BIO407H5 Lecture Notes - Species, Species Problem, Species Complex
Document Summary
Each of the three agrees that species are evolutionarily independent units that are isolated by lack of gene flow, but each employs a different criterion for the determining that independence is actually in effect. 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. Species that are indistinguishable morphologically, but divergent in songs, calls, odor, or other traits. The biological species concept: under this concept, criterion for identifying evolutionary independence is reproductive isolation. Lack of gene flow is the litmus test of evolutionary independence in organisms that reproduce sexually. Applying species concepts: two case histories: species can be identified by distinctive morphological traits, reproductive isolation, and/or phylogenetic independence.
