House cats not far removed from wild, genome shows

cat bacon test

IT may not surprise the average cat owner, but a team of researchers has discovered that the genome of domestic mousers differs only slightly from that of wildcats.

In other words, after 9,000-odd years of living alongside humans, the house cat remains only semi-domesticated.

After comparing the genome of an Abyssinian cat named Cinnamon to those of humans, tigers, cows, dogs and another white-pawed cat breed known as the Birman, researchers discovered that cats retain many of the hunting, sensory and digestive traits of their wild kin.

Where researchers did find a signal for human influence on cat evolution, however, was in fur color and pattern, as well as a set of genes that are thought to be associated with tameness.

“We believe we have created the first preliminary evidence that depicts domestic cats as not that far removed from wildcat populations,” said senior author Wes Warren, an associate professor of genomics at the Genome Institute at Washington University, in St. Louis.

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Unlike dogs, which some reseachers say began their association with humans roughly 30,000 years ago, archeological evidence suggests that cats first entered our living space when we began to grow crops.

Researchers hypothesize that early farmers welcomed the felines due to their ability to hunt grain-eating rodents. Farmers rewarded the efficient rodent-slayers with extra bits of food, researchers say.

Yet it’s only in the last 200 years that humans have placed intense selection pressure on cats, producing up to 40 different breeds, Warren said.

Warren and his colleagues said that this relatively short period of breeding was partly responsible for the modest influence domestication has so far had on the evolution of Felis silvestris catus. However, it wasn’t the only reason.

“Most importantly, some continue to interbreed with wildcat populations,” Warren said.

When examining the cat’s genetic makeup, the researchers found that the animals retained qualities of wild hypercarnivores — hunters that eat meat almost exclusively.

All cats should be indoor cats, regardless of anything else. Until everyone has their cats spayed or neutered and keeps them safely indoors, cats–as well as birds and other wildlife–will continue to suffer.

“Carnivores are endowed with extremely acute sensory adaptations, allowing them to effectively locate potential prey before being discovered,” the authors wrote. “Within carnivores, cats have the broadest hearing range, allowing them to detect both ultrasonic communication by prey as well as their movement.”

In addition to retaining visual acuity that enables them to hunt in low-light conditions, cats are also able to metabolize high-protein, high-fat diets.

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“Cats fed a diet rich in saturated and polyunsaturated fatty acids showed no effects on plasma lipid concentrations that in humans are risk factors for coronary heart disease and atherosclerosis,” authors wrote.

While breeding of cats has focused mostly on controlling hair color and pattern, the authors identified gene changes that some researchers say are associated with the “domestication syndrome hypothesis.”

That hypothesis argues that when animals are bred for domestication, changes occur in a group of embryonic stem cells called the neural crest. These changes can result in a number of qualities that appeal to humans, such as diminished fearfulness. The hypothesis has yet to be proven experimentally, however.
“Our results 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,” authors wrote.

Today, it’s believed that there are as many as 600 million cats worldwide…



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