Problem 2
What assumptions underlie the cost-benefit approach to optimality models? Is it possible to test whether or not an animal is acting optimally? Could there be cases in which animals might not be well adapted? Krebs and Davies (1993) discuss these questions.
Problem 3
Altruism-personal sacrifice on behalf of others-is difficult for behavioral ecologists and evolutionary biologists to explain because natural selection favors the interests of individuals. Nevertheless, altruistic behaviors toward relatives are observed in many animal societies. Is there any way that altruism among nonrelatives can evolve in animal societies? How might altruism arise in human societies if it is based on selfinterest? Gintis et al. (2003) discuss this question.
Problem 5
In Scotland, female offspring of red grouse disperse to surrounding areas, while male offspring take up a territory next to their father, if they survive. A male's territory is always occupied exclusively by one bird. Describe how the aggression associated with territorial defense might differ if a male is surrounded by his sons or by unrelated males. Mougeot et al. (2003) describe this system and some experiments on this issue.
