Homo sapiens is a distinct species of the hominid family of primates, which includes all the great apes. Over their evolutionary history, humans gradually developed traits such as bipedalism, dexterity, and complex language. Modern humans interbred with archaic humans, indicating that their evolution was not linear but weblike. The study of the origins of humans involves several scientific disciplines, including physical and evolutionary anthropology, paleontology, and genetics; the field is also known by the terms anthropogeny, anthropogenesis, and anthropogony—with the latter two sometimes used to refer to the related subject of hominization.