Hominidae
Encyclopedia
The Hominidae as the term is used here, form a taxonomic family, including four extant genera
: chimpanzee
s (Pan), gorilla
s (Gorilla), human
s (Homo), and orangutan
s (Pongo).
It is also common to use the term in a more restricted sense of humans and relatives of humans closer than chimpanzees. In this usage, all species other than Homo sapiens are extinct.
A number of known extinct genera are grouped with humans in the Homininae
subfamily, others with orangutans in the Ponginae
subfamily. The most recent common ancestor
of the Hominidae lived roughly 14 million years ago, when the ancestors of the orangutans speciated from the ancestors of the other three genera. The ancestors of the Hominidae family had already speciated from those of the Hylobatidae family, perhaps 15-20 million years ago.
skull, classified as Sahelanthropus tchadensis
and nicknamed "Toumaï", was discovered in Chad
, Africa
. It is possibly the earliest hominine fossil
ever found. In addition to its age, Toumaï, unlike the three- to four-million-year younger gracile australopithecine dubbed "Lucy
", has a relatively flat face without the prominent snout seen on other pre-Homo
hominids. There is some dispute over the importance of Sahelanthropus tchadensis. Professor Daniel E. Lieberman has suggested this previously unknown species may be a direct ancestor of modern humans (or at least closely related to a direct ancestor). Others, such as Professor Bernard Wood, argue that one fossil is not enough to make such a claim because appearance is an unreliable method of determining evolutionary relations.
Researchers, such as David Reich, Eric Lander and others, argue that the species associated with the divergence between chimpanzees and proto-humans swapped genes over time through interbreeding, before finally separating. It is generally believed that the Pan/Homo separation occurred about 6 – 8 million years ago, but the molecular clock
(a method of calculating evolution based on the rate at which genes mutate) suggests the genera division 4.6 – 6.2 million years ago. Previous studies looked at average genetic differences between human and chimp. The new study compares the ages of key sequences of genes of modern humans and modern chimps. Some sequences are younger than others, indicating that chimps and humans gradually separated over a period of 4 million years. The youngest human chromosome is the X chromosome
which is about 1.2 million years more recent than the 22 autosomes. The X sex chromosome is known to be vulnerable to selective pressure. Its age suggests there was an initial division between the two species, followed by gradual divergence and interbreeding that resulted in younger genes, and then a final separation.
An alternative minority viewpoint is that Homo diverged from a common ancestor with Pongo perhaps as early as 13 million years ago, while Pan is more closely related to Gorilla. This alternative is supported by characteristics uniquely shared between humans and orangutans, such as dental structure, thick enamel, shoulder blade structure, thick posterior palate, single incisive foramen, high estriol production, and beard and mustache. There are at least 28 such well-corroborated features compared with perhaps as few as one unique feature shared between humans and chimpanzees. It is widely believed that these physical features are misleading, but an alternative possibility is that orangutans have undergone more genetic change than humans and African apes have since their divergence from the common ancestor. If this had happened, then the apparent genetic similarity between humans and chimpanzees would not necessarily be due to a close evolutionary relationship. This hypothesis has been proposed as an explanation as to why early hominids, such as the australopiths
, not only look more like orangutans than either African ape, but also share characters unique to orangutans and their close fossil relatives, such as a thickened posteror palate and anterior zygomatic roots.
, i.e. only humans and their closest relatives. The meaning of the taxon
changed gradually, leading to the modern meaning of "hominid", which includes all great apes and humans.
The primatological
term hominid is easily confused with a number of very similar words:
Many scientists, including anthropologists, continue to use the term hominid to mean humans and their direct and near-direct bipedal ancestors.
As mentioned, Hominidae was originally the name given to humans and their extinct relatives, with the other great ape
s being placed in a separate family, the Pongidae. However, that definition made Pongidae paraphyletic because at least one great ape species appears to be more closely related to humans than to other great apes. Most taxonomists nowadays encourage monophyletic groups – this would require the use of Pongidae to be restricted to one of the great ape groups (containing Pongo, the orangutans) only. Thus, many biologist
s consider Hominidae to include Pongidae as the subfamily Ponginae
, or restrict the latter to the orangutans and their extinct relatives, such as Gigantopithecus
. The taxonomy shown here follows the monophyletic groupings according to the two theories of human and great ape relationships.
Especially close human relatives form a subfamily, the Homininae
. A few researchers go so far as to include chimpanzees and gorillas in the genus Homo
along with humans. Alternatively, those fossil relatives more closely related to humans than the nearest living great ape species represent members of Hominidae without necessarily assigning subfamily or tribal categories. If the orangutan is the closest living relative of humans, there would be a sister group relationship between Hominidae and Pongidae, with the African apes comprising a separate family (Panidae) according to the morphological evidence.
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 (as defined to encompass humans and chimpanzees) include Gigantopithecus
, Orrorin, Ardipithecus
, Kenyanthropus, and the australopithecine
s Australopithecus
and Paranthropus
. In the orangutan model of human origin, the Hominidae would include the australopiths, and possibly Orrorin and Kenyanthropus, but not Ardipithecus and Sahelanthropus that lack features necessary to provide strong corroboration as hominids.
The exact criteria for membership in the Homininae
under the chimpanzee theory of human origins are not clear, but the subfamily 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 culture
s beyond the family or band. The theory of mind
including such faculties as mental state attribution, empathy and even empathetic deception 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, whereas it has neither been proven nor disproven that gorillas and chimpanzees develop a theory of mind. This is also the case for some New World monkey
s outside the family of great apes, as, for example, the capuchin monkeys.
However, without the ability to test whether early members of the Homininae (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 also been shown to have culture comparable to that of chimpanzees, and some say the orangutan may also satisfy these criteria. These scientific debates take on political significance for advocates of Great Ape personhood
.
