E 3 Innate and learned behavior Innate and

E 3 Innate and learned behavior

Innate and learned behavior Innate Learned Instinctive (Fixed Action Pattern), based on genetics Based on experience Not modified by individual & unaffected by environment Modified by individual by trial and error & affected by environment Low variation in population High variation in population Evolved through natural selection Capacity to learn is a product of natural selection Examples: Newborn instincts Migration of blackcaps Examples: Acquisition of language and social skills Domesticated behavior in pets Training dolphins to perform

Design of innate behavior experiments • Taxis = locomotion of an organism in a particular direction in response to an external stimulus • Positive taxis = towards stimulus, Negative taxis = away from stimulus • Examples: – Planaria (flatworm) moves towards food = positive chemotaxis – Euglena (protist) moves towards light = positive phototaxis

Design of innate behavior experiments • Kinesis = the movement (as opposed to growth) of an organism or a cell in response to a stimulus • Intensity affects the rate of kinesis • Example: – Orthokinesis: speed of movement altered as response to stimulus – Klinokinesis: rate of turning altered as response to stimulus – Porcello scaber (woodlice) move about less in optimum, humid, conditions, and more in unfavorable, dry conditions

Today • Read pill bug experimental design (p. 475 477) • Looking ahead – Create a schedule for mock exam study – Unit Test (E 1, E 2 and E 3)

E 3 Innate and learned behavior

Innate and learned behavior Innate Learned Instinctive (Fixed Action Pattern), based on genetics Based on experience Not modified by individual & unaffected by environment Modified by individual by trial and error & affected by environment Low variation in population High variation in population Evolved through natural selection Capacity to learn is a product of natural selection Examples: Newborn instincts Migration of blackcaps Examples: Acquisition of language and social skills Domesticated behavior in pets Training dolphins to perform

Classical conditioning • Classical conditioning = process of learning which pairs a stimulus with a response • Pavlov's dog: classical conditioning in dog salivation in response to food paired with a ringing bell – innate: unconditioned stimulus (US), smell of food --> unconditioned response (UR), salivation – experience: food (US) + conditioned stimulus (CS), bell -salivation (UR) – generalization: bell (CS) --> salivation (UR becomes CR, conditioned response)

Operant conditioning • Operant conditioning = process of learning in which positive behaviors are rewarded (positive reinforcement) and negative are punished (negative reinforcement ) • BF Skinner’s experiment – Rats and pigeons were trained to push levers and perform actions to receive food rewards – Electrical shock punished incorrect actions

Imprinting • Imprinting = process by which young animals become attached to their mother within the first day or soon after • Konrad Lorenz – Sign stimulus (moving object) at a critical period triggers innate releasing mechanism

Learning and Natural Selection • Goslings vary in their ability to imprint (variation) • Goslings that are able to imprint on their mother, will avoid predators by remaining close to her, increasing their chances of survival (natural selection) • Alleles allowing imprinting are passed on to their offspring at a higher rate than alleles without imprinting ability (heritability) • Thus, imprinting alleles accumulate (evolution) and the trait becomes common in the population (adaptation)

Bird Song • Uses song to deter males from entering territory or attract other mates • Both inherited and innate – Species specific crude template (innate) – Adult song (inherited) • Sensitive period in which imprinting takes place • Captive birds may not be reproductively successful in the wild because they were not imprinted with the correct mature song.