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Population Biology Biological Diversity

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1973 President Nixon signed into law the ENDANGERED SPECIES ACT. This law made it illegal to harm any species on the endangered species list. ... – PowerPoint PPT presentation

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Title: Population Biology Biological Diversity


1
Population BiologyBiological Diversity
Conservation
2
Population Growth
  • An increase in the size of a population over time.

3
Population Growth Rate
  • Population growth is not Linear.
  • Example of Linear growth
  • 5.00/hour, 1hr 5.00, 2hr 10.00
  • 3hr 15.00, 4hr 20.00.

4
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Population Growth is Exponential
  • Starts out slow ends up fast.
  • Do Problem Solving Lab 4-1 page 99.

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Limits of Exponential Growth
  • All populations have the potential to grow
    exponentially.
  • What prevents the world from being overrun will
    all kinds of living things?

9
  • Through population experiments, scientists have
    found limits to population growth.
  • Limiting factors such as food or space, cause
    populations to stop increasing.

10
Carrying Capacity
  • The number of organisms of one species that an
    environment can support.

11
  • When populations exceed the carrying capacity
    deaths exceed births.
  • When populations are under the carrying capacity
    births exceed deaths.

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Patterns of Population Growth
  • Why are mosquitoes more abundant at certain times
    of the year?
  • Why dont they reach carrying capacity and become
    stable?

14
  • Mosquitoes reproduce very rapidly and produce
    many offspring.

15
Unstable Environments
  • Organisms in unstable environments live in an
    unpredictable and rapidly changing areas,
    therefore they have to be able to grow and
    reproduce quickly.

16
  • Typically, these organisms have small body size,
    mature rapidly, reproduce early, and have a short
    life span.

17
  • Once conditions change to unfavorable they die
    out. The small surviving populations will
    increase exponentially when conditions are again
    favorable.

18
Stable Environments
  • Elephants, Humans, Bears, Whales, and long lived
    plants are large and reproduce slowly. These
    organisms maintain populations near the carrying
    capacity of their environments.

19
  • Rapid life history patterns are found in
    unpredictable environments.
  • Long life history patterns are found in stable
    environments.

20
Environmental Limits to Growth
  • Limiting Factors can be either Biotic or Abiotic.
  • Two Kinds of Limiting Factors...

21
Density-dependent Factors
  • Include Disease, Competition, Parasites, and
    Food.
  • These have an increasing effect as the population
    increases.

22
EXAMPLE
  • Disease spreads more rapidly in populations where
    its members live close together.
  • Smaller populations usually live farther apart,
    so it is harder for the disease to spread.

23
Density-independent Factors
  • Include Floods, Droughts, Earthquakes,
    Hurricanes, Bombs, Very Cold Long Winters, etc.
  • Affect all populations, regardless of their
    density.

24
EXAMPLE
  • Hurricane Mitch, hits south Florida. Does
    extensive damage to both densely populated areas
    as well as sparsely populated areas.

25
Organism Interactions Limit Population Size
  • Predator - Prey
  • Competition
  • Over Crowding

26
Predator-Prey Relationships
  • Lynx eat Hares.
  • If Hares get eaten they can not reproduce.
  • This means less Hares.

27
  • Less Hares means Lynx starve and die.
  • Less Lynx means Hares can reproduce.
  • This means more Hares.

28
  • Lynx eat Hares.
  • If Hares get eaten they can not reproduce.
  • This means less Hares.

29
  • Less Hares means Lynx starve and die.
  • Less Lynx means Hares can reproduce.
  • This means more Hares.

30
  • Lynx eat Hares.
  • If Hares get eaten they can not reproduce.
  • This means less Hares.

31
  • Less Hares means Lynx starve and die.
  • Less Lynx means Hare can reproduce.
  • This means more Hares.

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36
Benefits of Predation
  • Usually in Prey populations the young, old or
    injured members are caught.
  • Predation helps improve the odds that there will
    be sufficient resources for the healthiest
    individuals in the population.

