 |
| 1 . |
|
Set up the following experiment to help you understand some of the factors that affect population growth of a single species. Examine the population size plot. What is your estimate of the carrying capacity for the population of brown sparrows? Repeat this same experiment at least three or four times to determine if the results from this experiment are consistent.
|
|
| 2 . |
|
Formulate a hypothesis below to predict the effects of a decrease in clutch size on the population number of the brown sparrow.
|
|
| 3 . |
|
Prove or disprove your hypothesis in Question 2 by carrying out three different experiments with mean clutch size set to different values such as 0, 0.5, 1.0, 1.5, and so on, up to the maximum of 10 eggs, keeping all other parameters at their default values. Repeat each experiment several times, study the plots of population size, and then answer the following questions. What did you discover? Did the results agree with your hypothesis? Why or why not?
|
|
| 4 . |
|
Is there a threshold clutch size needed to keep the population from going extinct? What happens to the variability in population numbers as clutch size gets smaller? If you were a conservation biologist, what would you say about your ability to predict population numbers when clutch size decreases?
|
|
| 5 . |
|
Formulate a hypothesis to predict the effects of an increase in clutch size on population number, then design and carry out experiments to test your hypothesis.
|
|
| 6 . |
|
What happens to population size as clutch size gets larger? What happens to populations with very large clutch sizes? What do you think is causing the pattern that you see?
|
|
| 7 . |
|
Investigate the effects of increasing mortality rates by decreasing life span and keeping all other parameters at their default values. Examine the plots of population size. Is there a threshold life span needed to keep the population from going extinct? Explain this result.
|
|
| 8 . |
|
Investigate the effects of decreasing mortality rates by increasing life span. What happens to the variability in population numbers over time as life spans get longer? If you were a conservation biologist, what would you say about your ability to predict population numbers as life span changes?
|
|
| 9 . |
|
Investigate the effects of decreasing and increasing seed density by running experiments with a decreased resource density for seeds and separate experiments with an increased resource density for seeds. For both experiments, keep all other parameters at their default values. Examine the plots of population size. How does changing the amount of available resources affect population size? Why is this so?
|
|
| 10 . |
|
Formulate a hypothesis to explain how changes in life span might affect the threshold clutch size needed to keep a population of brown sparrows from going extinct, then design experiments to test your hypothesis. What did you discover? Did the results of your experiment support or refute your hypothesis? Explain your results.
|
|
|
