We might finally have an answer to the question of what killed off the mammoth. According to a 10-year research project, whose findings were published this week, its extinction 4,000 years ago was not due to overhunting by humans. It appears the culprit was the rate at which the climate changed: too fast for these woolly cousins of elephants to adapt.
As reported in the journal Nature, the researchers analyzed DNA samples from ancient plant and mammal communities found in 535 permafrost and lake sediment sites across the Arctic. These span the past 50,000 years and provide incredible insights into how the environment changed in the region.
Mammoths roamed Earth for 5 million years and weathered several ice ages, but the last one was too much for them. They lived alongside modern humans for 30,000 years and were hunted by our ancestors for meat, bone, tusks, and fur. But, say the researchers, it was the climate that killed them in the end.
“The most recent Ice Age — called the Pleistocene — ended 12,000 years ago when the glaciers began to melt and the roaming range of the herds of mammoths decreased. It was thought that mammoths began to go extinct then but we also found they actually survived beyond the Ice Age all in different regions of the Arctic and into the Holocene — the time that we are currently living in — far longer than scientists realized,” lead author Dr Yucheng Wang from the University of Cambridge said in a statement.
“We zoomed into the intricate detail of the environmental DNA and mapped out the population spread of these mammals and show how it becomes smaller and smaller and their genetic diversity gets smaller and smaller too, which made it even harder for them to survive.”
The data suggest that the change in climate brought forth a change in precipitation, leading to the formation of lakes, rivers, and marshes. The vegetation in the regions changed, leaving the mammoths struggling to find food. Based on the new model, humans had no impact on them.
“We have finally been able to prove was that it was not just the climate changing that was the problem, but the speed of it that was the final nail in the coffin — they were not able to adapt quickly enough when the landscape dramatically transformed and their food became scarce,” senior author Professor Eske Willerslev, also from the University of Cambridge, said. “As the climate warmed up, trees and wetland plants took over and replaced the mammoth's grassland habitats.”
Humans have been responsible for wiping out many species on our planet, and that doesn't appear to be slowing down, but it seems that the demise of the woolly mammoth was not on us.