1. 1 Where did they originate ?

2. 2 Theory of Spontaneous Generation 1. Living organisms arose “spontaneously” 2. Believed to explain “animalcules”

3. 3 Aristotle (384 –322 BC) 1. Proposed theory of spontaneous generation 2. Also called abiogenesis 3. lasted 2000 years

4. 4

5. 5 Examples of Spontaneous Generation

6. 6 Example #1 Observation: Every spring, Nile River flooded areas of Egypt, leaving behind nutrient-rich mud that enabled the people to grow that year’s crop of food. However, along with the muddy soil, large numbers of frogs appeared that weren’t around in drier times Observation: Every spring, Nile River flooded areas of Egypt, leaving behind nutrient-rich mud that enabled the people to grow that year’s crop of food. However, along with the muddy soil, large numbers of frogs appeared that weren’t around in drier times

7. 7 Example #1 Conclusion: perfectly obvious that muddy soil gave rise to frogs

8. 8 Example #2 Observation: farmers stored grain in barns with thatched roofs (like Shakespeare’s house). leaking. leads to spoiled or moldy grain, and of course there were lots of mice around. Observation: farmers stored grain in barns with thatched roofs (like Shakespeare’s house). leaking. leads to spoiled or moldy grain, and of course there were lots of mice around.

9. 9 Example #2 Conclusion: It was obvious to them that the mice came from the moldy grain.

10. 10 Example #3 Observation: for centuries Sewage flowed down the streets, and left over food was thrown out into the streets. Many cities had major rat problems and a disease called Bubonic plague. Observation: for centuries Sewage flowed down the streets, and left over food was thrown out into the streets. Many cities had major rat problems and a disease called Bubonic plague.

11. 11 Example #3 Conclusion: sewage and garbage turned into the rats.

12. 12 Example #4 Observation: no refrigerators meant battling flies around meat. Observation: no refrigerators meant battling flies around meat. Typically, carcasses were “hung by their heels,” customers selected which chunk the butcher would carve off for them. Typically, carcasses were “hung by their heels,” customers selected which chunk the butcher would carve off for them.

13. 13 Example #4 Conclusion: rotting meat was the source of the flies.

14. 14 Abiogenesis Recipes Recipe for bees: Recipe for bees: Kill a young bull, and bury it in an upright position so that its horns protrude from the ground. After a month, a swarm of bees will fly out of the corpse.

15. 15 Abiogenesis Recipes Recipe for mice: Recipe for mice: Place a dirty shirt or some rags in an open pot or barrel containing a few grains of wheat. In 21 days, mice will appear.

16. 16 Disproving Spontaneous Generation

17. 17 C. Francesco Redi (1668) 1. hypothesis was “rotten meat does not turn into flies”

18. 18 Redi’s Findings 2. Evidence against SG: 1. Unsealed – maggots on meat 2. Sealed – no maggots 3. Gauze –maggots on gauze only 3. Gauze –maggots on gauze only

19. 19 Results of Redi’s Experiments results only accepted for larger organisms results only accepted for larger organisms

20. 20 Disproving Spontaneous Generation of Microbes

21. 21 D. John Needham (1745) 1. Showed microorganisms flourished in soups exposed to air 2. Claimed a “life force” could cause spontaneous generation

22. 22 Needham’s Results 3. bacteria were already present didn’t boil long enough didn’t boil long enough

23. 23 E. Lazzaro Spallanzani’s (1765) 1. Boiled soups for an hour and sealed containers by melting. 2. soups remained clear. 3. Later, broke seals & soups became cloudy

24. 24 Spallanzani’s Results

25. 25 Conclusion 4. Critics said sealed vials did not allow “life force”

26. 26 The Theory Finally Changes

27. 27 F.Louis Pasteur (1822- 1895) 1.Performed experiments to disprove Theory of SG.

28. 28 a. Pasteur's Experiment - Step 1 S-shaped Flask S-shaped Flask shape intended to trap any dust containing bacteria shape intended to trap any dust containing bacteria

29. 29 b. Pasteur's Experiment - Step 2 Flasks boiled Flasks boiled Microbes Killed Microbes Killed

30. 30 c. Pasteur's Experiment - Step 3 Flask left at various locations Flask left at various locations Did not turn cloudy Did not turn cloudy

31. 31 Pasteur's Experimental Results

32. 32 Proved biogenesis Proved biogenesis The Theory of Biogenesis Figure 1.3

33. 33 Evolution Diversity of Life

34. 34 “Nothing in biology makes sense EXCEPT in the light of evolution.” Theodosius Dobzhansky Evolution Charles Darwin in later years

35. 35 History of Evolutionary Thought

36. 36 Early Ideas On Earth’s Organisms Aristotle believed species were fixed creations arranged by their complexity Aristotle believed species were fixed creations arranged by their complexity Idea lasted 2000 years Idea lasted 2000 years

37. 37 Early Ideas On Earth’s Organisms Linnaeus – 1 st to group similar organisms and assign them Latin names Linnaeus – 1 st to group similar organisms and assign them Latin names Two word name (Genus species) Two word name (Genus species) Known as Binomial nomenclature Known as Binomial nomenclature

38. 38 Evolutionary Timeline

39. 39 Lamarck’s Theory of Evolution Jean-Baptiste Lamarck, 1809 Jean-Baptiste Lamarck, 1809 Change Occurs Over Time Change Occurs Over Time Changes Are acquired in an organism’s lifetime Changes Are acquired in an organism’s lifetime acquired changes were passed to offspring acquired changes were passed to offspring

40. 40 Lamarck’s Theory of Evolution Idea called Law of Use and Disuse Idea called Law of Use and Disuse If a body part were used, it got stronger If a body part were used, it got stronger

41. 41 Lamarck’s Theory of Evolution Inheritance of Acquired Characteristics Inheritance of Acquired Characteristics Traits Could Then Be Passed On To Their Offspring Traits Could Then Be Passed On To Their Offspring Over Time This Led To New Species Over Time This Led To New Species

42. 42 Lamarck’s Theory of Evolution Use & Disuse - Could Change The Size Or Shape Use & Disuse - Could Change The Size Or Shape Giraffe’s Necks Longer from stretching) Giraffe’s Necks Longer from stretching)

43. 43

44. 44 Lamarck’s Theory of Evolution Inheritance Of Acquired Traits Inheritance Of Acquired Traits –Traits Acquired During Ones Lifetime Would Be Passed To Offspring Clipped ears of dogs could be passed to offspring!

