1. Do Now:
Did life always exist on earth? How has it changed over time?

2. Aim: What Is Biodiversity and Why Is It Important?
Concept 4-1 The biodiversity found in genes, species, ecosystems, and ecosystem processes is vital to sustaining life on earth.

3. Chapter 4 Biodiversity and Evolution
There is grandeur to this view of life… that, whilst this planet has gone cycling on… endless forms most beautiful and most wonderful have been, and are being, evolved. - Charles Darwin
There is grandeur to this view of life… that, whilst this planet has gone Cycling on… endless forms Most beautiful and most wonderful have been, and are being, evolved. - Charles Darwin

4. Threatened Sharks
Figure 4.1: The threatened whale shark (left), which feeds on plankton, is the largest fish in the ocean. The endangered scalloped hammerhead shark (right) is swimming in waters near the Galapagos Islands, Ecuador. They are known for eating stingrays, which are related to sharks.
Fig. 4-1, p. 80

5. Core Case Study: Why Should We Protect Sharks?
400 known species
6 deaths per year from shark attacks
79-97 million sharks killed every year
Fins
Organs, meat, hides
Fear
32% shark species threatened with extinction
Keystone species
Cancer resistant

6. Biodiversity Is a Crucial Part of the Earth’s Natural Capital (1)
Species: set of individuals who can mate and produce fertile offspring
8 million to 100 million species
1.9 million identified
Unidentified are mostly in rain forests and oceans

7. Biodiversity Is a Crucial Part of the Earth’s Natural Capital (2)
Species diversity
Genetic diversity
Ecosystem diversity
Biomes: regions with distinct climates/species
Functional diversity
Biodiversity is an important part of natural capital

8. Natural Capital: Major Components of the Earth’s Biodiversity
Figure 4.2: Natural capital.
This diagram illustrates the major components of the earth’s biodiversity—one of the earth’s most important renewable resources and a key component of the planet’s natural capital (see Figure 1-4, p. 9). See an animation based on this figure at CengageNOW. Question: What role do you play in such degradation?
Fig. 4-2, p. 82

9. What role do you play in such degradation?
Functional Diversity The biological and chemical processes such as energy flow and matter recycling needed for the survival of species, communities, and ecosystems.
Ecological Diversity The variety of terrestrial and aquatic ecosystems found
in an area or on the earth.
Solar energy
Chemical nutrients (carbon dioxide, oxygen, nitrogen, minerals)
Heat
Heat
Heat
Decomposers (bacteria, fungi)
Producers (plants)
Consumers (plant eaters, meat eaters)
Heat
Heat
What role do you play in such degradation?
Figure 4.2: Natural capital.
This diagram illustrates the major components of the earth’s biodiversity—one of the earth’s most important renewable resources and a key component of the planet’s natural capital (see Figure 1-4, p. 9). See an animation based on this figure at CengageNOW. Question: What role do you play in such degradation?
Genetic Diversity The variety
of genetic material within a species or a population.
Species Diversity The number and abundance of species present in different communities.
Fig. 4-2, p. 82

10. Two Species: Columbine Lily and Great Egret
Figure 4.3: Two of the world’s 1.9 million known species are the Columbia lily (left) and the great egret (right). In 1953, the National Audubon Society adopted an image of this egret in flight as its symbol. The society was formed in 1905, partly to help prevent the widespread killing of this bird for its feathers.
Fig. 4-3, p. 82

11. Genetic Diversity
Figure 4.4: Genetic diversity among individuals in a population of a species of Caribbean snail is reflected in the variations in shell color and banding patterns. Genetic diversity can also include other variations such as slight differences in chemical makeup, sensitivity to various chemicals, and behavior.
Fig. 4-4, p. 83

12. Major Biomes
Figure 4.5: The major biomes found along the 39th parallel across the United States are shown in this diagram. The differences in tree and other plant species reflect changes in climate, mainly differences in average annual precipitation and temperature.
Fig. 4-5, p. 84

13. Coastal mountain ranges Mississippi River Valley
Denver
Baltimore
San Francisco
Las Vegas
St. Louis
Coastal mountain ranges
Sierra Nevada
Great American Desert
Rocky Mountains
Great Plains
Mississippi River Valley
Appalachian Mountains
Figure 4.5: The major biomes found along the 39th parallel across the United States are shown in this diagram. The differences in tree and other plant species reflect changes in climate, mainly differences in average annual precipitation and temperature.
Coastal chaparral
and scrub
Coniferous forest
Desert
Coniferous forest
Prairie grassland
Deciduous forest
Fig. 4-5, p. 84

14. Pause…Think…Write
What are three ways in which sharks support one or more of the four components of biodiversity within their environment?

