Alien-Interiew-Footnote-links
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| 197 "species" "In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are often used, such as based on similarity of DNA or morphology. Presence of specific locally-adapted traits may further subdivide species into subspecies. The commonly used names for plant and animal taxa sometimes correspond to species for example, "lion" "walrus" and "Camphor tree" each refers to a species. In other cases common names do not for example, "deer" refers to a family of 34 species, including Eld's Deer, Red Deer and Wapiti (Elk. The last two species were once considered a single species, illustrating how species boundaries may change with increased scientific knowledge. Each species is placed within a single genus. This is a hypothesis that the species is more closely related to other species within its genus than to species of other genera. All species are given a binomial name consisting of the generic name and specific name (or specific epithet. For example, Pinus palustris (commonly known as the Longleaf Pine. A usable definition of the word "species" and reliable methods of identifying particular species are essential for stating and testing biological theories and for measuring biodiversity. Traditionally, multiple examples of a proposed species must be studied for unifying characters before it can be regarded as a species. Extinct species known only from 279 fossils are generally difficult to give precise taxonomic rankings to. A species which has been described scientifically can be referred to by its binomial names. Nevertheless, as Charles Darwin remarked, look at the term species as one arbitrarily given for the sake of convenience to a set of individuals closely resembling each other .... it does not essentially differ from the term variety, which is given to less distinct and more fluctuating forms. The term variety, again in comparison with mere individual difference, is also applied arbitrarily, and for mere convenience sake' Because of the difficulties with both defining and tallying the total numbers of different species in the world, it is estimated that there are anywhere between 2 million and Download 2 Mb. Share with your friends:
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