Unit 27 Behavioral Biology


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Unit 27 Behavioral Biology

  1. 1. KEY CONCEPT Behavior lets organisms respond rapidly and adaptively to their environment.
  2. 2. <ul><li>Behavioral responses to stimuli may be adaptive. </li></ul><ul><li>Detecting and responding to stimuli is key to an individual’s survival. </li></ul><ul><li>Internal stimuli tell an animal what is occurring in its own body. </li></ul><ul><ul><li>hunger </li></ul></ul><ul><ul><li>thirst </li></ul></ul><ul><ul><li>pain </li></ul></ul>
  3. 3. <ul><li>External stimuli give an animal information about its surroundings. </li></ul><ul><ul><li>sound </li></ul></ul><ul><ul><li>sight </li></ul></ul><ul><ul><li>changes in day length or temperature </li></ul></ul>
  4. 4. <ul><li>Specialized cells that are sensitive to stimuli detect sensory information. </li></ul><ul><ul><li>information is transferred to the nervous system </li></ul></ul><ul><ul><li>nervous system may activate other systems in response </li></ul></ul><ul><li>Animal behaviors help to maintain homeostasis. </li></ul>
  5. 5. <ul><li>Kinesis and taxis are two types of movement-related behaviors. </li></ul><ul><ul><li>Kinesis is an increase in random movement. </li></ul></ul><ul><li>Taxis is movement in a particular direction. </li></ul>
  6. 6. <ul><li>Internal and external stimuli usually interact to trigger specific behaviors. </li></ul><ul><li>Most behaviors are a response to both internal and external stimuli. </li></ul><ul><li>External stimuli may trigger internal stimuli. </li></ul><ul><li>Green anole reproductive behavior is triggered by internal and external stimuli. </li></ul>
  7. 7. <ul><li>Some behaviors occur in cycles. </li></ul><ul><li>A circadian rhythm is the daily cycle of activity. </li></ul><ul><ul><li>occurs over 24-hour period </li></ul></ul><ul><ul><li>run by a biological clock </li></ul></ul>
  8. 8. <ul><li>Behaviors may occur daily, monthly, seasonally, or annually. </li></ul><ul><ul><li>During hibernation, an animal enters a seasonal dormant state. </li></ul></ul>
  9. 9. <ul><li>Behaviors may occur daily, monthly, seasonally, or annually. </li></ul><ul><ul><li>During migration, animals move seasonally from one portion of their range to another. </li></ul></ul><ul><ul><li>During hibernation, an animal enters a seasonal dormant state. </li></ul></ul>
  10. 10. KEY CONCEPT Both genes and environment affect an animal’s behavior.
  11. 11. <ul><li>Innate behaviors are triggered by specific internal and external stimuli. </li></ul><ul><li>An instinct is a complex inborn behavior. </li></ul><ul><li>Instinctive behaviors share several characteristics. </li></ul><ul><ul><li>innate, or performed correctly the first time </li></ul></ul><ul><ul><li>relatively inflexible </li></ul></ul>
  12. 12. <ul><ul><li>releaser is a simple signal: touch, sight, sound, scent </li></ul></ul><ul><ul><li>herring gulls chicks and red dot releaser </li></ul></ul><ul><ul><li>environmental factors can affect innate behaviors </li></ul></ul><ul><li>Many innate behaviors are triggered by a releaser. </li></ul>
  13. 13. <ul><li>Many behaviors have both innate and learned components. </li></ul><ul><li>Learning takes many forms. </li></ul><ul><li>Habituation occurs when an animal learns to ignore a repeated stimulus. </li></ul><ul><li>Imprinting is a rapid and irreversible learning process. </li></ul><ul><ul><li>critical period </li></ul></ul><ul><ul><li>Konrad Lorenz and graylag geese </li></ul></ul>
  14. 14. <ul><li>In imitation, animals learn by observing the behaviors of others. </li></ul><ul><ul><li>young male songbirds learn songs by listening to adult males </li></ul></ul><ul><ul><li>snow monkeys and potato-washing behavior </li></ul></ul>
  15. 15. <ul><li>Learning is adaptive. </li></ul><ul><li>Animals that can learn can better adapt to new situations. </li></ul><ul><li>In associative learning, a specific action is associated with its consequences. </li></ul><ul><li>Conditioning is one type of associative learning. </li></ul>
  16. 16. <ul><li>There are two types of conditioning. </li></ul><ul><ul><li>Classical conditioning: previously neutral stimulus associated with behavior triggered by different stimulus </li></ul></ul><ul><ul><li>Ivan Pavlov and salivating dog </li></ul></ul>
  17. 17. <ul><li>There are two types of conditioning. </li></ul><ul><ul><li>Operant conditioning: behavior increased or decreased by positive or negative reinforcement </li></ul></ul><ul><ul><li>B.F. Skinner and “Skinner boxes” </li></ul></ul>
  18. 18. KEY CONCEPT Every behavior has costs and benefits.
