The PhyloCode and the Distinction between Taxonomy and Nomenclature

In a recent report on the First International Phylogenetic Nomenclature Meeting, Pickett (2005:81) concluded that the “architects of the PhyloCode have reversed their positions on the three main points of contention that they have articulated for some 15 years—namely that taxonomy must be a monophyletic, rankless, system that rejects the type concept.” Contrary to Pickett's interpretation, advocates of the PhyloCode have not reversed their positions on any of these issues. The rejection of nomenclatural types (which should not be confused with typological or essentialist philosophies) was never a fundamental principle of phylogenetic nomenclature (see de Queiroz and Gauthier, 1992:459–460), and the reason that the PhyloCode does not prohibit the recognition of nonmonophyletic taxa or the use categorical ranks is simply that it is a code of nomenclature rather than of taxonomy. In this paper, I highlight the distinction between taxonomy and nomenclature and use it to explain two of Pickett's misunderstandings about the PhyloCode. My purpose is to call attention to this important but under-appreciated distinction using Pickett's criticisms of the PhyloCode as examples; it is not intended to be a point-by-point rebuttal of his criticisms (for such a rebuttal, see Laurin et al., 2005).