Biology / Unit 8 Bio 1649 short lesson, about 20 seconds
Descent with Modification
Captions available
The idea
Descent with modification is Darwin's term for how natural selection, acting repeatedly across generations, gradually changes a lineage's inherited traits over time.
In practice
Darwin's only diagram in On the Origin of Species depicts descent with modification as a branching pattern of ancestry.
Where people slip
Descent with modification describes gradual change within a lineage — it names the pattern selection produces, not a separate mechanism.
Your place on the trail
Every lesson rests on earlier ones and opens later ones. Tap any to jump.
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