What makes the cat?
A large international research effort has analyzed the genetic difference between the domestic cat and its wild cousin. Though cat domestication was relatively recent, and the two species interbreed, some interesting differences were found in genes that help mediate aggressive behavior, that form memories, that are related to learning, and that relate to digestion, enabling some benefit from plant-based foods. Your house cat is an obligatory carnivore, and will die if fed no meat. But his wild cousin is hyper-carnivorous, and gets zero value from plant-based food. As with dogs, domestication made their brains smaller. Though I don’t see how that directly relates to the genetic changes identified. (Cite.)