Chapter 2. EVOLUTION III—OVERVIEW

Learning Objectives

Pre-Lab—Models and Genetic Equilibrium
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General Purpose

Conceptual

  • Define the term gene pool and explain how it relates to the concept of evolution.
  • Gain an understanding of the concept of genetic equilibrium and the conditions required for it to occur.
  • Gain an understanding of the relationship between genetic equilibrium and evolution.
  • Gain an understanding of the impact of selection.

In the last two labs you have used models (benchtop and computer) to explore various aspects of population genetics and its place in the process of evolution. Using the various models, you have seen that when the requirements for genetic equilibrium are not met, the result is a change in the gene pool of the population (i.e., evolution). Those requirements for genetic equilibrium are:

  1. The population is large enough to be unaffected by random gene changes.
  2. There is no gene flow (immigration or emigration).
  3. There are no mutations occurring or there is mutational equilibrium.
  4. There is random mating.
  5. There is no selection (natural or artificial).

You have seen that the distribution of genotypes in a population can be used to determine the frequencies of the alleles in the gene pool for that population by using the Hardy-Weinberg equation.

p2 + 2pq + q2 = 1

You have also seen that when the allele frequencies for genes are known, then the expected genotype frequencies for the next generation of the population can be calculated based on the Hardy- Weinberg equation and the assumption that the population is in genetic equilibrium.

Evolution is often discussed as one of the central principles of biology. In order to have the best possible understanding of biology, it is critical to have a good core understanding of evolution.

Please view the following video to get an overview of the importance of evolution to the field of biology.

Pre-Lab Quiz

Proceed to the Pre-Lab Quiz