Posted on 07/24/2015 10:12:25 AM PDT by Red Badger
This image shows mammoth vertebrae in ice, Yukon Territory, Canada. Credit: Photo Kieren Mitchell, University of Adelaide
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New research has revealed abrupt warming, that closely resembles the rapid man-made warming occurring today, has repeatedly played a key role in mass extinction events of large animals, the megafauna, in Earth's past.
Using advances in analysing ancient DNA, radiocarbon dating and other geologic records an international team led by researchers from the University of Adelaide and the University of New South Wales (Australia) have revealed that short, rapid warming events, known as interstadials, recorded during the last ice age or Pleistocene (60,000-12,000 years ago) coincided with major extinction events even before the appearance of man.
Published today in Science, the researchers say by contrast, extreme cold periods, such as the last glacial maximum, do not appear to correspond with these extinctions.
"This abrupt warming had a profound impact on climate that caused marked shifts in global rainfall and vegetation patterns," said University of Adelaide lead author and Director of the Australian Centre for Ancient DNA, Professor Alan Cooper.
"Even without the presence of humans we saw mass extinctions. When you add the modern addition of human pressures and fragmenting of the environment to the rapid changes brought by global warming, it raises serious concerns about the future of our environment."
The researchers came to their conclusions after detecting a pattern, 10 years ago, in ancient DNA studies suggesting the rapid disappearance of large species. At first the researchers thought these were related to intense cold snaps.
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Abseiling into Natural Trap Cave, Wyoming -- Professor Alan Cooper descending the 100ft pitch into the cave to excavate ice age megafaunal bones. Credit: Photo by Laura Weyrich, University of Adelaide
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However, as more fossil-DNA became available from museum specimen collections and through improvements in carbon dating and temperature records that showed better resolution through time, they were surprised to find the opposite. It became increasingly clear that rapid warming, not sudden cold snaps, was the cause of the extinctions during the last glacial maximum.
The research helps explain further the sudden disappearance of mammoths and giant sloths that became extinct around 11,000 years ago at the end of the last ice age.
"It is important to recognize that man still played an important role in the disappearance of the major mega fauna species," said fellow author Professor Chris Turney from the University of New South Wales.
"The abrupt warming of the climate caused massive changes to the environment that set the extinction events in motion, but the rise of humans applied the coup de grace to a population that was already under stress."
In addition to the finding, the new statistical methods used to interrogate the datasets (led by Adelaide co-author Professor Corey Bradshaw) and the new data itself has created an extraordinarily precise record of climate change and species movement over the Pleistocene.
This new dataset will allow future researchers a better understanding of this important period than has ever been possible before.
Explore further: Giant moa had climate change figured out
More information: Science, www.sciencemag.org/lookup/doi/10.1126/science.aac4315
Journal reference: Science
Read more at: http://phys.org/news/2015-07-mammoths-abrupt-climate.html#jCp
Thanks Red Badger. Nice two-list ping topic! Three, if we count the Digest list...
good one!
I stopped reading right there.
OMG
too bad toll booths didn’t stay extinct
My Wife and I thought that show was great, although I have no idea why. It just cracked us up.
I think it was a combination of The Honeymooners and the Flintstones.
It must have been all those huge smokestacks belching out tons of pollution that I saw on “The Flintstones” when I was a kid.
There is nothing new about this idea, THEY just buried it for their political agenda. I’m 65. In the first grade we we taught that frozen wooly mammoth carcasses found in Siberia still had green grass in their mouths. The assumption was that the cold hit them suddenly.
DAMN YOU, GEORGE BUSH!
How do they explain the fact that Asian and African elephants, which are closely related to the Mammoth, survived. Furthermore, how do they explain that Wolly Mammoths and Channel Island Mammoths went extinct only about 4000 years ago, well past the date of the Ice Age figures given in this article. I don’t believe that there were not enough grassy lands available to support large mammals. If so the bison would’ve gone extinct in North America as well.
I saw that “flash-frozen” notion on a nature show on TV once. Narrated by Charleton Heston. Fascinating. The explanation (for how a wooly mammoth died by freezing to death within minutes of dining on fresh daisies) was a sudden shift in the complete outer crust of Earth. The theory was that over time one pole or the other will become so large and heavy with ice build-up that the outer surface of the planet shifts on the molten core. So,....the tropics might suddenly become located at a pole, or some such.......
The Asian and African elephants were probably safe being way further south so never ran out of food sources.
The gestation period for Asian elephants is 617 days and African elephants is 645 days, almost 2 years, so I think the mammoth would be similar. Whereas the gestation period for a bison is only 285 days, so they reproduce much faster...............
When the sun goes nova, warmists are finally going to be right.
The earth will be long gone and burned to a cinder before the sun goes nova. It will become a Red Giant first, expanding to near the orbit of Mars.......................
https://en.wikipedia.org/wiki/Betelgeuse
Could go supernova any day in the next million years........................
I think it was a combination of The Honeymooners and the Flintstones.
Flintstones was definitely a derivative of The Honeymooners, so you could call Dinosaurs a grand-child.
"Not the mama!
It's not your fault, but it's still your fault.
I read once that a paleontologist theorized that the primitive human societies probably killed few mammoths. They most likely would kill one, then tell the tale around the campfires for decades...................
Elephants can be found living today as far north as the desert area of Mali. The lack of widespread grasslands there seems to be no encumbrance to their survival. Furthermore, Colombian Mammoths lived all over North America including Mexico, which is approximately the same latitude.
I find it simply inconceivable that grasslands would have been so greatly diminished due to any global warming period around that time as to have caused the complete extinction of such a wide ranging species.
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