Species Concepts and Beyond: Selected Topics Relating to the Species Problem

Abstract

This chapter is best viewed as an attempt at going a little bit deeper into various aspects of the species problem while at the same time serving the overall aim of this book: to provide biologists with a distillation, as it were, of the species debate(s). Therefore, none of the subchapters claim to present an exhaustive discussion of its topic or species concept. Rather, they are best viewed as short commentary sections. As in many other sections of this book, the reader will see that often seemingly different views actually have a lot in common. I am not denying that there are important differences between various species concepts, but sometimes they are exaggerated, and the theoretical solution to the species problem (or at least an important part of it) in the form of a hierarchy of species concepts is proof that there is enough common ground for reconciliation. Cracraft (2000, p. 7) was right when he remarked on the similarity of species concepts saying “Similarities: all else is rhetoric” and “A student of species concepts must be able to sort through the rhetoric, unless, of course, the goal is to use it for one’s own gain”. In this book I argue that all species concepts are based on biological realities. Thus, none of them can simply be wrong. Some may be more general or more consistent with research results in different disciplines, and one or several may be superior to others (as indeed, I think, is the case with the Evolutionary Species Concept or General Lineage/Unified Species Concept), but all are real in the sense that they capture biological phenomena. This should be kept in mind because as Stamos (2003, p. 355) put it: “And indeed there is ‘something natural and something beautiful’ in each and every species concept, which taken together in their diversity reveal a conceptual world as rich and as breathtaking, in its own way, as anything to be found in the biological world. And if symbiosis in the biological world is truly a source of evolutionary innovation, there is no reason why it cannot also be so in the conceptual world of theories. All the more reason, then, to value rather than slash and burn the diversity of solutions to the species problem, for out of that diversity endosymbiotic innovations may be born”. This is not to say, and Stamos also adds this, that there are not better and less good solutions, but it is worth remembering when species debates become heated.