Ape

From Wikipedia, the free encyclopedia

Hominoids or Apes
Bornean orangutan (Pongo pygmaeus)
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Order:	Primates
Suborder:	Haplorrhini
Infraorder:	Simiiformes
Parvorder:	Catarrhini
Superfamily:	Hominoidea Gray, 1825
Type species
Homo sapiens Linnaeus, 1758
Families
†Proconsulidae †Afropithecidae Hylobatidae Hominidae

Apes (Hominoidea) are a branch of Old World tailless anthropoid catarrhine primates native to Africa and Southeast Asia and distinguished by a wide degree of freedom at the shoulder joint indicating the influence of brachiation. There are two main branches: the gibbons, or lesser apes; and the hominids or great apes.

• Lesser apes (Hylobatidae) include four genera and sixteen species of gibbon, including the lar gibbon, and the siamang, all native to Asia. They are highly arboreal and bipedal on the ground. They have lighter bodies and smaller social groups than great apes.

• The Hominidae include orangutans, gorillas, chimpanzees, bonobos and humans.^[1][2] Alternatively, the family are collectively described as the great apes.^[3][4][5][6] There are two extant species in the orangutan genus (Pongo), two species in the gorilla genus, and a single extant species Homo sapiens in the human genus (Homo). Chimpanzees and bonobos are closely related to each other and they represent the two species in the genus Pan.

Members of the superfamily are called hominoids (not to be confused with the family of "hominids" – great apes, the subfamily of hominines, the tribe of "hominins" aka the human clade, or the subtribe of hominans).

Some or all hominoids are also called "apes". However, the term "ape" is used in several different senses. It has been used as a synonym for "monkey" or for any tailless primate with a humanlike appearance.^[7] Thus the Barbary macaque, a kind of monkey, is popularly called the "Barbary ape" to indicate its lack of a tail. Biologists have used the term "ape" to mean a member of the superfamily Hominoidea other than humans,^[3] or more recently to mean all members of the superfamily Hominoidea, so that "ape" becomes another word for "hominoid".^[6][8] See also Primate: Historical and modern terminology.

Except for gorillas and humans, hominoids are agile climbers of trees. Their diet is best described as frugivorous and folivorous, consisting mainly of fruit, nuts, seeds, including grass seeds, and in some cases other animals,^[9][10] either hunted or scavenged (or farmed solely in the case of humans), along with anything else available and easily digested.

Most non-human hominoids are rare or endangered. The chief threat to most of the endangered species is loss of tropical rainforest habitat, though some populations are further imperiled by hunting for bushmeat.

Historical and modern terminology

"Ape", from Old English apa, with cognates in several other Germanic languages, is a word of uncertain origin.^[11] It is possibly an onomatopoetic imitation of animal chatter.^{[citation needed]} The term has a history of rather imprecise usage. Its earliest meaning was that of any non-human primate, later often specialized to mean a tailless (and therefore exceptionally human-like) primate.^[7][12] The original usage of "ape" in English might have referred to the baboon, an Old World monkey.^{[citation needed]} Two tailless species of macaque have common names including "ape": the Barbary ape of North Africa (introduced into Gibraltar), Macaca sylvanus, and the Sulawesi black ape or Celebes crested macaque, M. nigra.

As zoological knowledge developed, it became clear that taillessness occurred in a number of different and otherwise distantly related species. The term "ape" was then used in two different senses, as shown in the 1910 Encyclopædia Britannica entry. Either "ape" was still used for a tailless humanlike primate or it became a synonym for "monkey".^[7]

Sir Wilfrid Le Gros Clark was one of the primatologists who developed the idea that there were "trends" in primate evolution and that the living members of the order could be arranged in a series, leading through "monkeys" and "apes" to humans. Within this tradition, "ape" refers to all the members of the superfamily Hominoidea, except humans.^[3] Thus "apes" are a paraphyletic group, meaning that although all the species of apes descend from a common ancestor, the group does not include all the descendants of that ancestor, because humans are excluded.^[13]

Greater and lesser

The diagram below shows the commonly accepted evolutionary relationships of the Hominoidea,^[2] with the group traditionally called "apes" marked by a bracket.

