What Does Systematics Study?
This question is asked and answered by the ontology of a scientific discipline, in which cognitive activity is aimed at comprehending the “nature of things.” It can be reduced to finding out what diversity of these “things” is and why they are different. Why are there different cosmic bodies—galaxies, stars, planets? Why are there different microparticles—say, hadrons and leptons? Why are there different chemicals—for example, alkalis and acids? Why are there different ethnic groups and different languages? In biology in general and in systematics in particular, cognitive activity is associated with description and explanation of the diversity of organisms: it begins with questions about how, to what extent, and why they are different or similar, and ends with answers.
Thus, consideration of systematics as a scientific discipline begins from this point—what exactly it studies. Obviously, the understanding of the tasks solved by systematics depends on this. Therefore this point was designated in the previous section as one of the first among the principal issues in developing the theoretical foundations of systematics. Currently, there is no single satisfactory understanding of its subject area: depending on the preferences of respective authors, its definitions either cover the entire diversity of organisms without differentiating its manifestations or are too narrow' and reduce the scope of systematics to one or another particular manifestation of this diversity (phylogenetic, typological, species, etc.).
The key question for systematics about its object (subject area) is considered in Section 4.2.1, so here a few important points should be noted. Its definition should be sought at a theoretical level, and not be limited to indicating certain manifestations of biodiversity. In general, the object of systematics is denoted as TD; it is not identical to biological diversity as a whole, but is one of its manifestations. Its other manifestations, which systematics is not directly involved in, are ecological diversity (studied by ecology, biocenology), biochorological (studied by biogeography), partonomic diversity within organisms themselves (studied by anatomy, developmental biology, physiology, histology, etc.), biosocial (studied by social biology, ethology), etc. Of course, all of them, in one way or another, fall within the sphere of interests of systematics as “suppliers” of characters for elaborating classifications, but they do not form its own subject area.
The TD itself is structured, so its own different manifestations (aspects, elements, etc.) can be distinguished as subject areas of respective research programs. Of the aspects of TD, the following are most clearly outlined:
- • The typological aspect includes diversity of structural features of organisms (structural plans, ontogenetic patterns, etc.), studied by typology.
- • The phylogenetic aspect includes the hierarchy of monophyletic groups, studied by phylogenetics.
- • The biomorphological aspect includes diversity of biomorphs (life forms), studied by biomorphics.
- • The population aspect includes diversity of populations and species, studied by biosystematics (in its narrow sense).
One of the important issues related to a general understanding of TD is to find out what the different elements of its structure are. In this case, we are talking primarily about taxa (for example, what is a species?), about ranks in taxonomic hierarchy, and about partons (what is homology?).
How Does Systematics Study?
The questions of how systematic research is carried out are considered by epistemology at a theoretical level. At more practical levels, they are summarized as “principles of systematics” in many manuals, with varying detail according to the theoretical positions of their authors. After reading them, one is convinced that there are too many of these principles and their list is hardly exhaustive. The reason is that, if a taxonomic research procedure is to be worked out rigorously and with sufficient detail, certain working principles need to be formulated for each particular research task.
An overview of the most important principles that form the backbone of the epi-stemic foundations of taxonomy is presented in the theoretical chapter of this book (see Section 4.1.2). Here several important issues are pointed out.
First is the choice of a certain theoretical background. Contrary to what empiricists usually assert, such a choice is always present initially, even though in an implicit form; in fact, rejection of theorizing is also a kind of “theorizing,” albeit very reduced. Thus, any study begins with a choice, whether consciously or not, of some classification approach that best suits the researcher’s preference—empirical, typological, phylogenetic, etc. This choice affects preferences as regards characters and methods, which in turn affect the results of taxonomic research.
The choice of characters is an important part of composing a research sample, to which some exploratory method is to be applied. This choice is largely dictated by the requirements of the respective theoretical background chosen initially: in phylogenetic research characters should allow monophyletic groups to be recognized; in typological research they should allow body plans to be uncovered, etc.
The choice of method is a very important issue in taxonomic research because the latter’s result largely depends on the method applied. This choice depends, in turn, on many attendant circumstances, including the theoretical context. The latter defines, in particular, which method can be considered scientific and if it is compatible with the particular theoretical background of the research. At a more “technical” level, of prime importance is the correct application of the method chosen. In sum, if a method is incompatible or incorrectly applied, the desired result will not be achieved: although the resulting classification may look quite respectable, it will present a highly biased estimate of a certain aspect of TD studied.