ECOLOGY SPRING 2009 Florida International University生态春季2009 佛罗里达国际大学.pptVIP

What do you understand by behavior? Learning Animal cognition Migratory behavior Ecology Reproduction Behavior: the way an animal responds to stimulus in its environment Two components of behavior Immediate cause Evolutionary origin Proximate causation:“how” of behavior Measure: hormone level - testosterone Impulse of nerve signal Ultimate causation: “why” of behavior Determine how behavior influences reproductive success or survival Controversy: Is behavior determined by individual’s genes Or by learning and experience Nature (instinct) or nurture (experience) Innate behavior: instinctive, does not require learning Preset paths in nervous system Genetic: fixed action pattern Example: goose replacing an egg from her nest Egg retrieval behavior is triggered by a sign stimulus Innate releasing mechanism or fixed action pattern is the stereotyped act Not very specific: anything round will trigger the goose’s reaction Once pattern begins, it goes to completion; even if the egg is removed Artificial selection data has shown that behavioral differences among individuals often result from genetic differences Genetics of learning Human twin study Identical twins: identical genetically 50 sets, twins raised separately Similarity in personality, temperament, leisure time activities Indicates that genetics plays a role in determining behavior in humans, Learning: altered behavior as a result of previous experiences Nonassociative learning: does not require an animal to form an association between two stimuli or between a stimulus and response Habituation: decrease in response to a repeated stimulus No positive or negative consequences Associative learning: association between two stimuli or between a stimulus and a response Conditioned behavior through association Two major types: Classical conditioning Operant conditioning Differ in the way associations are established Classical conditioning: the paired presentation of two different kinds of stimuli