HOME
TheInfoList



In biological classification, the term subspecies refers to one of two or more populations of a
species In biology, a species is the basic unit of biological classification, classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individu ...
living in different subdivisions of the species' range and varying from one another by morphological characteristics. A single subspecies cannot be recognized independently: a species is either recognized as having no subspecies at all or at least two, including any that are extinct. The term may be abbreviated to subsp. or ssp. The
plural The plural (sometimes list of glossing abbreviations, abbreviated ), in many languages, is one of the values of the grammatical number, grammatical category of number. The plural of a noun typically denotes a quantity greater than the default qua ...
is the same as the singular: ''subspecies''. In
zoology Zoology ()The pronunciation of zoology as is typically regarded as nonstandard, though it is not uncommon. is the branch of biology that studies the animal kingdom, including the anatomy, structure, embryology, evolution, Biological classificat ...
, under the
International Code of Zoological Nomenclature The International Code of Zoological Nomenclature (ICZN) is a widely accepted Convention (norm), convention in zoology that rules the formal scientific name, scientific naming of organisms treated as animals. It is also informally known as the IC ...
, the subspecies is the only taxonomic rank below that of species that can receive a name. In
botany Botany, also called , plant biology or phytology, is the science Science (from the Latin word ''scientia'', meaning "knowledge") is a systematic enterprise that Scientific method, builds and Taxonomy (general), organizes knowledge in th ...

botany
and mycology, under the International Code of Nomenclature for algae, fungi, and plants, other infraspecific ranks, such as variety, may be named. In bacteriology and
virology Virology is the Scientific method, scientific study of virusessubmicroscopic, parasitic particles of genetic material contained in a protein coatand virus-like agents. It focuses on the following aspects of viruses: their structure, classificatio ...
, under standard bacterial nomenclature and virus nomenclature, there are recommendations but not strict requirements for recognizing other important infraspecific ranks. A taxonomist decides whether to recognize a subspecies. A common criterion for recognizing two distinct populations as subspecies rather than full species is the ability of them to interbreed without a fitness penalty. In the wild, subspecies do not interbreed due to geographic isolation or
sexual selection File:Sexual Selection with Peafowl.gif, 250px, Sexual selection is a form of natural selection where one sex prefers a specific characteristic in an individual of the other sex. Peafowls exhibit sexual selection in that peahens look for peacocks ...
. The differences between subspecies are usually less distinct than the differences between species.


Nomenclature

The
scientific name Science (from the Latin Latin (, or , ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally spoken in the area around Rome, known as Latium. Through the power of the ...
of a species is a Binomial nomenclature, binomial or binomen, and comprises two Latin words, the first denoting the Genus (biology), genus and the second denoting the species. The scientific name of a subspecies is formed slightly differently in the different nomenclature codes. In zoology, under the ''
International Code of Zoological Nomenclature The International Code of Zoological Nomenclature (ICZN) is a widely accepted Convention (norm), convention in zoology that rules the formal scientific name, scientific naming of organisms treated as animals. It is also informally known as the IC ...
'' (''ICZN''), the scientific name of a subspecies is termed a trinomen, and comprises three words, namely the binomen followed by the name of the subspecies. For example, the binomen for the leopard is ''Panthera pardus''. The trinomen ''Panthera pardus fusca'' denotes a subspecies, the Indian leopard. All components of the trinomen are written in italics. In
botany Botany, also called , plant biology or phytology, is the science Science (from the Latin word ''scientia'', meaning "knowledge") is a systematic enterprise that Scientific method, builds and Taxonomy (general), organizes knowledge in th ...

botany
, subspecies is one of many ranks below that of species, such as Variety (botany), variety, subvariety, form (botany), form, and subform. To identify the rank, the subspecific name must be preceded by "subspecies" (which can be abbreviated to "subsp." or "ssp."), as in Totora (plant), ''Schoenoplectus californicus'' subsp. ''tatora''. In Microbiology, bacteriology, the only rank below species that is regulated explicitly by the code of nomenclature is ''subspecies'', but infrasubspecific taxa are extremely important in bacteriology; Appendix 10 of the code lays out some recommendations that are intended to encourage uniformity in describing such taxa. Names published before 1992 in the rank of ''variety'' are taken to be names of subspecies (see ''International Code of Nomenclature of Prokaryotes''). As in botany, ''subspecies'' is conventionally abbreviated as "subsp.", and is used in the scientific name: ''Bacillus subtilis'' subsp. ''spizizenii''. Full text available from PDF link at this page; direct URL to PDF is auto-generated and expires.


Nominotypical subspecies and subspecies autonyms

In zoological nomenclature, when a species is split into subspecies, the originally described population is retained as the "nominotypical subspecies" or "nominate subspecies", which repeats the same name as the species. For example, ''Motacilla alba alba'' (often abbreviated ''M. a. alba'') is the nominotypical subspecies of the white wagtail (''Motacilla alba''). The subspecies name that repeats the species name is referred to in botanical nomenclature as the subspecies "Autonym (botany), autonym", and the subspecific taxon as the "autonymous subspecies".


Doubtful cases

When zoologists disagree over whether a certain population is a subspecies or a full species, the species name may be written in parentheses. Thus ''Larus (argentatus) smithsonianus'' means the American herring gull; the notation within the parentheses means that some consider it a subspecies of a larger European herring gull, herring gull species and therefore call it ''Larus argentatus smithsonianus'', while others consider it a full species and therefore call it ''Larus smithsonianus'' (and the user of the notation is not taking a position).


Criteria

A subspecies is a taxonomic rank below species – the only such rank recognized in the zoological code, and one of three main ranks below species in the botanical code. When geographically separate populations of a species exhibit recognizable Phenotype, phenotypic differences, biologists may identify these as separate subspecies; a subspecies is a recognized local variant of a species. Botanists and mycologists have the choice of ranks lower than subspecies, such as variety (varietas) or form (forma), to recognize smaller differences between populations.


Monotypic and polytypic species

In biological terms, rather than in relation to nomenclature, a Polytypic taxon, polytypic species has two or more genetically and phenotypically divergent subspecies, Race (biology), races, or more generally speaking, populations that differ from each other so that a separate description is warranted. These distinct groups do not interbreed as they are isolated from another, but they can interbreed and have fertile offspring, e.g. in captivity. These subspecies, races, or populations, are usually scientific description, described and Scientific name, named by zoologists, botanists and microbiologists. In a Monotypic taxon, monotypic species, all populations exhibit the same genetic and phenotypical characteristics. Monotypic species can occur in several ways: * All members of the species are very similar and cannot be sensibly divided into biologically significant subcategories. * The individuals vary considerably, but the variation is essentially random and largely meaningless so far as genetic transmission of these variations is concerned. * The variation among individuals is noticeable and follows a pattern, but there are no clear dividing lines among separate groups: they fade imperceptibly into one another. Such Cline (biology), clinal variation always indicates substantial gene flow among the apparently separate groups that make up the population(s). Populations that have a steady, substantial gene flow among them are likely to represent a monotypic species, even when a fair degree of genetic variation is obvious.


See also

* Breed * Glossary of scientific naming * Cultivar in botany * Form (botany) * Form (zoology) * Landrace * Polymorphism (biology) * Race (biology) * Strain (biology) * Variety (botany) * Species complex


References


Citations


Sources

* * *


External links

* {{DEFAULTSORT:Subspecies Subspecies, Taxa by rank Botanical nomenclature Plant taxonomy, 1rank25 Zoological nomenclature, rank25 Biology terminology