Question

3. [This question is based on a real study, but I've changed things.] Researchers caught over 300 female anoles (lizards) and randomly divided them into two groups. One group had their ovaries removed ("ovariectomy"), so they cannot reproduce. The other group didn't have anything done to them. All the anoles were released back into the wild. (12 pts) 100% O a. Do this experiment suggest that wild anoles experience a tradeoff? yes no Circle one, and explain. ovariectomy Ono procedure 75% anoles still alive 50% 25% 0% May ovariectomy / no procedure I can't tell Sept next May b. Which anoles group likely has higher fitness? Circle one, and explain. c. It is not clear whether the observed difference is due to the presence of ovaries, or the surgical procedure itself (anesthetizing, cutting, and patching each anole). What treatment group could you add to distinguish these two hypotheses? d. Suppose the researchers used your answer to partc as a third group. Add (fake) data to the graph from this new group that would suggest the presence of ovaries caused the difference in the "ovariectomy" and "no procedure" treatments.

Answer 1

a. The wild anoles experience a tradeoff as the increase in population of impotent female anoles can result in reduction of chances of offsprings. ( Information about their habitat, resources, male counterparts not given)

b.Cant tell as fitness cannot be just defined by survival rates, other factors like food, predators, other advantages from the experiments can affect.

c. Follow up investigations on both the population and their conditions can be done to examine their survival and differentiate the hypothesis. Also control groups of anoles with excised one ovary can be introduced.

d. The new control population with one ovary excised show better survival.