MechanismofEvoTable - founder events cause population...

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Mechanism of Evolution populations Migration Movement of individuals (genes) between increases the number of alleles/genotypes population of the same species. per population. Decreases the differences in genetic composition among populations Mutation Random changes to the DNA sequence as a result of errors during replication. per population. Because mutations are Is the source genetic variation but doesn’t different each time, they enhance differences have a large influence on allele freq. in genetic composition between populations Genetic drift Random changes in the Decreases number of alleles/genotypes per frequency of alleles and genotypes. population. Populations will change in Strongest when the number of individuals different directions and thus drift increases in the population is low – as some differences in genetic composition between genotypes will contribute more than populations.
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Unformatted text preview: founder events cause population crashes which leads to drift. Natural Selection Non-random difference in reproduction & Generally (directional) selection leads to a survival (fitness) among phenotypes in a decrease in the number of alleles/genotypes particular environment. Phenotypes best per population. If different populations have equipped for a particular environment have different environments, natural selection can the highest fitness. increase differences between populations. Non-random mating The tendency for individuals to mate Causes no change in allele diversity, but with other individuals of the same affects genotype diversity. When most phenotype (and genotype) more mating is between similar phenotypes often than random. Can also refer to then the frequency of homozygotes consistent mating between different increases. When most mating is between phenotypes. dissimilar phenotypes (& genotypes) then the frequency of heterozygotes rises....
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This note was uploaded on 12/08/2011 for the course BIOL 1030 taught by Professor Ferguson during the Fall '09 term at University of Guelph.

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