Animal behavior.txt

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Animal behavior.txt
2009-11-10 21:13:38
sexual selection

lec 19
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  1. what is the batemen experiment?
    • 3 males and three females in each vial . each fly had a unique dominant marker allowing him to ID the parent of all the offspring.reproductive success increased in males as the number of mates increased. males have higher potential because egg production limits reproductive rate
    • also males show greater variation in reproductive success than females, so traits influencing male reproductive success are under selection.
  2. what does degree of sexual dimorphism indicate?
    it indicates intensity of sexual selection.
  3. epigamic selection, why are females so choosy?
    • choice provide direct benefits to female ( find fertile mate, improve immediate survival)
    • choice provides genetic benefits to offspring ( fisher's runway process where choosy daughters produce ornamented sons, and good genes where choosy females produce offspring with higher viability)
  4. what is the direct benefit in sedge wrablers?
    males with large song repertoires provide more food to nestling.
  5. why males only provid sperm?
    • because females should select for indirect benefits ( genetic characteristics that their sons and daughters will inherit)
    • genes that influence male attractiveness produce sexy sons
    • good genes are those that influence viability
  6. what mechanism does good gene model require?
    • it requires mechanism for maintaining heritable variation in offspring viability.
    • handicap models refer to male traits that can only be displayed by males in good condition. ( there are honest indicators of male condition)