In defense of species

In this paper, I address the charge that the category species should be abandoned in biological work. The widespread appeal to species in scientific discourse provides a presumption in favor of the category’s usefulness, but a defeasible presumption. Widely acknowledged troubles attend species: these troubles might render the concept unusable by showing that ‘species’ is equivocal or meaningless or in some similar way fatally flawed. Further, there might be better alternatives to species. I argue that the presumption in favor of species is not defeated on these scores. Troubles attending species, which arise on account of contextual variation attending the use of ‘species’, do not indicate that the concept is unusable. And alternatives to the use of ‘species’, which have been proposed in connection with rank-free systematics and in connection with conservation efforts, fail to provide a proper replacement for species.