37
Competition
  • Density-dependent factor
  • Within a population members compete for food,
    shelter, mates, etc.

38
  • The smaller the population the greater the
    resources thus competition is low.
  • The larger the population the fewer the resources
    increasing competition.

39
Play Habitat lab sit Oh Deer
40
Over Crowding
  • When populations or organisms become crowded,
    individuals may exhibit stress.

41
  • Populations of rats and mice when crowded exhibit
    aggression, they fight and kill one another, eat
    the babies, decreased parental care, decreased
    fertility, and decreased resistance to disease.

42
  • Homework SA 4.1 pg 103 and CA4
    1,2,3,5,7,8,11,12,14,16,18,20,23,24,25.
  • Page 111

43
Bio-diversity
  • Refers to the variety of life in an area.
  • Canada 163 species of mammals
  • United States 367 species of mammals
  • Mexico 439 species of mammals

44
  • The trend shows a greater bio-diversity as you
    move toward the equator.

45
  • The richest environments for bio-diversity are
    all warm places, Tropical rain forests, coral
    reefs, and large tropical lakes.

46
Importance of Biodiversity
  • Esthetically pleasing.
  • Parking lot vs Mountain Vista

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49
Why Else is it Important?
  • Life Depends on Life.
  • Predators keeps populations in check.
  • Plants depend on pollinators.

50
  • Animals could not exist without green plants.
  • Plants need decomposers to break down dead
    material into nutrients they can use.

51
  • A pest can easily destroy all the corn in a
    field.
  • Its much harder to completely destroy a single
    plant species in a forest, because the plant
    could exist in many different parts of the forest.

52
  • The fewer the number of species in an ecosystem
    the easier it is to disrupt life in that
    ecosystem.

53
Important to Humans
  • Oxygen is supplied and removed by plants and
    algae.
  • Give us a diverse diet.
  • Building materials
  • Clothing

54
  • Almost all drugs were first found in plants,
    before being made synthetically.
  • Pennicillium, antibiotic, mold.
  • Antimalarial drug quinine, tree bark.

55
  • Aspirin, willow bark.
  • Drugs for treatment of leukemia, Rosy periwinkle.
  • Taxol, anti cancer drug, Pacific yew tree.

56
  • Preserving biodiversity ensures there will be a
    large supply of living things to provide for the
    future.

57
Loss of Biodiversity
  • Extinction the disappearance of a species when
    the last of its members dies.
  • Natural process, however humans usually speed it
    up.

58
  • Since 1980 almost 40 species have become extinct.
  • Threatened species When a population rapidly
    declines.

59
  • 1970s about 3,000,000 wild elephants.
  • 1990s about 700,000 wild elephants.

60
  • Endangered species Species numbers become so
    low that extinction is very likely.
  • California condor, Florida manatee, Black rhino,
    Siberian tiger, hard working student.

61
United States
  • Extinct 179
  • Critically Endangered 235
  • Endangered 179

62
Threats to Biodiversity
  • 8 main reasons biodiversity is being threatened.

63
1 Habitat loss
  • Rain forest is made into a pasture.
  • Meadow is made into a parking lot.
  • Swamp is drained for a subdivision.

64
  • Habitat loss is the number 1 threat to
    biodiversity.
  • Once the habitat is gone the organisms either die
    or have to move.

65
2 Habitat fragmentation
  • Roads. Fences, Cities cut across our wilderness.
  • This separates the wilderness thus preventing
    species from thriving.

66
  • Smaller wilderness areas support less life.
  • Do PSL 5-1 page 119.

67
Biotic issues
  • Large predators cannot obtain enough food in
    small wilderness areas.
  • Bears need vegetative cover in order to survive.
    They hate to be in the wide open.

68
Abiotic issues
  • Habitat fragmentation can change the climate of
    the area.
  • Cut the trees down, more sun exposure, less
    moisture.

69
3 Habitat degradation
  • Damage to the habitat by pollution.
  • 3 main kinds of pollution
  • Air, Land , Water.

