Evolution

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Evolution

• Change Over Time

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Your Turn

• Looking at the picture and create your own
  definition of evolution

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EVOLUTION

• The diversity among living organisms is a result
  of evolution
• If organisms do not evolve they will become
  extinct

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Theories of Evolution - Lamarck

• Jean Baptiste de Lamarck (1744-1829)

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Theories of Evolution Lamark

• Believed that species have changed over time for
  the purpose of adaptation
• Use and disuse
• Structures grew or shrank based on how much they
  were used
• Transmission of acquired traits
• Parents could transmit the characteristics
  acquired through use and disuse in their lifetime
  directly to their offspring

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Your Turn

• Based on Lamarcks theory describe why the
  giraffes had long or short necks and how that
  affected their offspring.

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Your Turn

• Weisman Experiment
• He bred 2 mice whos tails he had cut.
• The offspring all had long tails.
• DOES THIS EXPERIMENT SUPPORT LAMARCKS THEORY?
  EXPLAIN.

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Theories of Evolution - Lamarck

• Lamarcks theory was proven to be incorrect
• Weismans rat experiment

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Theories of Evolution - Darwin

• Charles Darwin (1809-1882)

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Theories of Evolution - Darwin

• Newer forms appearing in the fossil record are
  the modified descendants of older species
• ALL species descended from one or a few original
  types of life
• Evolution occurs as a result of natural selection

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Theories of Evolution - Darwin

• Individuals with favorable adaptations or traits
  would survive and reproduce more successfully
  than individuals without these favorable traits
• Survival of the fittest
• Does not mean strength

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Your Turn

• Look at the following cartoons. Pick one and
  create your own definition of survival of the
  fittest and natural selection

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Darwin developed his theory while working as a
naturalist on the HMS Beagle (1831)

• Darwin noticed
• Variations existed among individuals in a species
• Individuals will compete for resources like food
  and space
• Competition would lead to the death of some
  individuals while others would survive
• Individuals that had the favorable variations
  were more likely to survive and reproduce
• Darwins finches

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