1 / 37

Behavioral Biology Chapter 54

Behavioral Biology Chapter 54. Approaches. 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. Approaches.

chul
Download Presentation

Behavioral Biology Chapter 54

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Behavioral BiologyChapter 54

  2. Approaches • 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

  3. Approaches • 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 or nurture

  4. Innate behavior • 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 • Once pattern begins, it goes to completion; even if the egg is removed

  5. Innate Behavior • Male stickleback fish will attack anything with a red underside • Does not need to be a fish • Supernormal stimuli: given a choice: animals respond to a larger stimuli over a normal size stimuli

  6. Behavioral Genetics • Artificial selection data has shown that behavioral differences among individuals often result from genetic differences • Genetics of learning

  7. Behavioral Genetics • Mice: fosB gene • Determines whether female mice nurture their young • Both fosB alleles disabled: ignore young • Normal mothers: protective maternal behavior • Protein expressed by fosB activates other enzymes and genes that affect neural circuitry within the hypothalamus

  8. Behavioral Genetics • fosB present: mother cares for her young • fosB absent: young are ignored and eventually die

  9. Behavioral Genetics Vasopressin receptor • Prairie voles are monogamous • Montane voles mate and do not work together to raise young • Different response to oxytocin and vasopressin • Peptide receptor sequence and location in brain different

  10. Learning • 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

  11. Learning • 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

  12. Classical conditioning: the paired presentation of two different kinds of stimuli with an association formed between them • Pavlovian conditioning • Unconditioned stimulus: meat • Unconditioned response: salivating • Conditioned stimulus: bell ringing • Conditioned response: After time, the dog salivates with only the ringing of the bell

  13. Learning • Operant conditioning: animal learns to associate its behavior response with a reward or punishment • B.F. Skinner • Trial and error learning • Today it is believed that instinct guides learning by determining what type of information can be learned through conditioning

  14. Development of Behavior • Parent-offspring interactions influence cognition and behavior • Imprinting: formation of social attachment to other individuals or develop preferences that will influence behavior later in life • Filial imprinting: attachment between parents and offspring • Konrad Lorenz

  15. Development of Behavior • Instinct and learning may interact as behavior develops • White-crowned sparrow males sing species-specific courtship song during mating • Genetic template: innate program to learn the appropriate song • Can not learn the song unless they hear it at a critical period in development

  16. Development of Behavior • Exposed to own species song during development • Not exposed to song

  17. Orientation and Migratory Behavior • Orientation: goal-oriented movements • Track stimuli in the environment • Homing instinct • Taxis: movement toward or away from a stimulus • Kineses: more or less active when stimulus intensity increases

  18. Orientation and Migratory Behavior • Migrating animals must be capable of orientation and navigation • Navigation: the ability to set or adjust a bearing • Sun and stars: general direction • Earth’s magnetic field: specific path • Information from the stars overrides the magnetic information if they conflict

  19. Orientation and Migratory Behavior Migratory behavior of starlings

  20. Communication • Communication can play a key role in behaviors • Among members of the same species • Between species • Successful reproduction depends on appropriate signals and responses • Stimulus-response chain: behavior of one individual releases a behavior by another individual

  21. Communication Long-distance communication • Pheromones: chemical messengers • Sex attractant • Males have sensory receptors • Some insect pheromones can be detected as far as 7km away • Acoustic signals • Vocal calls, wing clicking • Light signals: firefly

  22. Communication • Communication facilitates group living The waggle dance of honeybees

  23. Communication • Chimpanzees and gorillas can learn to recognize a large number of symbols and use them to communicate abstract concepts • Complexity of human language • Differences are superficial • 3000 languages draw from the same set of 40 consonant sounds

  24. Behavioral Ecology • Behavioral ecology: study of how natural selection shapes behavior • Adaptive significance of behavior • Reproductive success, fitness • Questions asked • Is behavior adaptive • How is it adaptive • Enhance energy intake, increase mating success, decrease predation

  25. Behavioral Ecology Foraging behavior can directly influence individual fitness • Foraging involves a trade-off between food’s energy content and the cost of obtaining the food • Optimal foraging theory: natural selection favors individuals whose foraging behavior is energetically efficient

  26. Behavioral Ecology Optimal foraging makes two assumptions • Natural selection will only favor behavior that maximizes energy acquisition if the increased energy reserves lead to increases in reproductive success • Avoid predators • Find mates

  27. Behavioral Ecology Optimal diet. The shore crab selects a diet of energetically profitable prey

  28. Behavioral Ecology Territorial behavior secures resources • Home range: where the animal lives and forages; defends territory • Defense against intrusion by other individuals • Birds sing or display to signal their territory; energetically costly • Benefit: increased food intake

  29. Sexual Selection • Reproductive strategies: decisions about mating • How many mates to have • How much time devoted to rearing offspring • How much energy devoted to rearing offspring • Evolved partly in response to cost of reproduction...efficient strategies in a niche

  30. Sexual Selection Advantage of male mate choice. Male Mormon crickets choose heavier females as mates, larger females have more eggs • Male Mormon crickets use 30% of their body weight making up a spermatophore (nutritive protein containing packet) for the female

  31. Sexual Selection • Mating systems reflect adaptations for reproductive success in a niche • Energy costs, food resources, nest sites, distribution of opposite sex • Mating systems • Monogamy: one male one female • Polygyny: one male many females • Polyandry: one female many males

  32. Sexual Selection • Mating systems influenced by ecology • Territory size • Needs of offspring • Both parents: monogamy • Altricial: offspring require long care • Precocial: little care required • Polyandrous systems: males usually care for the young, females mate with many males

  33. Altruism • Altruism: the performance of an action that benefits another individual at a cost to the actor • Question: if altruism imposes a cost to an individual, how could an allele be favored by natural selection? • Group selection: rare • Among groups: leads to a decrease in allele’s frequency • Within groups: may favor the allele • Kin selection: direct genetic advantage; selection favors relatives

  34. Social Systems • Society: a group of organisms of the same species that are organized in a cooperative manner • Advantages • Kin selection: greater odds of alleles surviving in the gene pool • Greater protection from predators • Increase feeding and mating success

  35. Social Systems Flocking behavior decreases predation

  36. Social Systems • Insect societies include individuals specialized for different tasks • Castes: groups of individuals that differ in size and morphology and perform different tasks • Workers and soldiers • Honeybees • Leaf-cutter ants • Fire ants

More Related