Primate

? Primates
Scientific classification
Kingdom: Animalia Phylum: Chordata Class: Mammalia Subclass: Eutheria (unranked) Euarchontoglires Superorder: Euarchonta Order: Primates Linnaeus, 1758
Families
15, See classification

A primate (L. prima, first) is any member of the biological order Primates, the group that contains all lemurs, monkeys, apes, and humans. The English singular primate is a back-formation from the Latin name Primates, which itself was the plural of the Latin primas ("one of the first, excellent, noble"). Colin Groves lists about 350 species of primates in Primate Taxonomy.

All primates have five fingers ( pentadactyly), a generalized dental pattern, and a primitive (unspecialized) body plan. Another distinguishing feature of primates is fingernails. Opposing thumbs are also a characteristic primate feature, but are not limited to this order; opossums, for example, also have opposing thumbs. In primates, the combination of opposing thumbs, short fingernails (rather than claws) and long, inward-closing fingers is a relic of the ancestral practice of brachiating through trees. Forward-facing colour binocular vision was also useful for the brachiating ancestors of humans, particularly for finding and collecting food. All primates, even those that lack the features typical of other primates (like lorises), share eye orbit characteristics, such as a postorbital bar, that distinguish them from other taxonomic orders.

Relative sizes

As the table below illustrates, in many primate species, the males are larger than the females. However this picture is incomplete. All but one of these are Old World species, and in this group the mating system is usually polygynous; sexual dimorphism is expected with this kind of social structure. As the table shows, sexual dimorphism is much less in the marmosets ( New World) than in the other species listed, and this is characteristic of marmosets and tamarins in comparison with the Old World monkeys and apes. This is because marmosets and tamarins generally form pair bonds.

Species	Female	Male
Gorilla	105 kg (231 lb)	205 kg (452 lb)
Human	62.5 kg (137.5 lb)	78.4 kg (172 lb)
Patas Monkey	5.5 kg (12 lb)	10 kg (22 lb)
Proboscis Monkey	9 kg (20 lb)	19 kg (42 lb)
Pygmy Marmoset	120 g (4.2 oz)	140 g (5 oz)

Classification and evolution

Close relations

The Primate order lies in a tight clustering of related orders (the Euarchontoglires) within the Eutheria, a subclass of Mammalia. Recent molecular genetic research on primates, flying lemurs, and treeshrews has shown that the two species of flying lemur ( Dermoptera) are more closely related to the primates than the tree shrews of the order Scandentia, even though the tree shrews were at one time considered primates. These three orders make up the Euarchonta clade. This clade combines with the Glires clade (made up of the Rodentia and Lagomorpha) to form the Euarchontoglires clade. Variously, both Euarchonta and Euarchontoglires are ranked as superorders. Also, some scientists consider Dermoptera a suborder of Primates and call the "true" primates the suborder Euprimates.

 Euarchontoglires
    
|-- Glires
    |    |--rodents 
( Rodentia)
    |    |--rabbits, hares, pikas 
( Lagomorpha)
    
\-- Euarchonta
         |--tree shrews 
( Scandentia)
         \--N.N.
              |--flying lemurs 
( Dermoptera)
              \--N.N.
                   
|-- Plesiadapiformes (extinct)
                   \--primates 



(Primates)

Classification

In older classifications, the Primates were divided into two superfamilies: Prosimii and Anthropoidea. The Prosimii included all of the prosimians: all of Strepsirrhini plus the tarsiers. The Anthropoidea contained all of the simians.

In modern, cladistic reckonings, the Primate order is also a true clade. The suborder Strepsirrhini, the " wet-nosed" primates, split off from the primitive primate line about 63 million years ago. The seven strepsirhine families are the four related lemur families and the three remaining families that include the lorises, the Aye-aye, the galagos, and the pottos. Some classification schemes wrap the Lepilemuridae into the Lemuridae and the Galagidae into the Lorisidae, yielding a three-two family split instead of the four-three split as presented here. Other lineages of lower primates inhabited Earth. During the Eocene, most of the northern continents were dominated by two dominant groups, the adapids and the omomyids. The former is considered a member of Strepsirrhini, but it does not have a tooth comb like modern lemurs. The latter was related closely to tarsiers, monkeys, and apes. Adapids survived until 10 mya; omomyids on the other hand perished 20 million years earlier.