Hominoidea  Hominidae  Homininae  Hominini  humans (genus Homo)  chimpanzees (genus Pan)   gorillas (genus Gorilla)   orangutans (genus Pongo)   gibbons (family Hylobatidae)

apes

The "apes" are traditionally divided further into the "lesser apes" and the "great apes":^[14]

Hominoidea  Hominidae  Homininae  Hominini  humans (genus Homo)  chimpanzees (genus Pan)   gorillas (genus Gorilla)   orangutans (genus Pongo)   gibbons (family Hylobatidae)

great apes lesser apes

In summary, there are three common uses of the term "ape": English-speaking non-biologists may not distinguish between "monkeys" and "apes", or may use "ape" for any tailless monkey or non-human hominoid, whereas English-speaking biologists commonly use the term "ape" for all non-human hominoids as shown above.

In recent years biologists have generally preferred to use only monophyletic groups in classifications;^[15] that is, only groups which include all the descendants of a common ancestor.^[16] The superfamily Hominoidea is one such group (or "clade"). Some then use the term "ape" to mean all the members of the superfamily Hominoidea. For example, in a 2005 book, Benton wrote "The apes, Hominoidea, today include the gibbons and orang-utan ... the gorilla and chimpanzee ... and humans".^[6] The group traditionally called "apes" by biologists is then called the "non-human apes".
See the section History of hominoid taxonomy below for a discussion of changes in scientific classification and terminology.

Biology

The shoulder joints of hominoids, like the orangutan, are adapted to brachiation, or movement by swinging in tree branches.

The "lesser apes" are the gibbon family, Hylobatidae, with sixteen medium-sized species. Their major differentiating characteristic is their long arms, which they use to brachiate through the trees. As an evolutionary adaptation to this arboreal lifestyle, their wrists are ball and socket joints. The largest of the gibbons, the siamang, weighs up to 14 kg (31 lb). In comparison, the smallest "great ape" is the bonobo at 34 to 60 kg (75 to 132 lb).

The "great apes" were formerly treated as the family Pongidae. As noted above, this definition makes the Pongidae paraphyletic. Current evidence indicates that humans share a common extinct ancestor with the chimpanzee line, from which they separated more recently than the gorilla line.

The superfamily Hominoidea falls within Catarrhini, which also includes the Old World monkeys of Africa and Eurasia. Within this group, both families (Hylobatidae and Hominidae) can be distinguished from Old World monkeys by the number of cusps on their molars (hominoids have five—the "Y-5" molar pattern, Old World monkeys have only four in a bilophodont pattern). Hominoids have more mobile shoulder joints and arms due to the dorsal position of the scapula, broad ribcages that are flatter front-to-back, and a shorter, less mobile spine compared to Old World monkeys, with caudal (tail) vertebrae greatly reduced, resulting in complete tail loss in living species. These are all anatomical adaptations to vertical hanging and swinging locomotion (brachiation), as well as better balance in a bipedal pose. However, there are also primates in other families that lack tails, and at least one (the pig-tailed langur) that has been known to walk significant distances bipedally. The front skull is characterised by its sinuses, fusion of the frontal bone and post-orbital constriction.

Although the hominoid fossil record is far from complete, and the evidence is often fragmentary, there is enough to give a good outline of the evolutionary history of humans. The time of the split between humans and other living hominoids used to be thought to have occurred 15 to 20 million years ago. Some species occurring within that time period, such as Ramapithecus, used to be considered as hominins, and possible ancestors of humans. Later fossil finds indicated that Ramapithecus was more closely related to the orangutan, and new biochemical evidence indicated that the last common ancestor of humans and other hominins occurred between 5 and 10 million years ago, and probably in the lower end of that range.

