The species problem in biology – another look

Abstract

The modern species problem in biology is defined as a contradiction between the need for general notion of the species having a unified contents in various branches of biology, and impossibility to reach it. Any species concept becomes biologically valid under conditions of a biologically sound basic theory, which defines what is the species in a general case and why and how does it come to existence. There a hierarchy of species concepts and definition exist, with a most general «ideal» concept (a kind of «species theory») belonging to its highest level of generality. No such concept is known to exist at the moment; one of its version could be elaborated within a theoretical framework of synergetic model of developing and structuring biota, with the species being an element of the biota’s structure. A number of particular contentwise species concepts belong to the middle level of that hierarchy, each corresponding to a particular aspect of consideration of the biota’s structure. Different middle-level species concepts and definitions could be valid for the different taxonomic groups and for the different tasks of exploration of that structure. Operational species concepts belong to the lower level of that hierarchy, which principal aim is to elaborate particular methods of recognition of particular species. To be biologically sound, they are to be consistent with certain middle-level concept(s). With the universal, biologically sound species concept being absent, it is the taxonomic species concept that is a classificatory unversalia. However, its biological contents is different in different groups of organisms. Judgments about species diversity are special kind of the «taxonomic hypotheses», which are dawn and tested within a framework of certain basic biological theory fixing certain aspect of consideration of the biota’s structure. Personal knowledge plays an important role in understanding of both the species problem in general and the ways it could be resolved in form of particular species concepts and definitions.