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Binomial nomenclature

2007 Schools Wikipedia Selection. Related subjects: General Biology

   In biology, binomial nomenclature is the formal method of naming
   species. As the word "binomial" suggests, the scientific name of a
   species is formed by the combination of two terms: the genus name and
   the species descriptor. Although the fine detail will differ, there are
   certain aspects which are universally adopted:
     * Scientific names are usually printed in italics, such as Homo
       sapiens. When handwritten they should be underlined.
     * The first term (genus name / generic name) is always capitalized,
       while the specific descriptor (in zoology, the " specific name", in
       botany, the " specific epithet") never is, even when derived from a
       proper name.

          For example, Canis lupus or Anthus hodgsoni. Note that this is a
          modern convention: Carolus Linnaeus always capitalized the
          specific descriptor, and up to the early 20th century it was
          common to capitalize the specific descriptor if it was based on
          a proper name. Although not correct according to modern
          practices, a capitalized specific descriptor is sometimes still
          used in non-scientific literature based on older sources.

     * In scholarly texts, the main entry for the binomial is followed by
       the abbreviated (botany) or full (zoology) surname of the scientist
       who first published the classification. If the species was assigned
       to a different genus in the description than it is today, the
       abbreviation or name of the describer and the description date is
       set in parentheses.

          For example: Amaranthus retroflexus L. or Passer domesticus
          (Linnaeus, 1758) - the latter was originally described as member
          of the genus Fringilla, hence the parentheses.

     * When used with a common name, the scientific name usually follows
       in parentheses.

          For example, "The house sparrow ( Passer domesticus) is
          decreasing in Europe."

     * The scientific name should generally be written in full when it is
       first used or when several species from the same genus are being
       listed or discussed in the same paper or report. It may then be
       abbreviated by just using an initial (and period) for the genus;
       for example Canis lupus becomes C. lupus. In rare cases this
       abbreviation form has spread to more general use — for example the
       bacterium Escherichia coli is often referred to as just E. coli,
       and Tyrannosaurus rex is perhaps even better known simply as T.
       rex.
     * The abbreviation "sp." (zoology) or "spec." (botany) is used when
       the actual specific name cannot or need not be specified. The
       abbreviation "spp." (plural) indicates "several species".

          For example: "Canis sp.", meaning "one species of the genus
          Canis".

     * Easily confused with the former is the abbreviation "ssp."
       (zoology) or "subsp." (botany) indicates an unspecified subspecies
       (see also trinomen, ternary name). "sspp." or "subspp." indicates
       "a number of subspecies".
     * The abbreviation " cf." is used when the identification is not
       confirmed.

          For example Corvus cf. splendens indicates "a bird similar to
          the House Crow but not certainly identified as this species".

     * Mycology uses the same system as in botany.
     * Binomial nomenclature is also referred to as the 'Binomial
       Classification System'.

History

   The adoption of a system of binomial nomenclature is due to Swedish
   botanist and physician Carolus Linnaeus (1707–1778) who attempted to
   describe the entire known natural world and gave every species
   (mineral, vegetable or animal) a two-part name. However, binomial
   nomenclature in various forms existed before Linnaeus, and was used by
   the Bauhins, who lived nearly two hundred years before Linnaeus. Before
   Linnaeus, hardly anybody used binomial nomenclature. After Linnaeus,
   almost everybody did.

Value of binomial nomenclature

   The value of the binomial nomenclature system derives primarily from
   its economy, its widespread use, and the stability of names it
   generally favors:
     * Every species can be unambiguously identified with just two words.
     * The same name can be used all over the world, in all languages,
       avoiding difficulties of translation.
     * Although such stability as exists is far from absolute, the
       procedures associated with establishing binomial nomenclature tend
       to favour stability. For example, when species are transferred
       between genera (as not uncommonly happens as a result of new
       knowledge), if possible the species descriptor is kept the same.
       Similarly if what were previously thought to be distinct species
       are demoted from species to a lower rank, former species names may
       be retained as infraspecific descriptors.

   Despite the rules favoring stability and uniqueness, in practice a
   single species may have several scientific names in circulation,
   depending largely on taxonomic point of view (see synonymy).

   A major source of instability is the resurrection of forgotten names,
   which can claim priority of publication. In this case, however,
   conservation according to the nomenclature Codes is possible.

Codes of nomenclature

   From the mid nineteenth century onwards it became ever more apparent
   that a body of rules was necessary to govern scientific names. In the
   course of time these became Nomenclature Codes governing the naming of
   animals ( ICZN), plants (incl. Fungi, cyanobacteria) ( ICBN), bacteria
   ( ICNB) and viruses. These Codes differ.
     * For example, the ICBN, the plant Code does not allow tautonyms,
       whereas the ICZN, the animal Code does allow tautonymy.
     * The starting points, the time from which these Codes are in effect
       (retroactively), vary from group to group. In botany the starting
       point will often be in 1753 (the year Carolus Linnaeus first
       published Species Plantarum), in zoology in 1758. Bacteriology
       started anew, with a starting point in 1980).

   A BioCode has been suggested to replace several codes, although
   implementation is not in sight. There also is debate concerning
   development of a PhyloCode to name clades of phylogenetic trees, rather
   than taxa. Proponents of the PhyloCode use the name "Linnaean Codes"
   for the joint existing Codes and "Linnaean taxonomy" for the scientific
   classification that uses these existing Codes.

Derivation of names

   The genus name and species descriptor may come from any source
   whatsoever. Often they are Latin words, but they may also come from
   Ancient Greek, from a place, from a person (preferably a naturalist), a
   name from a local language, etc. In fact, taxonomists come up with
   specific descriptors from a variety of sources, including inside-jokes
   and puns.

   However, names are always treated grammatically as if they were a Latin
   sentence. For this reason the name of a species is sometimes called its
   "Latin name," although this terminology is frowned upon by biologists
   (and philologists), who prefer the phrase scientific name.

   There is a separate list of Latin and Greek words commonly used in
   systematic names.

   The genus name must be unique inside each kingdom. Species names are
   commonly reused, and are usually an adjectival modifier to the genus
   name, which is a noun. Family names are often derived from a common
   genus within the family.

   Retrieved from " http://en.wikipedia.org/wiki/Binomial_nomenclature"
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   with only minor checks and changes (see www.wikipedia.org for details
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