New study finds no evidence for theory humans wiped out megafauna

May 06, 2013
This is an artist's reconstruction of an extinct marsupial lion -- Thylacoleo carnifex. Artwork: Peter Schouten

Most species of gigantic animals that once roamed Australia had disappeared by the time people arrived, a major review of the available evidence has concluded.

The research challenges the claim that humans were primarily responsible for the demise of the in a proposed "extinction window" between 40,000 and 50,000 years ago, and points the finger instead at .

An international team led by the University of , and including researchers at the University of Queensland, the University of New England, and the University of Washington, carried out the study. It is published in the Proceedings of the National Academy of Sciences.

"The interpretation that humans drove the extinction rests on assumptions that increasingly have been shown to be incorrect. Humans may have played some role in the loss of those species that were still surviving when people arrived about 45,000 to 50,000 years ago – but this also needs to be demonstrated," said Associate Professor Stephen Wroe, from UNSW, the lead author of the study.

"There has never been any direct evidence of humans preying on extinct megafauna in Sahul, or even of a tool-kit that was appropriate for big-game hunting," he said.

About 90 giant animal species once inhabited the continent of Sahul, which included mainland Australia, New Guinea and Tasmania.

"These leviathans included the largest marsupial that ever lived – the rhinoceros-sized Diprotodon – and short-faced kangaroos so big we can't even be sure they could hop. Preying on them were goannas the size of large with toxic saliva and bizarre but deadly marsupial lions with flick-blades on their thumbs and bolt cutters for teeth," said Associate Professor Wroe.

The review concludes there is only firm evidence for about 8 to 14 megafauna species still existing when Aboriginal people arrived. About 50 species, for example, are absent from the of the past 130,000 years.

Recent studies of Antarctic ice cores, ancient lake levels in central Australia, and other environmental indicators also suggest Sahul - which was at times characterised by a vast desert - experienced an increasingly arid and erratic climate during the past 450,000 years.

Arguments that humans were to blame have also focused on the traditional Aboriginal practice of burning the landscape. But recent research suggests that the fire history of the continent was more closely linked to climate than activity, and increases in burning occurred long before people arrived.

"It is now increasingly clear that the disappearance of the megafauna of Sahul took place over tens, if not hundreds, of millennia under the influence of inexorable, albeit erratic, climatic deterioration," said Associate Professor Wroe.

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More information: Climate change frames debate over the extinction of megafauna in Sahul (Pleistocene Australia-New Guinea) www.pnas.org/cgi/doi/10.1073/pnas.1302698110

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User comments : 8

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NotParker
1.5 / 5 (16) May 06, 2013
Honestly, if they are rewriting history to blame "climate change" their theories are garbage.

"there is only firm evidence for about 8 to 14 megafauna species still existing when Aboriginal people arrived."

8 to 14. Sounds like climate science to me. Can't get an accurate number from them.

"About 50 species, for example, are absent from the fossil record of the past 130,000 years."

About 50? Why not 42 to 58?

They can't even decide whether 8 or 14 or in between were alive at one point, but are sure that 50 weren't there?

Jokers.
Shakescene21
2.1 / 5 (10) May 06, 2013
These clowns won't even admit that humans probably wiped out the 8 to 14 magafauna species that still existed when humans arrived. (and there may have been many more.)
Jeddy_Mctedder
2.8 / 5 (12) May 06, 2013
this is the stupidest article ever. mankind hunted the same PREY that the big predators relied upon EXCLUSIVELY for their diet. there is not direct manner in which it can be proven that we starved out other predator species. it is a fact that primitive man hunted large quantities of large mammals----elephants and plains animals. and yet---we are to believe other pedator species did not suffer from this. we are , and were always part of the evolutionary landscape of large predator species. we have ALWAYS competed with other species and will NEVER know precisely how, but our scientists can take a guess. mankind driving other species to extinction is a fact many people feel uncomfortable reckoning with because they don't accept our existence as mere animals in competition with other animals. civilization has given them a false sense of superiority. imagine living with no tools you couldn't build yourself from rocks and wood. then see how you feel about a pack of wild dogs on the road.
Dennis_Nilsson
2.3 / 5 (3) May 07, 2013
Funny how some commentators thinks that we humans are powerful and superior species. We aren't, but we are curios, and could learn. That's the difference...
Sinister1811
2 / 5 (8) May 07, 2013
There are a couple of aboriginal paintings thought to be of megafauna, but they're old and degraded. The early indigenous people probably would've seen some of these animals.

http://www.cosmos...ock-art/
http://www.abc.ne...d/847564
yeahitsme
3 / 5 (6) May 07, 2013
Is this paper meant to be introducing a new theory of sorts or just swinging off the back of current climate change fear-mongering and taxing (see Australia's carbon tax)? Also apparently the water is rising to swallow small islands yet it hasn't risen so much as 1mm on beaches anywhere else funnily enough - yes I live near a beach. Then again there's a new sucker born every minute on the internet so churning stories out like this has a whole fresh new audience every day.
ricarguy
1.6 / 5 (7) May 07, 2013
They have only guesses about any of this stuff. Make a guess test it if you can with little or no evidence, guess at what the evidence actually shows...change the guess.
Too bad the ancients forgot to take notes.

Who were those evil humans that caused the climate change 50,000 years ago?
Actually I like this theory as it shows what we all know, that the climate has always changed.

"it is a fact that primitive man hunted large quantities of large mammals" -JMcT

Please define "large quantities", and just how many of the "primitive man" do you figure there really were at any given time? Of course the multitudes of primitive mankind also hunted to extinction African and Indian elephants, rhinos, hippos, wildebeest, bison, deer, moose, llama, water buffalo, walrus and seals ... Man destroyed all of them, right? Who taught so many out there to be self-loathing, city-dwelling morons who somehow think that they understand how nature works and with no sense of time?
TheGhostofOtto1923
3.6 / 5 (7) May 07, 2013
Technology enabled us to hunt the creatures that were hunting us, thereby eliminating a major attritive element. Our numbers subsequently exploded and the tribal dynamic - internal altruism vs external animosity - became the main selector for human development. It gave us these large unwieldy, delicate, defect-prone, and unsustainable brains.

Of course we wiped out the megafauna. We set the fires which drove their herds off cliffs and into canyons where they could be slaughtered en masse. We built huts from their bones.
even of a tool-kit that was appropriate for big-game hunting," he said.
Fire, sharpened sticks, boulders.