**1. Please download the Apple Runtime for Java available for FREE at (if you already have the Apple Applet Viewer, skip to step 5):**

http://asu.info.apple.com/swupdates.nsf/artnum/n11572

**2. Once the program has downloaded, click on the the MRJ2.2.2.smi icon on your desktop.**

**3. Click on the MRJ Install icon to install the applet viewer. **

**4. Open the Apple Applet Runner Folder**

**5. Click on the Apple Applet Runner Icon**

**6. In the file menu select Open location**

**5. Copy the URL of this page and paste it into the Location box of the Applet Runner window.**

**6. Click Open. The applet may take a moment or two to load.**

**It will be worth your time, I promise!**

**NOTE: You can also save the applet in your Apple Applet Viewer Favorites if you want to access it more quickly next time. Do the following:**

**When the applet is loaded, go to the applets menu and select add applet to list.**

Selection at multiple loci can have considerably more complicated dynamics than selection at one locus. However, if the loci are independent with regards to selection, then multi-locus genotype frequencies will behave the same as they would in a one-locus system. Two-locus genotype frequencies can be found, for example, by multiplying the corresponding one-locus genotype frequencies.

For example, suppose that f(AA) in the next generation was calculated to be 0.4 and f(Bb) was calculated to be 0.3. Then the frequency of the two-locus genotype, f(AABb) would be 0.4*0.3=0.12.

When the two loci are not independent of each other, complications arise (for example, linkage disequilibrium can result). See the section on linkage equilibrium for more information.

**Adjust the initial allelic frequencies and the fitness values to the right:**

For best results, begin by setting the fitness values to 1.0, and initial allelic frequencies to 0.5. Then, decrease one or more of the fitness values by a small amount.

The initial allelic and genotypic frequencies are displayed below the graph whereas the run-time frequencies are displayed above the graph.

In this simulaiton, two loci are subjected to independent selection pressures in a population of 5000 individuals. Because the two loci in this simulation are independent with respect to selection gene frequencies at each locus will be identical to the case of one-locus selection.Two-locus genotype frequencies can be found by multiplying the two corresponding one-locus genotype frequencies.