Bio presentation section 24 point 3

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Bio presentation section 24 point 3

  1. 1. Section 24.3 Joe Smith
  2. 2.  Often results in sexual dimorphism • More intense with males Formof Natural Selection Female
  3. 3. 2 methods • Intrasexual  Competition within one sex for opportunity to mate with opposite sex • Intersexual  “Mate choice”  “Cryptic Female Choice”  Less Obvious These two methods can overlap
  4. 4.  Competing between members of one sex for opportunity to mate with the opposite Examples • Horns on male goats • Antlers on male deer • Enlarged claws on male fiddler crabs
  5. 5.  Females are picky • Seen in Indian peafowl • “Classic” form of intersexual selection “Cryptic female choice” • Less obvious • Female reproductive tract is selective for genetically un-related sperm
  6. 6.  NOT always beneficial for survival • Female guppies prefer brightly colored mates • Bright colors are easier seen by predators Effects can be measured by abundance of traits
  7. 7.  Many different hypotheses • Related to upbringing of offspring • Dependant on fitness  Age is a factor
  8. 8.  Governed by same processes • Directional • Stabilizing • Diversifying • Balanced
  9. 9. Feature InvestigationSeehausen and van Alphen Found That Male Coloration in African Cichlids Is Subject to Female Choice
  10. 10.  Cichlidae family one of largest and most diverse • Vary by:  Coloration  Body Shape  Behavior  Feeding Habits • Largest population in Eastern African lakes • Known for complex mating behavior
  11. 11.  P. pandamilia and P. nyerierei can interbreed Both found in Lake Victoria • Certain areas of the lake have interbreeding; others do not Coloration valued in female choice of mate

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