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Peer Review

Genetic Drift



Overall Numeric Rating:

4.33 stars
Content Quality: 4 stars
Effectiveness: 5 stars
Ease of Use: 5 stars
Reviewed: Jul 23, 2002 by Biology Editorial Board
Overview: This site is an easily interpreted simulation demonstrating the relationship of the starting frequency of allele p, population size, and the number of generations on the final gene frequency of allele p for single hypothetical gene locus. The user may vary each of the three parameters and see a graph of the frequency of the p allele over the number of generations selected. Up to eight differently colored plots can be displayed simultaneously for comparison. The user may clear the display at any time and start over or the display will automatically clear when the ninth plot is attempted. This simulation is one of several by the same author, all relating to Hardy-Weinberg genetics and evolution. However, there is no explanation of the underlying model on the site.
Type of Material:


Technical Requirements: Java enabled browser
Identify Major Learning Goals: Learn the relationship between starting allele frequency and population size on the change in allele frequency over time
Target Student Population:


Evaluation and Observation

Content Quality

Rating: 4 stars

Quality of Content: 4.0, 4.0 = 4.0

  • Applet is accurate and clearly demonstrates some key points in population
  • Instructions are adequate.
  • Different colors for each plot help point out changes in results as
    variables are changed.
  • Allows rapid sequence of trials with changes in variables.

  • Little explanation of the parameters of the plot.
  • More thorough explanation of (or link to) the model of selection being
    used as basis for simulation would be helpful.
  • Only showing a maximum of eight graphs at once makes it difficult to see
    the patterns produced by large numbers of runs with the same settings.

Potential Effectiveness as a Teaching Tool

Rating: 5 stars

Potential Effectiveness: 5.0, 4.0 = 4.5

  • Illustrates random effects on small populations.
  • Display of eight plots allows easy comparison as variables are changed.

  • Limited ability to change variables reduces effectiveness. Users
    restricted to three different starting allele frequencies (0.1, 0.5, 0.9), five
    different population sizes (10, 25, 50, 100, 250), and three different numbers
    of generations for the
    simulation (50, 100, 250).
  • Does not encourage or stress the importance of varying the parameters to
    observe the effects.
  • Does not have any suggested experiments or assignments for students that
    would lead them into a deeper investigation.

Ease of Use for Both Students and Faculty

Rating: 5 stars

Ease of Use: 4.0, 5.0 = 4.5

  • Rapid response to parameter changes.
  • Allows rapid sequence of trials with changes in variables.
  • The controls are all well labeled and easy to use

Other Issues and Comments:

Overall Rating: 4.33, 4.25 = 4.3