The experiments that you have conducted so far were designed to help you learn about the many factors and interactions that can influence the size and growth of a population. Since ecosystems are affected by random events such as changes in weather, applied ecologists must often make an assessment of "extinction risk." They do this by constructing simulation models similar to PopEcoLab and running multiple simulations. This assignment is designed to have you use PopEcoLab to evaluate extinction risk by running multiple simulations (e.g., 20 simulations) and noting the frequency with which a population becomes extinct.



Set your initial population sizes to the following: 1000 blue sparrows, 1000 brown sparrows, and 50 hawks. Design experiments to study how the risk of extinction changes for any single parameter excluding clutch size and initial population size. Make a hypothesis about the effect of your change.



Examine the extinction risk during a 500 year period. Be systematic in your experimental design. Tip: If you go to the Initial Population screen and click on the Multiple Run Mode button, you can set the number of runs to 10. This will give you ten independent simulations that you can examine by using the spinners on the output screen.



Did the results of your experiments support your hypothesis? Explain how the experimental conditions you set up were responsible for your results. Once you think you have an explanation for your findings, design and carry out additional experiments to support or refute your thesis (for your additional experiments you can set the parameters however you want).





-Did the results of your experiments support your hypothesis? If not, reformulate a new hypothesis and carry out additional experiments. Explain how the experimental conditions you set up were responsible for your results. Once you think you have an explanation for your findings, design and carry out additional experiments to support or refute your thesis.

Discuss the results of your experiment with your instructor to clarify questions that you may have about interpreting the results of your experiment and understanding the effects of the experimental conditions you created.