. The following classification is commonly accepted:
In addition to the extant species and subspecies above, archaeologists, paleontologists, and anthropologists have discovered numerous extinct great ape species. The list below are some of the genera of those discoveries.
at 30–40 kilograms in weight, and the largest being the gorillas, with males weighing 140–180 kilograms. In all great apes, the males are, on average, larger and stronger than the females, although the degree of sexual dimorphism
varies greatly among species. Although most living species are predominantly quadrupedal, they are all able to use their hands for gathering food or nesting materials, and, in some cases, for tool use.
Most species are omnivorous
, but fruit is the preferred food among all but humans. Chimpanzees and orangutans primarily eat fruit. When gorillas run short of fruit at certain times of the year or in certain regions, they resort to eating shoots and leaves, often of bamboo
, a type of grass. Gorillas have extreme adaptations for chewing and digesting such low-quality forage, but they still prefer fruit when it is available, often going miles out of their way to find especially preferred fruits. Humans, since the neolithic revolution
, consume mostly cereal
s and other starch
y foods, including increasingly highly processed food
s, as well as many other domesticated plants and meat
. Hominid teeth are similar to those of the Old World monkey
s and gibbon
s, although they are especially large in gorillas. The dental formula
is: Human teeth and jaws are markedly smaller for their size than those of other apes, which may be an adaptation to eating cooked food for more than a million years.
Gestation
in great apes lasts 8–9 months, and results in the birth of a single offspring, or, rarely, twins. The young are born helpless, and they must be cared for, for long periods of time. Compared with most other mammals, great apes have a remarkably long adolescence, not being weaned
for several years, and not becoming fully mature for eight to 13 years in most species (longer in humans). As a result, females typically give birth only once every few years. There is no distinct breeding season.
Gorillas and chimpanzees live in family groups of around five to ten individuals, although much larger groups are sometimes noted. Chimpanzees live in larger groups that break up into smaller groups when fruit becomes less available. When small groups of female chimpanzees go off in separate directions to forage for fruit, the dominant male(s) can no longer control them and the females often mate with other subordinate males, whether by choice or not. In contrast, groups of gorillas stay together regardless of the availability of fruit. When fruit is hard to find, they resort to eating leaves and shoots. Because gorilla groups stay together, the male is able to monopolize the females in his group. This fact is related to gorillas' greater sexual dimorphism than chimpanzees'. In both chimpanzees and gorillas, the groups include at least one dominant male, and females leave the group at maturity. By contrast, orangutans are generally solitary.
organizations, such as the Great Ape Project
, argue that nonhuman great apes are persons
and should be given basic human rights
. Some countries have instituted a research ban
to protect great apes from any kind of scientific testing.
On 25 June 2008, the Spanish parliament supported a new law that would make "keeping apes for circuses, television commercials or filming" illegal.
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
: chimpanzee
Chimpanzee
Chimpanzee, sometimes colloquially chimp, is the common name for the two extant species of ape in the genus Pan. The Congo River forms the boundary between the native habitat of the two species:...
s (Pan), gorilla
Gorilla
Gorillas are the largest extant species of primates. They are ground-dwelling, predominantly herbivorous apes that inhabit the forests of central Africa. Gorillas are divided into two species and either four or five subspecies...
s (Gorilla), human
Homo (genus)
Homo is the genus that includes modern humans and species closely related to them. The genus is estimated to be about 2.3 to 2.4 million years old, evolving from australopithecine ancestors with the appearance of Homo habilis....
s (Homo), and orangutan
Orangutan
Orangutans are the only exclusively Asian genus of extant great ape. The largest living arboreal animals, they have proportionally longer arms than the other, more terrestrial, great apes. They are among the most intelligent primates and use a variety of sophisticated tools, also making sleeping...
s (Pongo).
It is also common to use the term in a more restricted sense of humans and relatives of humans closer than chimpanzees. In this usage, all species other than Homo sapiens are extinct.
A number of known extinct genera are grouped with humans in the Homininae
Homininae
Homininae is a subfamily of Hominidae, which includes humans, gorillas and chimpanzees, and some extinct relatives; it comprises all those hominids, such as Australopithecus, that arose after the split from orangutans . Our family tree, which has 3 main branches leading to chimpanzees, humans and...
subfamily, others with orangutans in the Ponginae
Ponginae
Ponginae is a subfamily in the hominidae family. It contains a number of genera, all but one extinct:*Pongo *†Gigantopithecus*†Sivapithecus*†Lufengpithecus*†Ankarapithecus*†Ouranopithecus*†Griphopithecus...
subfamily. The most recent common ancestor
Most recent common ancestor
In genetics, the most recent common ancestor of any set of organisms is the most recent individual from which all organisms in the group are directly descended...
of the Hominidae lived roughly 14 million years ago, when the ancestors of the orangutans speciated from the ancestors of the other three genera. The ancestors of the Hominidae family had already speciated from those of the Hylobatidae family, perhaps 15-20 million years ago.
History
On July 19, 2001, a 7-million-year-old fossilFossil
Fossils are the preserved remains or traces of animals , plants, and other organisms from the remote past...
skull, classified as Sahelanthropus tchadensis
Sahelanthropus tchadensis
Sahelanthropus tchadensis is an extinct hominid species that is dated to about . Whether it can be regarded as part of the Hominina tree is unclear; there are arguments both supporting and rejecting it...
and nicknamed "Toumaï", was discovered in Chad
Chad
Chad , officially known as the Republic of Chad, is a landlocked country in Central Africa. It is bordered by Libya to the north, Sudan to the east, the Central African Republic to the south, Cameroon and Nigeria to the southwest, and Niger to the west...
, Africa
Africa
Africa is the world's second largest and second most populous continent, after Asia. At about 30.2 million km² including adjacent islands, it covers 6% of the Earth's total surface area and 20.4% of the total land area...
. It is possibly the earliest hominine fossil
Fossil
Fossils are the preserved remains or traces of animals , plants, and other organisms from the remote past...
ever found. In addition to its age, Toumaï, unlike the three- to four-million-year younger gracile australopithecine dubbed "Lucy
Lucy (Australopithecus)
Lucy is the common name of AL 288-1, several hundred pieces of bone representing about 40% of the skeleton of an individual Australopithecus afarensis. The specimen was discovered in 1974 at Hadar in the Awash Valley of Ethiopia's Afar Depression. Lucy is estimated to have lived 3.2 million years...