15. Science Focus: Have You Thanked the Insects Today?
Bad rep: sting us, bite us, spread disease, eat our food, invade plants
Pollination: lets flowering plants reproduce sexually
Free pest control: insects eat other insects
We need insects more than they need us

16. Individuals Matter: Edward O. Wilson: A Champion of Biodiversity
Loved bugs as a kid
Specialized in ants
Widened scope to earth’s biodiversity
Theory of island biogeography
First to use “biodiversity” in a scientific paper

17. Do Now:
While watching the following video clip, define natural selection in your own words and support it with an example.

18. Aim: How Does the Earth’s Life Change Over Time?
Concept 4-2A The scientific theory of evolution explains how life on earth changes over time through changes in the genes of populations.
Concept 4-2B 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).

19. Biological Evolution by Natural Selection
Fossils
Physical evidence of ancient organisms
Reveal what their external structures looked like
Fossil record: entire body of fossil evidence
Only have fossils of 1% of all species that lived on earth
Fossilized Skeleton of an Herbivore that Lived during the Cenozoic Era

20. Biological Evolution by Natural Selection Explains How Life Changes over Time (2)
Biological evolution: how earth’s life changes over time through changes in the genetic characteristics of populations
Darwin: Origin of Species
Natural selection: individuals with certain traits are more likely to survive and reproduce under a certain set of environmental conditions

22. Evolution of Life on Earth
Figure 1 This diagram provides an overview of the evolution of life on the earth into six major kingdoms of species as a result of natural selection.
Supplement 5, Fig. 2, p. S18

23. Evolution by Natural Selection Works through Mutations and Variations
Populations evolve by becoming genetically different
Genetic variations
First step in biological evolution
Occurs through mutations in reproductive cells
Mutations: random changes in DNA molecules

24. Evolution by Natural Selection Works through Mutations and Adaptations (2)
Natural selection: acts on individuals
Second step in biological evolution
Adaptation may lead to differential reproduction
Genetic resistance: ability of one or more members of a population to resist a chemical designed to kill it

25. Evolution by Natural Selection
Figure 4.7: Evolution by natural selection. (a) A population of bacteria is exposed to an antibiotic, which (b) kills all individuals except those possessing a trait that makes them resistant to the drug. (c) The resistant bacteria multiply and eventually (d) replace all or most of the nonresistant bacteria.
Fig. 4-7, p. 87

26. Case Study: How Did Humans Become Such a Powerful Species?
Strong opposable thumbs
Walk upright
Complex brain

27. Pause…Think…Write
An important adaptation of humans is strong opposable thumbs, which allow us to grip and manipulate things with our hands. Make a list of things you could not do if you did not have opposable thumbs.

28. Adaptation through Natural Selection Has Limits
Adaptive genetic traits must precede change in the environmental conditions…WHY?
Reproductive capacity
Species that reproduce rapidly and in large numbers are better able to adapt
What are some examples of species that have high reproductive capacity? Do humans? Explain?

29. Scenario:
In the face of snow and cold, a population of grey wolves with thick and thin fur live. As temperatures get colder and more now starts to fall, What will happen to the population of wolves? Be specific.

30. Three Common Myths about Evolution through Natural Selection
“Survival of the fittest” is not “survival of the strongest”
Organisms do not develop traits out of need or want
No grand plan of nature for perfect adaptation

31. Summary: How would you respond to someone who tells you:
a. That he or she does not believe in biological
evolution because it is just a “theory”?
b. That we should not worry about air pollution
because natural selection will enable humans to
develop lungs that can detoxify pollutants?

32. Do Now:
POP Vocabulary Quiz

33. Aim: How Do Geological Processes and Climate Change Affect Evolution?
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.

