Re: I thought about that, (with the dogs and horses) but technically, and genetically, it originated as a mutation. Dogs decended from wolves, and wolves don't have a naturally curled tail, when a pup was born that had a curly tail, it was a gene mutation, and bread with other dogs with the same mutation. Making it a common breed characteristic today, same with horses such as the Arabian. (I'm taking gene studies in university and have also worked with horses/dogs ally life) lol , nice to meet some people with common interests, :)