Behaviour and cognition

A series of images showing a gorilla utilizing a small tree trunk as a tool to maintain balance as she fished for aquatic herbs

Although there had been earlier studies, the scientific investigation of behaviour and cognition in non-human members of the superfamily Hominoidea expanded enormously during the latter half of the twentieth century. Major studies of behaviour in the field were completed on the three better-known "great apes", for example by Jane Goodall, Dian Fossey and Birute Galdikas. These studies have shown that in their natural environments, the non-human hominoids show sharply varying social structure: gibbons are monogamous, territorial pair-bonders, orangutans are solitary, gorillas live in small troops with a single adult male leader, while chimpanzees live in larger troops with bonobos exhibiting promiscuous sexual behaviour. Their diets also vary; gorillas are foliovores while the others are all primarily frugivores, although the common chimpanzee does some hunting for meat. Foraging behaviour is correspondingly variable.

All the non-human hominoids are generally thought of as highly intelligent, and scientific study has broadly confirmed that they perform outstandingly well on a wide range of cognitive tests – though there is relatively little data on gibbon cognition. The early studies by Wolfgang Köhler demonstrated exceptional problem-solving abilities in chimpanzees, which Köhler attributed to insight. The use of tools has been repeatedly demonstrated; more recently, the manufacture of tools has been documented, both in the wild and in laboratory tests. Imitation is much more easily demonstrated in "great apes" than in other primate species. Almost all the studies in animal language acquisition have been done with "great apes", and though there is continuing dispute as to whether they demonstrate real language abilities, there is no doubt that they involve significant feats of learning. Chimpanzees in different parts of Africa have developed tools that are used in food acquisition, demonstrating a form of animal culture.^[17]

Distinction from monkeys

Apes do not possess a tail, unlike most monkeys. Monkeys are more likely to be in trees and use their tails for balance. Apes are considerably larger than monkeys, with the exception of gibbons, which are smaller than some monkeys. Apes are considered to be more intelligent than monkeys, which are considered to have more primitive brains.^[18] Unlike female monkeys which go through the estrous cycle, great apes, including humans, go through a menstrual cycle.

History of hominoid taxonomy

The history of hominoid taxonomy is somewhat confusing and complex. The names of subgroups have changed their meaning over time as new evidence, from fossil discoveries and comparisons of anatomy and DNA sequences, has changed understanding of the relationships between hominoids.
There has been a gradual demotion of humans from a special position in the taxonomy to being one branch among many. This history illustrates the growing influence of cladistics (the science of classifying living things by strict descent) on taxonomy.

As of 2006, there are eight extant genera of hominoids. They are the four genera in the family Hominidae (Homo – humans, Pan – chimpanzees and bonobos, Gorilla, and Pongo – orangutans), and the four genera in the family Hylobatidae or gibbons (Hylobates, Hoolock, Nomascus and Symphalangus).^[1] (The genus for the hoolock gibbons was recently changed from Bunopithecus to Hoolock.^[19])

In 1758, Carolus Linnaeus, relying on second- or third-hand accounts, placed a second species in Homo along with H. sapiens: Homo troglodytes ("cave-dwelling man"). It is not clear to which animal this name refers, as Linnaeus had no specimen to refer to, hence no precise description. Linnaeus named the orangutan Simia satyrus ("satyr monkey"). He placed the three genera Homo, Simia and Lemur in the order of Primates.

The troglodytes name was used for the chimpanzee by Blumenbach in 1775 but moved to the genus Simia. The orangutan was moved to the genus Pongo in 1799 by Lacépède.

Linnaeus's inclusion of humans in the primates with monkeys and apes was troubling for people who denied a close relationship between humans and the rest of the animal kingdom. Linnaeus's Lutheran archbishop had accused him of "impiety." In a letter to Johann Georg Gmelin dated 25 February 1747, Linnaeus wrote:

It is not pleasing to me that I must place humans among the primates, but man is intimately familiar with himself. Let's not quibble over words. It will be the same to me whatever name is applied. But I desperately seek from you and from the whole world a general difference between men and simians from the principles of Natural History. I certainly know of none. If only someone might tell me one! If I called man a simian or vice versa I would bring together all the theologians against me. Perhaps I ought to, in accordance with the law of Natural History.^[20]

Accordingly, Johann Friedrich Blumenbach in the first edition of his Manual of Natural History (1779), proposed that the primates be divided into the Quadrumana (four-handed, i.e. apes and monkeys) and Bimana (two-handed, i.e. humans). This distinction was taken up by other naturalists, most notably Georges Cuvier. Some elevated the distinction to the level of order.

