Chapter 22 Descent with Modification

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Chapter 22Descent with Modification
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Chapter 22Descent with Modification

• Darwins context

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Chapter 22Descent with Modification

• Darwins context
• Linnaeus

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Chapter 22Descent with Modification

• Darwins context
• Linnaeus classification (taxonomy)

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Chapter 22Descent with Modification

• Darwins context
• Linnaeus classification (taxonomy)
• Hutton

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Chapter 22Descent with Modification

• Darwins context
• Linnaeus classification (taxonomy)
• Hutton gradual geological change

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Chapter 22Descent with Modification

• Darwins context
• Linnaeus classification (taxonomy)
• Hutton gradual geological change
• Lamarck

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Chapter 22Descent with Modification

• Darwins context
• Linnaeus classification (taxonomy)
• Hutton gradual geological change
• Lamarck species can change

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Chapter 22Descent with Modification

• Darwins context
• Linnaeus classification (taxonomy)
• Hutton gradual geological change
• Lamarck species can change
• Malthus

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Chapter 22Descent with Modification

• Darwins context
• Linnaeus classification (taxonomy)
• Hutton gradual geological change
• Lamarck species can change
• Malthus population limits

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Chapter 22Descent with Modification

• Darwins context
• Linnaeus classification (taxonomy)
• Hutton gradual geological change
• Lamarck species can change
• Malthus population limits
• Cuvier

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Chapter 22Descent with Modification

• Darwins context
• Linnaeus classification (taxonomy)
• Hutton gradual geological change
• Lamarck species can change
• Malthus population limits
• Cuvier fossils and extinction

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Chapter 22Descent with Modification

• Darwins context
• Linnaeus classification (taxonomy)
• Hutton gradual geological change
• Lamarck species can change
• Malthus population limits
• Cuvier fossils and extinction
• Lyell

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Chapter 22Descent with Modification

• Darwins context
• Linnaeus classification (taxonomy)
• Hutton gradual geological change
• Lamarck species can change
• Malthus population limits
• Cuvier fossils and extinction
• Lyell modern geology

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Chapter 22Descent with Modification

• Darwins context
• Linnaeus classification (taxonomy)
• Hutton gradual geological change
• Lamarck species can change
• Malthus population limits
• Cuvier fossils and extinction
• Lyell modern geology
• Mendel

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Chapter 22Descent with Modification

• Darwins context
• Linnaeus classification (taxonomy)
• Hutton gradual geological change
• Lamarck species can change
• Malthus population limits
• Cuvier fossils and extinction
• Lyell modern geology
• Mendel genetic inheritance.

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Chapter 22Descent with Modification

• Lamarcks theory of evolution (1809)
• Fossil record shows lines of descent
• Use and disuse of body parts
• Inheritance of acquired characteristics.

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Chapter 22Descent with Modification
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Chapter 22Descent with Modification
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Chapter 22Descent with Modification
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Chapter 22Descent with Modification

• Observation 1
• For any species, population size would increase
  exponentially if all individuals that are born
  reproduced successfully

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Chapter 22Descent with Modification

• Observation 1
• For any species, population size would increase
  exponentially if all individuals that are born
  reproduced successfully.
• Observation 2
• Nonetheless, populations tend to remain stable in
  size, except for seasonal fluctuations

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Chapter 22Descent with Modification

• Observation 1
• For any species, population size would increase
  exponentially if all individuals that are born
  reproduced successfully.
• Observation 2
• Nonetheless, populations tend to remain stable in
  size, except for seasonal fluctuations.
• Observation 3
• Resources are limited.

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Chapter 22Descent with Modification

• Inference 1
• Production of more individuals than the
  environment can support leads to a struggle for
  existence among individuals of a population, with
  only a fraction of their offspring surviving each
  generation.

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Chapter 22Descent with Modification

• Observation 4
• Members of a population vary extensively in their
  characteristics. No two individuals are exactly
  alike

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Chapter 22Descent with Modification

• Observation 4
• Members of a population vary extensively in their
  characteristics. No two individuals are exactly
  alike.
• Observation 5
• Much of this variation is heritable.

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Chapter 22Descent with Modification

• Inference 2
• Survival depends in part on inherited traits.
  Individuals whose inherited traits give them a
  high probability of surviving and reproducing in
  a given environment have higher fitness and are
  likely to leave more offspring than less fit
  individuals.

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Chapter 22Descent with Modification

• Inference 3
• This unequal ability of individuals to survive
  and reproduce will lead to a gradual change in a
  population, with favorable characteristics
  accumulating over generations.

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Chapter 22Descent with Modification

• Natural Selection

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Chapter 22Descent with Modification

• Natural Selection
• The differential success in reproduction among
  individuals that vary in their heritable traits

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Chapter 22Descent with Modification

• Natural Selection
• The differential success in reproduction among
  individuals that vary in their heritable traits.
• Over time, natural selection can increase the
  adaptation of organisms to their environment

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Chapter 22Descent with Modification

• Natural Selection
• The differential success in reproduction among
  individuals that vary in their heritable traits.
• Over time, natural selection can increase the
  adaptation of organisms to their environment.
• If an environment changes over time, or if a
  population moves to a new environment, natural
  selection may result in adaptation to these new
  conditions

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Chapter 22Descent with Modification

• Natural Selection
• The differential success in reproduction among
  individuals that vary in their heritable traits.
• Over time, natural selection can increase the
  adaptation of organisms to their environment.
• If an environment changes over time, or if a
  population moves to a new environment, natural
  selection may result in adaptation to these new
  conditions, sometimes giving rise to new species.

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Chapter 22Descent with Modification

• Evidence
• Evolution in action today
• Anatomical homologies
• Molecular homologies
• Biogeography
• The fossil record.

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Chapter 22Descent with Modification

• Some key points

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Chapter 22Descent with Modification

• Some key points
• Individuals do not evolve populations evolve
  over generations

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Chapter 22Descent with Modification

• Some key points
• Evolution does not move towards a goal

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Chapter 22Descent with Modification

• Some key points
• Adaptations are always based on existing
  structures

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Chapter 22Descent with Modification

• Some key points
• Events in the past are inferred, but natural
  selection and descent with modification are
  observable events happening today in the world
  and in the laboratory.

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Chapter 22Descent with Modification

• Some key points
• Evolution is just a theory like Newtons theory
  of gravitation.

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Chapter 22Descent with Modification

• Some key points
• Evolution is just a theory like Newtons theory
  of gravitation.
• Both make sense of massive amounts of data.

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Chapter 22Descent with Modification

• Some key points
• Evolution is just a theory like Newtons theory
  of gravitation.
• Both make sense of massive amounts of data.
• Both make accurate predictions.

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Chapter 22Descent with Modification

• Some key points
• Evolution is just a theory like Newtons theory
  of gravitation.
• Both make sense of massive amounts of data.
• Both make accurate predictions.
• Both are subject to constant questioning and
  revision.
• .