A ruminant (family Bovidae) domesticated from the Asiatic mouflon (Ovis orientalis) approximately 10,000–11,000 years ago in the Fertile Crescent. Adults weigh 45–160 kg depending on breed, with over 1,000 breeds selected for wool, meat (lamb/mutton), milk, and pelts. They have a stocky body, cloven hooves, and typically a woolly fleece that grows continuously and must be shorn annually. Horns are present in some breeds (both sexes or males only). They are obligate herbivores with a four-chambered ruminant stomach. Sheep are gregarious, exhibiting strong flocking behavior with sophisticated facial recognition abilities (recognizing 50+ individual sheep and 10 human faces for years). They are used in biomedical research: Dolly (1996) was the first mammal cloned from an adult somatic cell. They are models for prion diseases (scrapie), pulmonary physiology, and fetal surgery. Females (ewes) have a ~147-day gestation, producing 1–3 lambs. Global population: ~1 billion. The genome is sequenced (2n=54). Lifespan: 10–12 years.