23 May 2018

Australia’s first people planned their voyage

From Afternoons, 1:21 pm on 23 May 2018

There's long been speculation about how Aboriginal people arrived in Australia tens of thousands of years ago.

One school of thought was it was an accident and the ancestors of today's Aboriginal people drifted onto the Australian continent unintentionally and settled there.

Northwest Australia showing a now submerged string of islands between Australia and Timor/Roti

Northwest Australia showing a now submerged string of islands between Australia and Timor/Roti Photo: Supplied / The Conversation

But new research suggests that isn't the case in fact it was planned migration by skilled explorers.

In a study was published in Quaternary Science Reviews, experts came to the conclusion using wind and ocean current modelling, similar to that deployed in the search for missing Malaysia Airlines flight MH370.

Co-author Sean Ulm, archaeology professor at Queensland's James Cook University, says analysis of wind and currents between Timor Leste and north west Australia showed any arrival on Australian shores would have been planned and purposeful.

"If you launch a raft into the water, and just go by the wind and the currents, you basically never end up in Australia.

"But if you add a little bit of paddling, about half the minimum paddling speed we think Polynesian seafarers used in colonising the Pacific, even [with] that little bit of forward propulsion almost 100 percent of our craft in our modelling reached the Australian mainland at that time."

At that time Australia was about 300km nearer Timor Leste than it is today.

In fact, 65,000 years ago, Australia was 2 million square kilometres bigger and the sea levels 70 metres lower.

"Even then there was still 100 kilometres of open ocean to traverse to get to Australia from places like Timor Leste."

Until very recently it was thought Australia wouldn't be visible from islands in South East Asia but recent modelling shows that from high points on the coast of Timor, Australia could have been quite easily seen.

And those early voyagers were helped by a string of now submerged islands.

"We think the minimum distance to those now submerged islands from Timor is 87km so people still have to traverse a serious amount of open ocean.

"That voyage is the earliest evidence we have anywhere in the world of large scale long distance open sea voyaging," Professor Ulm says.

He says such a journey would take about four to seven days and would require sturdy craft, planning and provisioning.

"It tells us the voyage is purposeful and coordinated and that quite a large number of people ended up in Australia 60,000 years ago to become the founding members of the indigenous population of Australia."

Studies of the genetic make-up of present day Aboriginal people suggests the original settlers numbered between 100 and 300.

So why would these intrepid early voyagers leave the safety of their shores? Possibly food, possibly for social reasons, Prof Ulm says.

"Populations were building up in that part of the world around that time and those islands are small and quite heavily forested, so we think people may have been heavily reliant on marine resources.

"One school of thought is these coastally-adapted people were moving on to the next islands."

Once on the mainland Aboriginal people colonised the continent in the "blink of an eye", he says.

"Archaeologically we have people in the north west of Australia 65,000 years ago and before 50,000 years ago they're right in the southern part of Australia, in Victoria and certainly in Tasmania by 40,000 years ago."

He says it's still not understood how these people so quickly adapted to living in tropical rain forests of the north, deserts in the middle and snow-covered alpine regions in the south east.