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Ch 11
Biodiversity and
Conservation Biology
Part 2: Environmental Issues
and the Search for Solutions
PowerPoint® Slides prepared by
Jay Withgott and Heidi Marcum
Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
• Chap 9
Soil & Agricultute
• Chap 10
Agriculture, Biotechnology &
the Future of Food
• Chap 11
Biodiversity and
Conservation Biology
- Alternative Food
Start 10/23/2008
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This lecture will help you understand:
• The scope of Earth’s biodiversity
Diversity through change,
speciation and evolution (Chap 5)
• Background Extinction Rates
& Mass Extinction
• Causes of biodiversity loss
• The benefits of biodiversity
• Biodiversity conservation efforts
Sikhote-Alin Mts meets Pacific Ocean
2001, UNESCO World Heritage Site
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Central Case: Saving the Siberian tiger
• The largest cat in the world
11ft, 660 lbs, 4in teeth, 10~15yrs)
(cf. Lion : 9ft, 550 lbs; 10~14 yrs)
• The Russian Far East mountains
house the last remaining tigers
• Nearly became extinct due to
hunting, poaching and habitat
destruction
• International conservation groups
saved the species from extinction
- Research, education, zoos, and
captive breeding programs
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Biodiversity encompasses several levels
• Biodiversity – sum total of all
organisms in an area; Split into
three specific levels:
- Ecosystem diversity
various communities
- Species diversity
(in a community)
- Genetic diversity within
population
• Humans are reducing Earth’s
diversity of life
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Species:
A group of a particular type of organism with certain
characteristics, can breed freely & produce fertile offspring
• Species Diversity: the number or variety of species
in the world or in a particular region
- Richness: the number of species
- Relative abundance of each species:
distribution population among of species
- Speciation generates new species and adds to
species richness: (Allopatric & Sympatric)
- Extinction reduces species richness
- Mass Extinction Event triggers, promotes
speciation in the long run.
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The taxonomy of species
• Taxonomists: classified
organisms systematically
- Physical appearance and
genetics determines a species
- Genera: related species are
grouped together
- Families: groups of genera
• Every species has a two-part
scientific name: genus and
species
•King Phillip Came Over For Great Spaghetti
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The taxonomy of species
Eukarya, Bacteria, Archaea
Animals, Plants, Fungi, Protists
Chordata, Arthopoda, Mollusca, etc.
Mammals, Amphibia, Reptila, etc.
Primates, Carnivora, Insectivora, etc.
Hominidae, lemurs, monkeys, etc.
Homo, Apes(Chimpanzee, Gorilla, Orangutan)
Sapience (Human), Erectus, Neanderthal, etc.
(Tiger, Lion, Leopard, Juagar, etc)
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Subspecies: the level below a species
• Subspecies: populations of species that occur in different areas
and differ slightly from each other
- Divergence stops short of separating the species
- Subspecies are denoted with a third part of the scientific name
Bengal tiger =
Panthera tigris
tigris
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Siberian tiger =
Panthera tigris
altaica
Subspecies of Tigers: ~ 5,000 surviving
• Siberian Tiger: 400~600 (Forest Destruction for Farming)
(Panthera tigris altaica)
• South China Tiger: 60 captives (no sighting in wild )
• Indochina Tiger: ~1,500
• Malayan Tiger:
600~800
• Sumatran Tiger: 400~500
• Bengal Tiger: 3,642 (2002)
1,411 (2006)
1,706 (2011)
• Bali Tiger: Extinct(1940s)
• Java Tiger: Extinct (1980s)
• Caspian Tiger Extinct (1970s)
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Genetic diversity
• Encompasses the differences in DNA among
individuals within species and populations
• Populations with higher genetic diversity are
likely to survive in environmental change
• Populations with low genetic diversity are
vulnerable
- To environmental change
- Disease
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Ecosystem diversity: for Survival of Species
• Ecosystem diversity: the number and variety of
ecosystems
- encompasses differing communities and habitats
• Rapid vegetation change and varying landscapes
within an ecosystem promote higher levels of
biodiversity
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Species Diversity: Animal – more diverse than plant
Insects outnumber all other species
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Some groups contain more species than others
• Species are not evenly
distributed among taxonomic
groups
- Insects predominate over all
other life-forms
- 40% of all insects are
beetles
• Groups accumulate species by
- Adaptive radiation
(Branching Evolution)
- Allopatric speciation
Sympatric speciation
- Low rates of extinction
• Roaches:
350 M yrs
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(Survived several mass extinctions)
• Hominidae:
2 Myrs
Homo Sapiens: 0.25 Myrs.
