Environmental changes caused a drastic decline in their population, researchers say

Sep 12, 2013 00:11 GMT  ·  By

Several previous scientific papers have argued that woolly mammoths were driven to extinction by humans, who hunted one too many of them. However, a new study argues that, according to evidence at hand, climate change was the main culprit for these animals' demise.

In this paper, scientists explain that a thorough analysis of DNA samples has shown that, as the regions they used to inhabit started to warm, the mammoths experienced a fast and drastic decline in their population.

More precisely, new environmental conditions left them unable to roam over large portions of land. Being extremely sensitive to such changes, they found themselves confined to fairly small regions.

Researchers say that, according to their investigations, the mammoth population first dropped to a considerable extent about 120,000 years ago.

“We found that a previous warm period some 120,000 years ago caused populations to decline and become fragmented, in line with what we would expect for cold-adapted species such as the woolly mammoth,” study lead author Eleftheria Palkopoulou says, as cited by The Telegraph.

Once this period of warming came to an end and their natural habitats once again cooled, the mammoth population increased dramatically.

Thus, about 14,000 years ago, millions of them lived in Europe, Siberia and North America.

However, this cooling period only lasted for roughly 4,000 years. Specialists say that, 10,000 years ago, the planet began to warm and the mammoth population once again declined.

This time, the species did not recover and went extinct.

“This process [the mammoths' extinction] culminated with a severe decline in population size that started when temperatures began to increase at the end of the last Ice Age,” Dr. Jessica Thomas argues.

According to Professor Adrian Lister, it might be that humans also had a say in the mammoths' demise.

“Climate change squeezed them down to small patches and maybe in that situation human hunting could have dealt the final blow,” the researcher argues.

“It is very hard to find evidence of the mammoth being hunted, there are only a handful of fossils which have direct evidence such as marks from a spear head. So although we can say for sure that humans did hunt them, it would be quite a leap to say that they did so to such an extent that caused them to become extinct - at most it would have been the final straw,” he adds.