Why Does Systematics Study?
Any classification in any area of human activity performs two kinds of function. Within the taxonomic domain, classification is the goal of cognitive activity: it epitomizes the knowledge for which all research activity is carried out. Another function is to serve as a means of accomplishing other forms of activity in whatever scientific and applied fields.
In cognitive activity, taxonomic classifications developed by systematics appear as a primary form of ordering knowledge about certain manifestations (aspects, fragments, etc.) of biodiversity. Their task is to represent the structure of respective diversity in a form that is suitable for research in other biological disciplines (biogeography, biocenology, etc.). These latter use taxonomic classifications as initial data for their own research and build upon them their own classificatory or parametric systems to represent other manifestations of biodiversity. From this standpoint, classifications elaborated by systematics can be considered primary, while other biological disciplines use secondary’ classifications or parametrizations.
This is also true for those natural sciences in which parametrizing is considered basic. In them, detailed qualitative classifications are developed to serve as a basis for the subsequent application of quantitative parametric methods. Separation of different states of matter (solid, liquid, gas, plasma) in classical physics, separation of groups of elementary particles (leptons, hadrons, photons, etc.) in quantum mechanics, separation of groups of cosmic bodies (galaxies, stars, planets, etc.) in astrophysics—these are all well-known examples of this kind of primary classification.
One very important conclusion can be drawn from the previous consideration. Although in various disciplines, including the “parameterizing” ones, primary classifications do perform some kind of service function, no other function seems to be possible without them. The reason is quite obvious: any extrapolations based on secondary classifications and/or parametric descriptions are most reliable within certain classes that unite objects with certain properties. Therefore, such classes should not be distinguished arbitrarily, but to reflect the “nature of things” of whatever understanding. To emphasize this fact, such classes, following the philosopher John Mill, are usually called natural kinds [Magnus 2014]. Thus, respective primary classifications should be “natural” in the very classical sense that was incorporated in this concept in the 17th—18th centuries and traditionally adopted in systematics. This is what makes it possible to use “primary” classifications as so-called referencesystems, i.e., those reference to whom justifies correctly solving various kinds of “secondary” research and applied tasks.
As for the taxonomic classifications developed by systematics, their reference function is determined by the fact that different users, speaking figuratively, look at the diversity of organisms through the eyes of practicing taxonomists. What is distinguished in the latter’s classifications is accepted by all others as a kind of particular “taxonomic reality” (see Section 4.2.1), which is chiefly evident in the case of species. Indeed, it is only after a certain systematist identified and named a certain species, that others began to study it, recognize its biological properties, and, if necessary, protect it. But if another, more authoritative taxonomist decides that this is not a distinct species, but just an intraspecific form of another species, it drops from the user’s attention—it ceases to be a part of the above “taxonomic reality.”
It is clear from this that taxonomists should be interested in expanding the spheres of competent applications of taxonomic knowledge. The reason is that the demonstration of the practical significance of results of their research in the eyes of various kinds of users and especially decision makers serves as a “justification” for the very existence and development of systematics as a scientific discipline.
Below are indicated the areas of activity in which the results of taxonomic research are used most actively. This includes both scientific disciplines that use these results in their studies of biodiversity, and forms of strictly applied activity.
In biogeography dealing with biogeographic regionalization, the initial material is provided by faunistic and floristic lists, as well as general lists by taxonomic groups, if they include distribution data. In regionalization, strictly speaking, it is not taxa themselves that are analyzed and compared, but their ranges, although it is obvious that distribution data largely depend on how the taxa were initially recognized [Morrone 2018]. Therefore, biogeography is interested in having full-scale natural taxonomic classifications as reference systems to warrant recognition of natural areas of different ranks in biogeographic classifications. With this, particular research programs in biogeography evidently rely upon taxonomic classifications developed within taxonomic theories of respective content [Nelson and Platnick 1981; Santos and Amorim 2007].
In biostratigraphy dealing with the correlation of geological structures and events by the composition of fossils in them, taxonomic classifications of extinct organisms linked to the time scale are of great importance. In stratigraphic analysis, the main units are species and genera, whereas in paleogeographic reconstructions, taxa of higher ranks are usually taken into account. It is evident that taxonomic classifications of extinct organisms are to be as natural as possible to make historical reconstructions as reliable as possible [Meyen 1988; Forey et al. 2004].
In biocenology studying composition of ecosystems from structural and functional viewpoints, lists of taxa within them are used to develop various kinds of biocenological classifications. For instance, syntaxa and guilds are distinguished in such classifications; the former are diagnosed by dominant species, while the latter combine species with similar ecological functions [Mirkin 1985]. In some sections of autecology, the emphasis is placed not on species as such, but on biomorphs, which may correspond to several ecologically and morphologically indistinguishable species [Chernov 1991; Krivolutskiy 1999]; biomorphics is engaged in their study [Pavlinov 2010a],
In nature conservation, according to the current strategy, one of the main emphases is placed on biodiversity conservation [Wilson 1988]. The latter is most often understood in a simplified form as species diversity [Claridge et al. 1997; Wheeler et al. 2012; Sigwart 2018; Costello 2020]. Respectively, species classifications tied to specific biotic complexes and geographic regions are of key importance [Vogel et al. 2017]. Based on the lists of species presented by systematics, an assessment of the degree of their endemism (overlap with biogeography), abundance, and vulnerability (overlap with ecology), recommendations are made to identify protected natural areas and local biomes.
Various kinds of quarantine services (customs, agricultural, sanitary, etc.) monitor the movements of organisms and their derivatives, which are subject to certain restrictions (pests, vectors of dangerous diseases, protected ones, etc.), through control points. For them, as in the previous case, detailed classifications of species and subspecies with high-quality identification keys developed for respective groups of organisms, are of particular importance.
The main link between systematics and various users of the results of taxonomic research are three main types of publications: (a) reviews (checklists) of particular taxa on a global scale; (b) faunistic and floristic reviews for particular regions; and (c) identification keys or tables. In the first two, lists of taxa are provided, usually supplemented with their characters, distribution, etc.; the latter serve for allocation organisms to certain taxa, and many (the best) publications combine reviews with keys.
The quality of such publications prepared by taxonomists determines how useful the results of their research look from users’ viewpoint. And this, in turn, determines how much society is ready to support biological systematics as a science. Therefore, taxonomists should be interested in regularly publishing the results of their research in a form that is available for use in various research and applied activities.
Conceptual History of