Define behavior. • Visible result of an animal’s muscular activity • When a predator catches its prey • Fish raises its fins as part of a territorial display • Non-muscular behaviors • Animal secretes a chemical that attracts members of the opposite sex • Observable behaviors and underlying mechanism
Define fixed action patterns and give an example. • Sequence of unlearned behavioral acts that is essentially unchangeable and, once initiated, usually carried to completion • Triggered by an external sensory stimulus (sign stimulus) • Ex. Three-spined stickleback fish attacks other males that invade nesting territory • Sign stimulus = red underside of intruder
Define imprinting. • Type of behavior that includes both learning and innate components; generally irreversible • Sensitive period • Ex. Young geese follow mother
Explain how genes and environment contribute to behavior. • Genes and environment interact (not nature VS. nurture, but nature AND nurture) • Observe the “norm of reaction” • Vary based on environment? • Similar, despite environmental differences? • Developmentally fixed behavior is innate
Explain what is unique about innate behavior. • Developmentally fixed, despite differences in development • Under strong genetic influence
Distinguish between kinesis and taxis. • Kinesis – simple change in activity/turning rate in response to a stimulus • Sow bugs more active in dry, less active in humid areas • Taxis – automatic, oriented movement toward (positive) or away from (negative) some stimulus • Trout swim into current
Explain optimal foraging theory. • Compromise between the benefits of nutrition and the costs of obtaining food • Energy expenditure • Risks of being eaten by predator while foraging • Natural selection should favor behavior that minimizes costs and maximizes benefits.
Explain how predation risk may affect the foraging behavior of a prey species. • A “successful” forager will avoid areas of high risk, even though food availability might be higher in high-risk areas.
Define inclusive fitness and reciprocal altruism. Discuss conditions that would favor the evolution of altruistic behavior. • Inclusive fitness – total effect an individual has on proliferating its genes by producing its own offspring AND by providing aid that enables other close relatives, who share many of the same genes, to produce offspring. • Ex. Sterile worker bees labor on behalf of fertile queen • Ex. Naked mole rat.
Define the concept of kin selection. • Natural selection that favors altruistic behavior by enhancing reproductive success of relatives • Weakens with hereditary distance • Quantifiable