Mutations and if enough different mutations occur, the populations will diverge enough to become distinct species.ĭrift (a random genetic sampling process that can change allele frequencies and lead to fixation or loss of alleles) When populations are separated by geographic barriers, they will tend to develop independent Very far from Hardy-Weinberg equilibrium - over long enough time periods, though, even a weak force can have major effects (e.g., theĮrosion of the Grand Canyon). It is usually a weak force and therefore tends not to pull populations Mutation is difficult to measure or observe directly, and rates of Genetic variation to a population by producing novel alleles. Mutation is the random process that produces a gene or chromosome set differing from the wild-type (ancestral allele). Mutation (random source of new genetic variation) For example, new alleles arisingīy mutation in one population, will be carried to other populations by dispersing individuals. High gene flow will tend to maintain genetic similarity among populations. Migration (often referred to as " gene flow") is one of the major aims of population Assessing the patterns and importance of genetic Migration can restore genetic variation into isolated andĭifferentiated populations or reduce variation among populations when it occurs frequently. Genetic migration is the permanent movement of genes from one population into another. Genetic Migration (high gene flow maintains similarity among populations) We will now examineĮach of the other four forces of evolutionary change - migration, mutation, drift and selection. I ended the last lecture with a discussion of how non-random mating can produce genetic and evolutionary change. Violating Hardy-Weinberg assumptions (continued) Inbreeding coefficient from genotypic counts Go to worked example for take-home exam Go to Excel spreadsheet for calculating gene frequencies and local Return to Main Index page Go back to notes for Lecture 34, 19-Apr Go forward to lecture 36 Pop Ecol Lect 35 Lecture notes for ZOO 4400/5400 Population Ecology
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