Biology 1001A Lecture Notes - Lecture 16: Frequency-Dependent Selection, Plant Reproductive Morphology, Assortative Mating
17 Dec 2013
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Mutation is not random , but not directed towards the needs of the organism either. Of those that affect fitness, most are harmful! Other evolutionary mechanisms that cause hwe to change: Because it is the only source of new alleles. Mutation often opposes selection, but also provides raw material for adaptive evolution. However it is important for selection because selection require genetic variation and mutation is the only source of that raw material! Why most mutations that affect fitness are harmful: The general effects of mutation on fitness: recall that most mutations have actually no effect on fitness or very little effect on fitness, but the ones have effect on fitness, they tend to be harmful, ex. Effect of gene flow on genetic variation within a population: The effect of gene flow (migration) on genetic variation: it has a similar effect to mutation (increase genetic variation) Effect of gene flow on variation (differences) between populations:
