Humans, not climate change, wiped out Australian megafauna

January 20, 2017
A menagerie of megafauna that inhabited Australia some 45,000 years ago. Credit: Peter Trusler, Monash University

New evidence involving the ancient poop of some of the huge and astonishing creatures that once roamed Australia indicates the primary cause of their extinction around 45,000 years ago was likely a result of humans, not climate change.

Led by Monash University in Victoria, Australia and the University of Colorado Boulder, the team used information from a drilled in the Indian Ocean off the coast of southwest Australia to help reconstruct past climate and ecosystems on the continent. The core contains chronological layers of material blown and washed into the ocean, including dust, pollen, ash and spores from a fungus called Sporormiella that thrived on the dung of plant-eating mammals, said CU Boulder Professor Gifford Miller.

Miller, who participated in the study led by Sander van der Kaars of Monash University, said the sediment core allowed scientists to look back in time, in this case more than 150,000 years, spanning Earth's last full glacial cycle. Fungal spores from plant-eating mammal dung were abundant in the sediment core layers from 150,000 years ago to about 45,000 years ago, when they went into a nosedive, said Miller, a professor in the Department of Geological Sciences.

"The abundance of these spores is good evidence for a lot of large mammals on the southwestern Australian landscape up until about 45,000 years ago," he said. "Then, in a window of time lasting just a few thousand years, the megafauna population collapsed."

A paper on the subject was published online Jan. 20 in Nature Communications.

The Australian collection of megafauna some 50,000 years ago included 1,000-pound kangaroos, 2-ton wombats, 25-foot-long lizards, 400-pound flightless birds, 300-pound marsupial lions and Volkswagen-sized tortoises. More than 85 percent of Australia's mammals, birds and reptiles weighing over 100 pounds went extinct shortly after the arrival of the first humans, said Miller.

The ocean sediment core showed the southwest is one of the few regions on the Australian continent that had dense forests both 45,000 years ago and today, making it a hotbed for biodiversity, said Miller, also associate director of CU Boulder's Institute of Arctic and Alpine Research.

"It's a region with some of the earliest evidence of humans on the continent, and where we would expect a lot of animals to have lived," Miller said. "Because of the density of trees and shrubs, it could have been one of their last holdouts some 45,000 years ago. There is no evidence of significant climate change during the time of the megafauna extinction."

Scientists have been debating the causes of the Australian megafauna extinctions for decades. Some claim the animals could not have survived changes in climate, including a shift some 70,000 years ago when much of the southwestern Australia landscape went from a wooded eucalyptus tree environment to an arid, sparsely vegetated landscape.

Others have suggested the animals were hunted to extinction by Australia's earliest immigrants who had colonized most of the continent by 50,000 years ago, or a combination of overhunting and , said Miller.

Miller said the extinction may have been caused by "imperceptible overkill." A 2006 study by Australian researchers indicates that even low-intensity hunting of Australian megafauna - like the killing of one juvenile mammal per person per decade - could have resulted in the extinction of a species in just a few hundred years.

"The results of this study are of significant interest across the archaeological and Earth science communities and to the general public who remain fascinated by the menagerie of now extinct giant animals that roamed the planet - and the cause of their extinction - as our own species began its persistent colonization of Earth," said van der Kaars.

In 2016 Miller used burned eggshells of the 400-pound bird, Genyornis, as the first direct evidence that humans actually preyed on the Australian megafauna.

The new study also included Research Professor Scott Lehman of INSTAAR. The study was funded in part by the U.S. National Science Foundation and the German Research Foundation.

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Chris_Reeve
1 / 5 (8) Jan 20, 2017
Re: "There is no evidence of significant climate change during the time of the megafauna extinction"

Let's not forget that the Firestone group has produced 8 examples of North American mammoth tusks which have been peppered with small meteorites, all on one side. 7 of the 8 animals died from the bombardment.

There has been debate over the dates for these tusks, because the mammoths went extinct fairly recently -- somewhere around 10,000 years ago.

But, the tusks dated to something like 35,000 years ago.

It must be emphasized in all circumstances regarding some sort of catastrophe that the dates will not be reliable.

What I have noticed is that the climate researchers don't much care to talk about this sort of evidence. They always want to talk about how humans are responsible.

From what I can tell, there's not even been a systematic analysis of tusks across the world for these meteorite fragments.
gkam
1.9 / 5 (8) Jan 20, 2017
We will continue to kill for kicks until we have killed all the life which supports ours.

The spoiled Trump kids just shot an endangered Cheetah, for "sport:". I guess the Cheetah was unarmed, or they would not have tried it.

Real character.
Captain Stumpy
3.8 / 5 (10) Jan 20, 2017
@reeve/hannes the eu cult preacher
Let's not forget that the Firestone group has produced 8 examples of North American mammoth tusks which have been peppered with small meteorites, all on one side. 7 of the 8 animals died from the bombardment
1- what is your point?

2- can you verify where these "peppered" animals died from a bombardment?

3- if they're peppered on "one side" only it is just as likely that they were buried or partially exposed when "peppered" than "killed by the peppering"

you keep making this claim in various threads but you refuse to link any empirical evidence, the study, or it's validation by secondary sources

if you're versed in the scientific method then why refuse to actually present reputable evidence when making a claim?

that is how religion works, not how science works

another eu fail
Captain Stumpy
3.4 / 5 (10) Jan 20, 2017
@hannes/reeve eu cult acolyte cont'd
What I have noticed is that the climate researchers don't much care to talk about this sort of evidence. They always want to talk about how humans are responsible
funny thing is: i've tried to engage you on this topic in multiple threads but you can't actually present anything but your claims

I've seen *a* study (that i found on my own because you couldn't find anything reputable) but i've not seen any validation of your claims, nor have i seen you actually present any reputable evidence for your claims

that is how religion works, not how science works
From what I can tell, there's not even been a systematic analysis of tusks across the world for these meteorite fragments
that is because you seek validation of your beliefs, not evidence based science
Google Scholar says "About 16,700 results (0.07 sec)"

so again: you're promoting religion and beliefs over evidence based science
another eu fail
unrealone1
5 / 5 (2) Jan 20, 2017
Aboriginal fire stick farming wiped out Australian megafauna, surprise?
SamB
Jan 21, 2017
This comment has been removed by a moderator.
gkam
2 / 5 (8) Jan 21, 2017
Yeah, but we caused AGW.

Isn't it time you realized we live at the great expense of every other living thing?
carbon_unit
3.7 / 5 (6) Jan 21, 2017
Stumpy:
I've seen *a* study (that i found on my own because you couldn't find anything reputable) but i've not seen any validation of your claims, nor have i seen you actually present any reputable evidence for your claims

He works straight from the denier playbook: don't like the science evidence? Attack the scientists.

Gkam:
Isn't it time you realized we live at the great expense of every other living thing?
And the future. The conservative mantra of getting rid of any "inconvenient" regulations which inhibit jobs (translation: profits) is disturbing. Comrade Trump is making this an early priority. (Make externalized costs great again! ) Let future generations deal with the consequences which include loss of biodiversity and our coastal cities.
Chris_Reeve
2.3 / 5 (3) Jan 21, 2017
Re: "I've seen *a* study (that i found on my own because you couldn't find anything reputable) but i've not seen any validation of your claims, nor have i seen you actually present any reputable evidence for your claims"

They wrote a book on the subject. It's here:

https://www.amazo...irestone

I've placed a summary with screenshots here:

The Extinction of the Mammoths
https://plus.goog...nTz57wfZ

In addition to the tusks, a mammoth carcass partially draped in a black radioactive mat with exotic isotopes was found.

This stuff is not hard to find once you know the name of the researcher. A search on "firestone catastrophe" would get you to it.
Chris_Reeve
2.3 / 5 (3) Jan 21, 2017
Re: "so again: you're promoting religion and beliefs over evidence based science"

I am?

Seems to me that such findings are directly relevant to claims about extinction of megafauna, more broadly.
MarsBars
2.3 / 5 (3) Jan 22, 2017
Aboriginal fire stick farming wiped out Australian megafauna, surprise?

And the evidence for this assertion is... where, exactly? No mention of fire stick farming in the article. Cite your sources, please.
Lex Talonis
Jan 23, 2017
This comment has been removed by a moderator.
Mazarin07
Jan 23, 2017
This comment has been removed by a moderator.
eyallvy
1 / 5 (1) Jan 23, 2017
We will continue to kill for kicks until we have killed all the life which supports ours.

The spoiled Trump kids just shot an endangered Cheetah, for "sport:". I guess the Cheetah was unarmed, or they would not have tried it.

Real character.


I somewhat doubt that spear wielding humans who lived some 45,000 years ago in Australia, would have "killed for kicks". They killed in order to eat, just as animals kill each other for the same reason. Being clever as they were, they probably upset the balance of nature and inadvertently brought about extinctions, but... In the course of the history of the planet there have been massive extinctions that dwarf anything man has been able to do, which happened from totally natural causes.

So yes... I agree with you that hunting for sport is murder, but hunting in order to eat is perfectly natural.
Captain Stumpy
3.7 / 5 (3) Jan 23, 2017
@reeve/hannes the eu cult member
They wrote a book on the subject
and?
i can link dozens of "books" about whatever topic you want - that don't make them true, factual or even evidenciary of anything other than the opinion of the author

where is your study and where is the validation from secondary parties?

*that* is how the scientific method works and removes the bullsh*t from reality - it's what separates the fact from the opinion, etc

which you should know as you've claimed of being a "researcher" etc (or is that a blatantly false claim too?)
I am?
yes
without studies and validation it's called opinion or a belief, not fact
see: https://en.wikipe...c_method

Seems to me that such findings blahbblahblah
well, then it seems to me that you should be able to provide the studies and evidence supporting it, eh?
otherwise it's called (again) *opinion*, not fact
Edenlegaia
not rated yet Jan 23, 2017
They killed in order to eat, just as animals kill each other for the same reason. Being clever as they were, they probably upset the balance of nature and inadvertently brought about extinctions, but... In the course of the history of the planet there have been massive extinctions that dwarf anything man has been able to do, which happened from totally natural causes.

So yes... I agree with you that hunting for sport is murder, but hunting in order to eat is perfectly natural.


They probably hunted them for survival and protection as well. Dead threats no longer threatens.
And well, there were areas to conquer as well.
Captain Stumpy
3.7 / 5 (3) Jan 23, 2017
He works straight from the denier playbook: don't like the science evidence? Attack the scientists.
@Carbon_unit
yeah, i know

there is a lot you can learn from watching how he justifies his argument though, and it demonstrates the level of his dedications to his delusions

Lex Talonis
1 / 5 (2) Feb 13, 2017
"New evidence involving the ancient poop" - no it's not "poop" it's "SHIT".

"SHIT" COMES OUT YOUR ARSEHOLE.

Hey moderator - fuck you and your puritanical nazi bullshit too.

Deleting my comment?

Your a fucking idiot.
gkam
1 / 5 (4) Feb 13, 2017
Lex, the moderator position here must be an unpaid auditing spot for kids finding out what work looks like. They try, but are all over the place, trying to understand what is going on.

For some reason, they allow the snipers here to conduct their character assassinations. That I do not understand.

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