Species

Species

In biology, a species (plural: 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, the difficulty of defining species is known as the species problem. Differing measures are often used, such as similarity of DNA, morphology, or ecological niche. Presence of specific locally adapted traits may further subdivide species into "infraspecific taxa" such as subspecies (and in botany other taxa are used, such as varieties, subvarieties, and formae).

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Famous quotes containing the word species:

    The further our civilization advances upon its present lines so much the cheaper sort of thing does “fame” become, especially of the literary sort. This species of “fame” a waggish acquaintance says can be manufactured to order, and sometimes is so manufactured.
    Herman Melville (1819–1891)

    Any reading not of a vicious species must be a good substitute for the amusements too apt to fill up the leisure of the labouring classes.
    James Madison (1751–1836)

    Prohibition will work great injury to the cause of temperance. It is a species of intemperance within itself, for it goes beyond the bounds of reason in that it attempts to control a man’s appetite by legislation, and makes a crime out of things that are not crimes. A Prohibition law strikes a blow at the very principles upon which our government was founded.
    Abraham Lincoln (1809–1865)