Feline Genome Project Reveals That Cats Are Only 'Semidomesticated'

November 12, 2014

Chuck Bednar for redOrbit.com Your Universe Online

In news unlikely to surprise most cat owners, an analysis of the feline genome reveals that the DNA of the typical housecat differs only slightly from those living in the wild when compared to their canine counterparts.

Researchers from the Washington University School of Medicine in St. Louis, who published their findings earlier this week in the journal Proceedings of the National Academy of Sciences, found that unlike dogs, which arose from wolves over 30,000 years ago, the separation between domestic felines and wild cats occurred far more recently, when people began growing crops.

Cats, unlike dogs, are really only semidomesticated, senior author Wes Warren, associate professor of genetics at The Genome Institute at Washington University, explained in a statement Monday. They only recently split off from wild cats, and some even still breed with their wild relatives. So we were surprised to find DNA evidence of their domestication.

The research is part of the cat genome sequencing project, a National Human Genome Research Institute-funded project that began in 2007, and initially set out to study hereditary diseases in domestic cats. However, while comparing the genomes of domestic and wild cats, the authors found significant differences in specific regions of the domestic cat genome in particular, those linked with memory, fear and reward-seeking behavior.

Those behaviors, especially when it comes to animals seeking rewards, are believed to play an important role in the domestication process, the researchers found. When people began growing food, they likely offered some of it to cats in order to keep them around to keep the rodent population under control and away from grain harvests. As a result, cats that normally preferred to live solitary lives in the wild had additional incentive to stick around humans.

While cat domestication is believed to have begun about 9,000 years ago, Bloomberg News reporter Megan Scudellari explained that the majority of the 30-40 modern cat breeds originated just 150 years ago. In order to investigate the domestication process, Warren and his colleagues sequenced the genome of a female Abyssinian cat and compared her DNA to six other domestic cat breeds, two wild cat species and several other creatures.

Compared to omnivorous humans and herbivorous cows, carnivorous cats appear to have more quickly evolved genes that bestow an enhanced ability to digest heavy fats found in meat, Scudellari said. In addition, by comparing cat and dog genomes, the researchers found a unique evolutionary trade-off between the two groups: While dogs evolved an unsurpassed sense of smell, cats traded in those smell receptor genes for genes that enhanced their ability to sense pheromones, odorless substances that enable animals of the same species to communicate.

Warren told the Los Angeles Times that he believed he and his colleagues have created the first preliminary evidence that depicts domestic cats as not that far removed from wildcat populations, and the study authors wrote that their findings suggest that selection for docility, as a result of becoming accustomed to humans for food rewards, was most likely the major force that altered the first domesticated cat genomes.

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Feline Genome Project Reveals That Cats Are Only 'Semidomesticated'