biological taxonomy
the science of the classification of organisms. Traditional classifications group organisms into a hierarchical system of ranks, in ascending order: species, genus, family, order, class, phylum, and kingdom (see also domain). Species are named using binomial nomenclature, devised by Swedish biologist Carolus Linnaeus (1707–1778) in 1758: Each species is given two names, the first for the genus to which it belongs and the second identifying the species itself; thus, human beings are classified as Homo sapiens. Also called systematics. See also cladistics.