BIOL 226 Lecture Notes - Lecture 4: Reproductive Isolation, Microevolution, Genetic Drift
22 Jan 2017
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Document Summary
An ancestral population > ancestral population splits into separate populations, which occupy different islands > descendant populations evolve in different environments, their characteristics diverge. Origin of new species, focal point of evolutionary theory. Process by one species split into two or more species. Evolutionary theory has to explain how new species come to be and how the population evolves. Microevolution; adaptations that evolve within a population, in one gene pool. Macroevolution; evolution change above the species level appearance of evolutionary novelties (ex. Feather and flight in birds) used to define higher taxa. Defines species as a population or group of populations whose members have the potential to interbreed and resulting viable, fertile offspring. Biological species concept does not work in all cases ex: fossils, species that do not reproduce sexually, some sexual organisms for lack of knowledge about their ability to mate with different kinds of organisms. There is a need for alternative species concepts.
