Fitness inputs
Relative fitness values compare genotypes within the same environment.
| Input | Meaning |
|---|---|
| 1 | Reference or highest fitness |
| 0.8 | 20% lower relative fitness |
| 0 | No contribution after selection |
Natural Selection Calculator
Enter initial allele frequency and genotype fitness values to see how p and q change over generations.
Answer
0.8392
Final allele A frequency (p)
Final allele a frequency (q): 0.1608
Change in p: 0.2392
Mean fitness: 0.9665
Generation: 10
Use relative fitness values. A genotype with fitness 1 is the reference; lower values are selected against.
Final genotype frequencies after selection
AA0.7286
Aa0.2513
aa0.0201
Generation table
| Gen | p | q | Mean fitness |
|---|---|---|---|
| 0 | 0.6 | 0.4 | 0.912 |
| 1 | 0.6316 | 0.3684 | 0.9195 |
| 2 | 0.6615 | 0.3385 | 0.9266 |
| 3 | 0.6898 | 0.3102 | 0.9331 |
| 4 | 0.7163 | 0.2837 | 0.9392 |
| 5 | 0.741 | 0.259 | 0.9448 |
| 6 | 0.7639 | 0.2361 | 0.95 |
| 7 | 0.7852 | 0.2148 | 0.9547 |
| 8 | 0.8047 | 0.1953 | 0.959 |
| 9 | 0.8227 | 0.1773 | 0.963 |
| 10 | 0.8392 | 0.1608 | 0.9665 |
Formula
p' = (p^2 wAA + p q wAa) / wbarThe calculator uses diploid viability selection. Mean fitness is wbar = p^2 wAA + 2pq wAa + q^2 waa.
| Symbol | Variable | Description |
|---|---|---|
| p | Allele A frequency | Starting frequency of the A allele. |
| q | Allele a frequency | q = 1 - p. |
| w | Fitness | Relative fitness for each genotype. |
How to use it
- 1
Enter p
Use a value from 0 to 1 for the initial A allele frequency.
- 2
Set fitness
Enter relative fitness for AA, Aa, and aa.
- 3
Read the final frequency
The answer area shows final p, final q, and change in p.
Natural selection FAQ
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