Years of domestication result in the shrinking of cats' brains
We love our cats so much so that we even toss them around in microgravity. But our love and domestication may not be the best thing for them, according to a study in the journal Royal Society Open Science. The research suggests that years of domestication and coddling have resulted in cats with much smaller brains.
Cats' brains shrinking
Researchers studied the cranial measurements of house cats as well as African (Felis lybica) and European wildcats (Felis silvestris). The last two are species of wild cats which are currently the closest ancestors of domesticated cats.
What the scientists found is nothing short of extraordinary. Cranium size in house cats has diminished over the past 10,000 years especially compared to that of their wild ancestors. But does cranium size equal brain size? According to the researchers, it seems it does. "Selection for tameness in the domestication of animals may have caused a downregulation in the migration and proliferation of neural crest cells, leading to decreased excitability and fear," the scientists wrote in their research. "However, this downregulation may also cause correlated changes to morphology, stress response and brain size."
The findings aren't entirely new. Similar studies had been undertaken in the 1960s and 1970s but these had one major flaw: they compared house cats to only European wild cats.
Today's most recent genetic research has deduced that African wild cats are the closest living ancestor of modern domestic cats. It was essential therefore that the researchers compare house cats to both European and African species. Once they did that, the team could safely report that the old research was still valid: house cats had as much as 25% smaller cranium sizes as African and European wildcats. And it's a phenomenon that has been replicated with other animals as well. "Changes to the cranial volume have been well documented across species, including sheep, rabbits, dogs, and many more," the researchers concluded.
Of course, a smaller cranium does not make cats inherently a dumber species. Instead, more studies would have to be conducted testing their actual intelligence. After all, the research does clearly indicate that domestication is indeed affecting cats and that is something worth investigating.
Hey! If scientists can figure out why cats go crazy for catnip, they can figure out if they are becoming dumber.