Hominidae
Ponginae
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The
Hominids (
Hominidae) are a
biological family which includes
humans, extinct
species of humanlike creatures and the other
great apes:
chimpanzees and
bonobos (genus
Pan),
gorillas, and
orangutans (genus
Pongo).
Originally the group was restricted to humans and their
extinct relatives, with the other great apes being placed in a separate family, the
Pongidae. However, that definition makes Pongidae
paraphyletic, whereas most taxonomists nowadays encourage
monophyletic groups. Thus many
biologists consider Hominidae to include the Pongidae as the subfamily Ponginae, or restrict the latter to the orangutan and extinct relatives like
Gigantopithecus. The taxonomy shown here follows the monophyletic groupings.
Especially close human relatives form a
subfamily, the
Homininae. Some researchers go so far as to include chimpanzees and gorillas in the genus
Homo along with humans, but recent genetic evidence suggests that the human relationship to these species may not be as close as previously thought.
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,
Australopithecus and
Paranthropus.
The exact criterion for membership in the Homininae is not clear, but usually includes the
species who share more than 97% of their
DNA with the modern human
genome, and requires the capacity for
language and for simple
cultures beyond the family or band. The
theory of mind, providing the capacity to lie convincingly, is a controversial criterion distinguishing the adult human alone among the hominids. Humans acquire this capacity at about four and a half years of age in our cultures whereas the bonobo, gorilla and chimpanzee never seem to do so. However, without the ability to test whether early members of the Homininae such as
australopithecines,
Homo erectus, or
Homo neanderthalensis had a theory of mind, it is irrational to ignore similarities seen in their living cousins. Despite an apparent lack of real culture and significant physiological differences, some say that the orangutan may also satisfy these criteria. These scientific debates take on political significance for advocates of
Great Ape personhood, who some believe have influenced the debates in order to refer to "
ape genocide".
In
2002, a 6-7 million year old
fossil skull nicknamed Toumaï by its discoverers, and formally classified as
Sahelanthropus tchadensis, was discovered in
Chad and is possibly the earliest hominid
fossil ever found. In addition to its age, Toumaï, unlike the 3-4 million year younger
Australopithecine dubbed "Lucy", has a relatively flat face without the prominent snout seen on other pre-
Homo hominids. Some researchers have made the suggestion that this previously unknown species may in fact be a direct ancestor of modern humans (or at least closely related to a direct ancestor). Others contend that one fossil is not enough to make such a claim because it would overturn the conclusions of over 100 years of
anthropological study. A report on this finding was published in the journal
Nature on
July 11,
2002. While some scientists claim that it is merely the skull of a female gorilla, others have called it the most important hominid fossil since Australopithecus.
Classification
- Family Hominidae: great apes and humans
See also
