Taxa

Methods

In modern biology studies, a "good" or "useful" taxon is commonly taken to be one that reflects evolutionary relationships. Many modern systematists are advocates of phylogenetic nomenclature; they use cladistic methods that require taxa to be monophyletic (i.e., show all the descendants of a common ancestor). Their basic unit, the clade, is equivalent to the taxon, and their using the clade implies that taxa should reflect evolutionary relationships. Similarly, among those contemporary taxonomists working with the traditional Linnean (binomial) nomenclature, only a few still propose taxa they know to be paraphyletic.