1. Unit 5 : Evolution Chapter 15 - Darwin’s Theory of Evolution

2. Charles Darwin English Born 1809 HMS Beagle - 1831 Naturalist Very Religious

3. Darwin’s Observations Animals and plants were well adapted Diverse reproductive strategies Puzzled by location of animals –Rabbits in Argentina, not in Australia Fossils –similar, dissimilar, Extinction

4. The Beagle’s Journey

5. Pinta Island Intermediate shell Pinta Isabela Island Dome-shaped shell Hood Island Saddle-backed shell Hood Floreana Santa Fe Santa Cruz James Marchena Fernandina Isabela Tower Giant Tortoises of the Galápagos Islands Section 15-1

6. The Galapagos Islands DesertLarge rainfall Intermediate Shell Domed Shell Saddle backed Shell Climate variation throughout

7. Tortoises of the Galapagos Saddleback long neck, curved shell, found on Hood Island, desert like Dome Shaped shorter neck, domed shell, lush vegetation, covers the ground, Isabela island

8. Many different varieties in different locations Finches

9. Journey Home Animals and plants varied a great deal from island to island Did the organisms on different islands belong to the same species? Was the ancestor from S. America?

10. Influences on Darwin Fossil Record

11. James Hutton - 1785 Earth - millions of years old, not 5700

12. Charles Lyell - 1833 Past events are explained by the processes that scientists can see today.

13. Jean-Baptiste Lamarck - 1809 Proposes 1st theory of evolution –use vs. disuse –acquired traits are passed on –leads to changes in species

14. Figure 15–7 Lamarck’s Theory of Evolution Section 15-2

15. Thomas Malthus - 1798 Economist - unchecked population growth leads to a lack of space and food Frog Eggs - What detemines survival?

16. Artificial Selection Farmers and breeders –Selective Breeding

17. Darwin’s View - On the Origin of the Species - 1859 Darwin: Reluctant Rebel

18. Natural Variation passed on to future generations

19. Struggle for Existence

20. Fitness Ability to survive and reproduce successfully

21. Adaptations - physical characteristics or behaviors Camouflage

22. Survival of the Fittest - (Natural Selection) Individuals that are best suited for their environment have high levels of fitness and therefore survive and reproduce

23. Descent with Modification Species change overtime All organisms share a common ancestor (common descent)

26. Darwin’s Evidence of Evolution Fossil Record Distribution of Living Species Homologous Body Structures Embryo Development

27. Fossil Record Evidence of change over time Age of the Earth

28. Distribution of Living Species - I Unrelated organisms look similar because of common ecological conditions - Convergent Evolution

29. Beaver NORTH AMERICA Muskrat Capybara SOUTH AMERICA Coypu Figure 15–14Geographic Distribution of Living Species Beaver Muskrat Beaver and Muskrat Coypu Capybara Coypu and Capybara

31. Distribution of Living Species - II Finches - all share a common mainland ancestor, differences are due to the environment

32. Homologous Structures - same basic design, modifications

33. Vestigial Organs - traces of homologous structures

34. Embryo Development Embryonic Cells develop in the same group and similar patterns

35. Reviewing Darwin’s Theory Variation Large amounts of offspring Competition Struggle for Existence Survival of the Fittest Descent with Modification via Natural Selection Common Descent How does evolution really work?evolution really work?