1. Chapter 5: Evolution and Community Ecology

2. Chapter 5 pages 126- …….. Section 1: Evolution
Answer the questions and define the terms:
Describe the four primary mechanisms of biological evolution
Describe how speciation and extinction affect the diversity of life on Earth.
TERMS: evolution, gene mutation, genetic drift, natural selection, fitness, adaptation, artificial selection, speciation, extinction.

3. Incredible Diversity of Life
1.5 to 1.8 million known species
Possibly million
Tropical Rain Forests, Coral Reefs and everywhere else
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4. Evolution What makes you, YOU?
What makes each species unique and different?

5. Genes Sequences of DNA codes for each particular trait
Tall, small, blue eyes, human, goldfish, pine tree
Evolution is a change of genes over time
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6. Evolution “Change over time” Change of Gene Pool over time
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Evolution
“Change over time”
Change of Gene Pool over time
Why would genes change over time?

7. 4 Ways Evolution Occurs Mutation Migration Genetic Drift
Natural Selection
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8. Mutation
Accidental change in DNA that can give rise to variation among individuals
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9. Migration: GENE FLOW
Movement of individuals into (immigration) or out of (emigration) a population
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Sometimes called “Gene Flow”

10. Gene Flow (Migration)

11. Genetic Drift Evolution that occurs by chance Natural Disasters
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Genetic Drift
Evolution that occurs by chance
Natural Disasters
Run in with human nets, etc.

12. Natural Selection
Process by which traits useful for survival and reproduction are passed on more frequently than those that are not
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13. 3 Conditions for Natural Selection
Organisms produce more offspring than can survive.
Individuals vary in characteristics, some of which are heritable.
Individuals vary in fitness, or reproductive success
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14. 3 Conditions for Natural Selection
Organisms produce more offspring than can survive.
Nature has limitations (limiting factors)
Struggle for survival
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15. 3 Conditions for Natural Selection
(2) Individuals vary in characteristics, some of which are heritable
Not every species is same
Some fish are faster, darker, smaller
Genes different
Heritable Differences
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16. 3 Conditions for Natural Selection
(3) Individuals vary in fitness, or reproductive success
Survival of Fittest
Fittest for its environment
Adaptation: an inherited trait that increases an organisms chance of survival and reproduction.
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17. Adaptations Desert plants have small or no leaves at all
The insect that blends in and is able to survive may be more likely to reproduce.

18. Adaptations White coat of polar bear helps in hunting
Results of natural selection all around us
NATURE SELECTS
Big ears of desert jack rabbit allow it to cool off quickly
Long neck of giraffe allow it to reach food

19. Artificial Selection: How Humans Use Evolution
Artificial Selection: selective breeding of organisms by humans
Selecting certain desirable traits
Size, sweetness, color, shape,
Very common
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20. Artificial Selection
Selecting desirable traits and breeding only those with those traits.

21. Resistance
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Resistance: the ability of one or more organisms to tolerate a chemical designed to kill it
Able to survive and reproduce
Pesticide resistance
Antibiotic resistance

22. Impacts of Natural Selection: Resistance

23. Why is this a problem?

24. Speciation: How did we get millions of species?
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Speciation: How did we get millions of species?

25. Process by which new species are generated
Speciation
Process by which new species are generated
Can occur in a number of different ways; the most important way is called allopatric speciation– Geographic Isolation
Has resulted in every form of life on Earth— today and in the past
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26. The canyon is a barrier to dispersal by small mammals, and as a consequence the isolated populations can diverge.

27. Sympatric Speciation
Sympatric speciation is the process through which new species evolve from a single ancestral species while inhabiting the same geographic region. Sympatric refers to organisms whose ranges overlap or are even identical, so that they occur together at least in some places, such a distribution may be the result of sympatric speciation.
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28. Extinction The disappearance of species from Earth
Generally occurs gradually, one species at a time, (BACKGROUND RATE of EXTINCTION). When environmental conditions change more rapidly than the species can adapt extinction occurs.
There are five known mass extinction events, each of which wiped out a large proportion of Earth’s species.
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29. Biodiversity has increased over time, but mass extinctions are also natural events (5 major events)
How do we get this data?
Did You Know? During the Permo-Triassic extinction 250 million years ago, 70% of all land species and 90% of all marine species went extinct.

30. Extinctions Species gone forever NORMAL
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Extinctions
Species gone forever
NORMAL
Mass Extinction: short period of time when large number of species go extinct (65 MYA)
Currently in mass extinction…caused by humans
Rapid climate change

31. Invasive Species
The zebra mussel has completely displaced 20 native mussel species in Lake St. Clair.

32. Invasive Species Adversely affect the habitats and bioregions.
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Invasive Species
Adversely affect the habitats and bioregions.
They invade economically, environmentally, and/or ecologically.
Invasive species can be either plants or animals and disrupt by dominating habitats.
The problem is they have no natural controls such as predators or competition for resources.

