Cats’ brains may have shrunk because of humans

According to one study, over the last 10,000 years, the skulls of domestic cats and their brains have shrunk significantly. Scientists believe that domestication could be the main cause.

In their article published on January 26 in the journal Royal Society Open Science, researchers have compared the skull size of domestic cats with that of the skulls of their closest ancestors, African wildcats and European wildcats. Note that skull size is used as an indicator of brain size.

The researchers indicated that prioritizing docility in domesticated animals may have inadvertently altered their brain development.

An evolution towards the reduction of the size of the skull

The new study was a replication of older studies done in the 1960s and 1970s. This research primarily compared the skull size of modern domestic cats with that of the skull of European wildcats (Felis silvestris). Researchers had discovered at the time that the brain size of domestic cats had experienced a significant reduction over the years.

Since the European wildcat is no longer considered to be the direct ancestor of the domestic cat, the authors of the new study wanted to update the information on skull size. For this, they used for comparison the African wildcat (Felis lybica), confirmed to be the closest living ancestor of modern cats.

The study thus demonstrated that the skull of domestic cats was 25% smaller than that of wild cats. On the other hand, the study of hybrid cats (wild/domestic) revealed that the size of their skulls was between that of domestic cats and that of wild species.

A threat to wildlife

The study confirmed that domestication had a significant effect on the evolution of cats over the past millennia. According to the scientists, these changes in cranial volume could also be noticed in other species domesticated by humans such as rabbits, dogs and sheep.

The researchers concluded that understanding this phenomenon could help determine the changes that domestication could bring about in wild animals. On the other hand, it also shows the risks that wild species could incur due to hybridization with domestic species.

SOURCE: Livescience

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