The domestication of cats occurred approximately 7,500 years ago, and a new study reveals that thousands of years of dependence on humans have led to a reduction in cat brain size.
In a study published on January 26 in the journal Royal Society Open Science, researchers compared the skull measurements (an indicator of brain size) of modern domestic cats with their closest wild ancestors, the African wildcat (Felis lybica), and the European wildcat (Felis silvestris).
The research team found that the skull and brain size of domesticated cats have significantly shrunk over the past 10,000 years compared to their wild ancestors.
Domesticated cats (catus) have smaller brain sizes than African (lybica) and European (silvestris) wildcats.
This does not necessarily mean that your pet cat is less intelligent than a wildcat. However, according to a hypothesis by the researchers, it suggests that the domestication of animals may have inadvertently altered the way their brains develop.
These changes might begin while the animals are still embryos, as they develop neural crest cells—a special type of cell found only in vertebrates that plays a crucial role in the development of the nervous system, among other things.
The researchers stated: “Selective domestication may have caused a reduction in the migration and proliferation of neural crest cells, leading to decreased excitability and fear responses. This reduction may also cause correlated changes in morphology, stress response, and brain size.“
Skull size and brain size in domesticated cats have significantly shrunk.
The team revisited some older studies from the 1960s and 1970s that compared the skull sizes of domestic and wild cats. These earlier studies supported the view that domesticated cats have significantly reduced brain sizes over thousands of years. However, some studies compared modern cats with European wildcats, a species no longer considered a direct ancestor.
In the new study, the authors aimed to update the findings by comparing domestic cats with the African wildcat, a species confirmed by genetic studies to be the closest ancestor of modern domestic cats.
The research team found that the older studies remain accurate, with domestic cats showing a skull size reduction of about 25% compared to the African and European wildcats.
Domestic cats have a skull size reduction of about 25% compared to African and European wildcats.
All of this indicates that domestication has had a significant impact on the evolution of cats over the past few thousand years—a phenomenon also observed in many other domesticated animal species.
The researchers noted: “Changes in skull volume have been clearly documented in domesticated species, including sheep, rabbits, dogs, and many others.”
They concluded: “Understanding this not only sheds light on some of the changes that domestication causes in wild animals but also raises concerns about wild species threatened by interbreeding with domestic animals.”
Domestic cats pose a significant threat to the Chinese mountain cat.
In a recent statistic from LiveScience, domestic cats are a significant threat to the Chinese mountain cat. They closely resemble domestic cats but have lynx-like ears, bushy tails, and green eyes. Their classification—Felis silvestris bieti—genetically differs from the European wildcat (Felis silvestris), but some are concerned that this wild species may lose its genetic traits as domestic cats interbreed with them, ultimately leading to the disappearance of the Chinese mountain cat’s genes.
