section_path: Etymology
section_name: Etymology
paragraph_text: Etymology
  
  The English name primates is derived from Old French or French primat, from a noun use of Latin primat-, from primus ('prime, first rank'). The name was given by Carl Linnaeus because he thought this the "highest" order of animals. The relationships among the different groups of primates were not clearly understood until relatively recently, so the commonly used terms are somewhat confused. For example, ape has been used either as an alternative for monkey or for any tailless, relatively human-like primate.
  
  Sir Wilfrid Le Gros Clark was one of the primatologists who developed the idea of trends in primate evolution and the methodology of arranging the living members of an order into an "ascending series" leading to humans. Commonly used names for groups of primates such as prosimians, monkeys, lesser apes, and great apes reflect this methodology. According to our current understanding of the evolutionary history of the primates, several of these groups are paraphyletic, or rather they do not include all the descendants of a common ancestor.
  
  In contrast with Clark's methodology, modern classifications typically identify (or name) only those groupings that are monophyletic; that is, such a named group includes all the descendants of the group's common ancestor.
  
  The cladogram below shows one possible classification sequence of the living primates: groups that use common (traditional) names are shown on the right.
  
  All groups with scientific names are clades, or monophyletic groups, and the sequence of scientific classification reflects the evolutionary history of the related lineages. Groups that are traditionally named are shown on the right; they form an "ascending series" (per Clark, see above), and several groups are paraphyletic:
  
  Thus, the members of the two sets of groups, and hence names, do not match, which causes problems in relating scientific names to common (usually traditional) names. Consider the superfamily Hominoidea: In terms of the common names on the right, this group consists of apes and humans and there is no single common name for all the members of the group. One remedy is to create a new common name, in this case hominoids. Another possibility is to expand the use of one of the traditional names. For example, in his 2005 book, the vertebrate palaeontologist Benton wrote, "The apes, Hominoidea, today include the gibbons and orangutan... the gorilla and chimpanzee... and humans "; thereby Benton was using apes to mean hominoids. In that case, the group heretofore called apes must now be identified as the non-human apes.
  
  As of 2021, there is no consensus as to whether to accept traditional (that is, common), but paraphyletic, names or to use monophyletic names only; or to use 'new' common names or adaptations of old ones. Both competing approaches can be found in biological sources, often in the same work, and sometimes by the same author. Thus, Benton defines apes to include humans, then he repeatedly uses ape-like to mean 'like an ape rather than a human'; and when discussing the reaction of others to a new fossil he writes of "claims that Orrorin... was an ape rather than a human".