Apes are a vaguely defined type of simian.  Originally "ape" was a synonym for "monkey" as both were generic terms for what are now considered non-human simians and both terms are colloquially still used interchangeably.   When the chimpanzee was discovered in the 17th century, it proved so much more human-like than other sub-human simians that more nuanced classifications were devised.  Non-human hominoids and non-hominoid simians were by now considered either sub-groups of a single non-human simian super-group (called apes or monkeys) or they were considered  separate groups.  When the non-human simian super-group was called "apes" the non-human hominoids were called "anthropoid apes" and the non-hominoid simians were called "monkeys".  When the non-human hominoids and the non-hominoid simians were separate groups, they were simply called "apes" and "monkeys" respectively.     

With the rise of cladistics, the science of classifying organisms based on common ancestry, regardless of phenotype or morphology, some scientists simply use "ape" as a synonym for hominoid.[1][2]


Pre-Enlightenment: Ape = Monkey edit

 
The fact that this monkey is named a Barbary ape reflects the flexibility of the terms "ape" and "monkey"

"Ape", from Old English apa, is possibly an onomatopoetic imitation of animal chatter. The term has a history of rather imprecise usage. Until the 1700s, it was a general category for any animal of what was then called the "monkey tribe"[3].  In this era there was no distinction between the definition of "ape" and "monkey".  Indeed the term monkey may have originated from the name "Moneke" given to a fictional ape.[4]  Colloquially, the terms "monkeys" and "apes" may still be used interchangeably.[5] Also, a few monkey species have the word "ape" in their common name, such as the the Barbary ape of North Africa (introduced into Gibraltar), Macaca sylvanus, and the Sulawesi black ape or Celebes crested macaque, M. nigra..The original usage of "ape" in English might have referred to the baboon, an Old World monkey.[citation needed]

Post 17th century: Distinguishing "ape" from "monkey" edit

 
The discovery of the chimpanzee inspired scientists to distinguish between "ape" and "monkey"

The notion that apes could be distinguished from monkeys emerged with the discovery of the chimpanzee.  Originally called an orang-outan, which meant "man of the woods"[6] English explorers were fascinated by the two-legged non-human primate and speculated that it was the product of sex between monkeys and Africans.  17th century British anatomist Edward Tyson dissected a chimpanzee which he thought was a pygmy and was so impressed by its human-like muscle and skeleton structure that he assigned the so-called pygmy a rank in between man and beasts on the Great Chain of Being.[7] 


In 1758 Carl Linnaeus classified H. sapiens (man) and H. troglodytes (anthropoid apes) as the two species in the genus Homo.  However by 1779, a study by Dutch anatomist Petrus Camper showed that orangutan's were not capable of talking, and he later also showed them to be incapable of bipedalism.  Such research convinced biologists that Linnaeus had been wrong to put both humans and non-human hominoids in the same genus.[8].


Apes as intermediate between man and monkey edit

Edward Tyson was credited with distinguishing apes from monkeys, pioneering the anatomical study of "man-like apes" and was very instrumental in creating the "hominoid ape" category, intermediate between humans and "monkeys".[9]  

17th century naturalist John Ray categorized all tailed simians except the baboon as "monkeys" and used the term "ape" only for the tailless sub-human simians.[10]

By 1972, "ape" was a term for all members of the Pongidae family.  Especially human-like apes were called anthropoid apes.  Gorillas, chimpanzees,  and orangutans were sometimes considered the "great apes" while  gibbons and siamangs were part of the sub-family known Hyblotinae.  The inferred link between humans, pre-humans and anthropoid apes caused all of these to be lumped into the superfamily Hominoidea.[11]  While apes had previously been classified  as a type of monkey by those scientists who defined "monkey" broadly, that broad definition was narrowing, and only non-anthropoid apes were by now classified as monkeys, or more narrowly, only the tailed "apes" (except baboons).  Lemurs and their allies known as "half apes"[12]        

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.[13] 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.[14] The diagram below shows the currently accepted evolutionary relationships of the Hominoidea,[15] with the apes marked by a bracket.





 Hominoidea

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":[16]

 Hominoidea

humans (genus Homo)

chimpanzees (genus Pan)

gorillas (genus Gorilla)

orangutans (genus Pongo)

gibbons (family Hylobatidae)

great apes
lesser apes

Apes and monkeys as subgroups of each other edit

Depending on the nomenclature, apes have been either a subset or superset of monkeys.

Ape as a type of monkey edit

 

 
19th century scientists viewed gorillas as a superior form of monkey

The 1854 book Types of Mankind described gorillas as a "superior type of monkey".[17]  By the early 20th century, zoologists still used the term monkey in  a wide sense (all primates except humans and lemurs)[18] and while this wide sense was scientifically obsolete by 1972, it is still part of common English usage and pop-culture.