34. Geologic Processes Affect Natural Selection
Tectonic plates affect evolution and the location of life on earth
Locations of continents and oceans have shifted
Species physically move, or adapt, or form new species through natural selection
Earthquakes
Volcanic eruptions

35. Movement of the Earth’s Continents over Millions of Years
Figure 4.8: Over millions of years, the earth’s continents have moved very slowly on several gigantic tectonic plates. This process plays a role in the extinction of species, as continental areas split apart, and also in the rise of new species when isolated island areas such as the Hawaiian Islands and the Galapagos Islands are created. Rock and fossil evidence indicates that 200–250 million years ago, all of the earth’s present-day continents were connected in a supercontinent called Pangaea (top left). About 180 million years ago, Pangaea began splitting apart as the earth’s tectonic plates moved, eventually resulting in the present-day locations of the continents (bottom right). Question: How might an area of land splitting apart cause the extinction of a species?
Fig. 4-8, p. 89

36. 225 million years ago
Figure 4.8: Over millions of years, the earth’s continents have moved very slowly on several gigantic tectonic plates. This process plays a role in the extinction of species, as continental areas split apart, and also in the rise of new species when isolated island areas such as the Hawaiian Islands and the Galapagos Islands are created. Rock and fossil evidence indicates that 200–250 million years ago, all of the earth’s present-day continents were connected in a supercontinent called Pangaea (top left). About 180 million years ago, Pangaea began splitting apart as the earth’s tectonic plates moved, eventually resulting in the present-day locations of the continents (bottom right). Question: How might an area of land splitting apart cause the extinction of a species?
Fig. 4-8, p. 89

37. 135 million years ago
Figure 4.8: Over millions of years, the earth’s continents have moved very slowly on several gigantic tectonic plates. This process plays a role in the extinction of species, as continental areas split apart, and also in the rise of new species when isolated island areas such as the Hawaiian Islands and the Galapagos Islands are created. Rock and fossil evidence indicates that 200–250 million years ago, all of the earth’s present-day continents were connected in a supercontinent called Pangaea (top left). About 180 million years ago, Pangaea began splitting apart as the earth’s tectonic plates moved, eventually resulting in the present-day locations of the continents (bottom right). Question: How might an area of land splitting apart cause the extinction of a species?
Fig. 4-8, p. 89

38. 65 million years ago
Figure 4.8: Over millions of years, the earth’s continents have moved very slowly on several gigantic tectonic plates. This process plays a role in the extinction of species, as continental areas split apart, and also in the rise of new species when isolated island areas such as the Hawaiian Islands and the Galapagos Islands are created. Rock and fossil evidence indicates that 200–250 million years ago, all of the earth’s present-day continents were connected in a supercontinent called Pangaea (top left). About 180 million years ago, Pangaea began splitting apart as the earth’s tectonic plates moved, eventually resulting in the present-day locations of the continents (bottom right). Question: How might an area of land splitting apart cause the extinction of a species?
Fig. 4-8, p. 89

39. Present
Figure 4.8: Over millions of years, the earth’s continents have moved very slowly on several gigantic tectonic plates. This process plays a role in the extinction of species, as continental areas split apart, and also in the rise of new species when isolated island areas such as the Hawaiian Islands and the Galapagos Islands are created. Rock and fossil evidence indicates that 200–250 million years ago, all of the earth’s present-day continents were connected in a supercontinent called Pangaea (top left). About 180 million years ago, Pangaea began splitting apart as the earth’s tectonic plates moved, eventually resulting in the present-day locations of the continents (bottom right). Question: How might an area of land splitting apart cause the extinction of a species?
Fig. 4-8, p. 89

40. 225 million years ago 135 million years ago 65 million years ago
Present
Stepped Art
Fig. 4-8, p. 89

41. Climate Change and Catastrophes Affect Natural Selection
Ice ages followed by warming temperatures
Collisions between the earth and large asteroids
New species
Extinctions

42. Changes in Ice Coverage in the Northern Hemisphere During the last 18,000 Years
Figure 4.9: These maps of the northern hemisphere show the large-scale changes in glacial ice coverage during the past 18,000 years. Other smaller changes in glacial ice on mountain ranges such as the European Alps are not shown. Question: What are two characteristics of an animal and two characteristics of a plant that natural selection would have favored as these ice sheets (left) advanced? (Data from the National Oceanic and Atmospheric Administration)
Fig. 4-9, p. 89

