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Exams returned W 2/13----Bonus #1 due F 2/15

Exams returned W 2/13----Bonus #1 due F 2/15. As DNA changes; traits change. DNA. Traits. Evolution: changes in DNA as information transmitted. O. O. O. Bacteria with mutation causing resistance. O. O. O. O. O. O. O. O. Changes to groups, not individuals.

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Exams returned W 2/13----Bonus #1 due F 2/15

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  1. Exams returned W 2/13----Bonus #1 due F 2/15

  2. As DNA changes; traits change. DNA Traits

  3. Evolution: changes in DNA as information transmitted O O O Bacteria with mutation causing resistance O O O O O O O O Changes to groups, not individuals.

  4. Evolution: changes in DNA as information transmitted O O O Bacteria with mutation causing resistance O O O O O O O O Changes to groups, not individuals. Apply antibiotic O Continues to replicate X X X O O O X X X O O O O O O O O O O O X X X X O O O O Kills most bacteria. Except if some have mutation that allow them to be resistant. O O O O Population of resistant bacteria

  5. Evolution: A species’ genetic component changes as the individuals reproduce. These changes are based on how the DNA changes and who reproduces.

  6. Natural Selection: Individuals that are most successful at reproducing will pass on more of their genetic information.

  7. Reproductive success = evolutionary success

  8. Are genes the only replicators?

  9. Memes: transmissible ideas • Ideas can act similarly to genes • Contain information • Replicate with imperfect fidelity

  10. Mutations

  11. Memes: transmissible ideas • Ideas can act similarly to genes or viruses • Contain information • Replicate with imperfect fidelity

  12. Memes: transmissible ideas • Ideas can act similarly to genes or viruses • Contain information • Replicate with imperfect fidelity Evolve: most successful replicators become most abundant

  13. Genes Slow replication High copy fidelity Universal in organisms Memes Rapid replication Low copy fidelity Limited to some organisms Only humans can transmit complex memes? Contrasts between memes and genes

  14. Selection of memes and genes can be at odds Evolution of memes and genes NvN chpt 8

  15. Humans can pass on genes and/or memes

  16. Do memes make humans unique?

  17. Human Population Growth

  18. Natural Selection: Individuals that are most successful at reproducing will pass on more of their genetic information.

  19. Artificial Selection: Individuals chosen by humans will reproduce and pass on their genetic information.

  20. from Teosinte Maize By artificial selection that began ~10,000 years ago.

  21. Wild Brassica oleracea: small side buds Artificial selection 1. Select individuals that have the largest side buds and breed them. 2. Of the offspring, select individuals that have the largest side buds and breed them. Number of Individuals 3. Of the offspring, select individuals that have the largest side buds and breed them. 4. After several generations, bud size increases dramatically. 0 1 2 3 Size of buds (cm) Brussels sprouts: extremely large side buds

  22. Wild Brassica oleracea: small side buds Selection only works if there is variability in the population Artificial selection 1. Select individuals that have the largest side buds and breed them. 2. Of the offspring, select individuals that have the largest side buds and breed them. Number of Individuals 3. Of the offspring, select individuals that have the largest side buds and breed them. 4. After several generations, bud size increases dramatically. 0 1 2 3 Size of buds (cm) Brussels sprouts: extremely large side buds

  23. Different foods from one species of plant. Created by artificial selection. CB 22.10

  24. Individuals are selected… But populations evolve via changes in DNA during reproduction.

  25. Evolution can only occur when both of these conditions are met: • Genetic diversity gives rise to individuals with different traits • and • Not all individuals can reproduce CB 22.9

  26. CB 23.11 Variation of a trait within a species

  27. Three basic types of selection… • Directional • Stabilizing • Disruptive

  28. CB 23.12 Directional Selection

  29. Directional Selection has led to an increase in swallow size

  30. CB 23.12 Stabilizing Selection

  31. Human birth weight has been stably selected

  32. CB 23.12 Disruptive Selection

  33. Disruptive Selection in blackbellied seedcrackers

  34. CB 23.12 The three different types of selection

  35. Evolution: • A species’ genetic component changes as the individuals reproduce due to… • Non-random changes (natural selection) • Random changes (genetic drift/bottleneck) • Mutations add new alleles or genes

  36. Exams returned W 2/13----Bonus #1 due F 2/15

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