BIOL 1001 Study Guide - Midterm Guide: Population Viability Analysis, Parapatric Speciation, Soltyrei
Document Summary
Vicariance = the fragmentation of a continuous geographic distribution by nonbiological factors. Explain why geographic isolation does not necessarily lead to reproductive isolation: secondary contact, same living conditions. Explain why islands provide such good examples of allopatric speciation. Island conditions often very different from mainland conditions usually reduced competition and different food sources: reduced immigration/emigration between island and mainland allows them to become genetically very different eventually can no longer interbreed. Explain why natural selection cannot directly promote the evolution of reproductive isolating mechanisms between allopatric populations. Individuals in allopatric populations don"t encounter one another no hybrids produced. Natural selection can"t select against the matings that would have produced them: no gene flow, therefore natural selection can"t directly promote speciation between allopatric populations. Describe how sexual selection and differences in mating habitat, time of mating, or food source could drive/lead to sympatric speciation: most frequent in insects that feed on one or two plants carry out life activities around.
