This is an old revision of this page, as edited by UtherSRG (talk | contribs) at 05:40, 21 June 2006 (Reverted edits by Eal (talk) to last version by AntiVandalBot). The present address (URL) is a permanent link to this revision, which may differ significantly from the current revision.
Revision as of 05:40, 21 June 2006 by UtherSRG (talk | contribs) (Reverted edits by Eal (talk) to last version by AntiVandalBot)(diff) ← Previous revision | Latest revision (diff) | Newer revision → (diff) This article is about the superfamily of primates. For the acronym, see APE.
| Apes | |
|---|---|
| |
| Lar Gibbon (Hylobates lar) | |
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Mammalia |
| Order: | Primates |
| Suborder: | Haplorrhini |
| Parvorder: | Catarrhini |
| Superfamily: | Hominoidea Gray, 1825 |
| Families | |
Apes are the members of the Hominoidea superfamily of primates, which includes humans. Under current classification, there are two families of hominoids:
- the family Hylobatidae consists of 4 genera and 12 species of gibbons, including the Lar Gibbon and the Siamang, collectively known as the "lesser apes"
- the family Hominidae consisting of gorillas, chimpanzees, orangutans, and humans, collectively known as the "great apes".
A few other primates have the word "ape" in their common names, but they are not regarded as true apes.
Except for gorillas and humans, all true apes are agile climbers of trees. They are best described as omnivorous, their diet consisting of fruit, grass seeds, and in most cases some quantities of meat and invertebrates—either hunted or scavenged—along with anything else available and easily digested. They are native to Africa and Asia, although humans have spread to all parts of the world.
Most non-human ape species 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" (Old Eng. apa; Dutch aap; Old Ger. affo; Welsh epa; Old Czech op) is a word of uncertain origin and is possibly an onomatopoetic imitation of animal chatter. The term has a history of rather imprecise usage. Its earliest meaning was a tailless (and therefore exceptionally human-like) non-human primate, but as zoological knowledge developed it became clear that taillessness occurred in a number of different and otherwise unrelated species.
The original usage of "ape" in English may have referred to the baboon, an African monkey. Two tailless species of macaque are commonly named as apes, the Barbary Ape of North Africa (introduced into Gibraltar), Macaca sylvanus, and the Sulawesi Black Ape or Celebes Crested Macaque, M. nigra.
Until a handful of decades ago, humans were thought to be distinctly set apart from the other apes (even from the other great apes), so much so that many people still don't think of the term "apes" to include humans at all. However, it is not considered accurate by many biologists to think of apes in a biological sense without considering humans to be included. The terms "non-human apes" or "non-human great apes" is used with increasing frequency to show the relationship of humans to the other apes while yet talking only about the non-human species.
A group of apes may be referred to as a troop of apes or a shrewdness of apes. Both of these collective nouns seems to be equally common.
Biology
The gibbon family, Hylobatidae, is composed of thirteen medium-sized species. Their major distinction are their long arms which they use to brachiate through the trees. As an evolutionary adaption to this arboreal lifestyle, their wrists are ball and socket joints. The largest of the gibbons, the Siamang, weighs up to 23 kg (50 lb). In comparison, the smallest great ape is the Common Chimpanzee at a modest 40 to 65 kg (88 to 143 lb).
The great ape family was previously referred to as Pongidae, and humans (and fossil hominids) were omitted from it, but on grounds of relatedness there is no argument for doing this. Chimpanzees, gorillas, humans and orangutans are all more closely related to one another than any of these four genera are to the gibbons. Awkwardly, however, the term "hominid" is still used with the specific meaning of extinct animals more closely related to humans than the other great apes (for example, australopithecines). It is now usual to use even finer divisions, such as subfamilies and tribes to distinguish which hominoids are being discussed. Current evidence implies that humans share a common, extinct, ancestor with the chimpanzee line, from which we separated more recently than the gorilla line.
