hello! do you know why piebaldism (the Ws allele in cats) is so common in domestic animals? to my knowledge it occurs in cats, dogs, horses, cows, mice, etc. it just seems weird that this specific mutation is so prevalent cross-species, is it just selective breeding? you're the only blog i know that talks about coat genetics in different species so i thought maybe you would know 😅
Piebaldism is an "easy" phenotype: all kind of different mutations that results in worse functioning melanocytes can give white patches. Horses for example have piebald mutations on at least five different genes (EDNRB, KIT, MITF, PAX3 and TRPM1). Probably all those animals you listed have different and unique piebald mutations.
I think this is why it's so common: it doesn't need a specific mutation, just something that turns down pigment production. And turning something off is always easier than changing it but keeping the main functionality.
Piebaldism is observed in all kind of wild animals too, it probably often turns up spontaneously; and by all likeliness that's what happened with early domestic animals too. From that it was simple selective breeding; humans always liked special-looking animals.