70
4 Acid Rain
  • SO2 from coal burning factories.
  • NO, NO2 for cars and trucks.
  • Now in the air dissolves into the water vapor in
    the clouds.
  • Turns to acid.

71
  • When it rains the land is now covered with acid.
  • The acid begins to kill the lakes and the plants.

72
5 Ozone layer depletion
  • We use CFCs which destroy the ozone layer. This
    lets in more UV radiation from the sun.
  • More frogs and toads are being born with
    deformities than before.

73
6 Water pollution
  • Fertilizers, animal waste, gets into a pond,
    lake, river etc. causes a algal bloom. As the
    algae dies it decays removing O2 from the water
    killing all other life in water.

74
  • Litter in the water also affects wildlife.
  • Sea turtles get tangled in plastic soda pop ring
    holders.
  • Eat plastic (look like jelly fish).
  • Caught in old nets.

75
7 Land Pollution
  • The average person produces 3.96 lbs. of solid
    waste daily. This is 1445.4 lbs. Yearly.
  • In the US there is 1,131,944,976 lbs of solid
    waste produced daily.

76
  • DDT and other insecticides pollute the land.

77
8 Introduction of Exotics
  • Exotic - Any plant or animal that is not native
    to the area.
  • Goats to Santa Catalina island destroyed 48
    native plants.
  • Sea lamprey into the great lakes. (Erie canal)

78
  • Russian cheet grass to the US.
  • Dyers woad in Utah.

79
  • Since they are not native to the area they
    usually do not have any natural predators. They
    grow unchecked and usually take over the are
    killing off the native species.

80
  • Show Video
  • Help Save the Planet Earth
  • Homework page 124 problems 1-5.

81
Conservation Biology
  • Field of Biology that studies methods and
    implements plans to protect biodiversity.

82
  • 1973 President Nixon signed into law the
    ENDANGERED SPECIES ACT.
  • This law made it illegal to harm any species on
    the endangered species list.

83
  • Harm includes changing an ecosystem where
    threatened species live.

84
CITES
  • Convention on International Trade in Endangered
    Species. Group of 120 countries that prohibit
    and control the trade of endangered species.

85
Preserving habitats
  • In 1872 the first National Park was created.
  • Yellowstone
  • The park system has been created to preserve and
    protect wildlife and unique geology.

86
  • In 1872 Elk, Bear, Moose, and bison were widely
    distributed across the U.S. as far east as
    Pennsylvania.

87
  • Now their range is almost reduced to only the
    National Parks and National Forest Land.

88
  • In Zaire, Africa, only 3.9 of the land is
    protected but 89 of the bird population is found
    there!

89
  • Only 6 of the Earths land surface is protected.

90
Sustainable use
  • A concept that allows people to use the resources
    of the wilderness areas in ways that will not
    damage the ecosystem.

91
Conservation Groups
  • Groups that raise money and purchase land that is
    then set aside for protection.

92
  • What would be the best strategy for purchasing
    land? One big 1000 acre plot or Ten 100 acre
    plots?

93
Habitat corridors
  • Natural strips that allow the migration of
    organisms from one area to another.
  • Help overcome some of the problems of habitat
    fragmentation.

94
Reintroduction programs
  • Release organisms into an area where their
    species once lived.

95
  • Brown pelican - DDT caused the birds to
    completely disappear from around the shores of
    the Gulf of Mexico.

96
  • After DDT was banned, 50 Birds were reintroduced
    from Florida.
  • Today there are 7000 birds.

97
  • Do PSL 5.2 page 128.

98
Captivity
  • An organism that is held by people.
  • Ginkgo trees - Thought to be extinct.
  • Found in a Chinese monastery.

99
  • Today the Ginkgo is found in all most all
    metropolitan areas in the U.S.
  • California Condor and Arabian oryx.

100
  • Watch video Common Ground.
  • Do SA 5.2 page 129 1-5.
  • CA 5 1-25. Page 133-135.
  • Vocab Due on day of test.
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