The high altitude environments of the Tibetan Plateau and other regions of the Himalayan Mountains may have been the evolutionary proving ground for adaptation of fauna that lived during the Ice Age. Fossils discovered by an international team of paleontologists led by Xiaoming Wang of the Natural History Museum of Los Angeles County support this new concept of mammal evolution.
The new theory is largely based on the discovery of Vulpes qiuzhudingi, a Tibetan fox, in the Himalayas in 2010. The remains are between three and five million years of age. Genetic analysis indicates the fossil fox is a direct ancestor of the modern Arctic fox (Vulpes lagopus). The fossils were discovered in the sediments of the Zanda Basin in Tibet. The area once bordered an ancient lake and has produced a multitude of high altitude fossils.
The researchers also discovered fossils of a three-toed horse, woolly rhino, snow leopard, blue sheep, antelope and 23 other extinct species that can be directly related to Ice Age mammals and some modern Arctic species. The finds indicate that many of the most well known Ice Age animals like the mammoth may have originated in Tibet and the Himalayas. The cold climate and the altitude prepared the animals for survival in the Ice Age through eons of adaptation.
The various Ice Ages on Earth lasted 2.5 million years. The Ice Ages were marked by the progression of ice sheets from the poles as far as the present tropics. During each expansion and contraction of the ice some animal species adapted to the climate change and some that could not cope became extinct. At the beginning of the Ice Age period of time the continents of the Earth were connected. The animals that adapted in Tibet to cold could have migrated to other regions during warm periods and survived.