BMEN 515 Lecture Notes - Species, Species Problem, Species Complex
Document Summary
In traditional cultures, people name species based on morphological similarities and differences. In biology, careful analyses of phenotypic differences are the basis of identifying morphospecies. Morphospecies can be identified in species that are extinct or living, and in species that reproduce sexually or asexually. Fossil species that differed in color or the anatomy of soft tissues cannot be distinguished. Neither can populations that are similar in morphology but were strongly divergent in traits like songs, temperature, or drought tolerance, habitat use, or courtship displays: species like these are called cryptic species. Species that are indistinguishable morphologically, but divergent in songs, calls, odor, or other traits. Under this concept, criterion for identifying evolutionary independence is reproductive isolation. If populations of organisms do not hybridize regularly in nature, or if they fail to produce fertile offspring when they do, then they are reproductively isolated and considered good species.