co45 - CHAPTER 45 ANIMAL BEHAVIOR Chapter Outline 45.1...

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CHAPTER 45 A NIMAL B EHAVIOR Chapter Outline 45.1 Behavior Has a Genetic Basis A. Behavior Can be Observed and Described 1. Mechanistic questions are answered by describing how an animal is biologically organized and equipped to behave. 2. Survival value questions ask how the behavior helps animals exploit resources, avoid predators, or secure a mate. 3. Behavior is an observable coordinated response to environmental stimuli. B. Inheritance of Migratory Behavior in Birds 1. Migratory birds that are caged and prevented from migrating exhibit migratory restlessness. 2. Peter Berthold noted that German blackcap warblers migrate to Africa; Cape Verde warblers do not migrate. a. If the migratory behavior was inherited, crossbred birds might show an intermediate behavior. b. Hybrids of German and Cape Verde birds perch-hopped while the Cape Verde birds did not. 3. Andreas Helbig studied the same warbler species for migration patterns. a. German blackcaps fly southwest to Spain and Africa; Austrian blackcaps fly southeast to Israel and Africa. b. Hybrids in a funnel cage left directional marks showing they were intermediate in flight paths. 4. Both of these results support the hypothesis that behavior has at least some genetic basis. C. Feeding Behavior of Garter Snakes 1. Steven Arnold tested the garter snake ( Thamnophis elegans ) for food preference. 2. Inland populations are more aquatic and feed on frogs and fish; they refused to feed on slugs. 3. Coastal populations are more terrestrial and feed on slugs. 4. The hybrid newborn garter snakes had an intermediate acceptance of slugs. 5. Work with smell receptors and tongue flicks showed that physiological differences underlie the behavior. D. Egg-laying Behavior of the Sea Slug Aplysia 1. Sea slug behavior shows endocrine involvement in behavior. 2. Following copulation, the slug extrudes long strings of eggs and uses its head movements to attach the eggs to rocks. 3. Scientists isolated an egg-laying hormone (ELH) that causes the animal to lay eggs even if it has not mated. 4. ELH is a small protein of 36 amino acids that excites the reproductive tract and causes egg expulsion. 5. Recombinant DNA studies isolated the ELH gene and showed it controls the egg-laying behavior. E. Behavior: Nature or Nurture? 1. Twin studies in humans have been used to probe the nature-versus-nurture question. 2. Fraternal twins in same family are often different; identical twins reared apart are often similar. 3. 50% of differences in personality traits appear inherited; 50% appear to be due to environmental influence. 45.2 Behavior Undergoes Development A. Fixed Action Patterns (FAPs) 1. FAPs are always performed the same way and they are elicited by a sign stimulus . 2.
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This note was uploaded on 10/24/2009 for the course BIO 172 taught by Professor Clark during the Fall '08 term at University of Michigan.

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co45 - CHAPTER 45 ANIMAL BEHAVIOR Chapter Outline 45.1...

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