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Causes of Diversity and Evolution of Life on Earth

Causes of Diversity and Evolution of Life on Earth. Alfred Russell Wallace. Charles Darwin. Causes for Diversity of Life. All populations have the potential to increase in size Many populations retain a constant size Many individuals die young

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Causes of Diversity and Evolution of Life on Earth

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  1. Causes of Diversity and Evolution of Life on Earth Alfred Russell Wallace Charles Darwin

  2. Causes for Diversity of Life • All populations have the potential to increase in size • Many populations retain a constant size • Many individuals die young • Individuals in a population differ in their abilities • Some of these abilities affect survival • Best adapted individuals are most likely to survive and produce offspring (Natural Selection) • “Abilities” are passed on to offspring (Genetics) • Over time the “abilities” of the population shift to include advantageous traits (Evolution)

  3. Note:Natural Selection Affects IndividualsEvolution Affects Populations

  4. Net Result:Populations change with time to become better adapted to their environment (Evolution)

  5. Apply Antibiotic Survivor’s with Resistance Reproduce Example: Microbe Resistance

  6. Why is there Genetic Variation? (How do will fill the Gene Pool?)

  7. How does it Work? Variation is a result of (1) Mutations and (2) Sex Errors occur in DNA Replication On average 1:10,000-100,000 genes per individual per generation Errors increased by exposure to radiation, etc. Most Mutations are bad or at least neutral What is “good” depends on environmental conditions

  8. Evidence for Evolution

  9. Evidence for Evolution: Fossils

  10. Evidence for Evolution: Analogous Structures

  11. Evidence for Evolution:Homologous Structures

  12. Evidence for Evolution:Embryology

  13. Evidence for Evolution:Biochemistry of Life

  14. Evidence for Evolution:Gene Sequencing

  15. Evidence for Evolution:Artificial Selection

  16. Evidence for Evolution:Artificial Selection

  17. Evidence for Evolution:Modern Examples

  18. Some InterestingEffects of Evolution

  19. Evolution & Psuedoextinction Through time Species A evolves into Species B In effect, Species A goes extinct Species B Species A

  20. Extinction Sometimes a species cannot adapt fast enough to environmental change or competition Species A

  21. “Background Extinction”:Species Lifespan

  22. Mass Extinction

  23. Evolution & Speciation Species B Species A is separated into 2 isolated populations, each affected by different environmental conditions Species A Species C In effect, Species A goes Extinct

  24. Speciation ofKaibab & Abert Squirrels

  25. Speciation of Hawaiian Honeycreepers

  26. Diversity Increases

  27. Family Genus Species Classification:Based on Evolutionary Relationships

  28. Convergent Evolution

  29. Coevolution:Plants and Pollinators

  30. Coevolution:Predator/Prey

  31. Conclusions:Biodiversity, genetic diversity, and community complexity are all the result of 100’s million of years of evolution

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