1. The Theory of Evolution

2. How did biodiversity arise? Where did all the various types of organisms come from?

3. Evolution is… NOT the theory that we all came from monkeys!

4. Evolution is… Simply the theory that organisms change over time. A THEORY is a supported, testable explanation of a phenomena that occurred in the natural world.

5. History of Evolution The theory of evolution existed before Darwin. It was his Theory of Natural Selection that became widely accepted.

6. History of Evolution Before Darwin, it was believed that species were young and that they did not change. Lamarck first recognized that things changed over time and that they adapted over time.

7. History of Evolution Lamarck proposed that by selective use or disuse of organs, organisms acquired or lost certain traits. These traits are then passed on to offspring.

8. *History of Evolution Lamarck’s theories were good at the time but had a few flaws. In 1831, Darwin began a voyage around the world on his ship, the H.M.S. Beagle.

9. “ Their Primary Mission to survey the west coast of South America” Darwin’s role on ship was a naturalist and companion of the captain, his job was to collect biological and geological specimens Darwin read “Principles of Geology”, which the author proposed that the earth was millions of years old This influenced him as he studied marine fossils found up in the Andes mountains

10. *History of Evolution When the ship anchored, Darwin went ashore and collected plant and animal specimens for his collection. The organisms he saw were far more diverse than those of his native country.

11. The Galapagos Islands: Volcanic islands off the South American coast Island species varied from the mainland species, and from island-to-island Example: Each island had either long or short necked tortoises depending on the island's vegetation

12. * Beagle arrived in 1835 to the islands off the coast of Ecuador Darwin collected finches, mocking birds, other animals on the 4 islands he visited, he noticed that each island’s species were slightly different Only sparked a curiosity, even though Ecuador said that the islands’ tortoises could be identified by the different patterns on their shells Years later with the help of John Gould, an ornithologist, he learned that his finches and mockingbirds were exclusive to the islands and found no where else in South America With this in hand he came to the conclusion that the birds from the islands, which closely resembled mainland species must of changed when they came to the island and its unique environment.

14. Galapagos Finches Finches on the Galapagos Islands resembled a mainland finch, but there were more types Bill shapes are adaptations to different means of gathering food.

15. Darwin & Evolution This lead him to conclude that adaptation to the environment can cause diversification, including origin of new species.

16. Darwin’s Return Home With the help of information gathered by other scientists, Darwin begins his work.

17. Scientists that Influenced Darwin Hutton – Challenged the belief that earth was young – Showed that rock formation takes millions of years

18. Scientists that Influenced Darwin Lyell – Developed idea that Earth could change over time – Takes a lot of time to see the change

19. Scientists that Influenced Darwin Malthus – Human population will grow faster then the space and supplies needed to sustain it – Only those prepared to deal with this would survive

20. Darwin’s Work In 1859, Darwin published his ideas in a book called The Origin of Species The book questioned many of current theories and caused quite a reaction – but what exactly did he say?

21. the selective breeding of an organism to ensure only wanted traits are passed on to the next generation happens in new breeds of dogs, pigeons, and plants

22. Darwin’s Ideas OLD VIEW “Species are perfect and unchanging” DARWIN’S THEORY “ There ARE differences among individuals in a species and this is found in all organisms”

23. Darwin’s Ideas How do these differences appear? Natural Selection – –Those that possess traits to survive best in the environment will survive. –Those that do not die pass on their genetic code to their offspring.

24. Basic Principles of Natural Selection 1. Individuals in a population show variations among others of the same species 2. Variations are inherited 3. Animals have more young than can survive on the available resources 4. Variations that increase reproductive success will be more common in the next generation

25. Darwin’s Ideas In this way only the fittest of the species will survive and through this process of natural selection evolution (changes in the species) occur.

26. Survival of the Fittest Natural selection depends on the SURVIVAL OF THE FITTEST – FITNESS: how well an individual can survive and reproduce in its environment – Result of ADAPTATION

27. Survival of the Fittest Individuals compete to survive – STRUGGLE FOR EXISTENCE Those with adaptations well suited for their environment will survive and reproduce Those without will die off and/or leave few offspring

28. Natural Selection In this way, nature “selects” those organism who have the highest level of fitness Over time, natural selection results in overall changes in a population –DESCENT WITH MODIFICATION

29. Speciation These changes over time may lead to the development of an entirely new species Changes usually occur due to environmental conditions

30. Hunting The Peppered Moth Pretend you are a bird that preys on peppered moths Your hunting ground is the side of a tree full of peppered moths You will be given 1 second to make your choice of quadrant When a slide comes up, you will decide what quadrant to hunt in Here are the quadrants…

32. READY?

34. Hunting The Peppered Moth Which quadrant did you hunt in? Why did you choose this quadrant? How many moths were in this quadrant? How many moths were on the tree? Prepare to hunt again… Ready?

