They keep us company, they know when we are going to enter the house before we arrive, they lie placidly on our laps or our feet, they purr with pleasure when we pet them and they can even communicate with us, expressing their different needs with different types of meows. But cats brain is no longer what it was. It’s shrinking, getting smaller and smaller, and it’s totally our fault.
That is precisely the main conclusion of a study recently published in the journal ‘
Royal Society Open Science’ and carried out by researchers from the University of Vienna and the Department of Natural Sciences of the National Museums of Scotland. In their paper, the authors have compared the cranial measurements (an indicator of brain size) of modern domestic cats with those of two of their closest wild ancestors, the African wildcat (Lybica) and Europeans (Puma).
The team found that the size of the skull, and thus the brain, in domestic cats has shrunk significantly over the last 10,000 years compared to that of their wild ancestors.
which, according to the researchers, does not necessarily mean that our house cat is dumber, for example, than a wild cat. What it does seem to show is that the meekness of domestic animals may have changed the way these animals develop. The study suggests that these changes could begin when the cat is still an embryo and is just beginning to develop its neural crest cells, which only vertebrates have and which, among other things, play a key role in the development of the nervous system .
“Selection for tameness in animal domestication may have caused a downregulation in the migration and proliferation of neural crest cells, leading to decreased excitability and fear.” . However, this downregulation may also cause correlated changes in brain morphology, stress response, and size.”
In their study, the researchers replicated several previous works, from the past decades of the 1960s and 1970s, in which comparisons were already established between the size of the skulls of domestic and wild cats. However, some of those studies only compared modern cats to the European wildcat, which is no longer considered its direct ancestor.
Current research shows that the brain of domestic cats has undergone a substantial reduction of up to 25% compared to African and European wildcats. The researchers also examined a number of hybrid feral/domesticated cat species, and found that these cranial measurements fit well in the mean between the wild and domestic species.
The sum of all these data clearly shows that domestication has had a significant effect on the evolution of cats during the last thousands of years, a phenomenon that can also be observed in many other species of domesticated animals. “Changes in cranial volume have been well documented in other domestic species, including rabbits, sheep, dogs, and many more,” the authors write.
Understanding this brings a new perspective not only to the developmental changes induced by domestication, but also to the conservation of many wild species threatened by hybridization with domestic animals.