However, the many affinities between humans and other primates — and especially the "great apes" — made it clear that the distinction made no scientific sense. Charles Darwin wrote, in The Descent of Man:

The greater number of naturalists who have taken into consideration the whole structure of man, including his mental faculties, have followed Blumenbach and Cuvier, and have placed man in a separate Order, under the title of the Bimana, and therefore on an equality with the orders of the Quadrumana, Carnivora, etc. Recently many of our best naturalists have recurred to the view first propounded by Linnaeus, so remarkable for his sagacity, and have placed man in the same Order with the Quadrumana, under the title of the Primates. The justice of this conclusion will be admitted: for in the first place, we must bear in mind the comparative insignificance for classification of the great development of the brain in man, and that the strongly marked differences between the skulls of man and the Quadrumana (lately insisted upon by Bischoff, Aeby, and others) apparently follow from their differently developed brains. In the second place, we must remember that nearly all the other and more important differences between man and the Quadrumana are manifestly adaptive in their nature, and relate chiefly to the erect position of man; such as the structure of his hand, foot, and pelvis, the curvature of his spine, and the position of his head.^[21]

Changes in taxonomy

Until about 1960, the hominoids were usually divided into two families: humans and their extinct relatives in Hominidae, all other hominoids in Pongidae.[22]
The 1960s saw the application of techniques from molecular biology to primate taxonomy. Goodman used his 1964 immunological study of serum proteins to propose a division of the hominoids into three families, with the "great apes" in Pongidae and the "lesser apes" (gibbons) in Hylobatidae.[23] The trichotomy of hominoid families, however, prompted scientists to ask which family speciated first from the common hominoid ancestor.
Within the superfamily Hominoidea, gibbons are the outgroup: this means that the rest of the hominoids are more closely related to each other than any of them are to gibbons. This led to the placing of the "great apes" into the family Hominidae along with humans, by demoting the Pongidae to a subfamily; the Hominidae family now contained the subfamilies Homininae and Ponginae. Again, the three-way split in Ponginae led scientists to ask which of the three genera is least related to the others.
Investigation showed orangutans to be the outgroup, but comparing humans to all three other hominid genera showed that African "apes" (chimpanzees and gorillas) and humans are more closely related to each other than any of them are to orangutans. This led to the placing of the African hominoids in the subfamily Homininae, forming another three-way split. This classification was first proposed by M. Goodman in 1974.[24]
To try to resolve the hominine trichotomy, some authors proposed the division of the subfamily Homininae into the tribes Gorillini (African "apes") and Hominini (humans).
However, DNA comparisons provide evidence that within the subfamily Homininae, gorillas are the outgroup. This suggests that chimpanzees should be in Hominini along with humans. This classification was first proposed (though one rank lower) by M. Goodman et al. in 1990.[2] See Human evolutionary genetics for more information on the speciation of humans and "great apes".
Later DNA comparisons split the gibbon genus Hylobates into four genera: Hylobates, Hoolock, Nomascus, and Symphalangus.[1][19]

Classification and evolution[edit]

As discussed above, hominoid taxonomy has undergone several changes. Genetic analysis combined with fossil evidence indicates that hominoids diverged from the Old World monkeys about 25 million years ago, near the Oligocene-Miocene boundary.^[25] The gibbons split from the rest about 18 mya, and the hominid splits happened 14 mya (Pongo), 7 mya (Gorilla), and 3-5 mya (Homo & Pan).^{[citation needed]}

The families, and extant genera and species of hominoids are:

Skeletons of members of the ape family

• Superfamily Hominoidea^[1]
  • Family Hylobatidae: gibbons ("lesser apes")
    • Genus Hylobates
      • Lar gibbon or white-handed gibbon, H. lar
      • Bornean white-bearded gibbon, H. albibarbis
      • Agile gibbon or black-handed gibbon, H. agilis
      • Müller's Bornean gibbon or grey gibbon, H. muelleri
      • Silvery gibbon, H. moloch
      • Pileated gibbon or capped gibbon, H. pileatus
      • Kloss's gibbon or Mentawai gibbon or bilou, H. klossii
    • Genus Hoolock
      • Western hoolock gibbon, H. hoolock
      • Eastern hoolock gibbon, H. leuconedys
    • Genus Symphalangus
      • Siamang, S. syndactylus
    • Genus Nomascus
      • Black crested gibbon, N. concolor
      • Eastern black crested gibbon, N. nasutus
      • Hainan black crested gibbon, N. hainanus
      • Southern white-cheeked gibbon N. siki
      • White-cheeked crested gibbon, N. leucogenys
      • Yellow-cheeked gibbon, N. gabriellae
  • Family Hominidae: hominids ("great apes")
    • Genus Pongo: orangutans
      • Bornean orangutan, P. pygmaeus
      • Sumatran orangutan, P. abelii
    • Genus Gorilla: gorillas
      • Western gorilla, G. gorilla
      • Eastern gorilla, G. beringei
    • Genus Homo: humans
      • Human, H. sapiens
    • Genus Pan: chimpanzees
      • Common chimpanzee, P. troglodytes
      • Bonobo, P. paniscus

Evolution of primates

From Wikipedia, the free encyclopedia

Phylogenetic tree of the primates

Evolutionary history of the primates can be traced back 65 million years. The oldest known primate-like mammal species,^[1] the Plesiadapis, came from North America, but they were widespread in Eurasia and Africa during the tropical conditions of the Paleocene and Eocene.
Purgatorius is the genus of the four extinct species believed to be the earliest example of a primate or a proto-primate, a primatomorph precursor to the Plesiadapiformes, dating to as old as 66 million years ago.

Notharctus

David Begun^[2] concluded that early primates flourished in Eurasia and that a lineage leading to the African apes and humans, including Dryopithecus, migrated south from Europe or Western Asia into Africa. The surviving tropical population of primates, which is seen most completely in the upper Eocene and lowermost Oligocene fossil beds of the Faiyum depression southwest of Cairo, gave rise to all living species—lemurs of Madagascar, lorises of Southeast Asia, galagos or "bush babies" of Africa, and the anthropoids: platyrrhine or New World monkeys, catarrhines or Old World monkeys, and the great apes, which gave rise to the ancestors of Homo sapiens.

The earliest known catarrhine is Kamoyapithecus from uppermost Oligocene at Eragaleit in the northern Kenya Rift Valley, dated to 24 million years ago.^[3] Its ancestry is thought to be species related to Aegyptopithecus, Propliopithecus, and Parapithecus from the Fayum, at around 35 million years ago.^[4] In 2010, Saadanius was described as a close relative of the last common ancestor of the crown catarrhines, and tentatively dated to 29–28 million years ago, helping to fill an 11-million-year gap in the fossil record.^[5]

Reconstructed tailless Proconsul skeleton

In the early Miocene, about 22 million years ago, the many kinds of arboreally adapted primitive catarrhines from East Africa suggest a long history of prior diversification. Fossils at 20 million years ago include fragments attributed to Victoriapithecus, the earliest Old World Monkey. Among the genera thought to be in the ape lineage leading up to 13 million years ago are Proconsul, Rangwapithecus, Dendropithecus, Limnopithecus, Nacholapithecus, Equatorius, Nyanzapithecus, Afropithecus, Heliopithecus, and Kenyapithecus, all from East Africa.