", has a relatively flat face without the prominent snout seen on other pre-Homo
Homo (genus)
Homo is the genus that includes modern humans and species closely related to them. The genus is estimated to be about 2.3 to 2.4 million years old, evolving from australopithecine ancestors with the appearance of Homo habilis....
hominids. There is some dispute over the importance of Sahelanthropus tchadensis. Professor Daniel E. Lieberman has suggested this previously unknown species may be a direct ancestor of modern humans (or at least closely related to a direct ancestor). Others, such as Professor Bernard Wood, argue that one fossil is not enough to make such a claim because appearance is an unreliable method of determining evolutionary relations.
Molecular clock
The molecular clock is a technique in molecular evolution that uses fossil constraints and rates of molecular change to deduce the time in geologic history when two species or other taxa diverged. It is used to estimate the time of occurrence of events called speciation or radiation...
(a method of calculating evolution based on the rate at which genes mutate) suggests the genera division 4.6 – 6.2 million years ago. Previous studies looked at average genetic differences between human and chimp. The new study compares the ages of key sequences of genes of modern humans and modern chimps. Some sequences are younger than others, indicating that chimps and humans gradually separated over a period of 4 million years. The youngest human chromosome is the X chromosome
X chromosome
The X chromosome is one of the two sex-determining chromosomes in many animal species, including mammals and is common in both males and females. It is a part of the XY sex-determination system and X0 sex-determination system...
which is about 1.2 million years more recent than the 22 autosomes. The X sex chromosome is known to be vulnerable to selective pressure. Its age suggests there was an initial division between the two species, followed by gradual divergence and interbreeding that resulted in younger genes, and then a final separation.
An alternative minority viewpoint is that Homo diverged from a common ancestor with Pongo perhaps as early as 13 million years ago, while Pan is more closely related to Gorilla. This alternative is supported by characteristics uniquely shared between humans and orangutans, such as dental structure, thick enamel, shoulder blade structure, thick posterior palate, single incisive foramen, high estriol production, and beard and mustache. There are at least 28 such well-corroborated features compared with perhaps as few as one unique feature shared between humans and chimpanzees. It is widely believed that these physical features are misleading, but an alternative possibility is that orangutans have undergone more genetic change than humans and African apes have since their divergence from the common ancestor. If this had happened, then the apparent genetic similarity between humans and chimpanzees would not necessarily be due to a close evolutionary relationship. This hypothesis has been proposed as an explanation as to why early hominids, such as the australopiths
Australopithecus
Australopithecus is a genus of hominids that is now extinct. From the evidence gathered by palaeontologists and archaeologists, it appears that the Australopithecus genus evolved in eastern Africa around 4 million years ago before spreading throughout the continent and eventually becoming extinct...
, not only look more like orangutans than either African ape, but also share characters unique to orangutans and their close fossil relatives, such as a thickened posteror palate and anterior zygomatic roots.
Taxonomic history
The classification of the great apes has been revised several times in the last few decades. These various revisions have led to a varied use of the word "hominid" – the original meaning of Hominidae referred only to the modern meaning of HomininaHominina
The more anthropomorphic primates of the Hominini tribe are placed in the Hominina subtribe. Referred to as hominans, they are characterized by the evolution of an increasingly erect bipedal locomotion. The only extant species is Homo sapiens...
, i.e. only humans and their closest relatives. The meaning of the taxon
Taxon
|thumb|270px|[[African elephants]] form a widely-accepted taxon, the [[genus]] LoxodontaA taxon is a group of organisms, which a taxonomist adjudges to be a unit. Usually a taxon is given a name and a rank, although neither is a requirement...
changed gradually, leading to the modern meaning of "hominid", which includes all great apes and humans.
The primatological
Primatology
Primatology is the scientific study of primates. It is a diverse discipline and researchers can be found in academic departments of anatomy, anthropology, biology, medicine, psychology, veterinary sciences and zoology, as well as in animal sanctuaries, biomedical research facilities, museums and zoos...
term hominid is easily confused with a number of very similar words:
- A hominoid, commonly called an ape, is a member of the superfamily HominoideaApeApes are Old World anthropoid mammals, more specifically a clade of tailless catarrhine primates, belonging to the biological superfamily Hominoidea. The apes are native to Africa and South-east Asia, although in relatively recent times humans have spread all over the world...
: extant members are the lesser apes (gibbonGibbonGibbons are apes in the family Hylobatidae . The family is divided into four genera based on their diploid chromosome number: Hylobates , Hoolock , Nomascus , and Symphalangus . The extinct Bunopithecus sericus is a gibbon or gibbon-like ape which, until recently, was thought to be closely related...
s) and great apes (hominids). - A hominine is a member of the subfamily HomininaeHomininaeHomininae is a subfamily of Hominidae, which includes humans, gorillas and chimpanzees, and some extinct relatives; it comprises all those hominids, such as Australopithecus, that arose after the split from orangutans . Our family tree, which has 3 main branches leading to chimpanzees, humans and...
: gorillas, chimpanzees, humans (excludes orangutanOrangutanOrangutans are the only exclusively Asian genus of extant great ape. The largest living arboreal animals, they have proportionally longer arms than the other, more terrestrial, great apes. They are among the most intelligent primates and use a variety of sophisticated tools, also making sleeping...
s). - A hominin is a member of the tribe HomininiHomininiHominini is the tribe of Homininae that comprises Homo, and the two species of the genus Pan , their ancestors, and the extinct lineages of their common ancestor . Members of the tribe are called hominins...
: bonobos, chimpanzees and humans. - A hominan is a member of the subtribe HomininaHomininaThe more anthropomorphic primates of the Hominini tribe are placed in the Hominina subtribe. Referred to as hominans, they are characterized by the evolution of an increasingly erect bipedal locomotion. The only extant species is Homo sapiens...