The Aye-aye is difficult to place in Strepsirrhini. Its family, Daubentoniidae, could be a lemuriform primate and its ancestors split from lemur line more recently than the lemurs and lorises split, about 50 mya. Otherwise it is sister to all of the other strepsirrhines, in which case in evolved away from the main strepsirrhine line between 50 and 63 mya.

The suborder Haplorrhini, the "dry-nosed" primates, is composed of two sister clades. The prosimian tarsiers in family Tarsiidae (monotypic in its own infraorder Tarsiiformes), represent the most primitive division at about 58 mya. The Simiiformes contain the two unranked clades the New World monkeys in one, and the Old World monkeys, humans and the other apes in the other. This division happened about 40 mya. However about 30 mya, three groups split from the main haplorrhine lineage. One group stayed in Asia and are closest in kin to the "dawn monkey" Eosimias. The second stayed in Africa, where they developed into the Old World monkeys. The third rafted to South America to become the New World monkeys. Mysteriously the aboriginal Asian Haplorrhini vanished from record once Africa collided with Eurasia 24 mya. Apes and monkeys spread into Europe and Asia. Close behind came lorises and tarsiers, also African castaways. The first hominid fossils were discovered in Northern Africa and date back 7 mya. Modern humans did not appear until 0.2 mya, eventually becoming the most prevalent primate and mammal on Earth.

Extant primate families

• ORDER PRIMATES
  • Suborder Strepsirrhini: non-tarsier prosimians
    • Infraorder Lemuriformes
      • Superfamily Cheirogaleoidea
        • Family Cheirogaleidae: dwarf lemurs and mouse-lemurs
      • Superfamily Lemuroidea
        • Family Lemuridae: lemurs
        • Family Lepilemuridae: sportive lemurs
        • Family Indridae: woolly lemurs and allies
    • Infraorder Chiromyiformes
      • Family Daubentoniidae: Aye-aye
    • Infraorder Lorisiformes
      • Family Lorisidae: lorises, pottos and allies
      • Family Galagidae: galagos
  • Suborder Haplorrhini: tarsiers, monkeys and apes
    • Infraorder Tarsiiformes
      • Family Tarsiidae: tarsiers
    • Infraorder Simiiformes
      • Platyrrhini: New World monkeys
        • Family Cebidae: marmosets, tamarins, capuchins and squirrel monkeys
        • Family Aotidae: night monkeys, owl monkeys, douroucoulis
        • Family Pitheciidae: titis, sakis and uakaris
        • Family Atelidae: howler, spider and woolly monkeys
      • Catarrhini
        • Superfamily Cercopithecoidea
          • Family Cercopithecidae: Old World monkeys
        • Superfamily Hominoidea
          • Family Hylobatidae: gibbons or "lesser apes"
          • Family Hominidae: humans and other great apes

Some prehistoric primates

• Adapis, an adapid
• Australopithecus, a human-like animal
• Branisella boliviana, an early New World monkey
• Dryopithecus, an early ape
• Eosimias, an early catarrhine
• Sahelanthropus tchadensis, a possible ancestor of humans
• Aegyptopithecus zeuxis, an early haplorrhine
• Pliopithecus, ancestor of the modern gibbons
• Gigantopithecus, the largest ape
• Godinotia, an adapid
• Megaladapis, a giant lemur
• Notharctus, an adapid
• Plesiopithecus teras, a relative of lorises and galagos
• Protopithecus brasiliensis, a giant New World monkey
• Sivapithecus, an early ape
• Tielhardina, the earliest haplorrhines
• Victoriapithecus, an early Old World monkey
• Pierolapithecus catalaunicus, a possible ancestor of large apes

Primate hybrids

In "The Variation Of Animals And Plants Under Domestication" Charles Darwin noted: "Several members of the family of Lemurs have produced hybrids in the Zoological Gardens."

