Terminology hominid genera. The classification of the great apes has been
revised several times in the last few decades; these revisions have led to a varied use of the word "hominid" over time. The original meaning of the term referred to only humans and their closest relatives—what is now the modern meaning of the term "
hominin". The meaning of the
taxon Hominidae changed gradually, leading to a modern usage of "hominid" that includes all the great apes including humans. A number of very similar words apply to related classifications: • A
hominoid, sometimes called an
ape, is a member of the superfamily
Hominoidea: extant members are the gibbons (
lesser apes, family Hylobatidae) and the hominids. • A
hominid is a member of the family Hominidae, the great apes: orangutans, gorillas, chimpanzees and humans. • A
hominine is a member of the subfamily
Homininae: gorillas, chimpanzees, and humans (excludes orangutans). • A
hominin is a member of the tribe
Hominini: chimpanzees and humans. • A
homininan, following a suggestion by Wood and Richmond (2000), would be a member of the subtribe
Hominina of the tribe
Hominini: that is, modern humans and their closest relatives, including
Australopithecina, but excluding chimpanzees. • A
human is a member of the genus
Homo, of which
Homo sapiens is the only extant species, and within that
Homo sapiens sapiens is the only surviving
subspecies. A cladogram indicating common names (cf.
more detailed cladogram below):
Extant and fossil relatives of humans hominid exhibit at
The Museum of Osteology,
Oklahoma City, Oklahoma Hominidae was originally the name given to the family of humans and their (extinct) close relatives, with the other great apes (that is, the orangutans, gorillas and chimpanzees) all being placed in a separate family, the
Pongidae. However, that definition eventually made Pongidae
paraphyletic because at least one great ape species (the chimpanzees) proved to be more closely related to humans than to other great apes. Most taxonomists today encourage
monophyletic groups—this would require, in this case, the use of Pongidae to be restricted to just one closely related grouping. Thus, many
biologists now assign
Pongo (as the
subfamily
Ponginae) to the family Hominidae. The taxonomy shown here follows the monophyletic groupings according to the modern understanding of human and great ape relationships. Humans and close relatives including the tribes
Hominini and
Gorillini form the subfamily
Homininae (see classification graphic below). (A few researchers go so far as to refer the chimpanzees and the gorillas to the genus
Homo along with humans.) But, those fossil relatives more closely related to humans than the chimpanzees represent the especially close members of the human family, Many extinct hominids have been studied to help understand the relationship between modern humans and the other extant hominids. Some of the extinct members of this family include
Gigantopithecus,
Orrorin,
Ardipithecus,
Kenyanthropus, and the
australopithecines
Australopithecus and
Paranthropus. The exact criteria for membership in the tribe Hominini under the current understanding of human origins are not clear, but the taxon generally includes those
species that share more than 97% of their
DNA with the modern human
genome, and exhibit a capacity for
language or for simple
cultures beyond their "local family" or band. The
theory of mind concept—including such faculties as empathy, attribution of mental state, and even empathetic deception—is a controversial criterion; it distinguishes the adult human alone among the hominids. Humans acquire this capacity after about four years of age, whereas it has not been proven (nor has it been disproven) that gorillas or chimpanzees ever develop a theory of mind. This is also the case for some
New World monkeys outside the family of great apes, as, for example, the
capuchin monkeys. However, even without the ability to test whether early members of the Hominini (such as
Homo erectus,
Homo neanderthalensis, or even the australopithecines) had a theory of mind, it is difficult to ignore similarities seen in their living cousins. Orangutans have shown the development of culture comparable to that of chimpanzees, and some say the orangutan may also satisfy those criteria for the
theory of mind concept. These scientific debates take on political significance for advocates of
great ape personhood. ==Description==