Mammals who thrived during the last ice age may have originated in the Himalayan Mountains of Tibet, a new survey reveals. Cold-adapted animals from the region could have spread into other areas, taking advantage of a rapidly-changing climate that doomed many other species of animals.
That mountain range includes some of the tallest mountains in the world, including Mount Everest. It is sometimes called the third pole of the Earth, due to the extreme cold and harsh conditions on top of many of the peaks.
For the last 2.5 million years, the Earth has experienced periods of warming and cooling. These climatic changes also influenced the development and evolution of various species, the study concluded.
University of Southern California researchers wanted to know how these alternating periods of glaciation and thawing affected animals.
"Living Tibetan and arctic mammals share adaptations to freezing temperatures such as long and thick winter fur in arctic muskox and Tibetan yak," Xiaoming Wang, an adjunct professor of Earth sciences and biological sciences at USC, and his team wrote in an article detailing the study.
Wang and his researchers found evidence of dozens of ancient mammals which may have left Tibet during the last ice age. These include a woolly rhino, a blue sheep (also called a bharal), forms of a badger, snow leopard and a three toed-horse.
The team traveled and lived in extreme climatic conditions, at more than 14,000 feet above sea level. At these altitudes, water froze every night and it is difficult for the team members to breathe. Each morning, the group broke to search individually for fossils.
"There are a lot of challenges, but in paleontological terms, it is a relatively unexplored environment. Our efforts are rewriting a significant chapter of our planet's recent geological history," Wang said.
They found an evolutionary link between Vulpes qiuzhudingi, a type of fox that lived in the Himalayas between 5.08 and 3.6 million years ago, and the modern Arctic fox, Vulpes lagopus, which lives in the Arctic today. These two regions are more than 1,200 miles away from each other. Researchers believe this lends evidence to an "out-of-Tibet" theory, which claims these animals evolved the ability to live in harsh conditions before the last period of glaciation. The last ice age began roughly 2.6 million years in the past and lasted until roughly 10,000 years ago.
Study of how mammals from the Himalayas may have populated other regions during the last ice age was profiled in the journal Proceedings of the Royal Society B: Biological Sciences.