In biological classification, the
term subspecies refers to a unity of populations of a species living in
a subdivision of the species' global range and varies from other populations of
the same species by morphological characteristics. A 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 is
abbreviated subsp. in botany and bacteriology, or ssp. in zoology.
The plural is the same as the singular: subspecies.
In zoology, under the International Code of Zoological Nomenclature, the subspecies is the only taxonomic rank below that of species that can receive a name. In 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, 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 or not. A common criterion for a subspecies is its ability of interbreeding with a different subspecies of the same species and producing fertile offspring. In the wild, subspecies do not interbreed due to their geographic isolation and sexual selection. The differences between subspecies are usually less distinct than the differences between species.
In biological terms, rather than in relation to nomenclature, a polytypic species has two or more genetically and phenotypically divergent subspecies, races, or more generally speaking, populations that need a separate description. These are separate groups that are clearly distinct from one another and do not generally interbreed, although there may be a relatively narrow hybridization zone, but which may interbreed if given the chance to do so. These subspecies, races, or populations, can be named as subspecies by zoologists, or in more varied ways by botanists and microbiologists.
A monotypic species has no distinct population or races, or rather one race comprising the whole species. A taxonomist would not name a subspecies within such a species. Monotypic species can occur in several ways:
In zoology, under the International Code of Zoological Nomenclature, the subspecies is the only taxonomic rank below that of species that can receive a name. In 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, 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 or not. A common criterion for a subspecies is its ability of interbreeding with a different subspecies of the same species and producing fertile offspring. In the wild, subspecies do not interbreed due to their geographic isolation and sexual selection. The differences between subspecies are usually less distinct than the differences between species.
Monotypic and Polytypic
Species
In biological terms, rather than in relation to nomenclature, a polytypic species has two or more genetically and phenotypically divergent subspecies, races, or more generally speaking, populations that need a separate description. These are separate groups that are clearly distinct from one another and do not generally interbreed, although there may be a relatively narrow hybridization zone, but which may interbreed if given the chance to do so. These subspecies, races, or populations, can be named as subspecies by zoologists, or in more varied ways by botanists and microbiologists.
A monotypic species has no distinct population or races, or rather one race comprising the whole species. A taxonomist would not name a subspecies within such a species. 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 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.
No comments:
Post a Comment