43. Northern Hemisphere Ice coverage
18,000 years before present
Northern Hemisphere Ice coverage
Modern day
(August)
Legend
Figure 4.9: These maps of the northern hemisphere show the large-scale changes in glacial ice coverage during the past 18,000 years. Other smaller changes in glacial ice on mountain ranges such as the European Alps are not shown. Question: What are two characteristics of an animal and two characteristics of a plant that natural selection would have favored as these ice sheets (left) advanced? (Data from the National Oceanic and Atmospheric Administration)
Continental ice
Sea ice
Land above sea level
Fig. 4-9, p. 89

44. Science Focus: Earth Is Just Right for Life to Thrive
Temperature range: supports life
Orbit size: moderate temperatures
Liquid water: necessary for life
Rotation speed: sun doesn’t overheat surface
Size: gravity keeps atmosphere

45. Do Now: Movie Clip While watching the clip answer the following:
1) What is speciation?
2) What leads to speciation? Give at least two examples?

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

47. How Do New Species Evolve?
Speciation
Geographic isolation
Reproductive isolation

48. Speciation one species splits into two or more species
Happens for 2 reasons:
1. Geographic isolation
2. Reproductive isolation

49. Geographic Isolation Happens first
Physically isolated from one another for a long period of time.
Ex: Mountains, streams, roads, volcanic eruptions, tectonic plate movement.

50. Reproductive Isolation
Mutations and natural selection in geographically isolated populations lead to inability to produce viable offspring when members of two different populations mate.
Takes thousands to millions of years.

51. Geographic Isolation Can Lead to Reproductive Isolation
Figure 4.10: Geographic isolation can lead to reproductive isolation, divergence of gene pools, and speciation.
Fig. 4-10, p. 91

52. Spreads northward and southward and separates Early fox population
Adapted to cold through heavier fur, short ears, short legs, and short nose. White fur matches snow for camouflage.
Arctic Fox
Northern population
Different environmental conditions lead to different selective pressures and evolution into two different species.
Spreads northward and southward and separates
Early fox population
Gray Fox
Figure 4.10: Geographic isolation can lead to reproductive isolation, divergence of gene pools, and speciation.
Southern population
Adapted to heat through lightweight fur and long ears, legs, and nose, which give off more heat.
Fig. 4-10, p. 91

53. Do you understand geographic and reproductive isolation?

54. Movie Clip: Answer the following while watching the clip:
How many species go extinct each day? Year?
List 2 causes of species becoming extinct.
List 2 ways to reduce extinction.

55. Extinction is Forever Extinction Biological extinction: entire species
is lost globally.
Local extinction: large population
of species becomes extinct but not
globally.

56. Endemic Species Found only in one area Particularly vulnerable
Golden toad lived in the
Cloud forest in Costa Rica.
1989 became extinct
Because its habitat dried up.

57. Background Extinction
All species eventually become extinct.
Species disappear at a slow rate.
Usually 1-5 per million species each year.

58. Mass Extinction Exceeds background rates.
25-95% of all species are wiped out very quickly.
3-5 mass extinctions in the last 500 million years.

59. Summary:
How would you respond to someone who says that because extinction is a natural process, we should not worry about the loss of biodiversity when species become extinct as a result of our activities?

60. Case Study: Changing the Genetic Traits of Populations

61. Changing the Genetic Traits of Populations
Artificial selection
Use selective breeding/crossbreeding
Genetic engineering, gene splicing
With your table discuss the following:
What might be some beneficial and harmful effects on the evolutionary process if genetic engineering is widely applied to plants and animals?

62. 4-5 What Is Species Diversity and Why Is It Important?
Concept 4-5 Species diversity is a major component of biodiversity and tends to increase the sustainability of ecosystems.

