The study has found that while dogs and cats are genetically unrelated, breeding for certain features is making some dog and cat breeds look more alike. These include a flat face and large eyes, which are often bred for these features as they closely resemble human infants and trigger parental instincts. The study also revealed that there is more variation in the skulls of domesticated animals than wild ones due to artificial selection by breeders. The merging of dog and cats is part of convergent evolution, which occurs when unrelated organisms evolve similar characteristics due to environmental pressures. The research was conducted by evolutionary biologists Abby Drake (from Cornell University) and Jonathan Losos from Washington University.