Evolution

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  • Evolution

    1. 1. The effects of mutations can be: <ul><li>Neutral </li></ul><ul><li>Beneficial </li></ul><ul><li>Harmful </li></ul><ul><li>All of the above </li></ul>
    2. 2. A scientific theory is? <ul><li>Little more than a hunch </li></ul><ul><li>An unproven idea that may or maynot have evidence to support it </li></ul><ul><li>A related set of insights, supported by evidence </li></ul>
    3. 3. Darwin's Puzzle Or where did the theory of evolution come from
    4. 4. Setting the stage <ul><li>Charles Lyell </li></ul><ul><ul><li>Geological forces account for changes in the Earth’s surface </li></ul></ul><ul><li>Jean-Baptiste de Lamarck </li></ul><ul><ul><li>Organisms change over generations </li></ul></ul><ul><ul><ul><li>Inherited characterisitics </li></ul></ul></ul><ul><li>Georges Cuvier </li></ul><ul><ul><li>The extinction of species on earth </li></ul></ul><ul><ul><ul><li>Fossils show change in species over time </li></ul></ul></ul>
    5. 5. The voyage of the Beagle (1831-1836)
    6. 6. The first piece
    7. 7. The second piece
    8. 8. The third piece
    9. 9. Darwin’s Finches
    10. 10. Species Distributions
    11. 11. The Final Piece Fourth Piece
    12. 12. Variation Reproduction Adaptation Natural selection Just the beginning
    13. 13. Evolutions Core Principles <ul><li>Common descent through modification </li></ul><ul><li>Natural Selection </li></ul>
    14. 14. Common Descent with modification <ul><li>Fossil Record </li></ul><ul><ul><li>Similar layers hold similar fossils </li></ul></ul><ul><ul><li>New layers hold more complex fossils </li></ul></ul><ul><li>Morphology </li></ul>
    15. 15. Common Descent with modification Tracking Evolution With DNA
    16. 16. A. True B. False <ul><li>Evolution fashions organisms without any forethought or plan for their ultimate design </li></ul>
    17. 17. Darwin’s phrase “common descent with modification” means that: <ul><li>  Natural selection changes species over time.  </li></ul><ul><li>The species that exist today descended from other, preexisting species; species change over time. </li></ul><ul><li>  Humans descended from a preexisting ancestral species that lived in trees.   </li></ul><ul><li>The ancestral species of organisms that are alive today were more primitive. </li></ul>
    18. 18. <ul><li>Individuals </li></ul><ul><li>Offspring </li></ul><ul><li>Populations </li></ul><ul><li>Genes </li></ul>What is it that evolves?
    19. 19. What is it that evolves?
    20. 20. What is it that evolves?
    21. 21. What is it that evolves? <ul><li>Populations are the essential units that evolve </li></ul><ul><ul><li>A population is all of the members of a species that live in a defined geographic region at a given time </li></ul></ul>
    22. 22. How do populations evolve? <ul><li>Through genes! </li></ul><ul><li>Gene Pool ! </li></ul><ul><ul><li>Population + Their Genes + Their Alleles </li></ul></ul><ul><ul><li>All the alleles that exist in a population </li></ul></ul>
    23. 23. Definitions of Evolution <ul><li>Evolution: any genetically based phenotypic change in a population of organism over successive generations </li></ul><ul><li>Microevolution: a change in the frequency of alleles in a population over a short period of time </li></ul>
    24. 24. Microevolution: 5 agents of change <ul><li>Mutations: </li></ul><ul><li>Are a change in the nucleotide sequence </li></ul><ul><li>The only way new genetic information arises </li></ul><ul><li>Can be additive, build upon earlier mutations </li></ul><ul><li>All of these are true of mutations </li></ul><ul><li>Only some of these are true </li></ul>
    25. 25. 5 agents of change (cont): <ul><li>Gene Flow: </li></ul><ul><li>Migration of individuals or populations </li></ul><ul><li>immigration </li></ul><ul><li>emigration </li></ul>
    26. 26. 5 agents of change (cont): <ul><li>Genetic Drift: Chance alterations in allele frequencies </li></ul>Large population=10,000 Small population =10 Allele frequency = 1000/10,000 or 10% Allele frequency = 1/10 or 10% 50% Survive (450 with allele) 50% Survive Allele frequency =0/5 or 0% Allele frequency =450/5000 or 9%
    27. 27. 5 agents of change (cont): <ul><li>Sexual Selection </li></ul><ul><ul><li>Differential breeding success through ability to find/attract mates </li></ul></ul>
    28. 28. 5 agents of change (cont): <ul><li>Natural Selection: “survival of the fittest” </li></ul>What does it mean to be “fit”?
    29. 29. Modes of Selection Stabilizing Selection TIME
    30. 30. Modes of Selection
    31. 31. Modes of Selection

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