Ecology 203, Exam II, November 18, 1998 Name _________________ Section _____________ (1 point)

Rules: Read carefully, work accurately and efficiently. Answer questions to the best of your ability. Do only what you have to (e.g., 7 of 10 short answer questions). If you get stuck on a question move on and return if you have time. Good luck!

Multiple Choice. (Circle the one correct answer). (2 pts each; 10 pts total)

  1. According the "Theory of Island Biogeography" which of the following should have the highest

number of species? [submitted by student]

    1. small/far island
    2. large/far island
    3. small/near island
    4. large/near island
  1. Relative to herbivore territories, carnivore territories are generally
    1. more beautiful
    2. smaller
    3. larger
    4. more productive
  1. Kin selection is an important factor in the evolution of
    1. competition
    2. predation
    3. cooperation
    4. conception
  1. Gause’s law of competitive exclusion suggests that
    1. species cannot coexist indefinitely
    2. plants cannot coexist indefinitely
    3. predators cannot coexist indefinitely
    4. all of the above
    5. none of the above
  1. Which of the following is not a plant adaptation to herbivory
    1. Increased flower production in response to herbivory
    2. Secondary compound
    3. Thorn
    4. Induced compound

True-False – circle T for true, F for false (2 pts each; 10 pts total).

T F Genetic variation arises by mutation. [submitted by student]

T F Complex ecological systems are more stable (at least based on field work by McNaughton and Tilman). [submitted by student]

T F Assume you are comparing two different communities. If calculated correctly, the estimates for species richness and species diversity (the latter being the Shannon-Weiner index) between these two communities will give about the same results.

T F The observation that character displacement has occurred (e.g., bill shapes of finches are the same on islands where species do not coexist and different on islands where both species occur) is weak evidence that competition actually caused these differences.

T F Species diversity generally increases with increasing latitude

 

Short answer: Do any 7 of the following 10. (7 pts each; 49 pts total)

 

  1. When populations get small, they suffer from several problems that increase the chance of them getting smaller and, eventually going extinct. Identify two of these factors that small populations face and discuss one of them briefly.

a._____________________________ b._________________________

Discuss:

 

 

 

 

 

 

 

 

 

 

2. Describe the observations you would make to show that stotting by Thomson’s gazelles represents communication directed toward predators rather than other Thomson’s gazelles.

 

 

 

 

 

 

 

 

3. Analyze the outcome of competition between two species that have the following isoclines. Put in the vectors that the populations follow in the four different sectors of the graph (use large dots). Identify ALL equilibrium points and LABEL as either "stable" or "unstable."

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

4. Graph data that would support the "Resource Availability Hypothesis":

 

 

 

 

 

 

 

 

 

 

 

5. Fill in the relationships using "+", "-", or "0":

Effect on Effect on

Species A Species B

Competition

Predation

Parasitism

Mutualism

 

 

 

6. Discuss an example of an interaction between species that is mutualistic.

 

 

 

 

 

 

 

 

 

 

 

 

 

7. Discuss how oak trees influence the prevalence of Lyme Disease. You should draw on the work from Clive Jones and his colleagues for this answer.

 

 

 

 

 

 

 

 

 

 

 

 

8. Graph an example (real or made up) of evidence that would support the "Intermediate Disturbance Hypothesis." You must label your axes clearly.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 
  1. Graph the most frequently encountered relationship between species diversity and productivity. (Productivity represents how much energy is captured and converted into organismal biomass.)

ALSO: Briefly discuss why this particular relationship occurs.

 

 

 

 

 

 

 

 

10. Graph the relationship between colonization rates and the number of species found on islands (Equilibrium Theory of Island Biogeography). Identify any equilibrium points and note whether they are stable or unstable. (Note: you do not have to include small and large islands, or near and far islands. Just include lines that represent a single example of an island.)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Define any TWO of the following (identify those you are defining). (5 pts each; 10 pts total) BE CAREFUL: 5 POINTS EACH!

Zero isocline Top-down, bottom-up controversy

Predator functional response Keystone predator

Hot spot Community development

Niche Natural selection

 

 

 

 

 

 

Design an experiment (20 pts)

a. You suspect an herbivore reduces the effects of competition in a community. You have observed that with a large and steady population of buffalo two species of grasses seem to coexist indefinitely. Design an experiment to test whether buffalo influence competitive interactions between these two grass species. (10 pts)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

b. Graph the results from your experiment. Your graph will be evaluated more on the axes than the actually results. (10 pts)

 

 

 

EXTRA CREDIT (3 PTS)

What in the world are these folks doing? Provide some details of what’s going on.