After all, wild cats certainly don’t have white socks on their legs! That would completely impair them when they try to camouflage themselves in grasses while hunting! All domestic cats are descendant from tabby-coated cats, so how in the world did they get those white socks?
Domestication and artificial selection
It is therefore believed that human interference has a lot to do with the fact that some domesticated cats have white in their coat. A white and highly visible coat would not be naturally selected, but it is a highly prised colour for many popular domestic cat breeds today (Persians or Turkish Vans for instance).
White appearing in the coat is actually a result of the presence of the “piebald” allele. This mutation bleaches out the other colours in the coat, creating white patches.
Possibly linked to temperature
Usually, the expression of this allele starts at the bottom of the cat (legs, chest and belly), and this could very well be linked to how much heat the foetus receives as it grows.
Indeed, some scientists suggest that the placement of white on a cat’s coat is linked to the kittens’ position in the womb: curled up into a ball, they create a sort of “hot spot” in the centre of their bodies – which coincides exactly with where the white appears! This would also explain why some cats have random splotches of white on their coats (by sharing a womb with litter mates, they warm each other in random places).
Whatever the case may be, one thing is for sure: artificial selection and the piebald allele are both responsible for those adorable white socks you see on your kitty!