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There are many mechanisms that lead to evolutionary change. One of the most important mechanism in evolution is natural selection which is the differential success in the reproduction of different phenotypes resulting from the interaction of organisms with their e ....

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.... small populations that contain less than 100 individuals, but in large populations drift may have no significant effect on the population. Another mechanism is gene flow which is when a population may gain or lose alleles by the migration of fertile individuals between populations. This may cause the allele frequencies in a gene pool to change and allow the organism to evolve. The most obvious mechanism would have to be mutation that arises in the gene pool of a population or individual. It is also the original source of the genetic variation that serves as raw material for natural selection. Not only are there mechanisms of evolution, but there is a ....