The domestic sheep (Ovis aries) descends from the Mouflon, and in 2003 evidence is proposed that Ovis aries first got domesticated about 9000 BC in Iraq and has been a source of meat, milk, wool and hides since then. There still exist two populations of wild Mouflons: the Asiatic Mouflon and the European Mouflon, although the last may be feral as some sources suggest. The domestic sheep has a highly developed herding or flocking instinct, there is no leader among the sheep. This is quite an advantage, as a shepherd is able to control a large group of sheep. Ovis Aries has a complex stomach system which allows it to digest highly fibrous food that many other mammals cannot. Estimates are there are over 1 billion sheep in the world. The Oklahoma State University has an excellent page with all different breeds of sheep (282).
Breeds of livestock - Oklahoma State University