Measuring biodiversity is not easy
• Out of the estimated 3 - 100 million species on Earth,
only 1.7 - 2 million species have been successfully
catalogued
• Very difficult to identify species
- Many remote spots on Earth remain unexplored
- Small organisms are easily overlooked
- Many species look identical until thoroughly examined
• Entomologist Terry Erwin found 163 beetle species
specialized on one tree species
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Biodiversity is uneven geographically
• Living things are distributed
unevenly across Earth
• Latitudinal gradient: species
richness increases towards the
equator
Canada has 30 - 100 species of
breeding birds, while Costa Rica
has more than 600 species
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Biodiversity Losses and Species Extinction
• Extinction: occurs when the last member of a species dies
and the species ceases to exist
• Extirpation: the disappearance of a particular population
from a given area, but not the entire species globally
- Can lead to extinction
• Cause of Extinction:
Inability to adapt to changes in ecosystem
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Extinction is a natural process
• Paleontologists estimate 99% of all species that ever lived
are now extinct (Trilobites, Ammonites, Dinosaurs, etc. )
• Background rate of extinction:
extinctions occurs naturally even without big changes
- for mammals and marine species
0.1% would go extinct every 1,000 to 10,000 yrs
• Mass Extinction often occurs periodically
with an average rate of once every 20 ~100 M years
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Mass Extinction is a natural process
• Sudden Catastrophic Climate Changes:
- Destruction of Habitats, Ecosystem
•
Triggered by
- Volcanism, Earthquake, and other Plate Tectonics
- Impact of Meteorites: ~ 100 M tons/yr
Short hot spell in local area followed by
Long nuclear winter type spell globally
Asteroids: over a billions
Comets of Kuiper Belt: Several Thousands
Comets from Oort Cloud: billions (1.6 ly)
- Human Impact (Current or 6th ME)
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Meteorites:
How Solar System Debris go astray off from their orbits
• Solar system revolves around the galactic center
at 220 km/s, w/ a period of 250 M yrs
- do not follow the same path, and distance to near by
solar systems changes to cause gravitational disruptions
Some of the debris (Asteroids, KBO and Oort Cloud)
become off balanced, thrown off from the orbits and
being accelerated toward Sun (by gravitation).
• Our Solar System: 26,000 ly from the center of MWG
• Would occur more often if located closer to the center
less often if located further from center
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Our Solar System
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The Kuiper Belt (20~55 AU)
Eris, Pluto
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Oort Cloud (1 ly)
Milky way Galaxy: How Solar Debris go astray
Human Impact (Current or 6th ME)
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Andromeda Galaxy: 2.5 M ly away
Geological Times
• Ter./Qua: Homo
• Cre.: Birds (M)
• Jur.: Mammals
• Tri.: Dinosaur (M)
• Per. : Reptiles (V)
• Car.: Amphibians
• Dev.: Insects
• Sil.: Land Plants
• Ord.: Fishes
• Cam.: Vertebrates
• Marine animals
• Invertebrates
• Eukaryotes
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• Prokaryotes
Earth has experienced five mass extinctions
• In the past 440 million years, mass extinctions have
eliminated at least 50% of all species
• After every mass extinction the biodiversity returned to or
exceeded its original state
- Many new different
environment created
providing organisms
excellent opportunities
to evolve
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Possibility of civilization on other solar systems
Biodiversity in other planet systems?
• ~100 G suns in our galaxy (Milky way)
• How many of these have planets? (~ 200 found so far)
if 1 %, ~1 G solar systems; if 0.1 %, ~100M sol systems
• Is temperature of the planets right?
if 1 %, ~10 M planets;
if 0.1 %, ~100,000 planets
• Is the planets big enough to hold air and liquids?
If 1 %, ~100,000 planets;
if 0.1 %, ~100 planets
• Is the system located at right distance from the center?