: modern humans and their extinct relatives. - A human is a member of the genus HomoHomo (genus)Homo is the genus that includes modern humans and species closely related to them. The genus is estimated to be about 2.3 to 2.4 million years old, evolving from australopithecine ancestors with the appearance of Homo habilis....
, of which Homo sapiens is the only extant species, and within that Homo sapiens sapiens is the only surviving subspeciesSubspeciesSubspecies in biological classification, is either a taxonomic rank subordinate to species, ora taxonomic unit in that rank . A subspecies cannot be recognized in isolation: a species will either be recognized as having no subspecies at all or two or more, never just one...
.
Many scientists, including anthropologists, continue to use the term hominid to mean humans and their direct and near-direct bipedal ancestors.
As mentioned, Hominidae was originally the name given to humans and their extinct relatives, with the other great ape
Ape
Apes are Old World anthropoid mammals, more specifically a clade of tailless catarrhine primates, belonging to the biological superfamily Hominoidea. The apes are native to Africa and South-east Asia, although in relatively recent times humans have spread all over the world...
s being placed in a separate family, the Pongidae. However, that definition made Pongidae paraphyletic because at least one great ape species appears to be more closely related to humans than to other great apes. Most taxonomists nowadays encourage monophyletic groups – this would require the use of Pongidae to be restricted to one of the great ape groups (containing Pongo, the orangutans) only. Thus, many biologist
Biologist
A biologist is a scientist devoted to and producing results in biology through the study of life. Typically biologists study organisms and their relationship to their environment. Biologists involved in basic research attempt to discover underlying mechanisms that govern how organisms work...
s consider Hominidae to include Pongidae as the subfamily Ponginae
Ponginae
Ponginae is a subfamily in the hominidae family. It contains a number of genera, all but one extinct:*Pongo *†Gigantopithecus*†Sivapithecus*†Lufengpithecus*†Ankarapithecus*†Ouranopithecus*†Griphopithecus...
, or restrict the latter to the orangutans and their extinct relatives, such as Gigantopithecus
Gigantopithecus
Gigantopithecus is an extinct genus of ape that existed from roughly one million years to as recently as three hundred thousand years ago, in what is now China, India, and Vietnam, placing Gigantopithecus in the same time frame and geographical location as several hominin species...
. The taxonomy shown here follows the monophyletic groupings according to the two theories of human and great ape relationships.
Especially close human relatives form a subfamily, the Homininae
Homininae
Homininae is a subfamily of Hominidae, which includes humans, gorillas and chimpanzees, and some extinct relatives; it comprises all those hominids, such as Australopithecus, that arose after the split from orangutans . Our family tree, which has 3 main branches leading to chimpanzees, humans and...
. A few researchers go so far as to include chimpanzees and gorillas in the genus Homo
Homo (genus)
Homo is the genus that includes modern humans and species closely related to them. The genus is estimated to be about 2.3 to 2.4 million years old, evolving from australopithecine ancestors with the appearance of Homo habilis....
along with humans. Alternatively, those fossil relatives more closely related to humans than the nearest living great ape species represent members of Hominidae without necessarily assigning subfamily or tribal categories. If the orangutan is the closest living relative of humans, there would be a sister group relationship between Hominidae and Pongidae, with the African apes comprising a separate family (Panidae) according to the morphological evidence.
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 (as defined to encompass humans and chimpanzees) include Gigantopithecus
Gigantopithecus
Gigantopithecus is an extinct genus of ape that existed from roughly one million years to as recently as three hundred thousand years ago, in what is now China, India, and Vietnam, placing Gigantopithecus in the same time frame and geographical location as several hominin species...
, Orrorin, Ardipithecus
Ardipithecus
Ardipithecus is a very early hominin genus. Two species are described in the literature: A. ramidus, which lived about 4.4 million years ago during the early Pliocene, and A. kadabba, dated to approximately 5.6 million years ago ....
, Kenyanthropus, and the australopithecine
Australopithecine
The term australopithecine refers generally to any species in the related genera Australopithecus or Paranthropus. These species occurred in the Plio-Pleistocene era, and were bipedal and dentally similar to humans, but with a brain size not much larger than modern apes, lacking the...
s Australopithecus
Australopithecus
Australopithecus is a genus of hominids that is now extinct. From the evidence gathered by palaeontologists and archaeologists, it appears that the Australopithecus genus evolved in eastern Africa around 4 million years ago before spreading throughout the continent and eventually becoming extinct...
and Paranthropus
Paranthropus
The robust australopithecines, members of the extinct hominin genus Paranthropus , were bipedal hominids that probably descended from the gracile australopithecine hominids...
. In the orangutan model of human origin, the Hominidae would include the australopiths, and possibly Orrorin and Kenyanthropus, but not Ardipithecus and Sahelanthropus that lack features necessary to provide strong corroboration as hominids.
The exact criteria for membership in the Homininae
Homininae
Homininae is a subfamily of Hominidae, which includes humans, gorillas and chimpanzees, and some extinct relatives; it comprises all those hominids, such as Australopithecus, that arose after the split from orangutans . Our family tree, which has 3 main branches leading to chimpanzees, humans and...
under the chimpanzee theory of human origins are not clear, but the subfamily generally includes those species
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
that share more than 97% of their DNA
DNA
Deoxyribonucleic acid is a nucleic acid that contains the genetic instructions used in the development and functioning of all known living organisms . The DNA segments that carry this genetic information are called genes, but other DNA sequences have structural purposes, or are involved in...
with the modern human genome
Genome
In modern molecular biology and genetics, the genome is the entirety of an organism's hereditary information. It is encoded either in DNA or, for many types of virus, in RNA. The genome includes both the genes and the non-coding sequences of the DNA/RNA....
