A cave on the island of Timor has given archaeologists an important clue to the route taken by historical people after they first made their solution to the Australian continent.

It’s recognized from archaeological proof in Australia’s Northern Territory that folks had been there at the very least 65,000 years in the past. At the moment, when sea ranges had been decrease, Australia and New Guinea had been half of a bigger landmass often called Sahul.

Researchers imagine there are two possible routes individuals may have taken from South-East Asia to Sahul. One is a southern route through Timor. Alternatively, Homo sapiens may have travelled through Sulawesi, an island to the north of Timor.

Now, Sue O’Connor on the Australian Nationwide College in Canberra and her colleagues imagine they’ve discovered proof ruling out the chance that the primary arrivals got here by means of Timor.

In different areas on Timor, the oldest proof of human occupation was lower than 50,000 years outdated. Archaeologists had been unable to search for older artefacts as, in any respect the opposite websites they studied, they hit bedrock moderately than sediment layers that might doubtlessly comprise proof of an earlier presence, says O’Connor.

In 2019, her workforce dug a brand new pit at a cave referred to as Laili, on the north coast of East Timor, and found a wealthy deposit of archaeological proof together with tens of 1000’s of stone instruments, proving that people had occupied the island for 44,000 years.

Crucially, nonetheless, this layer of occupation was underlain by sediments with no proof of people. This implies it’s possible that earlier than 44,000 years in the past, individuals had been absent, says O’Connor.

“That is the primary time in Timor that we’ve sterile, non-occupation layers under proof of individuals’s presence,” she says.

O’Connor says such a transparent boundary between no proof of people adopted by tens of 1000’s of years of artefacts known as an “arrival signature”.

The cave’s distinguished location and entry to assets offers the researchers confidence that it’s unlikely to have been missed by any early people travelling by means of the world.

“It’s a extremely, actually huge cave with a giant flowing river in a braided floodplain and really near the coast,” says O’Connor. “It’s an ideal place for individuals to determine an occupation base camp. You couldn’t discover a extra very best setting.”

Due to the proof that folks had been in Australia 65,000 years in the past however not in Timor till 44,000 years in the past, it means people almost certainly migrated through the islands to the north, says O’Connor.

“Trying on the layers in Laili cave, it’s like ‘bang’ – you’ll be able to actually see clearly when the individuals arrive,” she says. “It was like a line had been drawn between the 2 layers – earlier than individuals and after individuals. It was so clear.”

Peter Veth on the College of Western Australia says the case for a later date for the occupation of Timor is constructing. He says historical Australians weren’t as remoted as was as soon as believed and that there have been in all probability a number of waves of migration to Sahul.

“I believe an earlier northern route appears believable. It is a extremely vital web site as, primarily based on a broad suite of shellfish, fish, crustacea and different assets discovered within the cave, it exhibits there was a completely fledged maritime financial system in place when Timor was settled.”