The Evolution of the Fastest

By Stefanie Rach

Like so many animal and plant species, cheetahs are feeling the pressure of extinction due to habitat loss and climate change. But while there is hope that many other species can adapt to at least some of the environmental changes, it is doubtful that this is the case for cheetahs. This is because cheetahs have an exceptionally small gene pool and thus low genetic variability to be able to react accordingly to changes in their environment.

Researchers believe that the reason for this lies in two so-called genetic bottlenecks that cheetahs went through in their past: About 100,000 years ago, cheetahs, which probably descended from the American puma, also spread to Africa, Europe and Asia. And this happened so quickly that the cheetahs were spread over a huge area and thus ultimately inbred to reproduce at all.

The second genetic bottleneck probably occurred at the end of the last ice age (i.e. 10,000 to 12,000 years ago). Along with the many mammal species that did not survive the Ice Age, the cheetahs in North America and Europe also became extinct. Of those in Asia and Africa, there were only a small number, so that inbreeding happened again.

Meanwhile, cheetahs are on the brink of extinction again. There are only about 8,000 cheetahs left in the wild in Africa, and probably a mere 50 in Asia. In addition, cheetahs have a low reproductive rate. So they are facing a third genetic bottleneck event, while at the same time their environment is radically changing. Whether cheetahs will survive this is questionable.