, and exhibit a capacity for language
Language
Language may refer either to the specifically human capacity for acquiring and using complex systems of communication, or to a specific instance of such a system of complex communication...
or for simple culture
Culture
Culture is a term that has many different inter-related meanings. For example, in 1952, Alfred Kroeber and Clyde Kluckhohn compiled a list of 164 definitions of "culture" in Culture: A Critical Review of Concepts and Definitions...
s beyond the family or band. The theory of mind
Theory of mind
Theory of mind is the ability to attribute mental states—beliefs, intents, desires, pretending, knowledge, etc.—to oneself and others and to understand that others have beliefs, desires and intentions that are different from one's own...
including such faculties as mental state attribution, empathy and even empathetic deception 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, whereas it has neither been proven nor disproven that gorillas and chimpanzees develop a theory of mind. This is also the case for some New World monkey
New World monkey
New World monkeys are the five families of primates that are found in Central and South America: Callitrichidae, Cebidae, Aotidae, Pitheciidae, and Atelidae. The five families are ranked together as the Platyrrhini parvorder and the Ceboidea superfamily, which are essentially synonymous since...
s outside the family of great apes, as, for example, the capuchin monkeys.
However, without the ability to test whether early members of the Homininae (such as Homo erectus
Homo erectus
Homo erectus is an extinct species of hominid that lived from the end of the Pliocene epoch to the later Pleistocene, about . The species originated in Africa and spread as far as India, China and Java. There is still disagreement on the subject of the classification, ancestry, and progeny of H...
, Homo neanderthalensis, or even the australopithecines) had a theory of mind, it is difficult to ignore similarities seen in their living cousins. Orangutans have also been shown to have culture comparable to that of chimpanzees, and some say the orangutan may also satisfy these criteria. These scientific debates take on political significance for advocates of Great Ape personhood
Great Ape personhood
Great ape personhood is a movement to create legal recognition of bonobos, common chimpanzees, gorillas, and orangutans as bona fide persons.-First steps:...
.
Classification
The seven living species of great ape are classified in four generaGenus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
. The following classification is commonly accepted:
- Family Hominidae: humans and other great apes; extinct genera and species excluded
- Subfamily PonginaePonginaePonginae is a subfamily in the hominidae family. It contains a number of genera, all but one extinct:*Pongo *†Gigantopithecus*†Sivapithecus*†Lufengpithecus*†Ankarapithecus*†Ouranopithecus*†Griphopithecus...
- Genus PongoOrangutanOrangutans are the only exclusively Asian genus of extant great ape. The largest living arboreal animals, they have proportionally longer arms than the other, more terrestrial, great apes. They are among the most intelligent primates and use a variety of sophisticated tools, also making sleeping...
- Bornean orangutanBornean OrangutanThe Bornean orangutan, Pongo pygmaeus, is a species of orangutan native to the island of Borneo. Together with the slightly smaller Sumatran orangutan, it belongs to the only genus of great apes native to Asia....
, Pongo pygmaeus- Pongo pygmaeus pygmaeus
- Pongo pygmaeus morio
- Pongo pygmaeus wurmbii
- Sumatran orangutanSumatran OrangutanThe Sumatran orangutan is one of the two species of orangutans. Found only on the island of Sumatra, in Indonesia, it is rarer and smaller than the Bornean orangutan. The Sumatran orangutan grows to about tall and in males...
, Pongo abelii
- Bornean orangutan
- Genus Pongo
- Subfamily HomininaeHomininaeHomininae is a subfamily of Hominidae, which includes humans, gorillas and chimpanzees, and some extinct relatives; it comprises all those hominids, such as Australopithecus, that arose after the split from orangutans . Our family tree, which has 3 main branches leading to chimpanzees, humans and...
- Tribe GorilliniGorillaGorillas are the largest extant species of primates. They are ground-dwelling, predominantly herbivorous apes that inhabit the forests of central Africa. Gorillas are divided into two species and either four or five subspecies...
- Genus GorillaGorillaGorillas are the largest extant species of primates. They are ground-dwelling, predominantly herbivorous apes that inhabit the forests of central Africa. Gorillas are divided into two species and either four or five subspecies...
- Western gorillaWestern GorillaThe western gorilla is a great ape and the most populous species of the genus Gorilla.-Taxonomy:Nearly all of the individuals of this taxon belong to the western lowland gorilla subspecies whose population is approximately 95,000 individuals...
, Gorilla gorilla- Western lowland gorillaWestern Lowland GorillaThe western lowland gorilla is a subspecies of the western gorilla that lives in montane, primary, and secondary forests and lowland swamps in Angola, Cameroon, Central African Republic, Congo, Democratic Republic of the Congo, Equatorial Guinea and Gabon. It is the gorilla usually found in zoos...
, Gorilla gorilla gorilla - Cross River gorillaCross River GorillaThe Cross River gorilla is a subspecies of the western gorilla that can be found on the border between Nigeria and Cameroon, in both tropical and subtropical moist broadleaf forests which are also home to the Nigeria-Cameroon Chimpanzee, another subspecies of great ape...
, Gorilla gorilla diehli
- Western lowland gorilla
- Eastern gorillaEastern GorillaThe eastern gorilla is a species of the genus Gorilla and the largest living primate. At present, the species is subdivided into two subspecies. The eastern lowland gorilla is the most populous, at about 5,000 individuals. The mountain gorilla has only about 700 individuals...
, Gorilla beringei- Mountain gorillaMountain GorillaThe Mountain Gorilla is one of the two subspecies of the Eastern Gorilla. There are two populations. One is found in the Virunga volcanic mountains of Central Africa, within three National Parks: Mgahinga, in south-west Uganda; Volcanoes, in north-west Rwanda; and Virunga in the eastern Democratic...
, Gorilla beringei beringei - Eastern lowland gorillaEastern Lowland GorillaThe Eastern Lowland Gorilla is a subspecies of Eastern Gorilla that is now only found in the forests of eastern Democratic Republic of the Congo...
, Gorilla beringei graueri
- Mountain gorilla
- Western gorilla
- Genus Gorilla
- Tribe HomininiHomininiHominini is the tribe of Homininae that comprises Homo, and the two species of the genus Pan , their ancestors, and the extinct lineages of their common ancestor . Members of the tribe are called hominins...
