BSC 101 Lecture Notes - Lecture 7: Reproductive Isolation, Mating Call, Speciation
Document Summary
Selection pressures: conditions that exert natural selection on an organism at its particular stage of life: examples . Random events are nonselective and do not produce better adapted organisms they favor or eliminate individuals regardless of their fitness. Speciation: the process that produces new species: species are members of a population that can interbreed in nature by sharing a similar set of genes, populations diverge from an ancestral population. Speciation occurs when an ancestral population diverges into new habitats under different selection pressures. As they diverge, they first become races, then species. Races: two different populations of the same species that can interbreed, but display different phenotypes and appearances. Reproductive isolation: when a race or population accumulates enough phenotypic and genetic differences and are unable to interbreed, leading to separate species. Drives speciation: reproductive barriers isolate populations and drive speciation. Reproductive barriers: conditions that prevent two organisms or populations from breeding.