36. Hunting The Peppered Moth Which quadrant did you hunt in? Why did you choose this quadrant? How many moths were in this quadrant? How many moths were on the tree? Prepare to hunt again… Ready?

38. Hunting The Peppered Moth Let’s take a closer look at the first slide How many moths were in your quadrant? How many moths are on the tree?

40. Hunting The Peppered Moth Did you choose the 3 rd quadrant? Did you notice the black moths? This is how the peppered moth evolved in Manchester England Now let’s take a look at how the moths changed slowly over time once the trees were polluted

41. Evolution of the Peppered Moth

47. Peppered Moth Simulation Notice how the white moths were the first to be eaten due to their lack of environmental fitness Eventually all the white moths were gone and the dark moths prevailed

48. Types of Adaptation Structural – thorns on roses, webbed feet Physiological – venom in snakes, ink of an octopus Behavioral – bird migration, plants growing toward light

49. Look at these claws!! What is each adapted for?

50. Grasping - Raptors use their large curved claws to snatch fish from the water. Scratching - Pheasants scratch the soil for food & have nail-like toes. Swimming - Ducks use their feet like paddles. Perching - Robins have a long back toe, which lets them grab a perch tightly. Running - Many fast-running birds have three toes rather than four. Climbing - A woodpecker's hind toes enable it to climb without falling backward.

51. Other Interesting Adaptations….

52. Camouflage

53. Mimicry

54. Antibiotic resistance is a physiological adaptation in bacteria that evolves rapidly

55. What is the Evidence for Evolution? Fossil Record Biogeography Comparative Anatomy Comparative Embryology Comparative Biochemistry

56. provides a record of species that lived long ago show ancient species that share similarities with species that live on Earth today important source of info for determining the ancestry of organisms and the patterns of evolution

57. Fossils Some present species are not present in the fossil record Some current species are similar, but not identical, to some previous species.

58. Derived Traits – newly evolved features such as feathers, that do not appear in the fossils of common ancestors Ancestral Traits – more primitive features, such as teeth and tails that do appear in ancestral forms

59. Biogeography Organisms evolve to adapt to their particular environment, then spread to other locales. Evidence comes from the distribution of similar species found around the world Continental drift leads to geographic isolation

60. convergent evolution occurs when unrelated species occupy similar environments in different parts of the world. divergent evolution - species that were once similar to an ancestral species diverge, or become increasingly distinct.

61. Comparative Anatomy Related organisms share a unity of body plan. Structural features with a common evolutionary origin are called homologous structures. Example forelimbs

62. Homologous Structures – Anatomically similar structures inherited from a common ancestor forelimbs of vertebrates

63. Homologous Structures

64. Body parts that do not have a common evolutionary origin but are similar in function are called analogous structures. For example, insect and bird wings

65. Can be used for the same purpose but are not inherited from a common species wings on a beetle and an eagle

66. A body structure in a present-day organism that no longer serves a purpose, but was probably useful to an ancestor is called a vestigial structure Example: pelvic bones in the baleen whale

67. Structures that are the reduced forms of functional structures in different organisms appendix in humans wings on a kiwi

69. Other vestigial structures – Human appendix is useless yet in other mammals, including primates, it is necessary to aid in digestion of high cellulose diet. – Human external ear muscles still present but useless. – Humans have tailbones and some babies are occasionally born with tails.

70. Comparative Embryology Related organisms develop similarly. Early embryos of all vertebrates are very similar Early development reflects evolutionary origins Pharyngeal pouches Pharyngeal pouches Tail Fish ReptileBirdMammal

71. Do these look similar?

72. Comparative Biochemistry All living things use the same basic biological molecules for similar functions. - DNA, ATP, amino acids, etc. Metabolic systems are similar among species. - Photosynthesis, cell respiration, fermentation Basic cell structure is almost universal.

73. Modes of Selection

74. Stabilizing Selection An intermediate phenotype is favored Acts against individuals who deviate too far from the average Normal variation Selection for average size spiders

75. Example: Human Birth Weight

76. Directional Selection Favors individuals with extreme values of a trait; causes the population to move in a particular direction Normal variation Selection for longer beaks

77. Example: Biston betularia (peppered moth)peppered moth

78. Disruptive Selection Favors phenotypes of opposite extremes; disfavors intermediate phenotypes Selection for light limpets Normal variation Selection for dark limpets