If 1 %, ~1000 planets;
optimistic estimation
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if 0.1 %, ~0.1 (=0) planets;
pessimistic
The current mass extinction (6th) is human caused
• During this Quaternary period, we may lose more than
half of all species
- Hundreds of human-induced species extinctions,
and multitudes of others on the brink of extinction
• The current global extinction rate is 100 to 1,000 times
greater than the background rate
- This rate will increase tenfold in future decades due
to human population growth and resource
consumption
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Migration of Human out of Africa: 200,000 years ago
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People have hunted species to extinction for 150 millennia
Extinctions followed human arrival on islands and continents
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Habitat alteration has occurred in every biome
Particularly in tropical rainforests, savannas, and tropical
dry forests
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Invasive species cause biodiversity loss
• Introduction of non-native species to new environments
- Accidental (zebra mussels), or Deliberate (Kudzu)
• Invaders have no natural predators, competitors, or parasites
• Cost billions of dollars in economic damage
1860,
Silk Industry
Late 19th C
Outcompete
natives
1883,
Control rat
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(p307)
Pollution causes biodiversity loss
• Harms organisms in many ways
- Air pollution degrades forest ecosystems: acid rains
- Water pollution adversely affects fish and amphibians
- Agricultural runoff harms terrestrial & aquatic species
- The effects of oil and chemical spills on wildlife are
dramatic and well known
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Overharvesting causes biodiversity loss
• Vulnerable species are large, few in
number, long-lived, and have few
young (K-selected species)
- The Siberian tiger is hunted
without rules and regulations
- The early 1990s saw increased
poaching because of powerful
economic incentives
- Many other species affected:
Atlantic gray whale, sharks,
gorillas
Today the oceans contain only 10% of the large animals they
once did
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Climate change causes biodiversity loss
• Emissions of greenhouse gases warms temperatures
- Modifies global weather patterns and increases
the frequency of extreme weather events
- Increases stress on populations and forces
organisms to shift their geographic ranges
• Most animals and plants will not be able to cope
End 10/23/2008
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Warming has been the greatest in the Arctic
The polar bear is being considered for the endangered
species list
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Biodiversity loss has a variety of causes
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Biodiversity:
- provides free ecosystem services
• Provides variety of food, shelter, fuel
• Purifies air and water, and detoxifies wastes
• Stabilizes climate, moderates floods, droughts, wind,
temperature
• Generates and renews soil fertility and cycles nutrients
• Pollinates plants and controls pests and disease
• Maintains genetic resources
• Provides cultural and aesthetic benefits
• Allows us to adapt to change
The annual value of just 17 ecosystem services = $16 - 54 trillion per
year
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# of species for major food supply is very limited at present.
• 15 Crop species:
rice, wheat, potato, sweet potato, cabbage,
beans, lettuce, corn, tomato, carrots, etc.
• 8 Live stock species:
chicken, cow, pig,
mackerel, salmon, trout, shrimp
• Potato Blight: 1840s, Crop Failure Irish Famine
• Avian Flu: early 2000s, Southeast Asia/China,
Influenza A Virus (H5N1)
• Mad Cow Disease: late 1980s, Britain/Europe, Prion
over 4 M cattle slaughtered/burned.
=>Call for new potential food crops in the future
added
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3/31/2011
Some potential new food sources
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Organisms provide drugs and medicines
• Each year
pharmaceutical
products owing their
origin to wild species
generate up to $150
billion in sales
- The rosy periwinkle
produces
compounds that
treat Hodgkin's
disease and
leukemia
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Biodiversity generates economic benefits
• People like to experience protected natural areas, creating
economic opportunities for residents, particularly in
developing countries
- Costa Rica: rainforests
- Australia: Great Barrier Reef
- Belize: reefs, caves, and rainforests
• A powerful incentive to preserve natural areas and reduce
impacts on the landscape and on native species
• But, too many visitors to natural areas can degrade the
outdoor experience and disturb wildlife
Several Ecotourism Places being developed recently:
Indonesia, Some Amazon Jungles, Madagascar
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Conservation biology responds to
biodiversity loss
• Conservation biology:
devoted to understanding
the factors that influence
the loss, protection, and
restoration of biodiversity
- Arose as scientists
became alarmed at the
degradation of natural
systems
- An applied and goaloriented science
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Should conservation focus on endangered species?
• Endangered Species Act (1973) (ESA): forbids the
government and private citizens from taking actions that
destroy endangered species or their habitats
- To prevent extinction
- Stabilize declining populations
- Enable populations to recover
• As of 2007, the U.S. had 1,312 species listed as
endangered or threatened.
