Species, Genera, Families and others, or the Naturality of Taxonomical Categories

Abstract

Taxonomy, i.e. the science of classifying and naming organisms, has been an activity of man since the invention of language. However, the task of inventorying the Biodiversity on Earth is far from complete. With barely 2,000,000 species catalogued, a conservative estimate of a total of 11,000,000 species claims for exceptional efforts to cope with the task. Furthermore, new methodologies are needed, and possibly new approaches in systematics are required to make taxonomy a more modern discipline. To say it with Willy Hennig: “If systematics is to be a science it must bow to the self-evident requirement that objects to which the same label is given must be comparable in some way”. This has to do with the inconsistet and often ambiguous meaning that higher taxonomic categories (genus, family, order etc…) are given. A genus for an entomologist does not represent a category equivalent to a genus as used by a specialist in mammals, or in fishes: i.e. genera are not comparable across taxa. John Avise has engaged himself in at least two attempts to produce standardization metodologies for taxonomic categories, by referring to the only feature that is certainly shared by all organisms: time. Temporal banding and temporal clipping are discussed as potentially useful methods of standardization of higher taxonomic categories.