  19. 19. <ul><li>Even beneficial behaviors have associated costs. </li></ul><ul><li>The benefits of a behavior are increased survivorship and reproduction rates. </li></ul><ul><ul><li>both increase an individual’s fitness </li></ul></ul><ul><ul><li>both have costs </li></ul></ul>
  20. 20. <ul><li>Behavioral costs can be divided into three categories. </li></ul><ul><ul><li>energy costs </li></ul></ul><ul><ul><li>opportunity costs </li></ul></ul><ul><ul><li>risk costs </li></ul></ul>
  21. 21. <ul><li>Animals perform behaviors whose benefits outweigh their costs. </li></ul><ul><li>Behaviors evolve only if they improve fitness. </li></ul><ul><li>Territoriality refers to the control of a specific area. </li></ul><ul><ul><li>benefits: control resources </li></ul></ul><ul><ul><li>costs: energy and time </li></ul></ul>
  22. 22. <ul><li>Optimal foraging states that natural selection favors behaviors that get animals the most calories for the cost. </li></ul><ul><ul><li>benefits: amount of energy gained </li></ul></ul><ul><ul><li>costs: energy used to search for, catch, and eat food; risk of capture; time </li></ul></ul>
  23. 23. KEY CONCEPT Social behaviors enhance the benefits of living in a group.
  24. 24. <ul><li>Living in groups also has benefits and costs. </li></ul><ul><li>Social behaviors evolve when the benefits of group living outweigh its costs. </li></ul><ul><ul><li>benefits: improved foraging, reproductive assistance, reduced chance of predation </li></ul></ul><ul><ul><li>costs: increased visibility, competition, disease contraction </li></ul></ul><ul><li>Group living requires learning social structure and membership. </li></ul>
  25. 25. <ul><li>Social behaviors are interactions between members of the same or different species. </li></ul><ul><li>Animals use communication to keep in contact. </li></ul><ul><ul><li>visual </li></ul></ul><ul><ul><li>sound </li></ul></ul><ul><ul><li>touch </li></ul></ul><ul><ul><li>chemical </li></ul></ul>
  26. 26. <ul><li>Courtship displays are used to evaluate the fitness of a potential mate. </li></ul><ul><li>Defensive behaviors are used to protect the individual and/or the group. </li></ul>
  27. 27. <ul><li>Some behaviors benefit other group members at a cost to the individual performing them. </li></ul><ul><li>There are many types of helpful social behavior. </li></ul><ul><ul><li>cooperation </li></ul></ul><ul><ul><li>reciprocity </li></ul></ul><ul><ul><li>altruism </li></ul></ul>
  28. 28. <ul><li>In altruism, an individual reduces its own fitness to help other members of its social group. </li></ul><ul><ul><li>inclusive fitness </li></ul></ul><ul><ul><li>kin selection </li></ul></ul>
  29. 29. <ul><li>Eusocial behavior is an example of extreme altruism. </li></ul><ul><li>Eusocial species live in large groups of mostly nonreproductive individuals. </li></ul><ul><ul><li>haplodiploid species: social insects (wasps, bees, ants) </li></ul></ul>Queen Minor worker Major worker <ul><ul><li>diploid species: termites, snapping shrimp, naked mole rats </li></ul></ul><ul><li>Eusocial behaviors likely evolve by kin selection. </li></ul>
  30. 30. KEY CONCEPT Some animals other than humans exhibit behaviors requiring complex cognitive abilities.
  31. 31. <ul><li>Animal intelligence is difficult to define. </li></ul><ul><li>Cognition is the mental process of knowing through perception or reasoning. </li></ul><ul><li>Other factors affecting an animal’s behavior may seem like cognition. </li></ul><ul><ul><li>awareness </li></ul></ul><ul><ul><li>ability to judge </li></ul></ul><ul><li>ability to solve complex problems </li></ul>
  32. 32. <ul><li>Some animals can solve problems. </li></ul><ul><li>Insight is the ability to solve a problem mentally without repeated trial and error. </li></ul><ul><ul><li>observed in primates, dolphins, and corvids </li></ul></ul><ul><ul><li>chimpanzee retrieving hanging bananas </li></ul></ul>
  33. 33. <ul><li>Tool use helps an animal accomplish a task. </li></ul><ul><ul><li>some dolphins use sponges to protect and hunt </li></ul></ul><ul><ul><li>crows and chimpanzees make probing sticks </li></ul></ul><ul><ul><li>capuchin monkeys use rocks to crack nuts </li></ul></ul>
  34. 34. <ul><li>Cognitive ability may provide an adaptive advantage for living in social groups. </li></ul><ul><li>Intelligence in animals seems to be correlated with two characteristics. </li></ul><ul><ul><li>relatively large brains for their body size </li></ul></ul><ul><ul><li>live in complex social groups </li></ul></ul>
  35. 35. <ul><li>Cultural behavior spreads through a population by learning, not by selection. </li></ul><ul><ul><li>taught to one generation by another </li></ul></ul><ul><ul><li>aided by living in close proximity </li></ul></ul>