BIO 258 Notes
WEEK #7.
NATURAL SELECTION

• Adaptation. (Futuyma ch. 12; Minkoff ch. 10; E17).
  • Structural adaptations
  • Biochemical adaptations
  • Color & pattern adaptations:
    camouflage, industrial melanism, mimicry
  __________
• Selection for single-gene traits (Futuyma ch. 13; Minkoff Ch. 11; E18).
  • Survivorship & fitness coefficients
  • Selection against dominants
  • Selection against recessives
  • Selection agaiunst heterozygotes
  • other possibilities
  __________
• Selection for quantitative traits (Futuyma ch. 14; E19)
• Forms of selection:
  • Stabilizing (centripetal) selection (e.g., Bumpus' sparrows)
  • Disruptive (centrifugal) selection
  • Directional selection
    examples: Aristelliger, corn, mice, humans
• Agents of selection:
  • Artificial selection (by human agency)
  • Natural selection (by natural agency)
    1. by predators
    2. by pathogens, parasites, & other diseases
    3. by starvation
    4. by environmental (climatic) extremes (of temperature, etc.)
    5. other physical agents: fire, landslides, etc.
    6. sexual selection
  __________
• Persistence of variability (Minkoff Ch. 12; E20)
  • Importance of maintaining variability
  • Forces that erode variability
  • Maintaining variability cytologically
  • Maintaining variability ecologically: polymorphism; maintaining balanced polymorphism
  • Measuring genetic variability in populations; electrophoresis
  • Neutral gene theory, etc.

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