• Bald eagles, peregrine falcons, brown pelicans, and
others have recovered and are no longer listed
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Protecting biodiversity
• Captive breeding – individuals are
bred and raised with the intent of
reintroducing them into the wild
- Zoos and botanical gardens
• Some reintroductions are controversial
- Ranchers opposed the reintroduction
of wolves to Yellowstone National
Park
- Some habitat is so fragmented, a
species cannot survive
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International conservation efforts
• UN Convention on International Trade in Endangered Species
of Wild Fauna and Flora (CITES)
80 nations at Washington, DC (1973)
to protect endangered species by banning international transport of
their body parts
• Convention on Biological Diversity
signed at the Earth Summit in Rio de Janeiro (1992)
- Seeks to conserve biodiversity, providing incentives
- Use biodiversity in a sustainable manner
- Ensure the fair distribution of biodiversity’s benefits
- By 2007, 188 nations had signed on
- Iraq, Somalia, the Vatican, and the U.S. did not join
End 10/23/2008
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Biodiversity hotspots
• Biodiversity hotspots – prioritizes
regions most important globally for
biodiversity
- Support a great number of
endemic species:= species
found nowhere else in the world
- The area must have at least
1,500 endemic plant species
(0.5% of the world total)
- It must have lost 70% of its
habitat due to human impact
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Tamarin: Brazil Rain Forest
Darwin’s Frog: Chile
(Temperate Rain Forest)
Lemur: Madagascar
There are 34 global biodiversity hotspots
2.3% of the planet’s land surface contains 50% of
the world’s plant species and 42% of all terrestrial
vertebrate species
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Conclusion
• Loss of biodiversity will result in a mass extinction
• Primary causes of biodiversity loss are:
- Habitat alteration, invasive species, pollution,
overharvesting of biotic resources, and climate change
• Human society cannot function without biodiversity’s
benefits
• Science can help save species, preserve habitats, restore
populations, and keep natural ecosystems intact
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QUESTION: Review
Which level is NOT included in the concept of
biodiversity?
a)
b)
c)
d)
Species
Genetics
Ecosystems
All of the above are included in this concept
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QUESTION: Review
What happens when a species experiences “inbreeding
depression”?
a) The species becomes too large for the resource base
b) Genetically similar parents mate and produce inferior
offspring
c) Genetically similar parents mate and produce
superior offspring
d) The number and variety of species increases
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QUESTION: Review
According to the concept of “latitudinal gradient,”
which of the following happens?
a)
b)
c)
d)
Species richness increases towards the equator
Species richness decreases towards the equator
Species richness decreases over time
Countries like Canada have many more species than
expected
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QUESTION: Review
Which of the following is the major cause of extinction?
a)
b)
c)
d)
Invasive species
Pollution
Habitat loss
Overharvesting
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QUESTION: Review
Biodiversity does all of the following, except…
a)
b)
c)
d)
Provide ecosystem services
Decrease food security
Maintain ecosystem function
Provide aesthetic benefits
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QUESTION: Review
According to the theory of island biogeography, which
island would have the highest species richness?
a)
b)
c)
d)
A large island, close to the mainland
A large island, far from the mainland
A small island, close to the mainland
A small island, far from the mainland
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QUESTION: Review
A “biodiversity hotspot” is…?
a) An area located near the equator
b) An area that supports few, but large, species
c) An area that contains naturally high numbers of
people
d) An area that contains a large number of endemic
species
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QUESTION: Weighing the Issues
If a pharmaceutical company produces a medicine from a plant
found in Costa Rica that will earn millions of dollars, who should
reap the financial benefits?
a) The company, because it produced the drug
b) Costa Rica, because it had the plant that produced the drug
c) Taxpayers, because they fund lots of research through their
tax dollars
d) Both the company and Costa Rica, because both played a vital
part
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QUESTION: Weighing the Issues
Have you ever personally experienced evidence of
the biophilia hypothesis?
a)
b)
c)
d)
Yes, I frequently feel a connection to other
living things and nature
Yes, sometimes, on a particularly lovely day
Maybe, but I’m not sure
Definitely not, unless I was earning money
from using nature
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QUESTION: Interpreting Graphs and Data
Where would ecotourists go to view the maximum species
richness on these islands?
a)
b)
c)
d)
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Redonda
Montserrat
Puerto Rico
Hispaniola
QUESTION: Interpreting Graphs and Data
Which biome lost the most area by 1950; which biome
lost the most area in recent decades?
a) Temperate
grassland; tropical
dry forest
b) Desert; savanna
c) Chaparral; tundra
d) Temperate
grassland; desert
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