Concept 23

Concept 23 - phenotypes resulting from their interactions...

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Concept 23.3 Natural selection, genetic drift, and gene flow can alter frequencies in a population. Genetic Drift - Statistically, the smaller a sample the greater the chance of deviation from a predicted result - With small population sixes, allele frequencies can fluctuate unpredictably from one generation to the next - Tends to reduce genetic variation Gene Flow - Genetic additions to or subtractions from a population resulting from the movement of fertile individuals or gametes - Migration among populations - Tends to reduce variation among populations over time Concept 23.4 Natural Selection is the only mechanism that consistently causes adaptive evolution - Natural selection: differential success in the reproduction of different
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Unformatted text preview: phenotypes resulting from their interactions with the environment. Evolutionary Fitness-Fitness: the contribution an individual makes to the gene pool of the next generation, relative to the contributions of other individuals Sexual Selection-Type of selection that favors a trait giving an individual a competitive edge in attracting or keeping a mate-Can result in sexual dimorphism-Intrasexual selection: direct competition among individuals of one sex for mates of the opposite sex-Intersexual selection: individuals of one sex (usually females) are choosy in selecting their mates from individuals of the other sex...
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