Compare and Contrast How is mass extinction different from background extinction

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1. Compare and Contrast How is mass extinction
   different from background extinction
2. Relate Cause and Effect Why would evolution speed
   up when a small group of organisms migrates to a
   new environment
3. Relate Cause and Effect Why does adaptive
   radiation sometimes result in convergent
   evolution
4. Infer What role does the environment play in
   convergent evolution

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Ch 19 History of Life

• 19.2 Patterns and Processes of Evolution

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• The fossil record shows a parade of organisms
  that evolved, survived for a time, and then
  disappeared
• More than 99 percent of all species that have
  lived on Earth are extinct
• How have so many different groups evolved
• Why are so many now extinct.

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Macroevolutionary Patterns

• Transformations in anatomy, phylogeny, ecology,
  and behavior that occur in clades
• If more speciation than extinction occurs the
  clade survives
• If more extinction than speciation occurs the
  clade dies out.

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Macroevolution and Cladistics

• Fossils are also classified into clades.

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• Background extinction
• Slow but steady process of natural selection
• Mass extinction
• Affects many species over a relatively short
  period of time
• Entire ecosystems vanish and whole food webs
  collapse.

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• After mass extinction
• Survivors produce new species to fill empty
  niches
• Biodiversity recovers
• Takes between 5 and 10 million years.

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Gradualism

• Slow, steady change in a particular line of
  descent.

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Punctuated Equilibrium

• Long lengths of stability that is interrupted by
  brief periods of more rapid change.

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Rapid Evolution

• Occurs more often in a small population
• Occurs more often when migrating to new area
• Occurs more often after a mass extinction.

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Adaptive Radiation

• Single species or a small group of species
  evolves over a relatively short time into several
  different forms that live in different ways
• Occurs when species migrate to a new environment
  or when extinction clears an environment of a
  large number of inhabitants.

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Convergent Evolution

• Different groups develop the same adaptations due
  to living in similar environments
• These all eat ants and termites.

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Coevolution

• Two species evolve in response to changes in each
  other over time
• Flowers and pollinators.

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• 1 What is plotted on the y-axis
• 2 Which mass extinction killed of the highest
  percent of genera
• 3 Describe the overall pattern of extinction
• 4 What evidence
• is the graph
• probably based
• on