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Science Dept.

Biology BIO 100
The Theory of Evolution and Natural Selection

  1. Evolution: a Change in the Genes of or in the Gene Frequencies of a Population

  2. Evidence for Evolution

    1. Fossils

      1. Grand Canyon: 2 Billion Years of Earth History

      2. Law of Superposition: for Strata - Oldest at Bottom; Youngest at Top

      3. Horse Evolution: 55 million Years of Past Evolution

    2. Embryology: "Ontogeny Recapitulates Phylogeny"

      1. For Example the Pharyngeal Gill Clefts

    3. Intermediate Forms and "Living Fossils"

      1. Archaeopteryx, First Bird: Reptiles to Bird

      2. Peripatus: Annelids to Arthropods

      3. Metasequoia: "Dawn Redwood"

      4. The Coelacanth, Latimera, a Direct Relative of the Crossopterygian fish: Fish to Amphibian

    4. Vestigial Structures

      1. Hip Bones in Snakes

      2. Appendix in Man

      3. Coccyx in Man

      4. "Wisdom" Teeth in Man

    5. Molecular

      1. General: DNA, RNA

      2. Cytochrome C

  3. Historical Developement of the Theory of Evolution

    1. Anaximander

    2. Aristotle

    3. Buffon

    4. Hutton

    5. Lamark: "Inheritance of Acquired Characteristics"

    6. Darwin: The Voyage of the Beagle

    7. Wallace

  4. The Mechanism of Evolution

    1. The Darwin - Wallace Theory

      1. Variation Exists Among Members of a Particular Species

      2. Overproduction Usually Occurs and More Individuals Are Produced than Can Be Supported in a Particular Environment

      3. Competition Results from the Population Pressure on the Environmental Resources

      4. Natural Selection: Certain Individuals, with Favorable Characteristics for the Particular Environment, Survive

      5. When Favored Individuals Survive these Characteristics Can Be Passed on to their Offspring

    2. The Modern Concept - Neo Darwinism

      1. Variation Exists in Living Things Via Genes

      2. The Role of the Environment is Not to Produce the Variations but to Select the Variations, the Genes

      3. Genes, which Are of Value in the Environment, Persist

      4. Differential Reproduction Occurs Because of the Success of Favored Forms

      5. The Favored Genes Are Passed on

    3. Mutations Do Not Usually Play a Major Role

      1. Chromosomal

        1. Deletions

        2. Translocations

        3. Inversion

      2. Induced

        1. Radiation Particle

        2. Radiation EM

        3. Chemicals

        4. Virus

  5. Adaptations

    1. Gene Frequency Change due to Change in Environment

    2. For Example: Biston betularia Evidence from Personal and Museum Collections

      Color
      Variation      		 Light Grey Dark Grey Light Grey
      Background Light Lichens & Birch Dark Soot Covered Bark Light Lichens & Birch
      Situation Before Pollution Pollution
      & Industrial Revolution      		 After
      Pollution Abatement &
      Return to Natural State

  6. Speciation

    1. Time Factor of 10,000 and 1,000,000 Years

    2. Demes - Local Population

    3. Barriers

      1. Geographical

      2. Biological

        1. Differences in Behavior
        2. Differences in Breeding Season
        3. Biological Incompatibility (E.G. of Gametes)

  7. Divergence and Adaptive Radiation

    1. For Example: Finches on the Galapagos Islands

    2. The Mammal Line

  8. Convergence and Parallelism

    1. The Parallelism of Marsupials and Placentals

    2. The Shark, the Ichthyosaur and the Porpoise

  9. The Three Situations

    1. Adapt to the New Situation

    2. Migrate to a Similar Environment

    3. Go Extinct
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