What an Extinct Bird Re-Evolving Says About “Species”

On the phylogenetic species concept, the fossil rails and modern rails are different subspecies, since by dint of having split off from the mainland, rail species at different times, they have independent evolutionary origins. Part of the motivation for calling these the same subspecies based on morphology is that the bones of the fossil and modern rail are more similar in size than either is to their close ancestors—as the authors note, “Like D. c. aldabranus, it also differs considerably in size from D. c. cuvieri and D. c. abbotti.” The tape resets when the island reemerges with much the same environmental conditions as before and the mainland rail species recolonizes.

Source: nautil.us