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UNIT 4 – Evolution

UNIT 4 – Evolution. A BRIEF REVIEW OF SUBTOPICS. Adaptation & Variation. Extinction Adaptations: Structural Behavioural Physiological Variations How do variations develop? How do variations become adaptations?. Adaptation & Variation (con’t). Mutations Selective advantage

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UNIT 4 – Evolution

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  1. UNIT 4 – Evolution A BRIEF REVIEW OF SUBTOPICS

  2. Adaptation & Variation • Extinction • Adaptations: • Structural • Behavioural • Physiological • Variations • How do variations develop? • How do variations become adaptations?

  3. Adaptation & Variation (con’t) • Mutations • Selective advantage • Eg. Antibiotic resistance in staph. bacteria

  4. Darwin & Natural Selection • General info about Darwin • General info about voyage of Beagle, research and observations in Galapagos • Eg: Turtles & Finches • Origin of Species • Controversy surrounding Darwin

  5. Darwin & Natural Selection (con’t) Natural Selection • Process of change in populations over many generations • Individuals with certain traits survive local environmental conditions • Pass on favourable alleles to offspring • Environment exerts ‘selective pressure’ Assumptions of Natural Selection • Variation • Competition • Fitness • Adaptation

  6. Darwin & Natural Selection (con’t) Concepts: • Natural Selection • Fitness • Selective pressure • “Descent with Modification” • Artificial selection

  7. Mechanisms of Evolution Factors that Change Allele Frequencies: • Mutation • Gene Flow (Migration) • Non-Random Mating • Genetic Drift • Natural Selection

  8. Mechanisms of Evolution (con’t) • “The Bottleneck Effect” • “The Founder Effect”

  9. Types of Natural Selection RECALL: • Result of the environment selecting for individuals with certain traits that make them better suited to survive and reproduce • Over many generations, frequency of alleles of many different genes may change, resulting in significant changes

  10. Types of Natural Selection (con’t) • Stabilizing Selection • Directional Selection • Disruptive Selection • Sexual Selection

  11. Types of Natural Selection (con’t) Long Term Evolution: • Gradualism • Punctuated Equilibrium

  12. Evidence of Evolution Topics Discussed: • Fossil record • Radiometric Dating • Transitional forms • Biogeography

  13. Evidence of Evolution (con’t) Topics Discussed: • Embryonic development • Homologous structures • Vestigial structures • Atavisms • Micro-evolution happening today

  14. Evolution of Humans • Early primates • Brain development (cranial capacities) • Transition to 2 bipedal and life out of trees and onto plains • Eg: Ardi

  15. THE END … • Questions? • “Hey, quit Following me!”

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