63. Species Diversity: Variety, Abundance of Species in a Particular Place (1)
Species richness:
The number of different species in a given area
Species evenness:
Comparative number of individuals

64. Species Diversity: Variety, Abundance of Species in a Particular Place (2)
Diversity varies with geographical location
The most species-rich communities
Tropical rain forests
Coral reefs
Ocean bottom zone
Large tropical lakes

65. Variations in Species Richness and Species Evenness
Figure 4.12: These two types of ecosystems vary greatly in species richness. An example of high species richness is a coral reef (left), with a large number of different species. On the other hand, this grove of aspen trees in Alberta, Canada (right) has a small number of different species, or low species richness.
Fig. 4-12, p. 93

66. Global Map of Plant Biodiversity
Figure 6 Global map of plant biodiversity.
Supplement 8, Fig. 6, p. S36

67. Science Focus: Species Richness on Islands
Species equilibrium model, theory of island biogeography
Rate of new species immigrating should balance with the rate of species extinction
Island size and distance from the mainland need to be considered
Edward O. Wilson

68. Species-Rich Ecosystems Tend to Be Productive and Sustainable
Species richness seems to increase productivity and stability or sustainability, and provide insurance against catastrophe
How much species richness is needed is debatable

69. Do Now: While watching the following clip, answer the following:
1) Explain the difference between a keystone and indicator species. Give one example for each and be able to explain their impact on the ecosystem as a whole.

70. Aim: What Roles Do Species Play in an Ecosystem?
Concept 4-6B Any given species may play one or more of five important roles—native, nonnative, indicator, keystone, or foundation—in a particular ecosystem.

71. Each Species Plays a Unique Role in Its Ecosystem
Ecological niche, niche
Pattern of living: everything that affects survival and reproduction
Water, space, sunlight, food, temperatures
Generalist species
Broad niche: wide range of tolerance
Specialist species
Narrow niche: narrow range of tolerance

72. Specialist Species and Generalist Species Niches
Figure 4.13: Specialist species such as the giant panda have a narrow niche (left) and generalist species such as the raccoon have a broad niche (right).
Fig. 4-13, p. 95

73. Specialized Feeding Niches of Various Bird Species in a Coastal Wetland
Figure 4.14: This diagram illustrates the specialized feeding niches of various bird species in a coastal wetland. This specialization reduces competition and allows sharing of limited resources.
Fig. 4-14, p. 96

74. Case Study: Cockroaches: Nature’s Ultimate Survivors
3500 species
Generalists
Eat almost anything
Live in almost any climate
High reproductive rates

75. Do you understand the difference between a generalist and a specialist species?

76. Species Can Play Five Major Roles within Ecosystems
Native species
Nonnative species
Indicator species:
Keystone species
Foundation species: :

77. Native Species Normally live and thrive in a particular ecosystem.
Vital part of the food web
Plants and animals native to the same area have
adapted to one another so that animals can eat
the plants, but plants can defend themselves
enough to be able to reproduce successfully

78. Non-native (Invasive) Species
Migrate into an ecosystem…on purpose or accidental
Species considered to be alien or non-native to an ecosystem can cause environmental harm or harm to human health.

79. Indicator Species Early warnings of damage to ecosystem.
Plants and animals that are able to reveal something about the environment
• Examples: canary in the coal mine, global death of amphibians, spotted owl in old growth forests, butterflies, and frogs.

80. Key Stone Species
Role has a large effect on the types & abundance of other species in an ecosystem
Pollinators
Top Predators

81. Foundation Species Play a major role in shaping their communities
Create or enhance their habitats, which benefit others
• Examples: Elephants (break/uproot trees giving
space for grasses); Beavers (ecological engineers –
build dams)

82. Case Study: Why Are Amphibians Vanishing? (1)
Habitat loss and fragmentation
Prolonged drought
Pollution
Increase in UV radiation
Parasites
Viral and fungal diseases
Climate change
Overhunting
Nonnative predators and competitors

83. Case Study: Why Are Amphibians Vanishing? (2)
Importance of amphibians
Indicators of environmental changes
Adult amphibians
Important ecological roles in biological communities
Genetic storehouse of pharmaceutical products waiting to be discovered

84. Case Study: Why Should We Care about the American Alligator?
Largest reptile in North America
1930s: Hunters and poachers
Importance of gator holes and nesting mounds: a keystone species
1967: endangered species
1977: comeback, threatened species

85. Summary:
How would you experimentally determine whether an organism is:
a) a keystone species
b) a foundation species

86. Three Big Ideas
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).
Human activities are decreasing the earth’s vital biodiversity by causing the extinction of species and by disrupting habitats needed for the development of new species.

87. Three Big Ideas
Each species plays a specific ecological role (ecological niche) in the ecosystem where it is found.