Taxonomy

Taxonomies aim to group organisms according to shared characteristics against the background of biological diversity.

The major subdivisions employed in general taxonomies are: Domain, Kingdom, Phylum, Class, Order, Family, Genus, and Species. The mnemonic "Dashing King Philip Came Over From Greater Spain" applies.

These subdivisions may be further subdivided. It is common for bacteria to be subdivided into Divisions and further subdivided into Orders. The advent of genomics and examination of 16s ribosomal RNA has led to modifications in the classification of the prokaryotes, with the older nomenclatures revised into new classifications of Phyla.

Numerical Taxonomy: a common approach to phenetic taxonomy, which employs a number of phenotypic characteristics to generate similarity coefficients that may be mapped in dendrograms. Groupings based on numerical taxonomy may or may not correlate with evolutionary relationships.