The Biodiversity Crisis
Chapter 55
Types of biodiversity
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Genetic diversity:
• Genetic differences within a single
population and among geographically
separate populations
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Species diversity:
• All the different species on our planet
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Ecosystem diversity:
• The variety of interactions within and
among Earth’s different ecosystems
Loss of biodiversity
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Extinction is a natural biological process
The rate of extinction is now 50-500 times
the natural rate
Other mass extinctions have occurred in
Earth’s history
This one is different in that it is:
• due to human activities
• compressed into a short time frame
• happening much faster than new species
evolution can occur
Ways to protect biodiversity

Protection of habitats
• Habitat loss/degradation is the number
one cause of threatened and
endangered species in the U.S.
• Most of these species are ‘specialists’ –
species that occupy a narrow niche and
have specific requirements
• Habitat fragmentation makes it worse
• Degradation of habitat through pollution
can also cause problems
Ways to protect biodiversity…
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Control invasive species
• Biotic pollution introduces a non-native
species into an area
• It may prey on native species or
compete for food or habitat
• There may not be any natural controls
in that ecosystem – such as predators
or disease – to limit their population
Ways to protect biodiversity…
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Control other human activities
• Pest eradication practices
• Overhunting
• Poaching
• Commercial harvesting
Conservation Biology
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In situ conservation
• Preservation of ecosystems
• Biodiversity hotspots – areas in critical need of
help
• Restoration ecology – try to return an
ecosystem to it’s former state
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Ex situ conservation
• Preservation of the individual species
• Artificial insemination
• Host mothering
Legal protections
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U.S. Endangered Species Act
• Species listed must be protected
• Species are listed without regard for
economic impact of the listing
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Convention of International Trade in
Endangered Species (CITES)
• Enforcement varies from country to
country