History of the domestic sheep exact line of descent between domestic sheep and their wild ancestors is unclear. The most common hypothesis states that "Ovis aries" is descended from the Asiatic ("O. orientalis") species of mouflon. A few breeds of sheep, such as the Castlemilk Moorit from Scotland, were formed through crossbreeding with wild European mouflon. The urial ("O. vignei") was once thought to have been a forebear of domestic sheep, as they occasionally interbreed with mouflon in the Iranian part of their range. However, the urial, argali ("O. ammon"), and snow sheep ("O. nivicola") have a different number of chromosomes than other Ovis species,
Soay sheep rump patch and/or white patch under the chin (referred to as the Mouflon or wild pattern). Occasionally white markings on the face and/or body and legs occur. Rarely self-colored (solid color with no markings) black or tan individuals are seen. This breed has extremely fine fleece and, in contrast to mouflon, the inner fleece is highly developed and it is difficult to distinguish an outer coat. This is a clear indication that the Soay are indeed the product of a domesticated breed in prehistoric times. The breed also lacks the flocking instinct of many breeds. Attempts to work them using