Ape - Historical and Modern Terminology

Historical and Modern Terminology

"Ape", from Old English apa, is possibly an onomatopoetic imitation of animal chatter. The term has a history of rather imprecise usage. Its earliest meaning was a tailless (and therefore exceptionally human-like) nonhuman primate. The original usage of "ape" in English might have referred to the baboon, an Old World monkey. Two tailless species of macaque have common names including "ape": the Barbary ape of North Africa (introduced into Gibraltar), Macaca sylvanus, and the Sulawesi black ape or Celebes crested macaque, M. nigra.

As zoological knowledge developed, it became clear that taillessness occurred in a number of different and otherwise unrelated species. The term "ape" was then used in two different senses, as shown in the 1910 Encyclopædia Britannica entry. Either "ape" was still used for a tailless humanlike primate or it became a synonym for "monkey".

Sir Wilfrid Le Gros Clark was one of the primatologists who developed the idea that there were "trends" in primate evolution and that the living members of the order could be arranged in a series, leading through "monkeys" and "apes" to humans. Within this tradition, "ape" refers to all the members of the superfamily Hominoidea, except humans. Thus "apes" are a paraphyletic group, meaning that although all the species of apes descend from a common ancestor, the group does not include all the descendants of that ancestor, because humans are excluded. The diagram below shows the currently accepted evolutionary relationships of the Hominoidea, with the apes marked by a bracket.

The "apes" are traditionally divided further into the "lesser apes" and the "great apes":

In summary, there are three common uses of the term "ape": non-biologists may not distinguish between "monkeys" and "apes", or may use "ape" for any tailless monkey or nonhuman hominoid, whereas biologists traditionally used the term "ape" for all non-human hominoids as shown above.

In recent years biologists have generally preferred to use only monophyletic groups in classifications, that is only groups which include all the descendants of a common ancestor. The superfamily Hominoidea is one such group (or "clade"). Some then use the term "ape" to mean all the members of the superfamily Hominoidea. For example, in a 2005 book, Benton wrote "The apes, Hominoidea, today include the gibbons and orang-utan ... the gorilla and chimpanzee ... and humans". The group traditionally called "apes" by biologists is then called the "nonhuman apes".

See the section History of hominoid taxonomy below for a discussion of changes in scientific classification and terminology.