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,
Mouflon domesticated animals, where they have naturalized in the mountainous interiors of these islands over the past few thousand years, giving rise to the subspecies known as European mouflon ("O. orientalis musimon"). On the island of Cyprus, the mouflon or "agrino" became a different and endemic subspecies known as the Cyprus mouflon ("O. o. ophion"). The Cyprus mouflon population contains only about 3,000 animals. They are now rare on the islands, but are classified as feral animals by the IUCN. They were later successfully introduced into continental Europe, including Portugal, Spain, France, Germany, central Italy, Switzerland, Austria, the Netherlands, Belgium, the