Why Did the Woolly Mammoth and Other Ancient Creatures Go Extinct? Scientists Think They've Found the Answer
The existence of large animals known as megafauna is known to be a scientific fact. What scientists didn't understand was what caused those creatures to disappear. They knew environmental factors played a major role in the extinction of those behemoths, but they couldn't pinpoint the actual cause.
Finally, an international team led by the Australian Centre for Ancient DNA (ACAD) at the University of Adelaide has solved this puzzle. They analyzed 511 bones of both ancient and currently existing animals including a bison, horse and llama. The bones contained evidence of environmental changes on a continental scale.
Using carbon dating technology, the researchers noted that rangelands that flourished during the post-glacial period provided the optimal conditions for megafauna. As the landscape shifted between 11,000 and 15,000 years ago, the rangelands were replaced by forests.
Get Our Latest News for FREE
This environmental upheaval caused the glaciers to melt, dramatically increasing the landscape moisture and causing grasslands to turn into peatlands and bogs. This caused the ecosystem to collapse and resulted in the mass extinction of large herbivorous grazers like the woolly mammoth, giant sloth and saber-toothed cat.
Extinctions were most pronounced across Eurasia and the Americas, in what is now Europe, Siberia and North and South America. The effects were less profound in Africa, though. Considering that herbivore megafauna were critical to the food chain, any decline in their population would have a domino effect on the rest of the ecosystem and any species within it.
"The idea of moisture-driven extinctions is really exciting because it can also explain why Africa is so different, with a much lower rate of megafaunal extinctions and many species surviving to this day," said Prof. Alan Cooper, ACAD director, about the published study.
"Africa's position across the equator means that grassland zones have always surrounded the central monsoon region. The stable grasslands are what has allowed large herbivores to persist — rather than any special wariness of hunters learned from humans evolving there," Cooper added.
