BERKELEY — A genetic study of the salamander family that encompasses two-thirds of the world’s salamander species shows that periods of global warming helped the amphibians diversify and expand their range from North America into Europe and Asia, where pockets of them are still found today. Interestingly, while one period of warming allowed some salamanders to move northward into Asia via an arctic land bridge, the next warming period may have facilitated their return to North America.
David Vieites/UC Berkeley The recently discovered South Korean salamander Karsenia koreana (above) is a survivor of a populaton of plethodontid salamanders that moved into Asia during a period of global warming 80 million years ago. Between 40 and 50 million years ago, another warming spell got these salamanders wandering again, this time into Europe and back into North America. The California salamander Hydromantes brunus (below) is a descendent of this second diaspora.