The tabs at the top of the screen allow you to access the Introduction, Notebook, Assignments, Glossary, and Help. These tabs will lead you to information and tools that are outside the applet itself.
Notebook: Record your own notes on the results of the lab--your hypotheses, details about results, and conclusions. You can also move data from the Results pages directly to the Notebook - see Exporting.
Assignments: Doing the assignments is critical to understanding the concepts of this lab. The Assignments here were written to benefit a wide range of general biology classes and you should find them helpful, but check with your instructor before proceeding with any Assignments.
Main Window: The main section of the Notebook is an editable text box to which you can add text and modify it at any time. The contents of the Notebook are not saved between uses of the Lab; therefore, it is suggested that you "Export" and print the Notebook if you would like a lasting record of your work.
Input buttons allow you to change variable information that enables you to make comparisons between many different hypothetical population situations. Clicking on any of the input buttons on the left hand panel will bring up the controls for that variable. The controls for Genotype Frequency and Tree Types appear as red arrows on the pie chart in the middle of the screen. The controls for all other variables appear as a parameter slider bar at the bottom of the screen. For slider bar controls, follow the instructions that appear in black to the left of the slider bar. Instructions vary for different input buttons.
|PARAMETER ADJUSTMENT: PIE CHART CONTROLS AND SLIDER BARS|
The different parameters in PopGenLab are changed by using these controls to adjust the variable for each parameter. Ideally, you want to compare different values for each parameter. The parameter adjustments are described below:
Genotype Frequency: Allele frequency for wing color is shown for two alleles, A and a, as a pie chart of the phenotype resulting from each of the three possible genotypes: AA (black moths), Aa (brown moths), and aa (white moths). The different percentages of allele frequencies will impact the genotypes of future generations.
Tree Types: Three different tree types are available. The trees provide habitat and food for the moths. Each tree has a different color of bar, which corresponds to the color of each of the three moths. A mothıs survival from birds as predators depends on its ability to blend against tree bark that has a color similar to its wings.
Stand Size: Stand size indicated the number of trees in an individual stand. In this program, you can create stand sizes that range from 10-4000 trees. Stand size directly influences the number of moths that can live within the stand.
Migration Rate: The migration rate variable controls on the rate of migration and mixing of populations. You can adjust the migration rate from 1%-99%. Note: The Migration Rate button is shaded and inactive as its default setting at the beginning of an experiment because you must select at least two different populations (tree stands) for this input parameter to be active.
Mating Pattern: The type of mating can be selected as either assortative (individuals select partners with phenotypes similar to their own), random, or disassortative (individuals select partners with different phenotypes). The default is random mating. You can alter the degree of assortative or disassortative mating.
Disaster Frequency: You can control the frequency of tornadoes, hurricanes, and the weather effects that typically accompany these natural disasters. Any population of organisms can be influenced by environmental disasters such as drought, flooding, hurricanes, tornadoes, and disease. The default value is Never, and can be adjust to produce occasional or frequent disasters.
Results are given automatically after the Run button is clicked and an experiment is completed. The results are presented in various forms which can be accessed by clicking on the appropriate button in the frame on the left side of the page:
Genotype Frequency: Click and drag the slider to show genotype frequency as the frequency of AA (black), Aa ( brown), and aa (white) genotypes for each generation. Data is represented as a pie chart showing the percentage of each different colored moth in the total population for each generation.