What’s it about?
Species is a difficult concept in biology, even if it seems straightforward. The author of this paper shows that it really is as simple as it seems, but the means of distinguishing one species from another. The problem isn’t in the definition of species but in the distinction among species.
Why does it matter?
Students of biology are taught that a species is a population of organisms that will naturally reproduce, resulting is living and fertile offspring. This definition works well when dealing with modern organisms that reproduce sexually, but does not apply to organisms that reproduce by division or cloning and certainly cannot apply to fossil organisms. The notion that a species is a population of organisms that are evolving separately from other such populations along separate lineages (or ancestor-descendent series), is a broader definition that is used by all species concepts, even those dependent only upon morphology or genetic variation.
Thus, it’s possible to reconcile all the various concepts of species and accept that it’s really only how we delineate between species that is variable (and is driven entirely by the materials being studied and the questions being answered).
Why did I read this?
Last week we discussed the concept of species in my vertebrate paleontology class. This paper outlines several of the commonly used species concepts and is totally relevant to the discussions we had in my class.