Evidence for Evolution

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Evidence for Evolution
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Descent with Modification

• Over time, natural selection produces different
  organisms
• Different structures
• Different niches
• Different habitats
• Species today look different from their ancestors

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Descent with Modification

• Descent with modification also implies that all
  living organisms are related to each other
• Common descent- all living things were derived
  from common ancestors

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Evidence for Evolution

• Adaptations changes in a species that occur over
  a long period of time that make a species more
  successful in an ecosystem

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Darwins Evidence for Evolution

• Fossil Record
• By comparing fossils from older rock layers to
  fossils from newer rock layers, scientists can
  document that life on earth has changed.

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Fossils
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Darwins Evidence of Evolution

• Homologous Body Structures
• Features with a common evolutionary origin
• similar in arrangement and/or function.

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Darwins Evidence of Evolution

• Analogous Structures Have similar arrangement
  and/or function but do not have a common
  evolutionary origin.

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Evidence for Evolution

• Vestigial organs Organ that doesnt serve a
  useful function anymore
• The presence of these organs may not affect the
  organisms ability to survive
• Natural selection will not eliminate that organ

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Examples of Vestigial Structures

• Wings on flightless birds
• Eyes on blind fish
• The human appendix
• Hind leg bones on whales

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http//www.pbs.org/wgbh/evolution/library/03/4/l_0
34_05.html
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Darwins Evidence of Evolution

• Similarities in Embryology
• Embryos of many animals with a backbone are very
  similar
• The same group of embryonic cells develop in the
  same order and patterns in all vertebrate

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BIOCHEMISTRY

• By comparing DNA and RNA of different species, we
  can determine their relationships

http//www.pbs.org/wgbh/evolution/library/11/2/e_s
_5.html