Microevolution

  1. Microevolution is the generation to generation change in the allele frequencies of a population.
  2. Causes of microevolution include:
    1. Genetic Drift
      1. In small gene pool it's easy to lose alleles.
      2. Bottleneck effect - a reduction in population reduces alleles for population rebound.
      3. Founders effect - a colony is restricted to the allele frequency of its founder(s).
    2. Natural selection - leads to better adaptations.
      1. modes of selection
        1. stabilizing - birth weight
        2. directional - Geospiza animation
        3. disruptive - Pseudacraea eurytus, Pyrenestes ostrinus
      2. ecological selection
        1. reproductive isolation
        2. reproductive barriers
      3. sexual selection
    3. Mutation -
    4. Gene flow - migration and recruitment.
    5. Nonrandom mating -
    genetic variation
        single gene mutation
        chromosomal changes
            gene duplication
        exon shuffling
        sexual recombination