ancient tree resin artefacts discovered on an Indonesian island might hold the key to understanding when humans first spread through the Pacific, including to Australia.
The timeline of human arrival on the Australian continent has been hotly debated.
Research published in 2017 suggested that the Madjedbebe rock shelter in the Northern Territory’s Arnhem Land is evidence that the first humans in Australia arrived about 65,000 years ago. More conservative estimates place their arrival at about 47,000 years ago.
One thing that is generally agreed upon is the route that ancient people would have had to take to reach Australia and other parts of the Pacific.
Homo sapiens would have travelled through the Wallacea Islands stretching from Sulawesi to Timor to reach the landmass of Sahul which includes Australia and New Guinea. Along this route, the oldest evidence of human occupation dates to only 44,000 years ago.
New research published in the journal Antiquity reveals a human-made artefact dating to between 50,000 and 55,000 years ago. The tree resin artefact was found in Mololo Cave on Waigeo Island off the coast of New Guinea in Indonesia’s Southwest Papua province.
It is the oldest evidence of humans dispersing through the Pacific.
The piece was made by cutting into a tree and extracting the hardened sap. This is similar to ethnographic accounts of how Waigeo people extracted tree resin in modern times.
Tree resin has many uses and could have been extracted by the ancient people to fuel fires, construct boats or attaching stone tools to a wooden handle.
“The resin from Mololo demonstrates sophisticated technological processes innovated by people moving into rainforest environments (where the resin trees are found),” says first author Dylan Gaffney, an archaeologist at the University of Oxford, UK.
“This adds to our growing understanding of the adaptability and flexibility of early human forager groups in the Pleistocene.”
During the Late Pleistocene (127,000–11,700 years ago), Homo sapiens would have been able to travel using watercraft between the islands in the region. On average, the islands were 5–6km apart and separated by only 2.5km at the narrowest points.
“We used computer simulations of Pleistocene sea currents to model how long it would have taken to get between these islands,” Gaffney adds. “We found that there would have been a high rate of success for seafarers wanting to cross these water gaps, and skilled seafarers would have done this relatively easily.”
In addition to the tree resin artefacts, the archaeologists found bones of animals which were likely brought to the caves by humans who hunted them, as well as fish and sea urchin remains which would have been brought from the coast 15km away.
“Some bones in the deposit are likely natural, including smaller animals like small rodents and microbats. The other larger animals like terrestrial birds, marsupials and megabats are more likely to result from human predation,” Gaffney says.
