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,
European mouflon and birthing takes place in March/April. One or two lambs are born, the suckling time is about six months. The escape behaviour of European mouflon is adapted to their actual high mountain habitat: in case of danger, they flee to inaccessible rock faces. In the lowlands, they can only escape short distances and become easy prey for pursuers. It is unclear whether the European mouflon became largely extinct in Europe as a result of its habitats being cut off and through over-hunting between 3,000 and 4,000 years ago and survived only in Corsica and Sardinia, or whether it was only