Genetic Drift Calculator to Simulate Allele Fixa...
Calculate the probability of an allele becoming fixed or lost in a finite population due to genetic drift. Understand bottleneck effects and effective population ...
What is Genetic Drift?
Genetic drift is the random change in allele frequencies across generations due to chance events in reproduction, not selection. It is especially powerful in small populations and can cause rare alleles to become fixed (100% frequency) or lost entirely, regardless of their fitness.
🧬 Genetic Drift Calculator
Free calculator for instant results.
📐 Formula
P(fixation) = p (for neutral allele)
For a neutral allele with initial frequency p in a population of size N, probability of fixation = p. Time to fixation ≈ 4Ne generations (Ne = effective population size).
📝 Worked Example
Population N=20 (bottleneck), allele frequency p=0.1:
Probability of fixation = 0.1 (10%)
Expected time to fixation ≈ 4×20×0.1 ≈ 8 generations
📝 How to Use
❓ FAQ
Why does drift matter more in small populations?
In large populations, random errors average out. In small populations, one unlucky generation can eliminate an allele by chance.
What is effective population size?
Ne is the number of breeding individuals contributing genes to the next generation — usually much smaller than total population size.
Veer Kumavat
Founder & AuthorVeer is a 14-year-old student from Nashik, Maharashtra, who built SciFi Calculators to help students worldwide master STEM subjects. He is passionate about making complex science and math problems accessible through intuitive digital tools.