45. 45 Lamarck’s Mistakes Did NOT Know traits were inherited (passed through genes) Did NOT Know traits were inherited (passed through genes) Mutation Occurs Before An Organism Is Born Mutation Occurs Before An Organism Is Born

46. 46 Charles Darwin the Naturalist

47. 47 Voyage of the Beagle Charles Darwin Born 1809 Born 1809 Joined Crew of HMS Beagle, 1831 Joined Crew of HMS Beagle, 1831 Naturalist Naturalist 5 Year Voyage around world 5 Year Voyage around world

48. 48 A reconstruction of the HMS Beagle sailing off Patagonia. Darwin’s Voyage of Discovery

49. 49 Darwin Left England in 1831 Darwin returned 5 years later in 1836

50. 50 The Galapagos Islands West of South America West of South America Animals On Islands Unique Animals On Islands Unique »Tortoises »Iguanas »Finches

51. 51

52. 52 The Galapagos Islands More types of finches appeared on the islands where the available food was different (seeds, nuts, berries, insects…) More types of finches appeared on the islands where the available food was different (seeds, nuts, berries, insects…) different types of beaks adapted to their type of food gathering different types of beaks adapted to their type of food gathering

53. 53

54. 54 Darwin’s Observations & Conclusions The Struggle for Existence

55. 55 Evidence for Evolution – The Fossil Record

56. 56 Definition Evolution is the slow, gradual change in a population of organisms over time

57. 57 Darwin’s Observations populations tend to remain stable in size Environmental resources are limited

58. 58 Darwin’s Conclusion Overproduction leads to a struggle for existence Only a fraction survive each generation Survival of the Fittest

59. 59 Darwin’s Conclusion most fit for environment leave more offspring

60. 60 Darwin’s Theory of Evolution Organisms Change OverTime

61. 61 Common Descent with Modification organisms descended from common ancestors organisms descended from common ancestors diverge from a common form diverge from a common form

62. 62. Natural Selection Driving force for evolution Driving force for evolution struggle for resources, strongest survive & reproduce struggle for resources, strongest survive & reproduce

63. 63 Natural Selection Cannot Be Seen Directly Cannot Be Seen Directly It Can Only Be Observed As Changes In A Population Over Many Successive Generations It Can Only Be Observed As Changes In A Population Over Many Successive Generations –Radiation –Fossil Record

64. 64 Descent With Modification Takes Place Over of Time Takes Place Over Long Periods of Time Natural Selection Can Be As Changes In Natural Selection Can Be Observed As Changes In –Body Structures –Ecological Niches –Habitats

65. 65 Descent With Modification Species From Their Ancestors Species Today Look Different From Their Ancestors Each Living Species Has Each Living Species Has –Descended –With Changes –From Other Species –Over Time

66. Descent With Modification 66

67. 67 Theory of Evolution Today Supporting Evidence

68. 68 Homologous Structures

69. 69 Evidence for Evolution - Comparative Embryology Similarities In Embryonic Development

70. 70 Similarities in DNA Sequence

71. 71 Evolution of pesticide resistance in response to selection

72. 72 Evolutionary Time Scales Long time scale events that create and destroy species Macroevolution: Long time scale events that create and destroy species

73. 73 Microevolution: Short time scale events that change the genotypes and phenotypes of populations Evolutionary Time Scales

74. 74 Evidence of Evolution Key Concept Darwin Argued evidence Could Be Found In: –Fossil Record –Geographical Distribution of Species –Homologous Structures –Early Development

75. 75 Fossil Record Earth is Billions of Years Old Earth is Billions of Years Old Layers of Rock Showed Evidence Of Gradual Change Over Time Layers of Rock Showed Evidence Of Gradual Change Over Time

76. 76 Geographic Distribution Animals On Different Continents But Similar Adaptations Animals On Different Continents But Similar Adaptations

77. 77 Homologous Body Structures Similar Structure Similar Structure Differ In Function Differ In Function Limb Bones Develop In Similar Patterns Limb Bones Develop In Similar Patterns »Arms, Wings, Legs, Flippers

78. 78

79. 79

80. 80 Homologous Body Structures

81. 81 Analogous structures Butterflies or insects have wings but they are very different from the birds. Butterflies or insects have wings but they are very different from the birds. Copyright © The McGraw Hill Companies. Permission required for reproduction or display

82. 82 Anatomical studies show Vestigial parts – why does a whale have a pelvis and femur bones if it has no hind limbs?

83. 83 Vestigial structures

84. 84 Vestigial structures

85. 85 Vestigial Organs Not All Serve Important Functions Not All Serve Important Functions »Appendix In Man »Legs On Skinks

86. 86 Similarities In Early Development Embryonic Structures Show Significant Similarities Embryonic Structures Show Significant Similarities Embryo – early stages of vertebrate development Embryo – early stages of vertebrate development

87. 87 Human Fetus – 5 weeks

88. 88 ChickenTurtle Rat

89. 89