Climate Change Seen to Be Behind Extinction of Ice Age Giants
Mammoths like the elephant-sized sloth and powerful sabre-toothed cat thrived in the ice age climate. Various theories have been presented why these giant species suddenly went extinct around 12,300 years ago. A new study blames changes in environmental conditions as one of the driving forces behind the rapid extinctions.
The extinction of large animals — known as megafauna — happened between 15,000 and 11,000 years ago. The disappearance happened across vast swathes of Eurasia and the Americas in what are now Europe, Siberia, and North and South America. However, what caused this mass trend is unclear.
The extinction of megafauna occurred roughly the same time as humans expanded around the world, prompting some scientists to suggest that the creatures were hunted to extinction for their meat. But the wipeout was so widespread that others propose a perfect storm of rapidly warming climate and overkill by humans.
Get Our Latest News for FREE
Scientists at the University of Adelaide used DNA extracted from fossilized remains of Ice Age beasts to look for genetic signals of population collapse that signify extinction events. These were compared to climate data held in ice cores from Greenland. From the data, the researchers concluded that the extinction happened at the end of the last glacier period when the ecosystem was altered.
The rapidly warming climate caused the glaciers and permafrost to collapse. This caused moisture in the landscape to be released, turning grasslands to bogs and forcing peatlands to fragment. These warm periods may have also drastically changed rainfall patterns and vegetation in areas where the beasts thrived.
The realization that massive changes in climate and the environment may have caused global extinctions of species made scientists ponder on the future of today's humans. "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," Prof. Alan Cooper said.
