How to Calculate Genetic Drift
What is Genetic Drift?
Genetic drift is random change in allele frequencies due to chance — particularly influential in small populations where sampling error is large relative to gene pool size.
Step-by-Step Guide
- 1Variance per generation: p(1-p)/(2N)
- 2Small N → large fluctuations → faster drift to fixation or loss
Worked Examples
Input
p=0.5 · N=50
Result
σ per generation = ±5%
Small population drifts fast
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