Macroevolution

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Macroevolution

• Refers to the patterns, trends, and rates of
  change among lineages over geologic time.
• Evidence for evolution tells us that only
  populations that already exist can evolve.
• All species are related to one another by way of
  descent.

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Evidence for Evolution

• Fossils (Paleontology)
• Comparative Morphology
• common ancestry
• vestigial organs
• Patterns of Development (Embryology)
• Comparative Biochemistry (Molecular Biology)
• Biogeography study of distribution of plants
  and animals in the environment.

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Fossils

• Recognizable, physical evidence of ancient life
• Fossilization is VERY slow

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Types of Fossils

• Actual body parts left (hard body parts
  shells, bones, teeth, woody stems).
• minerals replace original remains
• (calcium replaced by limestone)
• remains trapped in resin amber
• remains trapped in ice or tar pits

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Figure 25.1a Dinosaur National Monument
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Figure 25.1c Petrified trees
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Figure 25.1g Scorpion in amber
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Figure 25.1h Mammoth tusks
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• Imprint type of fossil formed when a film of
  carbon remains after other elements of an
  organism have decayed.
• Mold fossil in which an impression of the
  shape or track of an organism has been left.
• Cast fossil in which sediment fills in the
  cavity left by a fossil mold. (3-dimensional)

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Figure 25.1d Leaf impression
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Figure 25.1f Dinosaur tracks
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Figure 25.0 Fossil of a fish perch
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Dating Fossils

• ?Relative dating vs. Absolute age
• relative determined by looking at a fossils
  position in sedimentary rock (if undisturbed
  layers) and comparing with other fossils found
• absolute determined by dating fossil with
  radioactive isotopes (see page 420).

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Evidence from Comparative Morphology

• Definition Comparative morphology field of
  inquiry that looks at anatomical comparisons of
  major lineages. (different body structures of
  different groups)
• WHEN INTRODUCING CHANGES IN BODYS DEVELOPMENT,
  EVOLUTION TENDS TO FOLLOW LINE OF LEAST
  RESISTANCE.

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Morphological divergence vs. Morphological
convergence

• Divergence changes away from normal body
  forms
• homologous structures Ex. Vertebrate
  forelimbs
• Convergence dissimilar lineages (only remotely
  related) evolve in similar directions (become
  more similar)
• analogous structures Ex. Flippers of
  penguins, porpoises, and sharks

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Figure 22.14 Homologous structures anatomical
signs of descent with modification
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Common Ancestry and Vestigial Organs

• If organisms show speciation, then evolved from a
  common ancestor
• Ex. - Finches with different beaks on
  Galapagos
• Vestigial organs are functionless parts that an
  organism has (and are often homologous to organs
  that are useful in other species.)
• Ex. - tailbone/appendix in humans
• -pelvic and limb bones in snakes

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Evidence from Patterns of Development

• Developmental Program of Vertebrates
• -early embryos strongly resemble one another
  because have inherited same ancient plan for
  development

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Evidence from Comparative Biochemistry

• Compare DNA, RNA, and proteins
• Protein comparisons hemoglobin comparison in
  Biochemical evidence for evolution lab

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Biogeography

• Distribution of organisms around the world

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Distributionof Living Species
Section 15-3
Beaver
Beaver Muskrat Beaver andMuskrat Coypu
Capybara Coypu andCapybara
NORTH AMERICA
Muskrat
Capybara
SOUTH AMERICA
Coypu