Rating Newest Oldest. Best Answer: Humans have canine teeth because it is a basal distinguishing trait for mammals. Mammals all share the specialized dentition, with canines as one class of teeth, that appeared in the ancestral synapsids in the late Permian through the Triassic periods.nly rodents and bovine species have lost canines as a class of teeth. Artiodactyls (bovines) have them only in the lower jaw where they are small and like an incisor while rodents have lost them completely. http://www.earthlife.net/mammals/teeth.h... http://www.mnh.si.edu/mammals/pages/how/...