Arctic Animals from the Ice Age May Have Evolved in High Tibet

Scientists have learned a bit more about how Arctic animals evolved. They've found that evolution of present-day animals in the Arctic region may be intimately connected to ancestors that first adapted to the cold in the high altitude regions of the Tibetan Plateau.

For the last 2.5 million years, our planet has experienced both cold and warm millennia-long cycles. During the cold periods, though, continental-scale ice sheets blanketed large tracts of the northern hemisphere. When things warmed up, the glaciers receded; this advance and retreat of ice has a huge impact on the geographic distribution of many animals.

Now, scientists may know a bit more about the cold-adapted animals. The researchers found a three to five-million-year-old specimen of a Tibetan fox from the Himalayan Mountains called Vulpes qiuzhudingi which is likely the ancestor of the living Arctic fox. They also discovered an extinct species of a wooly rhino, a three-toed horse, Tibetan bharal, chiru, snow leopard, badger and 23 other mammals.

In the past, the researchers believed that the origins of the cold-adapted Pleistocene megafauna were in the arctic tundra or in cold steppes elsewhere. Yet these latest findings seem to indicate otherwise; it's very possible that some of the Ice Age megafauna used ancient Tibet as a "training ground" for developing adaptations that allowed them to cope with extremely cold temperatures.

It's not all that surprising that the researchers are only making these findings now. Looking for fossils in Tibet is a grueling process with its more than 14,000-foot elevation; it's difficult to breathe, water freezes overnight in camps, and there are many other challenges.

"But in paleontological terms, it is a relatively unexplored environment," said Xiaoming Wang, one of the researchers, in a news release. "Our efforts are rewriting a significant chapter of our planet's recent geological history."

The findings are published in the journal Proceedings of the Royal Society B: Biological Sciences.