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Evidence for Evolution

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Evidence for Evolution Descent with Modification Over time, natural selection produces different organisms Different structures Different niches Different habitats ... – PowerPoint PPT presentation

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Title: Evidence for Evolution


1
Evidence for Evolution
2
Descent with Modification
  • Over time, natural selection produces different
    organisms
  • Different structures
  • Different niches
  • Different habitats
  • Species today look different from their ancestors

3
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

4
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

5
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.

6
Fossils
7
Darwins Evidence of Evolution
  • Homologous Body Structures
  • Features with a common evolutionary origin
  • similar in arrangement and/or function.

8
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9
Darwins Evidence of Evolution
  • Analogous Structures Have similar arrangement
    and/or function but do not have a common
    evolutionary origin.

10
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11
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

12
Examples of Vestigial Structures
  • Wings on flightless birds
  • Eyes on blind fish
  • The human appendix
  • Hind leg bones on whales

13
http//www.pbs.org/wgbh/evolution/library/03/4/l_0
34_05.html
14
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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16
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
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