Assignment 1

The first screen that will appear in EvolutionLab presents an initial summary (Input Summary) of the default values for each of the parameters that you can manipulate. Working within EvolutionLab and referring to the detailed instructions on Assignment 1, answer the questions below.


1 .		Develop a hypothesis to predict how changes in beak size will affect population numbers for these finches.

2 .		Look at the plots of average beak size over time. What do you observe? Do you notice any trends in beak size? Click on the Population button and look at the plots of population numbers over time. What changes do you see? Do the two islands differ? Does the data support or refute your hypothesis?

3 .		What happened to beak size on Darwin Island compared to Wallace Island over time? Is this what you expected? Why or why not?

4 .		Develop a hypothesis to consider how a decrease in precipitation on Darwin Island might affect beak size and develop a hypothesis to explain how a decrease in precipitation might influence population numbers for these finches over time.

5 .		Did you notice any trends in the distributions of beak size? What did you observe? Did you notice any trends in population number? What did you observe? Explain your answers.

6 .		What changes did you observe in beak size and population numbers? Do these results confirm or refute your hypothesis? If necessary, reformulate your hypothesis and test this hypothesis.

7 .		Did you notice any differences between precipitation, changes in beak size, and population numbers for the finches on Wallace Island compared with those on Darwin Island? Explain your answers.

8 .		Develop a hypothesis to consider how an increase in precipitation on Darwin Island might influence the evolution of beak size.

9 .		Look at the output results in the Beak Size and Population views. Do you notice any differences in this rerun compared with the previous run? Are the general trends observed in this run the same as the previous run? Explain your answers. Run and rerun each experiment for 100, 200, and 300 years. Perform another experiment to test your hypothesis by increasing precipitation on Wallace Island to 50 cm/year and increasing beak size to 28 mm. Run an experiment for 300 years and describe your results. Do these results support your hypothesis?

10 .		Decrease beak size on both of the islands to an intermediate value. Decrease rainfall on one island to a value close to zero. On the other island, increase rainfall close to the maximum value. Run the experiment for 300 years. Were the effects on each island the same or different? What did you observe? Were these the results you expected? Explain your answers to justify what is happening to finches on each island. Be sure to provide explanations for any differences in beak size and population numbers that you observed when comparing finches on both islands.