ABSTRACT
Everyone who deals with evolution has occasion to use and to understand statements in the special language of taxonomy and classification. Taxonomic language involves not only a very large number of different designative words but also several different kinds of designations. In zoological taxonomy the population is finite and concrete: a set of organisms existing in nature. The existence and characteristics of that population are inferred from the sample drawn from the population. A taxon is a group of real organisms recognized as a formal unit at any level of a hierarchic classification. A taxon is therefore a population, although the over-all population of one taxon may include many distinct populations of lesser scope. As most biologists understand modern taxonomic language, its implications are primarily evolutionary, but there is some persisting confusion even among professional taxonomists. Classification and taxonomic discussion of related but distinct contemporaneous groups, such as the living apes and living men, involves a pattern of evolutionary divergence.
