1. Evolution and Biodiversity Chapter 4

2.  Concept 4-3 As a result of biological evolution, each species plays a specific ecological role called its niche.  Niche – sometimes thought of as the job or vocation of a species; involves all of its environment  Habitat – the place where an organism lives; where you would go to find this organism

3. Unique Roles for Species Generalist species Specialist species Specialists prone to extinction – giant panda

4. Core Case Study: Life on Earth  Uniquely suited for life Temperature range Liquid water Gravitational mass Oxygen  Organisms contribute to relatively consistent planetary conditions – resilient and adaptive  Biodiversity and sustainability

5. Panda and its Food

6.  Fig. 4-4, p. 68  Niche  separation  Specialist species  with a narrow niche  Generalist species  with a broad niche  Niche  breadth  Region of  niche overlap Niches of Specialist and Generalist Species  Resource use  Number of individuals

7. Specialized Feeding Niches in Birds

8. Fig. 4-5, p. 68 Louisiana heron wades into water to seize small fish Black skimmer seizes small fish at water surface Ruddy turnstone searches under shells and pebbles for small invertebrates Avocet sweeps bill through mud and surface water in search of small crustaceans, insects, and seeds Brown pelican dives for fish, which it locates from the air Dowitcher probes deeply into mud in search of snails, marine worms, and small crustaceans Herring gull is a tireless scavenger Flamingo feeds on minute organisms in mud Scaup and other diving ducks feed on mollusks, crustaceans, and aquatic vegetation Piping plover feeds on insects and tiny crustaceans on sandy beaches Knot (sandpiper) picks up worms and small crustaceans left by receding tide Oystercatcher feeds on clams, mussels, and other shellfish into which it pries its narrow beak

9. Science Focus: Cockroaches Existed for 350 million years – 3,500 known species Highly adapted, rapidly producing generalists –Consume almost anything –Endure food shortage –Survive everywhere except polar regions –Avoid predation Carry human diseases

10. Cockroaches: Nature’s Ultimate Survivors  Fig. 4-A, p. 69

12. The Right Mix of Conditions Fig. 4-1, p. 63

13. 4-1 What Is Biological Evolution and How Does It Occur?  Concept 4-1A The scientific theory of evolution explains how life on earth changes over time through changes in the genes of populations.  Concept 4-1B Populations evolve when genes mutate and give some individuals genetic traits that enhance their abilities to survive and to produce offspring with these traits (natural selection).

14. Theory of Evolution  4.7 billion years  Explains why life so diverse  Supported by fossils, chemical analysis of primitive rock, DNA, and ice cores

15. Fossilized Skeleton of a Cenozoic Herbivore Fig. 4-2, p. 65

16. Population Changes over Time  Populations evolve by becoming genetically different  Genetic variability – mutation

17. Natural Selection  Genetically favorable traits to survive and reproduce  Trait – heritable and lead to differential reproduction  Faced with environmental change Adapt Migrate Become extinct

18. Coevolution  Changes in gene pool of one species lead to changes in gene pool of the other  Bats and moths

19. Science Focus: How Did We Become Such a Powerful Species?  Key adaptations – also enabled us to modify environment  Evolved very recently  Technology dominates earth’s life support systems and NPP

20. 4-2 How Do Geological and Climate Changes Affect Evolution?  Concept 4-2 Tectonic plate movements, volcanic eruptions, earthquakes, and climate change have shifted wildlife habitats, wiped out large numbers of species, and created opportunities for the evolution of new species.

21. Plate Tectonics  Locations of continents and oceans determine earth’s climate  Movement of continents allow species to move and adapt  Earthquakes and volcanoes affect biological evolution

22. Movement of Continents

23. Fig. 4-3, p. 67 Present 65 million years ago 135 million years ago 225 million years ago

24. Present 225 million years ago 65 million years ago 135 million years ago Fig. 4-3, p. 67 Stepped Art

25. Earth’s Long-term Climate Changes  Cooling and warming periods – affect evolution and extinction of species  Five mass extinctions Eliminated half of the earth’s species Many theories why this occurred  Opportunities for the evolution of new species

26. Northern Hemisphere over 18,000 Years

27. Fig. 4-4, p. 67 18,000 years before present Modern day (August) Northern Hemisphere Ice coverage

28. 4-3 What Is an Ecological Niche?  Concept 4-3 As a result of biological evolution, each species plays a specific ecological role called its niche.