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Invasive Species
Invasive species damage the lands and waters that native plants and animals need to survive.
They hurt economies and threaten human well-being. 
The estimated damage from invasive species worldwide totals more than $1.4 trillion – five percent of the global economy

34. Section 1: Evolution Review
Describe the four primary mechanisms of biological evolution
Describe how speciation and extinction affect the diversity of life on Earth.
TERMS: evolution, gene mutation, genetic drift, natural selection, fitness, adaptation, artificial selection, speciation, extinction

35. Section 1 Quiz
Which of the following best describes a successful individual in evolutionary terms?
A. A successful individual possesses traits that are different from the traits of the rest of the population.
B. A successful individual produces many offspring that possess unique traits.
C. A successful individual is well adapted to its environment and produces offspring that survive to pass on genes.
D. A successful individual will be well adapted to its environment and produce a few high quality offspring.
C. A successful individual is well adapted to its environment and produces offspring that survive to pass on genes.

36. 2) In the history of the world, how many mass extinctions have occurred? A. 5 B. 7 C. 10 D. 13

37. 3) In a mass extinction, the rate of extinction exceeds A. 99 percent
3) In a mass extinction, the rate of extinction exceeds A. 99 percent. B. 85 percent. C. the rate of environmental change. D. the rate of background extinction.
D. the rate of background extinction

38. 4) A reintroduced population of wolves in a national park is 90% grey and 10% black, consistent with the wolf population in other regions. After several generations in isolation, the national park’s wolf population is 60% grey and 40% black. The wolf population has likely experienced A. natural selection. B. genetic drift. C. mutations. D. migration.
genetic drift
Evolution that occurs by chance

39. 5) When the environment changes too quickly for an organism to adapt, what will occur? A) Evolution B) Speciation C) Genetic Drift D) Extinction
D. Extinction

40. True or False
6) Two populations of a deer species are separated when a glacier forms. After the glacier melts, the two populations have become different species. This is an example of allopatric speciation.
TRUE

41. Short Answer
7) A disaster wipes out 50 percent of a small population of birds. Prior to the disaster, about half the birds had a green wing patch and half had a blue wing patch. Several generations after the disaster, only 10% have a blue wing patch, and 90% have a green wing patch. What do you infer happened, and why?
The bird population experienced genetic drift as the result of a sudden catastrophe. The disaster reduced genetic diversity in the population and changed the proportion of birds with a green wing patch vs. a blue wing patch.

42. Short Answer
8) Pronghorn are a species of extremely fast hooved mammal that live on the plains of western North America. They are so fast that no current North American predator can catch them. During the ice age, cheetahs occupied North America. Speculate about how pronghorn became so fast.
Pronghorn probably evolved in an evolutionary “arms race” with the cheetah population. They became faster and faster to escape from cheetahs, which were probably fast enough to catch them.

44. Section 2: Species Interaction
Discuss the factors that influence an organisms niche
Compare and contrast predation, parasitism, herbivory
Describe mutualism and commensalism
TERMS: niche, tolerance, resource partitioning, predation, coevolution, parasitism, symbiosis, herbivory, mutualism, commensalism.

45. Species Interaction Competition for resources all around us
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What resources are the plants in this picture competing for?
Competition for resources all around us

46. Niche: Organisms JOB in life
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Niche: Organisms JOB in life
Describes an organism’s use of resources and functional role in a community
Habitat
Food It Eats
When, How Reproduces
What organisms does it interact with

47. Niche Impacted By Tolerance and Competition
Affected by an organism’s tolerance—its ability to survive and reproduce under changing environmental conditions
Often restricted by competition
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48. Tolerance Limits

49. A species with a Wide tolerance is called a generalist
A species with a restricted tolerance for environmental conditions is a specialist
A species with a Wide tolerance is called a generalist
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50. Fundamental vs. Realized Niche
Fundamental = Without competition Realized = With competition (restricted niche)
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51. Competition
Organisms compete when they seek the same limited resource.
In rare cases, one species can entirely exclude another from using resources.
To reduce competition, species often partition resources, which can lead to character displacement.
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52. Resource Partitioning

53. The zebra mussel has completely displaced 20 native mussel species in Lake St. Clair.

54. Predation (+/-)
The process by which a predator hunts, kills, and consumes prey
Causes cycles in predatory and prey population sizes
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56. Predation
Defensive traits such as camouflage, mimicry, and warning coloration have evolved in response to predator-prey interactions.
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57. Predation and Co-evolution
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Predation and Co-evolution
Some predator-prey relationships are examples of coevolution, the process by which two species evolve in response to changes in each other.
Rough-Skinned Newt
Did You Know? A single rough-skinned newt contains enough poison to kill 100 people. Unfortunately for the newt, its predator, the common garter snake, has coevolved resistance to the toxin.

