FACT SHEETS

Australia’s first thirsty travellers

25.09.17 by CABAH

The driest inhabited continent on the planet, Australia is a challenging land to traverse even with modern conveniences. Yet, Australia’s first people colonised much of the continent relatively quickly after their arrival. It stands to reason that water, the essence of life itself, had something to do with it.

There are differing views on when people first arrived in Australia, but geoscientist Prof. Michael Bird says something we know for sure is that when they arrived, they really motored.

“They put the pedal to the metal!” Prof. Bird said. “They managed to get all the way down to Lake Mungo within a couple of thousand years of arriving probably on the northern coast.”

If you’ve ever road-tripped in outback Australia, you’ll appreciate how epic a journey that is. Lake Mungo in the South-West of New South Wales, a site of archaeological significance, is several hours from the nearest coastline, and that’s in your late model SUV. Just imagine – no modern luxuries, just you and some local megafauna.

Given that Australia has large areas of inhospitable territory, how and why did these early Australians travel so far inland in that timeframe?

Hypothesised pathways for the colonisation of the Australian continent
Pedal to the metal
The first Australians migrated from the top of Australia to Lake Mungo (hours in your car from the nearest coast) within a couple of thousand years
Surprises on the driest continent
More than 100,000 water bodies were found that are there 90 percent of the time, including rivers and springs

"50-65 thousand years ago sounds like a long time, but geologically speaking it’s nothing"

It's likely that the first Australians 'followed the water'

Researchers have put much thought into answering the question of how the first Australians colonised the continent, and one thing is for certain, whatever the answer – the Australian landscape had something to do with it.

Back in the 1970s, researchers modelled a theory that these people went around the coasts, a terrain with which they would have been familiar prior to their arrival in Australia, and then headed inland.

There were other models that suggested that people just came and moved out indiscriminately, everywhere.

Just as we do today, Australia’s first people needed water. Plenty of it, after all, Australia is the driest inhabited continent on earth, so it stands to reason that they simply ‘followed the water’.

It sounds simple, but how do you now follow the water that people followed tens of thousands of years ago?

 

 

Diving in to discover more about our distant past

Prof. Bird says there’s a likelihood that the current points of permanent water, were also more or less present in much the same places as in the past.

“We know a fair few things about the nature of the climate back then, which suggests it wasn’t hugely different to how it is now,” Prof. Bird said.

“It probably cycled between slightly wetter or slightly drier depending on the particular time, but there would have been opportunities when the climate was much like now. Although 50-65 thousand years ago sounds like a long time, geologically speaking it’s nothing, so with a few exceptions, the rivers are going to be now pretty much where they were, and you only get springs in certain geological environments which would not have changed.”

Armed with the knowledge that Australia’s permanent water sources would’ve been quite similar to those today, and a theory that the first people in Australia would have ‘followed the water’, Prof. Bird and his team, including CABAH archaeologist Prof. Sean Ulm embarked on a project to collect water data and map possible migration paths through the vast continent.

Diving in to discover more about our distant past

Prof. Bird says there’s a likelihood that the current points of permanent water, were also more or less present in much the same places as in the past.

“We know a fair few things about the nature of the climate back then, which suggests it wasn’t hugely different to how it is now,” Prof. Bird said.

“It probably cycled between slightly wetter or slightly drier depending on the particular time, but there would have been opportunities when the climate was much like now. Although 50-65 thousand years ago sounds like a long time, geologically speaking it’s nothing, so with a few exceptions, the rivers are going to be now pretty much where they were, and you only get springs in certain geological environments which would not have changed.”

Armed with the knowledge that Australia’s permanent water sources would’ve been quite similar to those today, and a theory that the first people in Australia would have ‘followed the water’, Prof. Bird and his team, including CABAH archaeologist Prof. Sean Ulm embarked on a project to collect water data and map possible migration paths through the vast continent.

“If you look at Google Earth, you see lots and lots of water but quite often it’s only there for a couple of months in the wet season, particularly in the north,” Prof. Bird said.

“We wanted to distinguish water which is reliable – springs and permanent lakes, and we found a way to do that with a technology that I quite randomly came across, which tracks water observations from space.”

Researchers identified over 100,000 water bodies that are there 90 percent of the time, and excluded modern bores and dams. With that data, a map of permanent water points was created and an algorithm used to connect those water sources by the ‘path of least resistance’.

“The map showed us that there was a lot of water across the savannas in Northern Australia, as we already knew, but there’s also lots of water points coming down from the Gulf of Carpentaria into the major rivers which ultimately flow to Lake Eyre.”

With all that water, there were high degrees of connectivity between each source. A possible path of migration became clear, and it correlated with sites where archaeological items had been uncovered.

“If you map the water points now, against the old archaeological sites (older than 30,000 years), they are closely associated,” Prof. Bird said. “This also suggests that the water points were there when the archaeological sites were originally occupied.”

The findings are remarkably similar to that of a separate research project by CABAH researchers.

“We found out that, serendipitously, other CABAH people who were working independently on the genetics of Aboriginal hair, came up with their own model for how they thought people got around Australia. Independently from ours, the two were remarkably similar,” Prof. Bird said.

“It’s one of those moments in science where you have two different groups, using two different sets of information that come up with what looks like a similar answer, it gives you more confidence that it might actually be true.”

Although they can be hard to find, there are hundreds of permanent water points around Australia

A Key Element: How water could help uncover the next big discovery

The early human migration in Australia is fascinating in itself, but it now serves to inform further study. Water could be a key factor in researchers finding, for example, further confirmation that humans reached Australia 65,000 years ago – a date that, so far, has been found only at one site.

Analysis made by the research team placed over 80% of archaeological sites older than 30,000 years, within 20km of modern permanent water sources. Could an understanding of the link between water and migration pattern help researchers find further sites of archaeological significance?

“Water isn’t the only requirement, but when you start to layer that with things like surrounding geology, like rocks, cliffs and slopes, you can narrow down prospective sites,” Prof. Bird said.

“To make that big discovery, we need to put in a lot of effort in a lot of places, and one site out of ten, or a hundred will be that major place. We now, through CABAH, have seven years of funding to do things that we couldn’t otherwise do – to do exploratory research where we don’t know what we’re going to find.”

“I can’t tell you what the discoveries will be, but I can tell you that they will be made.”

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