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Biodiversity
Estimate over 1.5
million species
 Biodiversity is the
number of different
species in an area.
 Major environmental
issue.
 Why?
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Value of Biodiversity
Economic Value
 They can provide food, materials
for clothing, medicine, and other
products.
 Useful species still undiscovered.
 Ecotourism provides jobs and
money for many countries
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Ecological Value
All species in an ecosystem share
resources and are dependent on
each other for food and shelter.
Some species are the center
stone of their ecosystem. These
keystone species are species that
influence the survival of many
other species in an ecosystem
1800 sea otter extinction
Factors Affecting Biodiversity
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Area
The larger the area the more
species can be found (100 vs. 10)
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Climate
Species increase from the poles
toward the equator.
Tropical rain forests are near the
equator.
Make up 7% of land mass but contain
more than half the species in the
world. Coral reef which are 1% of the
ocean but have 20% of sea species.
Due to the constant warm
temperature. This allows niche
diversity, where species don’t have to
compete as much.
Gene Pool Diversity
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Genes carry organism’s hereditary
information
Each organism has different genes
from other individuals.
Individual differences make up the
total gene pool.
Less diversity=less ability to adapt
to changes in the environment
Extinction of species
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Extinction is the disappearance
of all members of a species
from the Earth.
Rate of extinction has
dramatically increased.
Once the size of a species
drops to a certain level they
may not recover.
Species in danger of
becoming extinct are
endangered species.
 Species that could become
endangered in the future
are called threatened
species.
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Causes of Extinction
Habitat Destruction
 Habitat fragmentation
(breaking large habitats into
smaller ones)
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Poaching
 Illegal killing or removal
of wildlife species
 Hunted for their skin, fur, teeth,
horns, etc
 Sold as exotic pets
Pollution
 This can pollute the water or air
killing animals or cause a low
birth rate.
Exotic Species
 Introducing exotic
species into an
ecosystem can threaten
biodiversity.
 Can outcompete or prey
on existing species.
Protecting Biodiversity
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Captive Breeding
Mating animals in the zoo or wildlife
preserves.
Scientist care for the young and
release them into the wild
Laws and Treaties
Endangered Species Act prohibits the
killing or trading of endangered
animals and/or products
Hard to enforce
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Habitat Preservation
The most effective way is to
preserve a whole ecosystem.
Must be large enough to
preserve the population,
contain a variety of niches, and
be a diverse ecosystem