BIOL 1108 Study Guide - Midterm Guide: Ring Species, Reproductive Isolation, Honda Fit
Document Summary
Species are not fixed, so they are different to define. Species are reproductively isolated from other species. The ability of two individuals to produce fertile offspring means they are of the same species, thereby belonging to a closed gene pool with alleles being shared among members of that species. The bsc is more useful in theory than in practice. The bsc does not apply to asexual or extinct organisms. Asexual species do not fit within the bsc since they do not sexually change genetic information, and extinct species do not apply either because the bsc depends on reproduction. Ring species and hybridization complicate the bsc. Ecology and evolution can extend the bsc. Prezygotic and postzygotic factors cause reproductive isolation, because they prevent fertilization from taking place and result in the failure of the fertilized egg to develop into a fertile individual. Prezygotic isolating factors occur before egg fertilization.