29. Unique Roles for Species  Generalist species  Specialist species  Specialists prone to extinction – giant panda

30. Panda and its Food

32.  Fig. 4-4, p. 68  Niche  separation  Specialist species  with a narrow niche  Generalist species  with a broad niche  Niche  breadth  Region of  niche overlap Niches of Specialist and Generalist Species  Resource use  Number of individuals

33. Specialized Feeding Niches in Birds

34. Fig. 4-5, p. 68 Louisiana heron wades into water to seize small fish Black skimmer seizes small fish at water surface Ruddy turnstone searches under shells and pebbles for small invertebrates Avocet sweeps bill through mud and surface water in search of small crustaceans, insects, and seeds Brown pelican dives for fish, which it locates from the air Dowitcher probes deeply into mud in search of snails, marine worms, and small crustaceans Herring gull is a tireless scavenger Flamingo feeds on minute organisms in mud Scaup and other diving ducks feed on mollusks, crustaceans, and aquatic vegetation Piping plover feeds on insects and tiny crustaceans on sandy beaches Knot (sandpiper) picks up worms and small crustaceans left by receding tide Oystercatcher feeds on clams, mussels, and other shellfish into which it pries its narrow beak

35. Science Focus: Cockroaches  Existed for 350 million years – 3,500 known species  Highly adapted, rapidly producing generalists Consume almost anything Endure food shortage Survive everywhere except polar regions Avoid predation  Carry human diseases

36. Cockroaches: Nature’s Ultimate Survivors  Fig. 4-A, p. 69

37. 4-4 How Do Extinction, Speciation, and Human Activities Affect Biodiversity?  Concept 4-4A As environmental conditions change, the balance between formation of new species and extinction of existing ones determines the earth’s biodiversity.  Concept 4-4B Human activities decrease the earth’s biodiversity by causing the premature extinction of species and by destroying or degrading habitats needed for the development of new species.

38. Speciation  Geographic isolation  Reproductive isolation  Millions of years in slow-producing species  Hundreds of years in rapidly reproducing species

39. Geographic Isolation

40. Fig. 4-6, p. 70 Spreads northward and southward and separates Arctic Fox Gray Fox Different environmental conditions lead to different selective pressures and evolution into two different species. Adapted to cold through heavier fur, short ears, short legs, and short nose. White fur matches snow for camouflage. Adapted to heat through lightweight fur and long ears, legs, and nose, which give off more heat. Northern population Southern population Early fox population

41. Extinction  Endemic species vulnerable to extinction  Background extinction  Mass extinction  Balance between speciation and extinction determines biodiversity of earth  Speciation generally more rapid than extinction

42. Extinction through Habitat Loss Fig. 4-7, p. 70

43. Human Activities and Extinction  Cause premature extinction of species  Earth took millions of years to recover from previous mass extinctions

44. 4-5 How Might Genetic Engineering Affect the Earth’s Life?  Concept 4-5 Genetic engineering enables scientists to transfer genetic traits between different species – a process that holds great promise and raises difficult issues.

45. Humans Change Population Genetics  Artificial selection – slow process  Selective breeding  Crossbreeding – not a form of speciation  Genetic engineering

46. Results of Genetic Engineering  Genetically modified organisms (GMOs)  Gene splitting rapid vs. artificial selection  Modified crops, new drugs, fast-growing animals

47. Steps in Genetic Engineering (1)

48. Steps in Genetic Engineering (2)

49. Fig. 4-8, p. 72

50. Fig. 4-8a, p. 72 Phase 1 Gene Transfer Preparations Host cell Enzymes integrate plasmid into host cell DNA. A. tumefaciens (agrobacterium) Agrobacterium takes up plasmid Foreign gene integrated into plasmid DNA, which can be used as a vector plasmid Extract plasmid A. tumefaciens Plant cell Foreign gene if interest Extract DNA Phase 2 Make Transgenic Cell

51. Fig. 4-8b, p. 72 Phase 3 Grow Genetically Engineered Plant Foreign DNA Host DNA Nucleus Transgenic plant cell Cell division of transgenic cells Cultured cells divide and grow into plantlets (otherwise teleological) Transgenic plants with desired trait

52. Pros and Cons of Genetic Engineering  Pros May help cure genetic defects May improve organisms May lead to development of secondary evolution  Cons Ethical issues Privacy issues Designer babies GMO crossbreeding with original organisms

53. Genetically Engineered Mice Fig. 4-9, p. 73

54. Animation: Carbon Bonds

55. Animation: Stanley Miller’s Experiment

56. Animation: Evolutionary Tree of Life

57. Animation: Stabilizing Selection

58. Animation: Disruptive Selection

59. Animation: Moth Populations

60. Animation: Adaptive Trait

61. Animation: Speciation on an Archipelago

62. Animation: Evolutionary Tree Diagrams

63. Animation: Gause’s Competition Experiment

64. Animation: Species Diversity By Latitude

65. Animation: Humans Affect Biodiversity

66. Animation: Habitat Loss and Fragmentation

67. Animation: Transferring Genes into Plants

68. Video: Ancient Human Skull PLAY VIDEO

69. Video: Asteroid Menace PLAY VIDEO

70. Video: Bachelor Pad at the Zoo PLAY VIDEO

71. Video: Cloned Pooch PLAY VIDEO

72. Video: Creation vs. Evolution PLAY VIDEO

73. Video: Dinosaur Discovery PLAY VIDEO

74. Video: Glow-in-the-Dark Pigs PLAY VIDEO

75. Video: Hsing Hsing Dies PLAY VIDEO

76. Video: Mule Clones PLAY VIDEO

77. Video: New Species Found PLAY VIDEO

78. Video: Penguin Rescue PLAY VIDEO