ABSTRACT
Among the issues Donn Rosen thoughtfully considered were the models used to circumscribe units of biodiversity (e.g., Rosen 1978, 1979). In particular, Rosen thought that the predominate models of his time, the Evolutionary Species Concept (ESC) and Biological Species Concept (BSC), failed to identify the fundamental unit for addressing research questions in systematics and evolutionary biology. He also identied an ontological problem with the subspecic taxonomic category: “if a ‘subspecies’ is, by denition, something less than a species, and yet a ‘species’ is the smallest cluster of individuals in nature that can be dened, then subspecies are, also by denition, unobservable and undenable” (Rosen 1979: 227). In response to such issues, Rosen used populations rather than species or subspecies in his biogeographic studies because he thought they were a better proxy for “the unit of evolutionary signicance” (1978: 176). Rosen’s criticisms draw attention to the deeper,
5.1 Introduction .................................................................................................... 49 5.2 Network Species Model ..................................................................................50 5.3 Process in Species Models .............................................................................. 52 5.4 Asexual Species .............................................................................................. 55 5.5 Species as Congurations of Processes .......................................................... 57 5.6 Species as Material Objects ............................................................................60 5.7 Application...................................................................................................... 62 5.8 Summary ........................................................................................................64 Acknowledgments ....................................................................................................65 References ................................................................................................................65
longstanding problem in biodiversity research: the lack of a sound theoretical model underpinning the term species.
