Many subsequent authors have proposed more formal definitions, known as species concepts, each useful for particular applications but not without idiosyncrasies. For example, in sexually reproducing ...

Quite simply, species are kinds, or types, of organisms ... The Phylogenetic Species Concept Is an Alternate Approach Because of the limitations of using the BSC to make decisions about species ...

The Florida Entomologist, Vol. 84, No. 4 (Dec., 2001), pp. 587-601 (15 pages) There is no lack of species concepts available for consideration, nor of discussion and speculation about what a species ...