Woolly Mammoths Were Killed Off by Trees


Cavemen have been getting a bad rap long before that awful show based on the Geico commercials came out.

For years we’ve taken it as gospel truth that the woolly mammoth was hunted to extinction by our hairy ancestors. Some scientists, however, are suggesting that what wiped out the mammoth was not hunting, but trees.

It is much easier to picture the violent extinction of a species than the opposing scenario. We can easily imagine fur clad hunters stabbing the giant beasts with spears until one day there were no more left. You could even picture the hair covered animals being too hot to survive in the rising temperatures at the end of the ice age. It’s a bit harder to imagine the mammoths being killed off by a lot of trees.

We’re not talking about any Lord of the Rings style fighting trees or anything, although that would be a much cooler article. The trees were just regular forests which expanded to previously uncovered territory at the end of the last ice age, but their marching expansion still spelled doom for the elephant relatives.

It all comes down to food. Mammoths thrived most in large areas of frozen grassland. Around 10,000 years ago, temperatures started to rise. The frozen grasslands where the animals lived and fed started to be replaced by forests expanding from the warmer climates. No more frozen grasslands meant no more food.

University College London palaeobiologist Adrian Lister conducted the study. Lister analyzed the DNA from hundreds of mammoth fossils, and found that the animals changed so slightly over the course of 20 thousand years or so that they would have been unable to adapt to the new environment.

Lister said: “The DNA we have been able to extract from mammoth bones is like a clock and allows us to trace the evolutionary story in great detail now.”

He thinks the story of the mammoths went something like this, saying:

“In the middle of the last ice age, around 30,000 years ago, there were millions of mammoths roaming over a huge area. Around 20,000 years later there were hardly any left. As the forests moved in, the mammoths were pushed out of their normal habitat. These animals are mostly governed by vegetation rather than climate and so they were squeezed into very small populations as the forests took over the cold grasslands. I don’t think that people played a major role in wiping them out, although they may have pushed those final populations over the edge. The major impact factor was the change in the vegetation from grassland to trees.”

There have been other recent suggestions as to how the mammoths became extinct. An American research team suggested that meteorites bombarding the earth caused the demise of the animals. They found tusks that had been hit with shrapnel from the meteorites in Alaska recently.

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