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Genes, Chromosomes, etc. PowerPoint Presentation
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Genes, Chromosomes, etc.

Genes, Chromosomes, etc.

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Genes, Chromosomes, etc.

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  1. Genes, Chromosomes, etc. The tiny mechanisms of evolution

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  3. Evolution at the Population Level

  4. Gene Flow • The Movement of Alleles • The Movement of AllelesMigration and Inter-breeding

  5. Genetic Drift • Random change in gene pool, • particularly powerful in small populations

  6. Genetic Drift

  7. Genetic Drift and Population Size

  8. Founder Effect • Small number of individuals from population migrate and form new population • May not carry all alleles in parent population • May carry alleles in different frequencies from parent population

  9. Bottleneck Effect • Catastrophic events (floods, diseases) leave a few survivors • Survivors may not carry all alleles in parent population • May carry alleles in different frequencies from parent population

  10. The Bottleneck Effect

  11. Forces of Evolution and Genetic Variation

  12. Speciation and Forces of Evolution • Time • Mutation and natural selection produce change over time • Enough time (and change) leads to appearance of new “kind” • Reproductive isolation • No gene flow to reduce differences between populations • Mutations, genetic drift, and natural selection increase differences