Species

A species is a reproductively isolated, independent evolutionary unit which occupies a certain niche. By definition, species are in biology "the lowest-level classifactory or taxonomic unit for biological organisms" (Keller and Lloyd, 1992). In biology it is a taxonomic group whose members can interbreed: a group of living organisms consisting of similar individuals capable of exchanging genes or interbreeding. It is one of the basic units of biological classification.

The two defining features are interaction and similarity: frequent interaction and interbreeding leads to similar individuals, which can be classified by different taxonomic groups. classes, and categories, and similar individuals more frequently interact than dissimilar ones.

The rise of a new species from an ancestor is called speciation. A number of speciations leads to a phylogenetic tree.

Links

• Wikipedia entry for species

References

• Evelyn Fox Keller and Elisabeth A. Lloyd, "Keywords in Evolutionary Biology", Harvard University Press, 1992