58. Example of Co-evolution
The Madagascar star orchid produces nectar at the bottom part of its slim, foot-long throat.
After observing a specimen, Charles Darwin predicted the existence of a moth with a proboscis long enough to reach that nectar.
Sure enough, decades later the giant hawk moth of Madagascar was discovered.
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59. Parasitism and Herbivory (+/–)
Parasitism: One organism (the parasite) relies on another (the host) for nourishment or for some other benefit
Herbivory: An animal feeding on a plant
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60. Parasitism and Herbivory (+/–)
Malaria is a disease caused by a parasite called Plasmodium that is spread to humans by the bite of an infected Anopheles mosquito.
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61. Parasitism and Herbivory (+/–)

62. Mutualism (+/+) and Commensalism (+/0)
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Mutualism: a relationship in which two or more species benefit
Commensalism: a relationship in which one species benefits while the other is unaffected

63. EXAMPLE of Mutualism (+/+)
Clown Fish and Sea Anemones demonstrate mutualism because Anemones provide the Clown Fish with protection from predators while Clown fish defend the Anemones from Butterfly fish who like to eat Anemones.
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64. Example of Commensalism (+/0)
Desert trees (Polo verde) and shrubs provide shade and leaf litter to the soil beneath the tree which allows the soil underneath to hold moisture. The area underneath the tree remains cooler and more moist than the surrounding desert area making it easier for other desert plants to germinate and grow
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66. Section 2 Review Species Interaction
Discuss the factors that influence an organisms niche
Compare and contrast predation, parasitism, herbivory
Describe mutualism and commensalism
TERMS: niche, tolerance, resource partitioning, predation, coevolution, parasitism, herbivory, mutualism, commensalism.

67. Section 2 Quiz B. Resource Partitioning
1) Madagascar, several species of lemur eat bamboo, but each species specializes in one part of the bamboo—one species eats mature bamboo stalks, one species eats bamboo shoots, and one species eats leaves. This is an example of
A. speciation.
B. resource partitioning.
C. competition.
D. niche partitioning.
B. Resource Partitioning

68. 2) In the example above, one lemur species eats only bamboo shoots
2) In the example above, one lemur species eats only bamboo shoots. Bamboo shoots contain a high level of cyanide, a toxic chemical. This lemur species has developed a tolerance for a certain amount of cyanide. What do you think will happen over time? A. The level of cyanide in the bamboo population will increase. B. The level of cyanide in the bamboo population will decrease. C. The level of cyanide in the bamboo population will remain the same. D. The level of cyanide in the lemur population will decrease.
A. The level of cyanide in the bamboo population will increase.

69. 3) Two species of finch live in the same environment
3) Two species of finch live in the same environment. Over time, one develops a larger beak to consume larger seeds, while the other develops a narrow beak to consume more delicate seeds. This is an example of A. resource partitioning. B. character displacement. C. coevolution. D. competitive exclusion.
C. coevolution.

70. 4) An interaction in which an individual of one species kills and consumes an individual of another is called A. predation. B. parasitism. C. herbivory. D. symbiosis.
A. predation

71. 5) In the western United States, at the southern edge of their range, moose are sometimes so severely infested with ticks that they die. The tick/moose relationship is best described as A. predatory. B. parasitic. C. symbiotic. D. mutualistic.
B. parasitic.

72. 6) A beehive depends on pollen from flowers to survive
6) A beehive depends on pollen from flowers to survive. Flowers depend on bees to pollinate them. The relationship among these two sets of organisms is A. parasitic. B. commensalist. C. herbivory D. mutualistic.
D. mutualistic.

73. 7) A niche restricted by competition is a A. fundamental niche. B
7) A niche restricted by competition is a A. fundamental niche. B. realized niche. C. resource partitioned niche. D. displaced niche.
B. realized niche

74. 8) A deer browsing on a shrub is an example of A. predation. B
8) A deer browsing on a shrub is an example of A. predation. B. parasitism. C. herbivory. D. photosynthesis.
C. herbivory.

75. True or False You have many species of bacteria living in your gut that help you with digestion. This relationship is best defined as commensalism.
False: Mutualism

76. Short Answer 9) Explain the difference between mutualism and commensalisms, with examples.
In mutualism and commensalism, both species are unharmed. In mutualism, both species benefit, as in the example of the hawk moth pollinating the flower; the flower is pollinated and the moth is fed. In commensalism, one species benefits while the other doesn’t experience a negative or a positive effect. Trees providing shade and moisture to desert shrubs is an example of commensalism.

78. NOW you can answer these 2 questions you wrote down at the beginning of this chapter.
Explain why a food web is a better representation of energy flow in a community than a food chain.
Explain how a sudden change in the environment either through a disaster or through shifts in conditions might affect the evolution of species in the area.
Compare and contrast what is likely to happen to an area that has just experienced a forest fire to what has happened to an area exposed to glaciations over centuries of time. Which will regrow more quickly and WHY?