Jump to content

Alpha taxonomy

From Wikipedia, the free encyclopedia

This is an old revision of this page, as edited by Joan-of-arc (talk | contribs) at 22:16, 4 February 2012 (→‎Alpha taxonomy and systematics: addd blue linking). The present address (URL) is a permanent link to this revision, which may differ significantly from the current revision.

For related disciplines concerning the classification of living things, see biological classification, taxonomy, and systematics.
Alpha taxonomy is the description and naming of species, such as this display of zoological specimens of beetles.

Alpha taxonomy is the discipline concerned with finding, describing and naming species of living or fossil organisms.[1] This field is supported by institutions holding collections of these organisms, with relevant data, carefully curated: such institutes include natural history museums, herbaria and botanical gardens.

The term "alpha" refers to alpha taxonomy being the first and most basic step in taxonomy.

Describing species

Type specimen of Cimbrophlebia brooksi, a fossil scorpion fly: by convention in many scientific collections, a red label denotes a type specimen.

A formal description of a species follow certain rules. From a collection of organisms, one or more specimen are selected as basis for the description, these ideally being "typical" specimen of the new species.[2] In living species where specimen are easily obtainable, these should ideally represent both adult and young individuals. Often they are not however, and with fossil specimen, the basis for the description can be fragmentary and often the only known specimen available. These are designated type specimen, and are to be kept as reference for the species in a special type collection. Mammals and birds are often kept as skin and skeletons (sometimes only the skull). Insects are commonly kept as dried specimens, while other animals are often preserved whole in alcohol or formaldehyde. Plants are preserved flattened and dry in herbaria.

For the new species to be valid, the formal description must be published in a scientific journal. Several journals exist devoted to the publishing of new species. The description of a species will contain a description of typical features of the organisms, and how it differs from other similar organisms. The new species is given a binominal name according to scientific naming conventions, usually accompanied by a formal biological classification giving Kingdom, Phylum or Division, Class, Order, Family, Genus, and Species.[3] Special rules apply in botany, where a formal description must have a summary in Latin giving a brief description of the shape of leaves and flowers.

Further information: [[:Species]]
Further information: [[:Binomial nomenclature]]
Further information: [[:Type specimen]]

About authors, authorities and auctors

Main article: Binomial nomenclature

In botany, an alpha taxonomist who names taxa is called an auctor, from the scholastic term for author. In zoology, the term auctor has been replaced with the terms "author" or "authority". A scientist who attempts to describe new taxa has to be intimately familiar with all the previously published scientific literature on that group of organisms. This is necessary in order to avoid errors such as describing an already-named species (thus creating an unnecessary junior synonym) or using a species name that is already taken. The literature on any one group of organisms often spans centuries, and is often written in several different languages, making alpha taxonomy very much the realm of specialists.[1]

Once a species (or any other taxonomic unit) is named, the name of the auctor is associated with the description. In zoology, the full formal name of a species contains not only the Latin binominal (genus and species name), but also the name of the original authority and the year of the original publication. While the overall name of a species may change (usually by the species being transferred to a new genus) the authority name and year still apply. The zoological code is considered to have started in 1758 with the 10th edition of Systema Naturæ. Many of the most well known animals thus have (Linnaeus, 1758) as the author-date, e.g. the common earth worm, Lumbricus terrestris (Linnaeus, 1758).

Names of certain very prolific authorities are sometimes abbreviated; this was quite common during the early years of Linnaean taxonomy. It is no longer done in zoology, but a system of abbreviations is still used in botany.[4] Many of the more well known species of plants were described by Carl Linnaeus in Species Plantarum, published in 1753, and this is considered the formal starting point for the botanical code. Thus the common buttercup is Ranunculus acris L., where the 'L' is the standardised abbreviation for Linnaeus. Unlike in zoology, the date (year) is not usually given. The same style of abbreviated author names can be found in old zoological work, and was kept the longest for Linnaeus himself, e.g. the tiger can be found as "Panthera tigris (L., 1758)" in older works.

Alpha taxonomy and systematics

For a long time the term "taxonomy" was used for what is today seen as alpha taxonomy. Over time, the term "taxonomy" has gained several other meanings and has thus become potentially confusing. To some extent it is being replaced, in its original (and narrow) meaning, by "alpha taxonomy". As such, alpha taxonomy deals mostly with actual organisms and fossils: species and lower ranking taxa. Higher ranking taxa (including clades and grades) mostly are the province of "beta taxonomy", more commonly called systematics. Systematics (as a science) deals with the relationships between taxa, especially at the higher levels. These days systematics is greatly influenced by data derived from DNA from nuclei, mitochondria and chloroplasts. This is sometimes known as molecular systematics which is becoming increasingly more common, perhaps at the expense of traditional morphological taxonomy.[5]

A specimen of the butterfly subspecies Morpho rhetenor helena

See also

References

  1. ^ a b Richard Fortey (2008). Dry Store Room No. 1: The Secret Life of the Natural History Museum. London: Harper Perennial. ISBN 0007209894.
  2. ^ Douglas J. Preston (1993). Dinosaurs in the Attic: an Excursion to the American Museum of Natural History. New York: St. Martin's Griffin. ISBN 0312104561.
  3. ^ International Code of Botanical Nomenclature, (St. Luis code), Electronic version, Chapter I, article 3
  4. ^ R. K. Brummitt & C. E. Powell, ed. (1992). Authors of Plant Names: A List of Authors of Scientific Names of Plants, with Recommended Standard Forms of Their Names, Including Abbreviations. Royal Botanic Gardens, Kew. ISBN 0947643443.
  5. ^ Quentin D. Wheeler (2004). H. C. J. Godfray & S. Knapp (ed.). "Taxonomy for the twenty–first century". Philosophical Transactions of the Royal Society. 359 (1444): 571–583. doi:10.1098/rstb.2003.1452. PMC 1693342. PMID 15253345. {{cite journal}}: |chapter= ignored (help)
Retrieved from "https://en.wikipedia.org/w/index.php?title=Alpha_taxonomy&oldid=475030421"