Study links domestic cats to ancestors 100,000 years ago

Genetic study links domestic cats to wild ancestors 100,000 years ago
By Steve Connor, Science Editor
Published: 29 June 2007
Independent UK

They were revered in ancient Egypt and are doted over in modern Britain. Now a study has revealed that the domestic cat is descended from a type of wildcat that lived in the Middle East thousands of years ago.

Scientists have traced the ancestry of all domestic cats alive today back to just five female wildcats that lived in the Fertile Crescent region of what is now Iraq and Syria. A study of feline DNA shows that cats were domesticated from their wild cousins much earlier than previously believed and that humans must have transported them around the world from their Middle Eastern homeland.

The study analysed the DNA of nearly a thousand cats - domestic and wild - from countries as far apart as China and Scotland in an attempt to identify the closest living relatives of the pet cat, Felis silvestris catus.

Scientists used both the DNA from inside the cell nucleus, which is inherited from both mothers and fathers, as well as DNA from the mitochondria structures outside the cell nucleus, which is inherited only from females. Professor David Macdonald, director of the Wildlife Conservation Unit at Oxford University, said that one of the most important findings was the discovery that domestic cats have a much older history than previously supposed.

"In our studies of mitochondrial DNA from these cats we found five distinct lineages dating back 100,000 years prior to any archaeological record of cat domestication," Professor Macdonald said.

"These appear to come from at least five female cats from the Near East whose descendants have been transported across the world by humans," he said.

A burial site in Cyprus dating to 7,500BC, with a human skeleton lying next to the skeleton of a cat, is the earliest archaeological record of feline domestication. There are no native wildcats on Cyprus so the cat must have been taken there by humans.

However, the latest DNA findings, published in the journal Science, suggest that cat domestication occurred much earlier than this and probably came about initially as a result of cats scavenging for food near human settlements. With the rise of agriculture, cats proved useful at guarding grain stores against rats and mice.

The study has also identified a genetic marker for the Scottish wildcat, which is endangered because breeding with domestic cats is diluting its gene pool. Scientists will now be able to work out how many Scottish wildcats are left.