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,
Domesticated red fox humans. Russian scientists achieved a population of domesticated foxes that are fundamentally different in temperament and behavior from their wild forebears. Some important changes in physiology and morphology became visible, such as mottled or spotted colored fur. Some scientists believe that these changes obtained from selection for tameness are caused by lower adrenaline production in the new population, causing physiological changes within relatively few generations yielding genetic combinations not present in the original species. This indicates that selection for tameness, e.g. did not flee, produces changes that are related to the emergence of other dog-like traits, e.g. raised tail, coming