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Unit 4: Mechanisms of Evolution The Evolution of Populations Review
  1. Natural selection acts on individuals, but evolve, based on genetic variations, the change in genetic makeup of a population over time is called .
  2. A is a localized group of individuals that are capable of interbreeding and producing offspring.
  3. As a population evolves, its and frequencies change. Such change can be analyzed by comparing it to a non-evolving population.
  4. A non-evolving population reaches the equilibrium due to Mendelian of alleles, under five idealized conditions:
    • Extremely population size.
    • No gene due to migration.
    • No .
    • mating.
    • No natural .
  5. Mendelian inheritance preserves frequencies in a population, resulting in constant variation.
  6. At Hardy-Weinberg equilibrium, the distribution of 2 p and q in a population can be modeled by these equations:
    • The frequencies are described by p + q = 1, where p is the dominant allele frequency and q is the recessive allele frequency.
    • The frequencies are described by p2 + 2pq + q2 = 1.
  7. Mutation and sexual produce the variation that makes evolution possible.
    • Genetic in small populations result tends to genetic variation. In very small populations the effect can contribute to severe loss of genetic diversity.
    • Gene from the movement of individuals or gametes between populations can affect allele frequencies and tends to genetic differences between populations.
    • is the basis for natural selection, and results in unequal reproduction of alleles.
    • Selection favors certain by acting on the of individuals.
      • selection favors individuals at one end of the phenotypic range.
      • selection favors individuals at both extremes of the phenotypic range.
      • selection favors intermediate phenotypes.
    • Summary.
  8. Heterozygotes sometimes may possess greater than homozygotes and preserve a recessive allele in a population due to advantage.
  9. In many species are choosy in selecting their mates, resulting in sexual . This is called selection, or choice.
  10. selection is the competition among males for access to mates, often at the peril of their own survival.
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