What Defines a Species?
Biological Species Concept: species are separated by reproductive barriers.
Organisms in the same species have the potential in nature to interbreed and
produce fertile offspring
Ecological Species Concept: species are defined by their ecological role (ie: niche),
the set of environmental resources a species uses
Pluralistic Species Concept: there is no universal explanation for species; factors
that define a species vary depending on the species and the circumstance
Morphological Species Concept: species defined by measurable anatomical
criteria
Genealogical Species Concept: species defined as a set of organisms with a
unique genetic history
Phylogenetic/Evolutionary Species Concept: species defined as a set of
organisms unique in their evolutionary branch