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Taxonomy (from ''taxis'', "arrangement," and ''-nomia'', "method") is the science of defining groups of biological organisms on the basis of shared characteristics and giving names to those groups. Organisms are grouped together into taxa (singular: taxon) and given a taxonomic rank; groups of a given rank can be aggregated to form a super group of higher rank and thus create a taxonomic hierarchy.〔Judd, W.S., Campbell, C.S., Kellogg, E.A., Stevens, P.F., Donoghue, M.J. (2007) Taxonomy. In ''Plant Systematics – A Phylogenetic Approach, Third Edition''. Sinauer Associates, Sunderland.〕 The Swedish botanist Carolus Linnaeus is regarded as the father of taxonomy, as he developed a system known as Linnaean classification for categorization of organisms and binomial nomenclature for naming organisms. With the advent of such fields of study as phylogenetics, cladistics, and systematics, the Linnaean system has progressed to a system of modern biological classification based on the evolutionary relationships between organisms, both living and extinct. An example of a modern classification is the one published in 2009 by the Angiosperm Phylogeny Group for all living flowering plant families (the APG III system). ==Definition== The exact definition of taxonomy varies from source to source, but the core of the discipline remains: the conception, naming, and classification of groups of organisms. Two other terms are related to taxonomy, namely "systematics" and "classification"; their exact relationship to taxonomy also varies from source to source because the usage of the three terms in biology originated independently.〔Wilkins, J. S. ''(What is systematics and what is taxonomy? )''.〕 As points of reference, recent definitions of taxonomy are presented below: #Theory and practice of grouping individuals into species, arranging species into larger groups, and giving those groups names, thus producing a classification〔 #A field of science (and major component of systematics) that encompasses description, identification, nomenclature, and classification〔 # The science of classification, in biology the arrangement of organisms into a classification〔Kirk, P.M., Cannon, P.F., Minter, D.W., Stalpers, J.A. eds. (2008) "Taxonomy". In ''Dictionary of the Fungi'', 10th edition. CABI, Netherlands.〕 #"The science of classification as applied to living organisms, including study of means of formation of species, etc." #"The analysis of an organism's characteristics for the purpose of classification" #"() studies phylogeny to provide a pattern that can be translated into the classification and names of the more inclusive field of taxonomy" (listed as a desirable but unusual definition) The varied definitions either place taxonomy as a sub-area of systematics (definition 2), invert that relationship (definition 6), or appear to consider the two terms synonymous. There is some disagreement as to whether biological nomenclature is considered a part of taxonomy (definitions 1 and 2), or a part of systematics outside taxonomy. For example, definition 6 is paired with the following definition of systematics that places nomenclature outside taxonomy:〔 *''Systematics'': "The study of the identification, taxonomy and nomenclature of organisms, including the classification of living things with regard to their natural relationships and the study of variation and the evolution of taxa". The broadest meaning of "taxonomy" is used here. The word ''taxonomy'' was introduced in 1813 by Candolle, in his ''Théorie élémentaire de la botanique''.〔Singh, Gurcharan (2004). ''(Plant systematics: an integrated approach )''. Science Publishers. ISBN 1578083516. p. 20.〕 抄文引用元・出典: フリー百科事典『 ウィキペディア(Wikipedia)』 ■ウィキペディアで「Taxonomy (biology)」の詳細全文を読む スポンサード リンク
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