Biology / Unit 8 Bio 1641 short lesson, about 20 seconds
Evolution Defined as Change in Allele Frequency
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The idea
Evolution, per Unit 1's Bio 0055, is a change in a population's allele frequencies across generations, not a change within any organism's lifetime.
In practice
A population where a beneficial allele's frequency rises across generations has evolved by this definition.
Where people slip
Seeing a trait's frequency rise across generations does not mean individuals changed mid-life — each one keeps its own genotype.
Your place on the trail
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