Evidence for Evolution

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Evidence for Evolution

• A slide extravaganza

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Types of evidence

• 1. Evidence from the fossil record (dead
  things)

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Fossil formation

• Bones and shells undergo mineral replacement and
  are turned into rock
• Soft material either disappears, or leaves an
  impression in the earth (that turns to rock)

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A selection of fossils
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(No Transcript)
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Fossils show transitions
The Archaeopterix -- between reptile and bird
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Scallops
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From early to modern horse
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(Living things show transitions too)
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Coelacanths - the living fossil
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Types of evidence

• 1. Evidence from the fossil record

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Types of evidence

• 1. Evidence from the fossil record
• 2. Comparative Anatomy

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A. Homologous Structures

• Homo - logy
• Homologous structures have the same underlying
  forms

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Wing anatomy comparison
And compared to our arm
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Arm anatomy comparison
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B. Analogous Structures

• Ana - logy
• Analogous structures have a similar outward
  appearance (but different underlying forms)

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Types of evolution

• Convergent evolution Distantly related
  organisms evolve similar external features
• Divergent evolution
• A common ancestor gives rise to organisms that
  evolve for different environments

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Which goes with which? .

• Homologous structures
• Analogous structures

• Convergent evolution Distantly related organisms
  evolve similar external features
• Divergent evolution
• A common ancestor gives rise to organisms that
  become more different with time.

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Which goes with which?

• Homologous structures
• Analogous structures

• Convergent evolution Distantly related organisms
  evolve similar external features
• Divergent evolution
• A common ancestor gives rise to organisms that
  become more different with time.

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C. Vestigial Structures

• Vestige - a left-over/ remnant
• Vestigial structures are evolutionary leftovers
  from an earlier ancestor

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The dew claw of a wild cat
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The human appendix
Fetal Human
Rabbit
Adult Human
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Membranes in our eyes
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Hip bones in whales
(Look at that hand too!)
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Types of evidence

• 1. Evidence from the fossil record
• 2. Comparative Anatomy

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Types of evidence

• 1. Evidence from the fossil record
• 2. Comparative Anatomy
• 3. Comparative Embryology

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Human embryo at 5 weeks
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Embryos

can you guess which one is human?
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Embryos
how about now?
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And now
Were you right?
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Types of evidence

• 1. Evidence from the fossil record
• 2. Comparative Anatomy
• 3. Comparative Embryology

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Types of evidence

• 1. Evidence from the fossil record
• 2. Comparative Anatomy
• 3. Comparative Embryology
• 4. Molecular Evidence

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Comparing DNA

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Determining relationships

• DNA similarity between species is used to
  determine how closely related they are.
• This is in turn used to construct possible
  evolutionary trees.

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How closely related are these fellows?

Mystery critter! (Im not telling)
Brown Bear
got your guess?
Giant Panda
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An Evolutionary Tree
This tree was constructed by looking at
similarity of DNA among bears

so why is he called a red panda?
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Types of evidence

• 1. Evidence from the fossil record
• 2. Comparative Anatomy
• 3. Comparative Embryology
• 4. Molecular Evidence

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Types of evidence

• 1. Evidence from the fossil record
• 2. Comparative Anatomy
• 3. Comparative Embryology
• 4. Molecular Evidence
• 5. Behavior

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Behavioral similarities

• Duck and other bird mating dances
• How primates carry their young
• Fish swimming motions and salamander walks
• And on and on and on.

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Types of evidence

• 1. Evidence from the fossil record
• 2. Comparative Anatomy
• 3. Comparative Embryology
• 4. Molecular Evidence
• 5. Behavior

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Types of evidence

• 1. Evidence from the Fossil Record
• 2. Comparative Anatomy
• 3. Comparative Embryology
• 4. Molecular Evidence
• 5. Behavior
• 6. Direct observation
• also known as microevolution

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Artificial selection

• Remember us?

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And look at us!
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And Natural Selection
Hawaiian Rock Wallabies!
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The Beak of the Finch

• Biologists Peter and Rosemary Grant documented
  natural selection occurring in populations of
  finches on the Galapagos islands over a period of
  only 20 years! This generation to generation
  changes in the frequency of certain traits is
  called microevolution.