Cheetahs migrated from North America to Africa 100,000 years ago

http://www.theguardian.com/us-news/2015/dec/09/cheetahs-migrated-north-america-to-africa

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Cheetahs, widely known as fleet-footed inhabitants of the African savannahs, started a rather slower journey around 100,000 years ago when they migrated from North America, according to new research.

An international team of scientists found that cheetahs descend from a relative of American pumas with their fossil records extending across the Americas, Europe and Asia.

Genetic analysis by the team, published in Genome Biology, shows that cheetahs had two population “bottlenecks” – events that severely reduced the population. The first of these occurred around 100,000 years ago when cheetahs moved into Asia across the Bering Sea land bridge. They then made their way south to Africa.

A second population crash occurred around 10,000 to 12,000 years ago, researchers say, with cheetahs disappearing from North America. Several large mammals such as saber-toothed tigers were lost to the continent around this time due to a glacial retreat.

As a result of their travels, cheetahs have a low genetic diversity – around 90% to 99% less variation seen in other mammals. This lack of diversity was fueled by the population losses and vast territory ranges, spanning unto 900 square miles, meaning that the predators were forced into incestuous mating.

Present-day cheetahs suffer from this troubled lineage. The species has difficulty reproducing, even when captive, and males often have a high level of deformed sperm.

Cheetahs are listed internationally as vulnerable, with around 6,700 of the animals left in the wild in Africa. The animals can go from 0 to 60 mph in around three seconds and can reach speeds of more than 70 mph in pursuit of prey, making it the world’s fastest land animal.

Researchers from the US, Russia, China and Namibia worked on the study, which involved the sequencing of the genome from a male Namibian cheetah, called Chewbaaka, and six other wild cheetahs from Tanzania and Namibia.

“Cheetahs grew up in North America before they traversed the Bering Straits and wandered down to Africa,” said Stephen O’Brien from Saint Petersburg State University in Russia and Nova Southeastern University in Florida.

“I don’t think they were much different from the animals we see today, they developed into a sprinting hunter in North America. It’s interesting that we lost about 40 species at the end of the ice age, including pumas and cheetahs. The pumas came back from South America and the cheetahs were fortunate to migrate into Asia and then into Africa. They have remained a top predator, unless they have had to deal with humans, of course.”