Mouflon vignei" (or "orientalis") "arkal" and "O. v./o. bochariensis", grouped with two different clades of argali ("Ovis ammon"). The ancestral sheep is presumed to have had 60 chromosomes, as in goats ("Capra"). Mouflon and domestic sheep have 54 chromosomes, with three pairs (1+3, 2+8, 5+11) of ancestral acrocentric chromosomes joined to form bi-armed chromosomes. This is in contrast to the argali and urial, which have 56 and 58 chromosomes respectively. If the urial is as closely related to the mouflons as mitochondrial DNA indicates, then two chromosomes would need to have split during its evolution away from the mouflon (sub)species. In
Dmitry Belyayev (zoologist) also been of great interest to Darwin. It was recognized that domesticated animals differ in several ways from their wild counterparts, but it was not known what principle of selection had guided the Neolithic farmers who had first domesticated these species thousands of years ago. Belyayev's hypothesis was that "all domesticated species had been selected for a single criterion: tameness." Belyayev further theorized that this attribute "had dragged along with it most of the other features that distinguish domestic animals from their wild forebears, like droopy ears, patches of white in the fur and changes in skull shape." In other