10'4 Evidence of Evolution

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10.4 Evidence of Evolution

• KEY CONCEPT Evidence of common ancestry among
  species comes from many sources.

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Evidence for evolution in Darwins time came from
several sources.

• Fossils provide evidence of evolution.
• Fossils in older layers are more primitive than
  those in the upper layers.

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• The study of geography provides evidence of
  evolution.
• island species most closely resemble nearest
  mainland species
• populations can show variation from one island to
  another

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• Embryology provides evidence of evolution.
• identical larvae, different adult body forms
• similar embryos, diverse organisms

larva
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• The study of anatomy provides evidence of
  evolution.
• Homologous structures are similar in structure
  but different in function.
• Homologous structures are evidence of a common
  ancestor.

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Analogous Structures

• Analogous structures have a similar function.
• are not evidence of a common ancestor.

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Structural patterns are clues to the history of a
species.

• Vestigial structures are remnants of organs or
  structures that had a function in an early
  ancestor.
• Ex Ostrich wings

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• Molecular and genetic evidence support fossil and
  anatomical evidence.
• Two closely-related organisms will have similar
  DNA sequences.

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Evolution unites all fields of biology.

• Scientist from any fields contribute to the
  understanding of evolution.
• The basic principles of evolution are used in
  many scientific fields.

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Patterns of Evolution

• Microevolution-
• change at the level of the population
• Ex A certain type of bacteria becoming
  resistant to antibiotics (MRSA) in a few years.

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• Macroevolution- Large-scale evolutionary changes
  that take place over long periods of time.
• Ex.
• a. the origin of eukaryotic cells
• b. extinction of the dinosaurs

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• Six important patterns of macroevolution are.

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• 1. Mass extinctions
• Extinction of Dinosaurs?

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• 2. Adaptive Radiation
• A single species or small group of species
  evolving into several different forms that live
  in different ways.
• Ex Dinosaurs being ancestors of present-day
  reptiles.

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• 3. Convergent Evolution
• Development of similar features in different
  lineages.
• Ex

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• 4. Coevolution toxic newts clip
• If one organism changes, another will change as
  well.

Moths with long feeding tubes feed from flowers
with nectar deep within the petals.
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• 5. Punctuated Equilibrium
• Rate of evolution happening in long, stable
  patterns, and then short, abrupt spurts.

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• 6. Changes in developmental genes
• Some genes are activated to establish different
  body plans.
• Ex The same insect may have different numbers of
  wings throughout history.