From more than 600 million cats worldwide less 10% belong to a certain breed. But are these purebred cats the result of human intervention, or did some of them arise naturally?
The answer is more complicated than it might seem. According to Leslie A. Lyonsfeline geneticist at the University of Missouri College of Veterinary Medicine, most cat breeds have evolved over the last 140 years as a result of human selection for certain physical traits.
According to Sarah Hartwelllover of cat genetics and founder of a resource about cats Dirty beastthe progenitors of natural breeds are formed under the same conditions as wild species.
“Natural breeds can be considered a step towards speciation,” she told Live Science. In most cases, they are formed as a result of adaptation to the environment. In Western Russia, cold and snowy conditions favored the appearance of cats with thick hair and large bones, which became the basis of the breed. Siberian breed of forest cats. In Southeast Asia and the coastal Indian Ocean, warm and humid conditions favored the emergence of short-haired, slender, large-eared cats, which paved the way for the emergence of Abyssinian.
In some cases, natural breeds begin as a result of geographic isolation. This phenomenon is known as founder effectoccurs when a gene that does not contribute to the survival of animals spreads because the population has a small, isolated gene pool. On the Isle of Man (a self-governing territory dependent on the British Crown in the Irish Sea), a mutation occurred that led to the spread of the short tail through inbreeding, resulting in the ancestors Manx cat. Unfortunately, Isle of Man cats can suffer from spinal defects due to tail mutations.
Although the ancestors of natural breeds developed in natural conditions, modern cats of these breeds are no longer so “natural”.
“All breeds, regardless of species, have an impact on humans,” Lyons told Live Science. According to journal research Animal genetics As she co-authored, selective breeding of cats has grown exponentially over the last century, which in turn has removed the environmental pressures that shaped natural breeds.
For example, the Manx breed would likely die out naturally due to the lack of genetic diversity and the detrimental effects of the short tail mutation. Today the breed is still widespread as a result of deliberate human breeding. However, there are those who are trying to eliminate this.
“The thought is to retire this breed or find a way to make it healthier,” Lyons told Live Science. “Maybe we [work toward] tailed manx.”
Some once-natural breeds are more closely tied to their roots than others. Modern Siberian cats, for example, are genetically and physically similar to their ancestors because breeders regularly bring in new cats found as strays or as pets in the breed's native region to add to breeding programs.
Other breeds have been altered both genetically and physically from their original appearance. Russian blues, for example, was cross with Siamese cats to prevent the breed from becoming extinct after World War II, breeders have since divided them into certain “types” that differ in appearance from the original cats.
So yes, “natural” cat breeds exist, but they are not entirely natural. Traits typical of Maine Coons purchased from a breeder, such as large size, a square jaw and often paws with six or more toes, may resemble Maine Coons discovered back in the 1800s, but they have been preserved—and in some cases exaggerated—through artificial selection.
“It all depends on popularity and what people prefer,” Lyons told Live Science. “One line of cats can become very popular and change the appearance of the breed, and then it can turn in the other direction depending on the next new fad.”
