Frozen Evolution. Or, that’s not the way it is, Mr. Darwin. A Farewell to Selfish Gene.

At the present time, three basic methodical approaches are employed for the creation of a taxonomic system. The phenetic approach attempts to form a natural system of organisms on the basis of their mutual similarity. The cladistic approach tries to create a natural system exclusively on the basis of the genealogical relatedness of organisms, i.e. entirely on the basis of cladogenesis (Hennig 1966). Cladists originally called themselves phylogenetic systematists; however, over time, they came to accept the originally pejoratively intended term cladists and the term cladistics as a designation for their approach to phylogenetics and taxonomy. The evolutionary systematic approach, sometimes also called eclectic taxonomy, attempts  to encompass both aspects of phylogenesis and to create a system of taxa that fully respects the progress of cladogenesis and simultaneously reflects the progress of anagenesis, i.e. the mutual similarity of organisms.