The way things are going, the cats with the greatest reproductive success will be feral, and the cats best adapted to living with people will have low fitness. Razib Khan has talked about this. There are a number of other cases in which humans are inadvertently selecting for outcomes they don’t like: deer are getting smaller antlers, we’re seeing more and more jack salmon, etc. And of course we’re selecting ourselves for this and that, none of it good.
Yet Carlos Driscoll, a University of Oxford biologist, says there’s nothing to worry about re cats. “The population of domestic cats has been stable for a very long time,” Driscoll said.
“There’s a lot of genetic inertia there.”
The thing is, there’s no such thing as genetic inertia. You can change any species with selection. Horseshoe crabs have been around for something like 450 million years – they’re older than most mountain ranges – but if you started selecting them for size, or a different reproductive schedule, or the ability to live in brackish water, or the ability to play Go – change would come.