Chapter 5: Subspecies are for Convenience

Abstract The century-long debate over the meaning and utility of the subspecies concept has produced spirited print but only superficial consensus. I suggest that genuine consensus about subspecies is an impossible goal, because trinomial epithets will inevitably be applied to a heterogeneous mix of evolutionary phenomena, thereby precluding genuine standardization of the concept. Populations that have intermediate levels of phenotypic differentiation and geographic isolation from one another often fall into a region I refer to as the "zone of art," where even skilled experts can disagree about the validity of any one subspecific treatment. The trinomial system cannot accurately represent the kind of information now available about genetic and character variation across space. Instead, ever more accurate tools are being perfected for quantitative, standardized descriptions of variation. These analyses—not subspecies classifications—will keep providing new scientific insights into geographic variation. Eve...