Both great apes and lesser apes fall within Catarrhini, which also includes the Old World monkeys of Africa and Eurasia. Within this group, both families of apes can be distinguished from these monkeys by the number of cusps on their molars (apes have five—the "Y-5" molar pattern, Old World monkeys have only four in a "bilophodont" pattern). Apes have more mobile shoulder joints and arms, ribcages that are flatter front-to-back, and a shorter, less mobile spine compared to Old World monkeys. These are all anatomical adaptations to vertical hanging and swinging locomotion (brachiation) in the apes. All living members of the Hylobatidae and Hominidae are tailless, and humans can therefore accurately be referred to as bipedal apes. 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.
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 living apes used to be thought to have occurred 15 to 20 million years ago, or even up to 30 or 40 million years ago. Some apes 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.
Cultural aspects of non-human apes
The intelligence and humanoid appearance of non-human apes are responsible for legends which attribute human qualities; for example, they are sometimes said to be able to speak but refuse to do so in order to avoid work. They are also said to be the result of a curse—a Jewish folktale claims that one of the races who built the Tower of Babel became non-human apes as punishment, while Muslim lore says that the Jews of Elath became non-human apes as punishment for fishing on the Sabbath. Christian folklore claims that non-human apes are a symbol of lust and were created by Satan in response to God's creation of humans. It is uncertain whether any of these references is to any specific non-human apes, since all date from a period when the distinction between non-human apes and monkeys was not widely understood, or not understood at all.
Humans and the other apes share many similarities, including the ability to properly use tools and imitate others. Recent studies at Yale test some of these similarities. A professor and his/her students gave a challenge to baby humans and baby chimps. Both groups were shown a way that might solve the challenge. However what both the baby humans and chimps did not know was that the way that was shown was incorrect. Both times the baby humans tried they imitated what they were shown and failed at the attempt. For the chimps, the first time they tried, they followed the same path and failed. However on a second time around they succeeded in finding a new path and actually completed the objective. The professor interpreted that baby chimps learned from experience while baby humans just imitated what they were shown. This gave scientists key information in understanding the cultural aspects of ape life and evolutionary similarities between humans and apes.
There have also been recent breakthroughs in evidence of ape culture that go beyond what was explained above. This was further explored by scientists at the convention in St. Louis.
New Subspecies?
In 2002, a new giant ape troop was discovered in the Democratic Republic of Congo. These apes share many features of both chimpanzees and gorillas. According to a report from BBC News Online,, the apes have large black faces, are two meters (6 feet) tall and make nests on the ground, all like gorillas. However, they live hundreds of kilometers from any other gorilla troops, and their diet is high in fruits, similar to the chimpanzee diet. They were given the common name of Bili Ape.
Subsequent molecular investigation of hair and pelt samples showed them to be Common Chimpanzees who had individually adapted to local conditions. This would indicate that they may be a subspecies of the common chimp.
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, anatomy comparisons and DNA sequences, has changed understanding of the relationships between hominoids. The story of the hominoid taxonomy is one of gradual demotion of humans from a special position in the taxonomy to being one branch among many. It also 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 great ape genera (Homo (humans), Pan (chimpanzees), Gorilla, and Pongo (orangutans)), and the four genera of gibbons (Hylobates, Hoolock, Nomascus, and Symphalangus). (The genus for the hoolock gibbons was recently changed from Bunopithecus to Hoolock.)
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 family 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. Linneaus's Lutheran Archbishop had accused him of "impiety." In a letter to Johann Georg Gmelin dated February 25, 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.
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, ie. 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.
Until about 1960, the hominoids were usually divided into two families: humans and their extinct relatives in Hominidae, the other apes in Pongidae.
The 1960s saw the application of techniques from molecular biology to primate taxonomy. Goodman used his 1963 immunological study of serum proteins to propose a division of the hominoids into three families, with the non-human great apes in Pongidae and the lesser apes (gibbons) in Hylobatidae. 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 other 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 apes in the subfamily Homininae, forming another three-way split. This classification was first proposed by M. Goodman in 1974.
