Lecture Notes: Natural Selection and AP Biology Exam Preparation

Introduction to Natural Selection

• Focus on Unit 7 of AP Biology, crucial for AP Bio exam.
• Encouragement to students for exam preparation.
• Daily review sessions available on Instagram and a comprehensive review guide.
• Importance of practice questions in preparation.

Resources for Review

• Recorded Free Response Questions (FRQs) from 2013-2023 available.
• 120 review games and quizzes available online.
• Review PowerPoints and live stream sessions provided.

Topics Covered

• Natural Selection
  • Proposed by Charles Darwin.
  • Key concept: descent with modifications.
  • Favorable traits lead to better survival chances.
  • Example: Peppered moths and antibiotic resistance.
• Artificial Selection
  • Human-driven selection for certain traits in organisms.
  • Examples: Dog breeds, wild mustard plant.

Types of Natural Selection

• Disruptive Selection
  • Extremes are favored over intermediates.
  • Example: Beak sizes in birds due to food availability.
• Stabilizing Selection
  • Favors intermediate traits.
  • Example: Birth weights in humans.
• Directional Selection
  • Favors a shift towards a particular phenotype.
  • Example: Size increase in horses.

Hardy-Weinberg Equilibrium

• Theory to measure if a population is evolving.
• Five Conditions
  • Large population size.
  • Random mating.
  • No mutations.
  • No gene flow.
  • No natural selection.
• Changes in allele frequency indicate evolution.
• Genetic Drift
  • Random changes in allele frequencies.
  • Examples: Founder effect, bottleneck effect.

Phylogeny and Evolution Evidence

• Biochemical and Morphological Evidence
  • DNA and protein analysis for evolutionary relationships.
  • Morphological similarities in traits and structures.
• Phylogenetic Trees and Cladograms
  • Used to represent evolutionary relationships.
  • Based on similarities and differences in genetic material.

Speciation

• Biological Species Concept
  • Species are groups that can interbreed and produce fertile offspring.
• Reproductive Barriers
  • Prezygotic: Prevents mating.
  • Postzygotic: Affects hybrid offspring viability.
• Sympatric and Allopatric Speciation
  • Sympatric: New species in the same geographic area.
  • Allopatric: New species due to geographic barriers.

Practice and Questions

• Emphasis on practice questions for exam readiness.
• Importance of understanding error bars in data interpretation.
• Encouragement to utilize various resources, such as Marco Learning and The Absolute Recap.

Study Tips and Resources

• Focus on spot-checking topics that are challenging.
• Use AP classroom resources and YouTube videos for more comprehensive reviews.
• Engage in practice exams and question reviews.

Conclusion

• Encourage students to continue preparing and use available resources effectively.
• Reassurance for success in the AP Biology exam.