Speciation

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Speciation

• evolution of a new species
• occurs when members of similar populations no
  longer interbreed to produce offspring in a
  natural environment

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• In order for their to be speciation, there must
  be isolation

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• Geographic isolation - when a physical barrier
  divides a population
• volcano
• earthquake (produce islands)
• flood

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• Gene pools will evolve separately
• can become different enough to be separate species

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Speciation
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• Reproductive isolation
• Populations can no longer produce fertile
  offspring
• genetic material can be so different that
  reproduction is not possible

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• Behaviors can also prevent reproduction
• mating at different times of the year

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Patterns of Evolution
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• 1) Convergent evolution
• distant related organisms evolve similar traits
• develop structures for the same function
• analogous structures

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Convergent evolution
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• 2)Divergent evolution
• pattern where species that were similar to an
  ancestral species become more distinct
• become less alike as they adapt to separate
  environments
• homologous

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Divergent Evolution
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• adaptive radiation - a species adapts into a
  variety of species to fit many diverse habitats
• Finches beaks adapted to food sources on
  Galapagos Islands

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Adaptive Radiation
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Adaptive Radiation
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ADAPTIVE RADIATION An example of divergent
evolution
http//www.vanderbilt.edu/AnS/english/Clayton/Gala
pago_finches.gif
http//evolution.berkeley.edu/evolibrary/home.php
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Artificial Selection

• Breeding organisms for desired traits
• Agriculture (plants and livestock)
• Dogs and other pets

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Artificial Selection
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What about Super Cow?