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 convincing 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.
Later DNA comparisons split the gibbon genus Hylobates into four genera: Hylobates, Hoolock, Nomascus, and Symphalangus.
Classification and evolution
As discussed above, hominoid taxonomy has undergone several changes. Current understanding is that the apes diverged from the Old World monkeys about 25 million years ago. The lesser and greater apes split about 18 mya, and the hominid splits happen 14 mya (Pongo), 7 mya (Gorilla), and 3-5 mya (Homo & Pan)
- Superfamily Hominoidea
- Family Hylobatidae: gibbons
- Genus Hylobates
- Genus Hoolock
- Genus Symphalangus
- Genus Nomascus
- Family Hominidae: great apes
- Family Hylobatidae: gibbons
Legal status
Human beings are the only ape recognized as persons and protected in law by the United Nations Universal Declaration of Human Rights and by all governments, though to varying degrees. Chimpanzees, Gorillas and Orangutans are not classified as persons, which means that where their interests intersect with that of humans they have no legal status.
Many argue that the other apes' cognitive capacity in itself, as well as their close genetic relationship to human beings, dictates an acknowledgement of personhood. The Great Ape Project, founded by Australian philosopher Peter Singer, is campaigning to have the United Nations endorse its Declaration on Great Apes, which would extend to all species of chimpanzees, gorillas, and orangutans the protection of three basic interests: the right to life, the protection of individual liberty, and the prohibition of torture.
See also
References
- ^ Groves, C. P. (2005). Wilson, D. E.; Reeder, D. M. (eds.). Mammal Species of the World: A Taxonomic and Geographic Reference (3rd ed.). Baltimore: Johns Hopkins University Press. pp. 178–184. ISBN 0-801-88221-4. OCLC 62265494.
- Corey Binns (2006-02-28). "Case Closed: Apes Got Culture". Livescience.com.
{{cite web}}: Check date values in:|year=(help)CS1 maint: year (link) - "'New' giant ape found in DR Congo". BBC News Online. 2004-10-10.
{{cite web}}: Check date values in:|year=(help)CS1 maint: year (link) - ^ Mootnick, A. (2005). "A new generic name for the hoolock gibbon (Hylobatidae)". International Journal of Primatology (26): 971–976.
{{cite journal}}: Unknown parameter|coauthors=ignored (|author=suggested) (help) - "Letter, Carl Linnaeus to Johann Georg Gmelin. Uppsala, Sweden, 25 February 1747". Swedish Linnaean Society.
- Charles Darwin (1871). The Descent of Man.
- G. G. Simpson (1945). "The principles of classification and a classification of mammals". Bull. Am. Mus. Nat. Hist. 85: 1–350.
- M. Goodman (1963). "Man's place in the phylogeny of the primates as reflected in serum proteins". In S. L. Washburn (ed.). Classification and human evolution. Aldine, Chicago. pp. 204–234.
- M. Goodman (1974). "Biochemical Evidence on Hominid Phylogeny". Annual Review of Anthropology. 3: 203–228.
- M. Goodman, D. A. Tagle, D. H. Fitch, W. Bailey, J. Czelusniak, B. F. Koop, P. Benson, J. L. Slightom (1990). "Primate evolution at the DNA level and a classification of hominoids". Journal of Molecular Evolution. 30: 260–266.
{{cite journal}}: CS1 maint: multiple names: authors list (link) - "Universal Declaration of Human Rights". United Nations. 1948-12-10.
{{cite web}}: Check date values in:|year=(help)CS1 maint: year (link)
External links
- Declaration on Great Apes at the Great Ape Project
This article incorporates text from a publication now in the public domain: Chisholm, Hugh, ed. (1911). Encyclopædia Britannica (11th ed.). Cambridge University Press. {{cite encyclopedia}}: Missing or empty|title=(help)
