Evolution of Eurosta Questions




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Eurosta solidaginis overwinters in the gall as larvae and emerges in the Spring as adults to mate and to lay eggs. During the winter months, chickadees prey on the fly larvae in the galls. Larger galls are easier to find. The activity of the chickadees could lead to selection.

1. What type of selection is caused by the chickadees?

2. Defend your answer by discussing how the mean and variance in gall size might change in the next generation after selection by chickadees. (2pts)

3. Eurytoma obtusiventris (the wasp with the short ovipositor) attacks galls after they have reached mature size. What type of selection would Eurytoma obtusiventris cause on gall size?

4. Assume both Eurytoma obtusiventris and chickadees attack galls during the fly life cycle. What type of selection would occur?

5. What is the potential evolutionary consequence when both Eurytoma obtusiventris and chickadees attack galls? Defend your answer.

6. Which of the following statements is true:

Statistics Questions: (Link to the Statistics Guide. Use the back button to return to this page.)

7-8. To determine if the system is evolving toward larger galls, you measure gall sizes over a 5-year period. What statistical test would you use to determine if mean gall size has increased from the first year to the last year? Defend your answer.

9. Suppose you want to determine if the distribution of parasite attacks is similar from year to year. What statistical test would you use?