Taxonomic Concepts and Taxonomic Evolution in European Characeae

This chapter not only explains the taxonomic concept applied in this book, but also introduces the reader into the general debate about species concepts, arising from their use for different purposes with taxonomy serving as a basic tool. Conceptually species determination starts with an individual. Several individuals that share enough characters can be grouped into ‘species’, distinct from other ‘species’. A description of those distinguishing characters should allow for indisputable identification. Whereas “species” is generally accepted as the basic entity for describing the overwhelming diversity to which life has evolved, there is still an ongoing debate in biology about “species concepts”. When this monograph was being prepared there were lively debates about “species” delineation. All of the arguments discussed turned out to be non-decisive by themselves—in fact, in each case scientists resolved on agreed concepts for species, instead of being completely objective. This illustrated once again that not only “species are hypotheses” but, moreover, species are man-made agreements, based on a certain concept which needs (A) to be defined accurately and (B) which has been developed with a well-articulated objective.