That little pink bud in the inside corner of your eye is actually a vestigial eyelid! Find out more about the plica semilunaris, in a short video that explains why vestigial structures hang around.

Concepts

eyes, vestigial structures, natural selection, the human body

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Additional Tags

science

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Instructional Ideas

• Have groups investigate other vestigial structures in the human body
• Chart the number of class members who have the palmaris longus muscle

Classroom Considerations

• In addition to the video, a comprehension check, links to related articles, and a discussion forum are provided

Pros

• The "Dig deeper" section includes articles about whales, the African rock python, and other topics sure to engage learners

Cons

• None