- Genus PanChimpanzeeChimpanzee, sometimes colloquially chimp, is the common name for the two extant species of ape in the genus Pan. The Congo River forms the boundary between the native habitat of the two species:...
- Common chimpanzeeCommon ChimpanzeeThe common chimpanzee , also known as the robust chimpanzee, is a great ape. Colloquially, the common chimpanzee is often called the chimpanzee , though technically this term refers to both species in the genus Pan: the common chimpanzee and the closely related bonobo, formerly called the pygmy...
, Pan troglodytes- Central chimpanzee, Pan troglodytes troglodytes
- West African chimpanzee, Pan troglodytes verus
- Nigerian chimpanzee, Pan troglodytes ellioti
- Eastern chimpanzee, Pan troglodytes schweinfurthii
- BonoboBonoboThe bonobo , Pan paniscus, previously called the pygmy chimpanzee and less often, the dwarf or gracile chimpanzee, is a great ape and one of the two species making up the genus Pan. The other species in genus Pan is Pan troglodytes, or the common chimpanzee...
(pygmy chimpanzee), Pan paniscus
- Common chimpanzee
- Genus HomoHomo (genus)Homo is the genus that includes modern humans and species closely related to them. The genus is estimated to be about 2.3 to 2.4 million years old, evolving from australopithecine ancestors with the appearance of Homo habilis....
- HumanHumanHumans are the only living species in the Homo genus...
, Homo sapiens sapiens
- Human
- Genus Pan
- Tribe Gorillini
- Subfamily Ponginae
In addition to the extant species and subspecies above, archaeologists, paleontologists, and anthropologists have discovered numerous extinct great ape species. The list below are some of the genera of those discoveries.
- Subfamily PonginaePonginaePonginae is a subfamily in the hominidae family. It contains a number of genera, all but one extinct:*Pongo *†Gigantopithecus*†Sivapithecus*†Lufengpithecus*†Ankarapithecus*†Ouranopithecus*†Griphopithecus...
(or Pongidae)- GigantopithecusGigantopithecusGigantopithecus is an extinct genus of ape that existed from roughly one million years to as recently as three hundred thousand years ago, in what is now China, India, and Vietnam, placing Gigantopithecus in the same time frame and geographical location as several hominin species...
† - SivapithecusSivapithecusSivapithecus is a genus of extinct primates. Fossil remains of animals now assigned to this genus, dated from 12.5 million to 8.5 million years old in the Miocene, have been found since the 19th century in the Siwalik Hills in what is now India, Nepal, and Pakistan...
† - LufengpithecusLufengpithecusLufengpithecus is a genus of extinct ape generally placed in the Ponginae subfamily.It contains three species: Lufengpithecus lufengensis, Lufengpithecus hudienensis and Lufengpithecus keiyuanensis....
† - AnkarapithecusAnkarapithecusAnkarapithecus is a genus of extinct ape. It was probably frugivorous, and would have weighed about 60 pounds. Its remains were found close to Ankara in central Turkey beginning in the 1950s. It lived during the Late Miocene. It was similar to Sivapithecus....
† - Ouranopithecus†
- Gigantopithecus
- Subfamily HomininaeHomininaeHomininae is a subfamily of Hominidae, which includes humans, gorillas and chimpanzees, and some extinct relatives; it comprises all those hominids, such as Australopithecus, that arose after the split from orangutans . Our family tree, which has 3 main branches leading to chimpanzees, humans and...
(or Hominidae)- HomoHomo (genus)Homo is the genus that includes modern humans and species closely related to them. The genus is estimated to be about 2.3 to 2.4 million years old, evolving from australopithecine ancestors with the appearance of Homo habilis....
– immediate ancestors of modern humanHumanHumans are the only living species in the Homo genus...
s- Homo habilisHomo habilisHomo habilis is a species of the genus Homo, which lived from approximately at the beginning of the Pleistocene period. The discovery and description of this species is credited to both Mary and Louis Leakey, who found fossils in Tanzania, East Africa, between 1962 and 1964. Homo habilis Homo...
† - Homo rudolfensisHomo rudolfensisHomo rudolfensis is a fossil human species discovered by Bernard Ngeneo, a member of a team led by anthropologist Richard Leakey and zoologist Meave Leakey in 1972, at Koobi Fora on the east side of Lake Rudolf in Kenya. The scientific name Pithecanthropus rudolfensis was proposed in 1978 by V. P...
† - Homo ergasterHomo ergasterHomo ergaster is an extinct chronospecies of Homo that lived in eastern and southern Africa during the early Pleistocene, about 2.5–1.7 million years ago.There is still disagreement on the subject of the classification, ancestry, and progeny of H...
† - Homo georgicusHomo georgicusHomo georgicus is a species of Homo that was suggested in 2002 to describe fossil skulls and jaws found in Dmanisi, Georgia in 1999 and 2001, which seem intermediate between Homo habilis and H. erectus. A partial skeleton was discovered in 2001. The fossils are about 1.8 million years old...
† - Homo erectusHomo erectusHomo erectus is an extinct species of hominid that lived from the end of the Pliocene epoch to the later Pleistocene, about . The species originated in Africa and spread as far as India, China and Java. There is still disagreement on the subject of the classification, ancestry, and progeny of H...
† - Homo cepranensisHomo cepranensisHomo cepranensis is a proposed name for a human species, known from only one skull cap discovered in 1994. The fossil was discovered by archeologist Italo Biddittu and was nicknamed "Ceprano Man" after a nearby town in the province of Frosinone, 89 kilometers Southeast of Rome, Italy.The age of...
† - Homo antecessorHomo antecessorHomo antecessor is an extinct human species dating from 1.2 million to 800,000 years ago, that was discovered by Eudald Carbonell, Juan Luis Arsuaga and J. M. Bermúdez de Castro. H. antecessor is one of the earliest known human varieties in Europe. Various archaeologists and anthropologists have...
