Assortative matings : Forbidden and Sterile

To start this module, select Panmixia and Assortative Matings on the main menu and then click on Assortative: Forbidden, Assortative: Sterile, Assortative: Positive w/ dominance, Assortative: Positive w/o dominance or Assortative:Negative(Disassortative).

A window like the figure below will be displayed for all cases. Follow these steps to start the representation. In the case of selecting pre-determined set of crossings (Positive or Negative) skip the first step as the mating groups are pre-determined. Click on the mating that you want to be forbidden or sterile, then enter the frequencies in the boxes. Check the number of generations to run and if you want the population points linked or not (just check the box if you want linked points, uncheck it if not). Click Ok and the run will start generating the points for the number of generations that was selected. Also, one diallelic locus is represented here.

The results are plotted inside the triangular coordinates, one point for each generation that was originally set. One advantage in this model is that different mating groups can be selected and analyzed in the same graph (not posible with pre-determined groups). One set of crossings can be selected, population points generated and then another set of crossings can be selected and have its points plotted. This makes easier the comparison of the effect of different assortative mating on the genotype and allele frequencies of a population.

Another aspect of the assortative mating that can be studied are the equilibrium points for each one of the possible crossings groups. Select the crossings that are forbidden or sterile and click on Equilibrium Points button. On the same graph window, WinPop plots the points and shows the stable and/or unstable equilibrium.

The Save File button saves the frequency values (alleles and genotypes) for all generations plotted in a ASCII text file, which can be edited on any text editor program. Clicking on the Generate Cart. Graph opens a new window with a regular Cartesian graph with the curves for each genotype frequencies and p.

Frequencies plotted in a Cartesian graph

Groups of matings available to study when in Forbidden and Sterile mode (these groups wil the crossings not ocurring or sterile in the population):

1 AA x aa, Aa x aa

2 AA x Aa, AA x aa, Aa x aa

3 AA x AA, Aa x Aa, aa x aa

4 AA x AA, aa x aa

5 AA x AA, Aa x Aa

6 AA x AA, AA x Aa, Aa x Aa

7 Aa x Aa

8 AA x AA

9 AA x Aa, Aa x aa

10 AA x AA, AA x Aa, Aa x aa

11 AA x aa, Aa x Aa

12 AA x AA, AA x Aa, Aa x Aa, aa x aa

13 AA x AA, AA x aa, Aa x Aa

14 Aa x aa, aa x aa

These groups are the ones that have an effect on the population's allele and genotype frequencies. Any other choice of crossings will resemble either panmixia or selection and would be impossible to determine if the population is under one of these two phenomena or assortative matings.