Vestigial structures are anatomical remnants that were important in the organism’s ancestors, but are no longer used in the same way.
3. Give an example of a vestigial structure from this activity: The eyes (or lack of) on the cave fish.
4. Below are some vestigial structures found in humans. For each, hypothesize what its function may have been.
Structure
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Possible function?
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Wisdom teeth
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Chewing, grinding raw plant matter.
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Appendix
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Digesting cellulose (found in plant matter, like leaves).
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Muscles for moving the ear
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Move the external ear so that it captures a specific sound source.
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Body hair
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Warmth, protection.
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Little toe
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Walking, and running, especially on four legs.
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Tailbone
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Primate tails are prehensile, meaning they can grasp things independently.
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5. How are vestigial structures an example of evidence of evolution?
By definition, these structures are not necessary or advantageous to the organism, so they have
been reduced. Evolution by natural selection is the only mechanism that explains why these structures
would exist at all – there must have been an ancestor species that did use the structure.
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