Monkey as a type of ape edit

The 1972 encyclopedia britannica divides the sub-human primates into three sub-groups: lemurs and their allies (half-apes), monkeys, and tailed apes (anthropoid ape).  It also said "monkey" can be narrowly defined as all "tailed apes" except the baboon. 

21st century: Ape = hominoid? edit

 

 
Scientists traditionally distinguished humans from apes by citing observable differences such as brain size and facial angle, however with the advent of cladistics, some scientists are merging the two groups
 
Cladogram (family tree) of a biological group. The red and blue boxes at right and left represent clades (i.e., complete branches). The green box in the middle is not a clade, but rather represents an evolutionary grade, an incomplete group, because the blue clade at left is descended from it, but is excluded.

Traditionally biologists classified organisms based on phenetics which is based on overall similarity, usually in morphology or other observable traits, regardless of their phylogeny or evolutionary relation.  Thus it was logical to conceive of humans and apes as distinct categories based on large phenotypic differences in intelligence, language, facial angle, body hair, physical strength and bipedalism.   However in recent years, the science of taxonomy has been dominated by cladistics where organisms are grouped together based on how recently they shared a common ancestor, regardless of how different the organisms may have become since diverging.  All the descendants of a common ancestor are called a clade and the superfamily Hominoidea is one such 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".[1] The group traditionally called "apes" by biologists is then called the "nonhuman apes".

However the notion of humans as apes is not recognized by the Webster dictionary and is not even consistently used by the proponents of this categorization.  For example Richard Dawkins is clear that he uses "apes" for Hominoidea, but he also uses "great apes" in ways which exclude humans. Thus in his 2005 book The Ancestor's Tale [19]he writes "Long before people thought in terms of evolution ... great apes were often confused with humans" and "gibbons are faithfully monogamous, unlike the great apes which are our closer relatives" [20]



Notes and references edit

  1. ^ a b Benton, Michael J. (2005), Vertebrate palaeontology, Wiley-Blackwell, ISBN 978-0-632-05637-8, retrieved 10 July 2011, p. 371
  2. ^ Dawkins 2005 harvnb error: multiple targets (4×): CITEREFDawkins2005 (help); for example "[a]ll apes except humans are hairy"  (p. 99), "[a]mong the apes, gibbons are second only to humans" (p. 126). Cite error: The named reference "DawkinsUse1" was defined multiple times with different content (see the help page).
  3. ^ Anon. (1911), "Ape", Encyclopædia Britannica, vol. XIX (11th ed.), New York: Encyclopædia Britannica, retrieved 10 July 2011
  4. ^ "Monkey".
  5. ^ Webster's New World College Dictionary, 4th Ed: Monkey
  6. ^ RUSSELL KF (1967). "Edward Tyson's Orang-Outang". Medical History. 11 (4): 417–423. doi:10.1017/S0025727300012643. PMC 1033760.
  7. ^ The End of Racism by Dinesh D'Souza pg 61
  8. ^ Rushton, J. P. (2000). Race, Evolution, and Behavior: A Life History Perspective (Third ed.). Port Huron, MI: Charles Darwin Research Institute. ISBN 0-9656836-1-3.pg 101-102
  9. ^ RUSSELL KF (1967). "Edward Tyson's Orang-Outang". Medical History. 11 (4): 417–423. doi:10.1017/S0025727300012643. PMC 1033760.
  10. ^ "monkey" entry from 1972 encyclopedia britannica
  11. ^ "ape" entry 1972 encyclopedia britannica
  12. ^ "monkey" entry from 1972 encyclopedia britannica
  13. ^ Dixson, A.F. (1981), The Natural History of the Gorilla, London: Weidenfeld & Nicholson, ISBN 978-0-297-77895-0, p. 13
  14. ^ Definitions of paraphyly vary; for the one used here see e.g. Stace, Clive A. (2010a), "Classification by molecules: What's in it for field botanists?" (PDF), Watsonia, 28: 103–122, retrieved 07 February 2010 {{citation}}: Check date values in: |accessdate= (help), p. 106
  15. ^ 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 (3): 260–266. doi:10.1007/BF02099995. PMID 2109087.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  16. ^ Dixson 1981, p. 16
  17. ^ The Mismeasure of Man by Stephen Jay Gould, pg 67
  18. ^ http://archive.org/stream/encyclopaediabri18chisrich#page/724/mode/2up
  19. ^ Dawkins, R. (2005), The Ancestor's Tale (p/b ed.), London: Phoenix (Orion Books), ISBN 978-0-7538-1996-8p, 114 Cite error: The named reference "DawkinsUse2" was defined multiple times with different content (see the help page).
  20. ^ Dawkins, R. (2005), The Ancestor's Tale (p/b ed.), London: Phoenix (Orion Books), ISBN 978-0-7538-1996-8p, 126

External links edit