Chapter 27

Summary		Questions		Media Resources
27.1 Evolutionary forces shape behavior.
• Many behaviors are ecologically important and serve as adaptations. • Foraging and territorial behaviors have evolved because they allow animals to use resources efficiently.		1.  What does optimal foraging theory predict about an animal's foraging behavior? What factors unrelated to this theory may also influence an animal's foraging choices? 2.  What are the benefits of territorial behavior, and what are its costs? Under what circumstances is territorial behavior disadvantageous?
27.2 Reproductive behavior involves many choices influenced by natural selection.
• Male and female animals maximize their fitness with different reproductive behaviors. The differences relate to the extent to which each sex provides care for offspring. • Usually, males are competitive and females show mate choice because females have higher reproductive costs. • A species' mating system is related to its ecology.		3.  Why does natural selection favor mate choice? What factor is most important in determining which sex exhibits mate choice? 4.  In birds, how does the amount of parental care required by the offspring affect the evolution of a species' mating system?
27.3 There is considerable controversy about the evolution of social behavior.
• Many animals show altruistic, or self-sacrificing, behavior. Altruism may evolve through reciprocity or be directed toward relatives. Cooperative behavior often increases an individual's fitness. • Individuals form social groups because it is advantageous for them to do so. • Animal societies are characterized by cooperation and conflict. The organization of a society is related to the ecology of a species.		5.  What is reciprocal altruism? What is kin selection? How does kin selection increase an individual's success in passing its genes on to the next generation?
27.4 Vertebrates exhibit a broad range of social behaviors.
• Human behavior is extremely rich and varied and may result from both biology and culture. • Evolutionary theory can give us important insight into human nature, but such an approach to the study of human behavior may be controversial.		6.  In vertebrate societies, what are the costs to an individual who makes an alarm call? Based on research in ground squirrels, which individuals are most likely to make alarm calls, and what benefits do they receive by doing so?		• Behavior Disordered Students •Flipper, A Senseless Killer?

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