The presence of other generalized non-cercopithecids of middle Miocene age from sites far distant—Otavipithecus from cave deposits in Namibia, and Pierolapithecus and Dryopithecus from France, Spain and Austria—is evidence of a wide diversity of forms across Africa and the Mediterranean basin during the relatively warm and equable climatic regimes of the early and middle Miocene. The youngest of the Miocene hominoids, Oreopithecus, is from coal beds in Italy that have been dated to 9 million years ago.

Molecular evidence indicates that the lineage of gibbons (family Hylobatidae) diverged from Great Apes some 18-12 million years ago, and that of orangutans (subfamily Ponginae) diverged from the other Great Apes at about 12 million years; there are no fossils that clearly document the ancestry of gibbons, which may have originated in a so-far-unknown South East Asian hominoid population, but fossil proto-orangutans may be represented by Sivapithecus from India and Griphopithecus from Turkey, dated to around 10 million years ago.^[6]

Evolution of lemurs

Lemurs, in the suborder Strepsirrhini, had been isolated on the island of Madagascar between 42 and 50 mya, allowing for their independent evolution. 

Evolution of the pelvis

In primates, the pelvis consists of four parts - the left and the right hip bones which meet in the mid-line ventrally and are fixed to the sacrum dorsally and the coccyx. Each hip bone consists of three components, the ilium, the ischium, and the pubis, and at the time of sexual maturity these bones become fused together, though there is never any movement between them. In humans, the ventral joint of the pubic bones is closed.

The most striking feature of evolution of the pelvis in primates is the widening and the shortening of the blade called the ilium. Because of the stresses involved in bipedal locomotion, the muscles of the thigh move the thigh forward and backward, providing the power for bi-pedal and quadrupedal locomotion.^[7]

Monkey

From Wikipedia, the free encyclopedia

Monkey
Macaque monkey Bonnet macaque
Scientific classification
Kingdom: Animalia Phylum: Chordata Class: Mammalia Order: Primates Suborder: Haplorhini Infraorder: Simiiformes[a] Haeckel, 1866
Included groups
Callitrichidae Cebidae Aotidae Pitheciidae Atelidae Cercopithecidae
Excluded groups
Hylobatidae Hominidae

Monkeys are haplorhine ("dry-nosed") primates, a group generally possessing tails and consisting of approximately 260 known living species. Many monkey species are tree-dwelling (arboreal), although there are species that live primarily on the ground, such as baboons. Most species are also active during the day (diurnal). Monkeys are generally considered to be intelligent, particularly Old World monkeys.

Lemurs, lorises, and galagos are not monkeys; instead they are strepsirrhine ("wet-nosed") primates. Like monkeys, tarsiers are haplorhine primates; however, they are also not monkeys. There are two major types of monkey: New World monkeys (platyrrhines) from South and Central America and Old World monkeys (catarrhines of the superfamily Cercopithecoidea) from Africa and Asia. Hominoid apes (gibbons, orangutans, gorillas, chimpanzees, and humans), which all lack tails, are also catarrhines but are not considered monkeys.^[3] (Tailless monkeys may be called "apes", incorrectly according to modern usage; thus the tailless Barbary macaque is sometimes called the "Barbary ape".) Because Old World monkeys are more closely related to hominoid apes than to New World monkeys, yet the term "monkey" excludes these closer relatives, monkeys are referred to as a paraphyletic group.

Historical and modern terminology

Monkeys often groom socially.

According to the Online Etymology Dictionary, the word "monkey" may originate in a German version of the Reynard the Fox fable, published circa 1580. In this version of the fable, a character named Moneke is the son of Martin the Ape.^[4] In English, no very clear distinction was originally made between "ape" and "monkey"; thus the 1910 Encyclopædia Britannica entry for "ape" notes that it is either a synonym for "monkey" or is used to mean a tailless humanlike primate.^[5] Such ambiguities persist. Colloquially, the terms "monkeys" and "apes" may still be used interchangeably.^[6] Also, a few monkey species have the word "ape" in their common name, such as the Barbary ape.

Later in the first half of the 20th century, the idea developed that there were trends in primate evolution and that the living members of the order could be arranged in a series, leading through "monkeys" and "apes" to humans.^[7] Monkeys thus constituted a "grade" on the path to humans and were distinguished from "apes".

