Behavior lecture 2013
- 2. AP Biology Why study behavior? Evolutionary perspective… part of phenotype acted upon by natural selection lead to greater fitness? lead to greater survival? lead to greater reproductive success?
- 3. AP Biology What questions can we ask? Proximate causes immediate stimulus & mechanism “how” & “what” questions Ultimate causes evolutionary significance how does behavior contribute to survival & reproduction adaptive value “why” questions male songbird → what triggers singing? → how does he sing? → why does he sing? male songbird → what triggers singing? → how does he sing? → why does he sing? → how does daylength influence breeding? → why do cranes breed in spring? → how does daylength influence breeding? → why do cranes breed in spring? Courtship behavior in cranes → what…how… & why questions Courtship behavior in cranes → what…how… & why questions
- 4. AP Biology The heart of Ethology……. 1. What is the basis of the behavior, including chemical, anatomical and physiological mechanisms? 2. How does development of the animal, from zygote to mature individual, influence the behavior? 3. What is the evolutionary history of the behavior? 4. How does the behavior contribute to survival and reproduction? Developed by Tinbergen in 1963
- 5. AP Biology What is behavior? Behavior everything an animal does & how it does it response to stimuli in its environment innate behaviors automatic, fixed, “built-in”, no “learning curve” despite different environments, all individuals exhibit the behavior ex. early survival, reproduction, kinesis, taxis learned behaviors modified by experience variable, changeable flexible with changing environment
- 6. AP Biology attack on red belly stimulus court on swollen belly stimulus Innate behaviors Fixed action patterns (FAP) Sequence of unlearned acts that are triggered by a sign stimulus. Usually carried out to completion male sticklebacks exhibit aggressive territoriality
- 7. AP Biology Complex Innate behaviors Use of environmental cues to carry out behavior Migration, Hibernation, Estivation, Courtship “migratory restlessness” seen in birds bred & raised in captivity navigate by sun, stars, Earth magnetic fields Monarch migration Sandpiper ancient fly-ways Bobolink Golden plover
- 8. AP Biology Innate: Directed movements Taxis Response movement toward (positive taxis) or away from (negative taxis) a stimulus phototaxis chemotaxis Kinesis Random movement in response to a stimulus ex: stopping, starting, or turning. ex: sowbug activity increases when conditions are dry.
- 9. AP Biology Learning: Imprinting Young animals go through a “critical period” whereafter they follow the organisms present during the period. Konrad Lorenz
- 10. AP Biology Learning: Associative learning to associate a stimulus with a consequence operant conditioning trial & error learning associate behavior with reward or punishment ex: learning what to eat classical conditioning Pavlovian conditioning associate a “neutral stimulus” with a “significant stimulus”
- 11. AP Biology Operant conditioning Skinner box mouse learns to associate behavior (pressing lever) with reward (food pellet) Basic animal training with rewards for behaviors.
- 12. AP Biology Learning: Habituation Loss of response to stimulus “cry-wolf” effect decrease in response to repeated occurrences of stimulus enables animals to disregard unimportant stimuli ex: falling leaves not triggering fear response in baby birds; animals standing next to hwy
- 13. AP Biology Learning: Spatial Establishment of memories that reflect the physical structure of the environment. Squirrels using physical markers to find buried food. Wasps using physical markers to find their nest.
