Biology / Unit 8 Bio 1667 short lesson, about 20 seconds
Comparative Embryology as Evidence
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The idea
Comparative embryology finds structures shared across related lineages' embryos that vanish before adulthood, evidence those lineages share a common ancestor.
In practice
All vertebrate embryos, including humans, briefly develop gill slits and a tail, persisting to adulthood only in some aquatic lineages.
Where people slip
A structure that disappears before adulthood still evidences common ancestry — its absence in the adult does not erase that history.
Your place on the trail
Every lesson rests on earlier ones and opens later ones. Tap any to jump.
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