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
*******************************************************************************************************************************************************************************************
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.
*****************************************************************************************************************************************************************************************
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
*******************************************************************************************************************************************************************************************
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
Not always, if it landed in the oceans. Some believe Hudson Bay is a meteor crater................
LOL!...............
Muffin tops, bottoms, fronts and backs. I bet she had more muffins coming out of her than Rachel Ray’s stove...................
We have consensus.........................
I dunno, I bet they had pretty big brains...................
Or they died of heat exhaustion.........................
And they know that it's warming in spite of evidence to the contrary because ... Once upon a time, I was in the middle of Pleistocene research. It didn't pay well and research grants were few and far between. Then along came the environmental movement and the requirements for environmental impact studies that lead the way to the real pot of gold: climate research. Woo hoo, life is good and everyone has jumped on the bandwagon with half assed studies, nonsense findings, and reports written from Wikipedia research. There is so much money being thrown around that everyone can cash in. The only ones excluded from the cash cow are those who suggest that this is nothing but a political phenomenon.
“Quite possibly a meteor impact.......................”, NO how about the results of a GLOBAL FLOOD!
Or they died from smoking.
Caused by massive global cooling.
“Mo’ Money....Mo’ Money.....Mo’ Money!”
Liars!
The climate change nonsense is a religion just like Islam.
Full of lies, chaos, and threats of death if you don’t convert.
Exactly.
About 12,500 years ago.
Abrupt = 100 years, or 100,000 years, or one million years...
Well, could their big brains solve those Sudoku puzzles?
Nope. Because they froze to death trying to figure out how to set one of those programable thermostats.
The other morning I heard an interview on the radio. It featured a chemistry professor from William and Mary and a art restorer from Colonial Williamsburg.
The professor stated that science was unfinished and that's what makes it exciting, if science were finished it would be boring.
Too bad it wasn't a call in show, I wanted to ask the professor wht her views on climate change were.
Thanks Red Badger. Nice two-list ping topic!
Flood, Fire, and Famine
in the History of Civilization
by Richard Firestone,
Allen West, and
Simon Warwick-Smith
Thanks Red Badger. Nice two-list ping topic!
|
Dinosaurs causing Global Warming
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.