- 14. AP Biologysea otter Learning: Problem-solving/Cognition Involves reasoning, awareness, recollection and judgment tool use crow Insight learning
- 15. AP Biology Social behaviors Interactions between individuals that develop into evolutionary adaptations communication / language agonistic behaviors dominance hierarchy cooperation altruistic behavior
- 16. AP Biology Language Honey bee communication dance to communicate location of food source waggle dance
- 17. AP Biology Communication by song Bird song species identification & mating ritual mixed learned & innate critical learning period Insect song mating ritual & song innate, genetically controlled Red-winged blackbird
- 18. AP Biology Social behaviors Agonistic behaviors threatening & submissive rituals symbolic, usually no harm done ex: territoriality, competitor aggression
- 19. AP Biology Social behaviors Dominance hierarchy social ranking within a group pecking order
- 20. AP Biology Social behaviors Pack of African dogs hunting wildebeest cooperatively White pelicans “herding” school of fish Cooperation working together in coordination
- 21. AP Biology Social interaction requires communication Pheromones chemical signal that stimulates a response from other individuals alarm pheromones sex pheromones
- 22. AP Biology Pheromones Spider using moth sex pheromones, as allomones, to lure its prey The female lion lures male by spreading sex pheromones, but also by posture & movements Female mosquito use CO2 concentrations to locate victims marking territory
- 23. AP Biology Behaviors should increase fitness! Foraging behavior – cost and benefits Mating systems – monogamy vs. polygamy Certainty of paternity Agonistic behavior Game theory – California lizard species Orange outcompetes blue Blue outcompetes yellow Yellow outcompetes orange
- 24. AP Biology Social behaviors Altruistic behavior reduces individual fitness but increases fitness of recipient kin selection increasing survival of close relatives passes these genes on to the next generation How can this be of adaptive value? Belding ground squirrel
- 25. AP Biology “Picture a hot dog that's been left in a microwave a little too long…add some buck teeth at one end, and you've got a fairly good idea of what a Naked Mole Rat looks like.” Colonial mammals are altruistic! Naked mole rats underground colony, tunnels queen, breeding males, non-breeding workers hairless, blind
- 26. AP Biology Make sure you can… Provide proximate and ultimate explanations for behaviors Compare innate and learned behaviors and provide examples of each Describe how a particular behavior can evolve Explain how particular behaviors contribute to an organism’s fitness Explain how altruistic behaviors can evolve in a population
Editor's Notes
- #4: Proximate cause questions Male songbirds sing during the breeding season as a response to a high level of testosterone which binds to hormone receptors in the brain & triggers the production of song. Ultimate cause questions The male sings to defend territory from other males & to attract a female with which to reproduce. This is the evolutionary explanation for the male’s vocalization. Proximate cause questions The red–crowned cranes, like many animals, breed in spring and early summer. A proximate question about the timing of breeding by this species might be, “How does day length influence breeding by red–crowned cranes”? A reasonable hypothesis for the proximate cause of this behavior is that breeding is triggered by the effect of increased day length on an animal’s production of and responses to particular hormones. Indeed, experiments with various animals demonstrate that lengthening daily exposure to light produces neural and hormonal changes that induce behavior associated with reproduction, such as singing and nest building in birds. Ultimate cause questions In contrast to proximate questions, ultimate questions address the evolutionary significance of a behavior. Ultimate questions take such forms as, Why did natural selection favor this behavior and not a different one? Hypotheses addressing “why” questions propose that the behavior increases fitness in some particular way. A reasonable hypothesis for why the red–crowned crane reproduces in spring and early summer is that breeding is most productive at that time of year. For instance, at that time, parent birds can find ample food for rapidly growing offspring, providing an advantage in reproductive success compared to birds that breed in other seasons.
- #8: Bird migration, a behavior that is largely under genetic control. Each spring, migrating western sandpipers (Calidris mauri), such as those shown here, migrate from their wintering grounds, which may be as far south as Peru, to their breeding grounds in Alaska. In the autumn, they return to the wintering grounds.
- #9: The sow bugs become more active in dry areas and less active in humid areas. Though sow bugs do not move toward or away from specific conditions, their increased movement under dry conditions increases the chance that they will leave a dry area and encounter a moist area. And since they slow down in a moist area, they tend to stay there once they encounter it. In contrast to a kinesis, a taxis is a more or less automatic, oriented movement toward (a positive taxis) or away from (a negative taxis) some stimulus. For example, many stream fish, such as trout, exhibit positive rheotaxis (from the Greek rheos, current); they automatically swim or orient themselves in an upstream direction (toward the current). This taxis keeps the fish from being swept away and keeps them facing the direction from which food will come.
- #10: But how do the young know on whom—or what—to imprint? How do young geese know that they should follow the mother goose? The tendency to respond is innate in the birds; the outside world provides the imprinting stimulus, something to which the response will be directed. Experiments with many species of waterfowl indicate that they have no innate recognition of “mother.” They respond to and identify with the first object they encounter that has certain key characteristics. In classic experiments done in the 1930s, Konrad Lorenz showed that the most important imprinting stimulus in graylag geese is movement of an object away from the young. When incubator–hatched goslings spent their first few hours with Lorenz rather than with a goose, they imprinted on him, and from then on, they steadfastly followed him and showed no recognition of their biological mother or other adults of their own species. Again, there are both proximate and ultimate explanations
- #17: View Waggle Dance AVI file: waggledance180x135.avi
- #19: View Lifewire territoriality video: “lizards cost of defending-lifewire.swf” Review setting up a behavior experiment:
- #23: The luring function of sex pheromones is a perfect way for predators to get heir prey without having to work too hard. The spider Mastophora hutchinsoni spreads sex pheromones of moths, using them as allomones. This way he can lure about enough moths to sustain. When the moths fly in, convinced they are about to mate, the spider shoots a sticky ball on wire towards them. As they stick to the ball, he drags them in and eats them.