Species

In biology, the most commonly used definition of species was first coined by Ernst Mayr. Species are "groups of actually or potentially interbreeding natural populations which are reproductively isolated from other such groups" (however, see other definitions of species below).

Importance in biological classification

The idea of species has a long history. It is one of the most important levels of classification, for several reasons:

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

• It often corresponds to what lay people treat as the different basic kinds of organism - dogs are one species, cats another.
• It is the standard binomial nomenclature (or trinomial nomenclature) by which scientists typically refer to organisms.
• It is the only taxonomic level which has empirical content, in the sense that asserting that two animals are of different species is saying something more than classificatory about them.

After thousands of years of use, the concept remains central to biology and a host of related fields, and yet also remains at times ill-defined and controversial.

~ ~ ~ ~ ~ ~ ~ ~ ~ ~