Biodiversity

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Biodiversity
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Biodiversity and Conservation

• Variation in three levels
• Genetic the variety of genes within a species
• Species the number of species per area
• Habitat the variety of places where life exists

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Genetic Diversity

• Range of genes for a particular trait
• May be different from another population of the
  same species
• Definitely different from another species
• Cause sexual reproduction and mutations

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Why is genetic diversity important?

• Allows for survival from disease, changes in
  climate or other local environmental conditions
• Provides the basis for evolution by natural
  selection
• A healthy population has a high genetic
  diversity.

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Habitat Diversity

• The range of different habitats
• Includes microhabitat or a major community
• Cause Atmospheric circulation

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Why is habitat diversity important?

• Provides different niches
• Provides a variety of services
• CO2 Fixation
• Pest Control
• Nitrogen Fixation
• Soil Binding
• Air Pollution Absorption

• Oxygen Production
• Water Purification
• Nutrient Storage
• Pollination

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Species Diversity

• Species organisms that interbreed and produce
  fertile offspring
• How many different species are there?
• 1.75 million known
• Many more unknown
• 5 50 million or more

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Interconnection of Diversity

• Increases in types of habitat leads to increase
  in different species which in turn increases
  genetic variation.

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Natural Selection

• Natural Selection
• Darwin proposed that population changes are based
  on natural differences.
• Survival of the fittest

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Five main propositions for the theory of
evolution by natural selection

• More offspring are produced than will survive and
  reproduce.
• There are more individuals than can be supported
  by resources of the habitat
• There is competition for resources among
  offspring.
• Struggle for survival based on environmental
  pressure

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Five main propositions for the theory of
evolution by natural selection

• There is variation of traits within populations
  of organisms.
• There is variety between individuals
• Some of these traits are more helpful than
  others.

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Five main propositions for the theory of
evolution by natural selection

• Because organisms with certain traits have
  greater chance of reproducing, there offspring
  will make up a larger part of the population
• Those more fit (able)to survive, do and pass
  their genes on to the next generation
• Changes in gene frequency lead to changes in
  population over time.
• Over long periods of time consistent selective
  pressure along with reproductive isolation can
  lead to speciation (new species

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Example of Natural Selection

• Black and gray peppered moths in 19th century
  England