Genetic Drift and "Soft Selection"

Select on the main menu Drift and then select Drift+"Soft Selection". To see Genetic Drift with Selection click here, with mutation click here and with both click here.

A window like the figure below will be displayed. The initial values have to be supplied for the simulation: population size, number of populations, initial allele frequency (p) and number of generations to simulate. After entering these values, enter fitness coefficients (w1 to AA, w2 to Aa and w3 to aa) and then click OK. The simulation will run for the determined number of generations and the resulting graph will be displayed.

The result will be plotted in a regular cartesian graph, the curves representing the allele frequency in each population. The final number of populations with fixed or lost alleles are displayed on the right top corner of the main graph. As an aid to understanding the drift process and its effects on allele frequencies a bar graph with 10 classes of allele frequencies is also shown on the right side of the window. Clicking on Save File will generate a text file with allele and genotype frequencies for all populations simulated along the selected number of generations.