It wasn’t our distant ancestors that were completely responsible for the extinction of the wooly mammoth and other megafauna (animals weighing more than 100 pounds) of the last ice age. It was sudden climate change. That’s what a new study recently published in the journal Science concludes.
The study authors write, “the mechanisms of Late Pleistocene megafauna extinctions remain fiercely contested, with human impact or climate change cited as principal drivers.”
Researchers from the University of Adelaide and the University of New South Wales detected a pattern during their research in ancient DNA studies. This pattern suggested the rapid disappearance of large species ranging from wooly mammoths to cave lions was tied to climate change. Researchers initially thought extreme cold snaps were responsible.
Instead, it’s the exact opposite. The study describes short, rapid warming events called interstadials during the last ice age between 60,000-12,000 years ago. Temperatures spiked between 7 and 29 degrees Fahrenheit in just a few decades. Large animals accustomed to cooler temperatures would have found it difficult to adapt in such a short time.
The rapid spikes in temperature had an immediate impact on the climate.
“This abrupt warming had a profound impact on climate that caused marked shifts in global rainfall and vegetation patterns,” said University of Adelaide Professor and lead author Alan Cooper.
Cooper adds, “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.”
Fellow author Professor Chris Turney from the University of New South Wales doesn’t let humans off the hook. “It is important to recognise that man still played an important role in the disappearance of the major megafauna species.”
Megafauna were a primary source of food for early humans. Migrating to new areas would have been challenging as hunting parties disrupted the animals’ environment even further.
The sudden spikes in temperature were the basis for the extinction events, but humans were the “coup de grâce to a population that was already under stress,” according to Turney.
Researchers’ methods for conducting their study helped create a more precise record of climate change during the Pleistocene age. This new information will assist other researchers in better understanding a vital period in our history.
Image: Wooly mammoth model at the Royal BC Museum. Credit: Wikipedia