Scientific classifications are now more often based on monophyletic groups, that is groups consisting of all the descendants of a common ancestor. The New World monkeys and the Old World monkeys are each monophyletic groups, but their combination is not, since it excludes hominoids (apes and humans). Thus the term "monkey" no longer refers to a recognized scientific taxon. The smallest accepted taxon which contains all the monkeys is the infraorder Simiiformes, or simians. However this also contains the hominoids (apes and humans), so that monkeys are, in terms of currently recognized taxa, non-hominoid simians. Colloquially and pop-culturally, the term is ambiguous and sometimes monkey includes non-human hominoids.^[8]

A group of monkeys may be commonly referred to as a tribe or a troop.^[9]

Physical description

Goeldi's marmoset (Callimico goeldii)

Monkeys range in size from the pygmy marmoset, which can be as small as 117 millimetres (4.6 in) with a 172-millimetre (6.8 in) tail and just over 100 grams (3.5 oz) in weight,^[10] to the male mandrill, almost 1 metre (3.3 ft) long and weighing up to 36 kilograms (79 lb).^[11] Some are arboreal (living in trees) while others live on the savanna; diets differ among the various species but may contain any of the following: fruit, leaves, seeds, nuts, flowers, eggs and small animals (including insects and spiders).^[12]

Some characteristics are shared among the groups; most New World monkeys have prehensile tails while Old World monkeys have non-prehensile tails or no visible tail at all. Old World monkeys have trichromatic color vision like that of humans, while New World monkeys may be trichromatic, dichromatic, or—as in the owl monkeys and greater galagos—monochromatic. Although both the New and Old World monkeys, like the apes, have forward-facing eyes, the faces of Old World and New World monkeys look very different, though again, each group shares some features such as the types of noses, cheeks and rumps.^[12]

Classification

Phylogeny of living (extant) primates

Primates   Haplorhini   Simiiformes   Catarrhini   Hominoidea  Cercopithecoidea   Platyrrhini   Tarsiiformes  Strepsirrhini monkeys

Monkeys (in green brackets) are a paraphyletic group, since they exclude hominoids.

Common squirrel monkey

Crab-eating macaque

The following list shows where the various monkey families (bolded) are placed in the classification of living (extant) primates.

• ORDER PRIMATES
  • Suborder Strepsirrhini: lemurs, lorises, and galagos
  • Suborder Haplorhini: tarsiers, monkeys, and apes
    • Infraorder Tarsiiformes
      • Family Tarsiidae: tarsiers
    • Infraorder Simiiformes: simians
      • Parvorder Platyrrhini: New World monkeys
        • Family Callitrichidae: marmosets and tamarins (42 species)
        • Family Cebidae: capuchins and squirrel monkeys (14 species)
        • Family Aotidae: night monkeys (11 species)
        • Family Pitheciidae: titis, sakis, and uakaris (41 species)
        • Family Atelidae: howler, spider, and woolly monkeys (24 species)
      • Parvorder Catarrhini
        • Superfamily Cercopithecoidea
          • Family Cercopithecidae: Old World monkeys (135 species)
        • Superfamily Hominoidea: apes
          • Family Hylobatidae: gibbons ("lesser apes") (17 species)
          • Family Hominidae: great apes including humans (7 species)

Relationship with humans

The many species of monkey have varied relationships with humans. Some are kept as pets, others used as model organisms in laboratories or in space missions. They may be killed in monkey drives (when they threaten agriculture) or used as service animals for the disabled.

In some areas, some species of monkey are considered agricultural pests, and can cause extensive damage to commercial and subsistence crops.^[13] This can have important implications for the conservation of endangered species, which may be subject to persecution. In some instances farmers' perceptions of the damage may exceed the actual damage.^[14] Monkeys that have become habituated to human presence in tourist locations may also be considered pests, attacking tourists.^[15]

In religion and culture, the monkey often represents quick-wittedness and mischief.