† - Homo heidelbergensisHomo heidelbergensisHomo heidelbergensis is an extinct species of the genus Homo which may be the direct ancestor of both Homo neanderthalensis in Europe and Homo sapiens. The best evidence found for these hominins date between 600,000 and 400,000 years ago. H...
† - Homo rhodesiensisHomo rhodesiensisHomo rhodesiensis is a hominin species described from the fossil Kabwe skull. Other morphologically-comparable remains have been found from the same, or earlier, time period in southern Africa , East Africa and North Africa...
† - Homo neanderthalensis†
- Homo sapiens
- Homo sapiens idaltuHomo sapiens idaltuHomo sapiens idaltu is an extinct subspecies of Homo sapiens that lived almost 160,000 years ago in Pleistocene Africa. is from the Saho-Afar word meaning "elder or first born"....
† - Archaic Homo sapiensArchaic Homo sapiensArchaic Homo sapiens is a loosely defined term used to describe a number of varieties of Homo, as opposed to anatomically modern humans , in the period beginning 500,000 years ago....
(Cro-magnonCro-MagnonThe Cro-Magnon were the first early modern humans of the European Upper Paleolithic. The earliest known remains of Cro-Magnon-like humans are radiometrically dated to 35,000 years before present....
)†
- Homo sapiens idaltu
- Homo floresiensisHomo floresiensisHomo floresiensis is a possible species, now extinct, in the genus Homo. The remains were discovered in 2003 on the island of Flores in Indonesia. Partial skeletons of nine individuals have been recovered, including one complete cranium...
†
- Homo habilis
- Oreopithecus†(hominid status disputed)
- ParanthropusParanthropusThe robust australopithecines, members of the extinct hominin genus Paranthropus , were bipedal hominids that probably descended from the gracile australopithecine hominids...
† - AustralopithecusAustralopithecusAustralopithecus is a genus of hominids that is now extinct. From the evidence gathered by palaeontologists and archaeologists, it appears that the Australopithecus genus evolved in eastern Africa around 4 million years ago before spreading throughout the continent and eventually becoming extinct...
† - Sahelanthropus†(hominid status highly problematic)
- Orrorin†
- ArdipithecusArdipithecusArdipithecus is a very early hominin genus. Two species are described in the literature: A. ramidus, which lived about 4.4 million years ago during the early Pliocene, and A. kadabba, dated to approximately 5.6 million years ago ....
† - Kenyanthropus†
- Homo
Physical description
The great apes are large, tailless primates, with the smallest living species being the bonoboBonobo
The bonobo , Pan paniscus, previously called the pygmy chimpanzee and less often, the dwarf or gracile chimpanzee, is a great ape and one of the two species making up the genus Pan. The other species in genus Pan is Pan troglodytes, or the common chimpanzee...
at 30–40 kilograms in weight, and the largest being the gorillas, with males weighing 140–180 kilograms. In all great apes, the males are, on average, larger and stronger than the females, although the degree of sexual dimorphism
Sexual dimorphism
Sexual dimorphism is a phenotypic difference between males and females of the same species. Examples of such differences include differences in morphology, ornamentation, and behavior.-Examples:-Ornamentation / coloration:...
varies greatly among species. Although most living species are predominantly quadrupedal, they are all able to use their hands for gathering food or nesting materials, and, in some cases, for tool use.
Most species are omnivorous
Omnivore
Omnivores are species that eat both plants and animals as their primary food source...
, but fruit is the preferred food among all but humans. Chimpanzees and orangutans primarily eat fruit. When gorillas run short of fruit at certain times of the year or in certain regions, they resort to eating shoots and leaves, often of bamboo
Bamboo
Bamboo is a group of perennial evergreens in the true grass family Poaceae, subfamily Bambusoideae, tribe Bambuseae. Giant bamboos are the largest members of the grass family....
, a type of grass. Gorillas have extreme adaptations for chewing and digesting such low-quality forage, but they still prefer fruit when it is available, often going miles out of their way to find especially preferred fruits. Humans, since the neolithic revolution
Neolithic Revolution
The Neolithic Revolution was the first agricultural revolution. It was the transition from hunting and gathering to agriculture and settlement. Archaeological data indicates that various forms of plants and animal domestication evolved independently in 6 separate locations worldwide circa...
, consume mostly cereal
Cereal
Cereals are grasses cultivated for the edible components of their grain , composed of the endosperm, germ, and bran...
s and other starch
Starch
Starch or amylum is a carbohydrate consisting of a large number of glucose units joined together by glycosidic bonds. This polysaccharide is produced by all green plants as an energy store...
y foods, including increasingly highly processed food
Food processing
Food processing is the set of methods and techniques used to transform raw ingredients into food or to transform food into other forms for consumption by humans or animals either in the home or by the food processing industry...
s, as well as many other domesticated plants and meat
Meat
Meat is animal flesh that is used as food. Most often, this means the skeletal muscle and associated fat and other tissues, but it may also describe other edible tissues such as organs and offal...
. Hominid teeth are similar to those of the Old World monkey
Old World monkey
The Old World monkeys or Cercopithecidae are a group of primates, falling in the superfamily Cercopithecoidea in the clade Catarrhini. The Old World monkeys are native to Africa and Asia today, inhabiting a range of environments from tropical rain forest to savanna, shrubland and mountainous...
s and gibbon
Gibbon
Gibbons are apes in the family Hylobatidae . The family is divided into four genera based on their diploid chromosome number: Hylobates , Hoolock , Nomascus , and Symphalangus . The extinct Bunopithecus sericus is a gibbon or gibbon-like ape which, until recently, was thought to be closely related...
s, although they are especially large in gorillas. The dental formula
Dentition
Dentition pertains to the development of teeth and their arrangement in the mouth. In particular, the characteristic arrangement, kind, and number of teeth in a given species at a given age...
is: Human teeth and jaws are markedly smaller for their size than those of other apes, which may be an adaptation to eating cooked food for more than a million years.
