by Avery Luetkemeyer

What do monkeys do?

A monkey is any nonhuman primate, with the usual exception of the lemurs and tarsiers.[1] Thus defined, there are three type of monkeys: (1)non-human hominoids (also known as apes), (2)old world monkeys, and (3)new world monkeys. However, only the latter two are currently considered "monkeys" by most biologists. There are about 280 known living species of monkey (260 if non-human hominoids are excluded). Many are arboreal, although there are species that live primarily on the ground, such as baboons. Monkeys are generally considered to be intelligent. Unlike apes, old and new world monkeys usually have tails. Tailless monkeys may be called "apes", incorrectly according to most modern biologists; thus the tailless Barbary macaque is called the "Barbary ape".

The New World monkeys (superfamily Ceboidea) are classified within the parvorder of Platyrrhini, whereas the Old World monkeys (superfamily Cercopithecoidea) form part of the parvorder Catarrhini, which also includes the hominoids (apes and humans). Thus, as Old World monkeys are more closely related to hominoids than they are to New World monkeys, the monkeys are not a unitary (monophyletic) group, and thus there is no scientific basis for biologists currently excluding non-human hominoids from the monkey category