As service animals for the disabled

Some organizations train capuchin monkeys as service animals to assist quadriplegics and other people with severe spinal cord injuries or mobility impairments. After being socialized in a human home as infants, the monkeys undergo extensive training before being placed with a disabled person.
Around the house, the monkeys assist with feeding, fetching, manipulating objects, and personal care.^[16]

In experiments

The use of monkeys in laboratories is controversial.

The most common monkey species found in animal research are the grivet, the rhesus macaque, and the crab-eating macaque, which are either wild-caught or purpose-bred.^[17][18] They are used primarily because of their relative ease of handling, their fast reproductive cycle (compared to apes) and their psychological and physical similarity to humans. Worldwide, it is thought that between 100,000 and 200,000 non-human primates are used in research each year,^[18] 64.7% of which are Old World monkeys, and 5.5% New World monkeys.^[19] This number makes a very small fraction of all animals used in research.^[18] Between 1994 and 2004 the United States has used an average of 54,000 non-human primates, while around 10,000 non-human primates were used in the European Union in 2002.^[19]

Sam, a rhesus macaque, was flown to a height of 55 miles (89 km) by NASA in 1959

The use of monkeys in laboratories is controversial. Animal rights activists claim that their use is cruel and produces little information of value, and there have been many protests, vandalism to testing facilities and threats to workers.^{[citation needed]} Others claim that it has led to many important medical breakthroughs such as the rabies vaccine, understanding of human reproduction and basic knowledge about brain function and that the prevention of harm to humans should be a higher priority than the possible harm done to monkeys. The topic has become a popular cause for animal rights and animal welfare groups.^{[citation needed]}

In space

A number of countries have used monkeys as part of their space exploration programmes, including the United States and France. The first monkey in space was Albert II, who flew in the US-launched V-2 rocket on June 14, 1949.^[20]

As food

Monkey brains are eaten as a delicacy in parts of South Asia, Africa and China.^[21] In traditional Islamic dietary laws, the eating of monkeys is forbidden. However, monkeys are sometimes eaten in parts of Africa, where they can be sold as "bushmeat".^[22]

Literature

Illustration of Indian monkeys known as bandar (बंदर) from the illuminated manuscript Baburnama (Memoirs of Babur)

Sun Wukong (the "Monkey King"), a character who figures prominently in Chinese mythology, is the main protagonist in the classic comic Chinese novel Journey to the West.

Monkeys are prevalent in numerous books, television programs, and movies. The television series Monkey and the literary characters Monsieur Eek and Curious George are all examples.

Simian statue at a Buddhist shrine in Tokyo, Japan

Informally, the term "monkey" is often used more broadly than in scientific use, and may be used to refer to apes, particularly chimpanzees, gibbons, and gorillas. Author Terry Pratchett alludes to this difference in usage in his Discworld novels, in which the Librarian of the Unseen University is an orangutan who gets very violent if referred to as a monkey. Another example is the use of Simians in Chinese poetry.

The Winged monkeys are prominent characters in The Wizard of Oz.

Religion and worship

Hanuman, a prominent divine entity in Hinduism, is a Human-like monkey god. He bestows courage, strength and longevity to the person who thinks about him or the god Rama.

In Buddhism, the monkey is an early incarnation of Buddha but may also represent trickery and ugliness. The Chinese Buddhist "mind monkey" metaphor refers to the unsettled, restless state of human mind. Monkey is also one of the Three Senseless Creatures, symbolizing greed, with the tiger representing anger and the deer lovesickness.

The Mizaru, or three wise monkeys, are revered in Japanese folklore, together they embody the proverbial principle to "see no evil, hear no evil, speak no evil".^[23]

The Moche people of ancient Peru worshipped nature.^[24] They placed emphasis on animals and often depicted monkeys in their art.^[25]

The Tzeltal people of Mexico worshipped monkeys as incarnations of their dead ancestors.

Zodiac

The Monkey (猴) is the ninth in the twelve-year cycle of animals which appear in the Chinese zodiac related to the Chinese calendar. Next year will be the year of the monkey..^[26]