Gestation
Gestation
Gestation is the carrying of an embryo or fetus inside a female viviparous animal. Mammals during pregnancy can have one or more gestations at the same time ....
in great apes lasts 8–9 months, and results in the birth of a single offspring, or, rarely, twins. The young are born helpless, and they must be cared for, for long periods of time. Compared with most other mammals, great apes have a remarkably long adolescence, not being weaned
Weaning
Weaning is the process of gradually introducing a mammal infant, either human or animal, to what will be its adult diet and withdrawing the supply of its mother's milk.The process takes place only in mammals, as only mammals produce milk...
for several years, and not becoming fully mature for eight to 13 years in most species (longer in humans). As a result, females typically give birth only once every few years. There is no distinct breeding season.
Gorillas and chimpanzees live in family groups of around five to ten individuals, although much larger groups are sometimes noted. Chimpanzees live in larger groups that break up into smaller groups when fruit becomes less available. When small groups of female chimpanzees go off in separate directions to forage for fruit, the dominant male(s) can no longer control them and the females often mate with other subordinate males, whether by choice or not. In contrast, groups of gorillas stay together regardless of the availability of fruit. When fruit is hard to find, they resort to eating leaves and shoots. Because gorilla groups stay together, the male is able to monopolize the females in his group. This fact is related to gorillas' greater sexual dimorphism than chimpanzees'. In both chimpanzees and gorillas, the groups include at least one dominant male, and females leave the group at maturity. By contrast, orangutans are generally solitary.
Legal status
Due to the close genetic relationship between humans and other great apes, certain animal rightsAnimal rights
Animal rights, also known as animal liberation, is the idea that the most basic interests of non-human animals should be afforded the same consideration as the similar interests of human beings...
organizations, such as the Great Ape Project
Great Ape Project
The Great Ape Project , founded in 1994, is an international organization of primatologists, anthropologists, ethicists, and other experts who advocate a United Nations Declaration of the Rights of Great Apes that would confer basic legal rights on non-human great apes: chimpanzees, bonobos,...
, argue that nonhuman great apes are persons
Great Ape personhood
Great ape personhood is a movement to create legal recognition of bonobos, common chimpanzees, gorillas, and orangutans as bona fide persons.-First steps:...
and should be given basic human rights
Human rights
Human rights are "commonly understood as inalienable fundamental rights to which a person is inherently entitled simply because she or he is a human being." Human rights are thus conceived as universal and egalitarian . These rights may exist as natural rights or as legal rights, in both national...
. Some countries have instituted a research ban
Great Ape research ban
A great ape research ban, or severe restrictions on the use of non-human great apes in research, is currently in place in the Netherlands, New Zealand, the United Kingdom, Sweden, Germany and Austria. These countries have ruled that chimpanzees, bonobos, gorillas, and orangutans are cognitively so...
to protect great apes from any kind of scientific testing.
On 25 June 2008, the Spanish parliament supported a new law that would make "keeping apes for circuses, television commercials or filming" illegal.
See also
- Great ape languageGreat Ape languageResearch into non-human great ape language has involved teaching chimpanzees, bonobos, gorillas, and orangutans to communicate with human beings and with each other using sign language, physical tokens, and lexigrams; see Yerkish...
- The Mind of an ApeThe Mind of an ApeThe Mind of an Ape is a 1983 book by David and Ann James Premack. In it, the authors argue that it is possible to teach language to great apes...
- The Mind of an Ape
- Primate cognitionPrimate cognitionPrimate cognition is the study of the cognitive abilities of non-human primates. Humans are also primates but, traditionally, humans have been thought to be different from other animals...
- List of apes – notable individual apes
- Ape extinctionApe extinctionApe extinction, particularly great ape extinction, is one of the most widely held biodiversity concerns.There are very few breeding populations of non-human great apes outside captivity, and all such populations are not only formally classified as endangered species, but in the direct path of human...
- Great Apes Survival ProjectGreat Apes Survival ProjectThe Great Apes Survival Project , established in 2001, aims to conserve the great apes and their habitat — primarily forested tropical ecosystems that provide important services to humanity, through pro-poor conservation and sustainable development strategies.GRASP is a UNEP and UNESCO-led World...
- Kinshasa Declaration on Great ApesKinshasa Declaration on Great ApesThe Kinshasa Declaration on Great Apes was a high-level political statement on the future of great apes. It was signed during the Intergovernmental Meeting on Great Apes and the first council meeting of the Great Apes Survival Project in Kinshasa, Democratic Republic of the Congo on September 9,...
- Great Apes Survival Project
- HomininaeHomininaeHomininae is a subfamily of Hominidae, which includes humans, gorillas and chimpanzees, and some extinct relatives; it comprises all those hominids, such as Australopithecus, that arose after the split from orangutans . Our family tree, which has 3 main branches leading to chimpanzees, humans and...
- Human evolutionHuman evolutionHuman evolution refers to the evolutionary history of the genus Homo, including the emergence of Homo sapiens as a distinct species and as a unique category of hominids and mammals...
- Timeline of human evolutionTimeline of human evolutionThe timeline of human evolution outlines the major events in the development of human species, and the evolution of humans' ancestors. It includes a brief explanation of some animals, species or genera, which are possible ancestors of Homo sapiens...
- Timeline of human evolution
External links
- Renderings of Hominid Exemplars at the Smithsonian
- Additional information on great apes
- NPR News: Toumaï the Human Ancestor
- Hominid Species at TalkOrigins ArchiveTalkOrigins ArchiveThe TalkOrigins Archive is a website that presents mainstream science perspectives on the antievolution claims of young-earth, old-earth, and "intelligent design" creationists...
- For more details on Hominid species, including excellent photos of fossil hominids
- New Scientist 19 May 2003 – Chimps are human, gene study implies
- Scientific American Magazine (April 2006 Issue) Why Are Some Animals So Smart?
- A new mediterranean hominoid-hominid link discovered, Anoiapithecus brevirostris, "Lluc": A unique Middle Miocene European hominoid and the origins of the great ape and human clade Link to graphical reconstruction