Traditional Classification of Anthropoid primates

    Traditional classification is based on recognition of groups of similar organisms, as indicated by the brackets at right. The anthropoid ("man-like") Apes are distinguished from Old World Monkeys by the absence of a tail. In this group in particular, there is a strong bias that humans are very distinct and (or) "structurally advanced," and therefore belong in a separate group (family Hominidae) apart from the Great Apes (chimps, gorillas, & orangutans) (subfamily Ponginae). Among the apes, tailless gibbons and siamangs are perceived as "lesser apes" that are more "monkey-like," and are therefore placed in a separate subfamily Hylobatinae, within the Ape family (Pongidae). The lesser apes may also be judged as a distinct, separate family, Hylobatidae.

    By "promoting" humans to a distinct family, this arrangement incorrectly implies that chimps are more closely related to gorillas than to humans, or that Lesser and Greater apes are more closely related to each other than the latter is to humans.