Red deer are ruminants, characterized by an even number of toes, and a four-chambered stomach. Genetic evidence indicates the red deer (Cervus elaphus) as traditionally defined is a species group rather than a single species, although it remains disputed as to exactly how many species the group includes.[4][5] The slightly larger American elk or wapiti, native to North America and eastern parts of Asia, represents a distinct species besides red deer. The ancestor of all red deer, including wapiti, probably originated in central Asia and probably resembled sika deer.[6]