Apes (collectively Hominoidea /hɒmɪˈnɔɪdi.ə/) are a clade of Old World simians native to sub-Saharan Africa and Southeast Asia (though they were more widespread in Africa, most of Asia, and Europe in prehistory), which together with its sister group Cercopithecidae form the catarrhine clade, cladistically making them monkeys. Apes do not have tails due to a mutation of the TBXT gene.[2][3] In traditional and non-scientific use, the term ape can include tailless primates taxonomically considered Cercopithecidae (such as the Barbary ape and black ape), and is thus not equivalent to the scientific taxon Hominoidea. There are two extant branches of the superfamily Hominoidea: the gibbons, or lesser apes; and the hominids, or great apes.
Except for gorillas and humans, hominoids are agile climbers of trees. Apes eat a variety of plant and animal foods, with the majority of food being plant foods, which can include fruits, leaves, stalks, roots and seeds, including nuts and grass seeds. Human diets are sometimes substantially different from that of other hominoids due in part to the development of technology and a wide range of habitation. Humans are by far the most numerous of the hominoid species, in fact outnumbering all other primates by a factor of several thousand to one.
All non-human hominoids are rare and threatened with extinction. The eastern hoolock gibbon is the least threatened, only being vulnerable to extinction. Five gibbon species are critically endangered, as are all species of orangutan and gorilla. The remaining species of gibbon, the bonobo, and all four species of chimpanzees are endangered. The chief threat to most of the endangered species is loss of tropical rainforest habitat, though some populations are further imperiled by hunting for bushmeat. The great apes of Africa are also facing threat from the Ebola virus. Currently considered to be the greatest threat to survival of African apes, Ebola infection is responsible for the death of at least one third of all gorillas and chimpanzees since 1990.[7]
"Ape", from Old English apa, is a word of uncertain origin.[b] The term has a history of rather imprecise usage—and of comedic or punning usage in the vernacular. Its earliest meaning was generally of any non-human anthropoid primate, as is still the case for its cognates in other Germanic languages.[c][8]Later, after the term "monkey" had been introduced into English, "ape" was specialized to refer to a tailless (therefore exceptionally human-like) primate.[9] Thus, the term "ape" obtained two different meanings, as shown in the 1911 Encyclopædia Britannica entry: it could be used as a synonym for "monkey" and it could denote the tailless human-like primate in particular.[10]
Some, or recently all, hominoids are also called "apes", but the term is used broadly and has several different senses within both popular and scientific settings. "Ape" has been used as a synonym for "monkey" or for naming any primate with a human-like appearance, particularly those without a tail.[10] Biologists have traditionally used the term "ape" to mean a member of the superfamily Hominoidea other than humans,[4] but more recently to mean all members of Hominoidea. So "ape"—not to be confused with "great ape"—now becomes another word for hominoid including humans.[6][d]
The taxonomic term hominoid is derived from, and intended as encompassing, the hominids, the family of great apes. Both terms were introduced by Gray (1825).[11] The term hominins is also due to Gray (1824), intended as including the human lineage (see also Hominidae#Terminology, Human taxonomy).