New evidence of human occupation in southeast Indonesia more than 40,000 years ago is offering fresh clues about the island-hopping route taken by some of the first humans to arrive in Australia and the near north.
Lead author of the research and Australian National University PhD candidate Hendri Kaharudin said the location of the discovery, at Elivavan on Indonesia's Tanimbar islands, makes it especially significant.
"Tanimbar is located just off the Sahul shelf, which encompasses modern-day Australia, as well as New Guinea," he said.
"The question of how our early ancestors arrived there from Southeast Asia is one of the most captivating in prehistoric migration, mainly because of the vast distances covered and advanced seafaring skills that would have been required."
There are two main routes explored by scientists as possibilities since the mid-20th century. One is a northern path via islands like Sulawesi and the other a southern track passing near Timor and the Tanimbar islands.
"This discovery marks one of the southern route's earliest known sites, making it a crucial piece of the puzzle," Mr Kaharudin said.
According to the research, while there are still unanswered questions about Elivavan's first inhabitants, the risky nature of the sea crossings suggests the colonists had developed advanced maritime technology some 42,000 years ago.
"They would have had to traverse bodies of water exceeding 100km in distance regardless of their direction of travel," Mr Kaharudin said.
"Along with tiny fragments of pottery, we also found evidence of things like bones, shells and sea urchins that point to the island's role as a hub for early maritime activities.
"As more work is done in lesser-explored regions like the Tanimbar islands, I expect we'll uncover more about early human life and migration patterns."
Mr Kaharudin said it was also clear the colonisation of Sahul was not a single event but "a gradual process involving successive waves of seafaring populations".
"Coastal communities likely navigated shorelines, exploiting marine resources and establishing resilient settlements along their journey," he said.
"This island-hopping strategy facilitated cultural exchange and adaptation, shaping diverse societies across the land mass."
The research has been published in Quanternary Science Reviews.