Many gibbons are hard to identify based on fur coloration and are identified either by song or genetics. These morphological ambiguities have led to hybrids in zoos. Zoo gibbons usually come from the black market pet trade in Southeast Asia, which transported gibbons across countries all over the region. As a result, perhaps as much as 95% of zoo gibbons are of unknown geographic origin. As most zoos rely on morphological variation or labels that are impossible to verify to assign species and subspecies names, it is unfortunately common for gibbons to be misidentified and housed together. For example, some collections' supposedly pure breeding pairs were actually mixed pairs or hybrids from previous mixed pairs. The hybrid offspring were sent to other gibbon breeders and led to further hybridization in captive gibbons. Within-genus hybrids also occur in wild gibbons where the ranges overlap ( Agile Gibbons and Pileated Gibbons x Lar Gibbons, Agile Gibbons x Müller's Bornean Gibbon, Yellow-cheeked Gibbons x Northern White-cheeked Gibbons).

Intergeneric gibbon hybridizations have only occurred in captivity. Silvery Gibbons (Hylobates moloch) and Müller's Bornean Gibbon (H. muelleri) have hybridized with Siamangs (Symphalangus syndactylus) in captivity - a female Siamang produced hybrid "Siabon" offspring on 2 occasions when housed with a male gibbon; only one hybrid survived.

Anubis Baboons and Hamadryas Baboons have hybridized in the wild where their ranges meet. A Rheboon is a captive-bred Rhesus Macaque/Hamadryas Baboon hybrid with a baboon-like body shape and macaque-like tail.

Different macaque species can interbreed. In "The Variation Of Animals And Plants Under Domestication" Charles Darwin wrote: A Macacus, according to Flourens, bred in Paris; and more than one species of this genus has produced young in London, especially the Macacus rhesus, which everywhere shows a special capacity to breed under confinement. Hybrids have been produced both in Paris and London from this same genus. The Japanese Macaque (Macaca fuscata) has interbred with the introduced Taiwanese Macacque (M. cyclopis) when the latter escaped into the wild from private zoos.

Various hybrid monkeys are bred within the pet trade, for example:

• Hybrid capuchin monkeys e.g. Tufted Capuchin (Cebus apella) x Weeper Capuchin (C. olivaceus)
• Liontail Macaque x Pigtail Macaque hybrids
• Rhesus Macaque x Stumptail Macaque hybrids.

Among Old World monkeys, natural hybridization is not uncommon. There numerous field reports of hybrid monkeys and detailed studies of zones where species overlap and hybrids occur.

Among the great apes, Sumatran and Bornean orangutans are considered separate species with anatomical differences, producing sterile or poorly fertile hybrids. Hybrid orangutans are genetically weaker, with lower survival rates than pure animals.

Legal status

Human primates are recognized as persons and protected in law by the United Nations Universal Declaration of Human Rights [1] and by all governments, though to varying degrees. Non-human primates are not classified as persons, which means their individual interests have no formal recognition or protection. The status of other apes particularly—as our closest genetic cousins—has generated much debate, particularly through the Great Ape Project [2] which argues for their personhood.

Thousands of primates are used every year around the world in scientific experiments because of their psychological and physiological similarity to humans. The species most commonly used are chimpanzees, baboons, marmosets, macaques, and African green monkeys. In the European Union, around 10,000 were used in 2004, with 4,799 experiments conducted on 3,073 non-human primates in the UK alone in 2003. [3]. As of 2004, 3,100 non-human great apes were living in captivity in the United States, in zoos, circuses, and laboratories, 1,280 of them being used in experiments. [4]