Diploid Selection Model


This model simulates the change in frequency of an allele of a diploid organism undergoing selection. Select fitness values for each genotype, as well as an initial frequency for the allele of interest. The model will re-run automatially any time a value is changed.


Details: Every generation, this applet updates the frequency, p, of allele A using the recursion equation:

which assumes that alleles combine at random during fertilization (i.e., the population is at Hardy-Weinberg before selection). Here, p' is the frequency of allele A in the next generation and is the average fitness in the population:

Because this model simulates an effectively infinite population, alleles never completely fix or disappear. This applet assumes an allele is fixed if it reaches a frequency of 0.9999, is lost if it reaches a frequency of 0.0001, and stabilizes if its frequency lies between 0.0001 and 0.9999 after 1000 generations.

Any questions? Send e-mail to Dr. Sally Otto or Chris Fonnesbeck