Which of the following is not required for a behavioral trait to evolve by natural selection?a. In each individual, the form of the behavior is determined entirely by genes.b. The behavior varies among individuals.c. An individual's reproductive success depends in part on how the behavior is performed.d. Some component of the behavior is genetically inherited.

Why does altruism seem paradoxical?a. Sometimes altruistic behavior is actually selfish.b. Altruism does not actually help others.c. Alleles that cause an organism to behave altruistically should be selected against since these alleles should lower the organism's fitness.d. Animals behave altruistically to help the species, but sometimes their behavior harms the species.

Although many chimpanzees live in environments with oil palm nuts, members of only a few populations use stones to crack open the nuts. The likely explanation is thata. the behavioral difference is caused by genetic differences between populations.b. members of different populations have different nutritional requirements.c. the cultural tradition of using stones to crack nuts has arisen in only some populations.d. members of different populations differ in learning ability.

Some airports have attempted to scare geese off by playing goose alarm calls over loudspeakers. This tactic kept the geese away initially, but soon the geese ignored the alarm calls. How would you explain this outcome?a. The alarm calls are a social signal that geese ignore unless they can see the other geese.b. The geese became imprinted on the alarm calls.c. The geese used spatial learning to navigate the environment of the airport.d. The geese became habituated to the alarm calls when no danger was present.

Is it true that all organisms forage optimally? Why or why not?

Almost all the behaviors of a housefly are innate. What are some advantages and disadvantages to the fly of innate behaviors compared with behaviors that are mainly learned?

The male cuttlefish in the chapter-opening photo can rapidly change their skin colors (under nerve control) to flash warning patterns to rivals. Predict the proximate and ultimate causes of this behavior.

In Module 35.3, you learned that Norway rat offspring whose mothers don't interact much with them grow up to be fearful and anxious in new situations. Suggest a possible ultimate cause for this link between maternal behavior and stress response of offspring. (Hint: Under what circumstances might high reactivity to stress be more adaptive than being relaxed?)

Propose an evolutionary hypothesis to explain the observation that some bird populations do not migrate if people supply food for them in feeders.