TABLE 1.
MATLAB simulations confirm analytic theory
| Selection | Alleles | Population size | Expected Φ | Observed Φ | Observed f |
|---|---|---|---|---|---|
| Overdominant | 2 | 100,000 | 2.2 | 2.1981 (2.1 × 10−4) | −0.0472 (1.1 × 10−5) |
| Underdominant | 2 | 100,000 | 1.8 | 1.8011 (1.5 × 10−4) | 0.0508 (2.1 × 10−5) |
| Neutral | 2 | 100,000 | 2 | 2.0005 (1.4 × 10−4) | −0.0001 (8.9 × 10−6) |
| Stochastic fitness | 2 | 100,000 | >2 | 2.0318 (6.9 × 10−2) | −0.0037 (4.3 × 10−3) |
| Stochastic fitness | 3 | 100,000 | >2 | 2.0010 (2.8 × 10−2) | 0.0013 (7.8 × 10−4) |
| Stochastic fitness | 4 | 100,000 | <2 | 1.9898 (1.5 × 10−2) | 0.0016 (3.0 × 10−4) |
| Directional | 2 | 1,000 | 2.0976 | 2.1639 (6.8 × 10−2) | −0.0195 (8.9 × 10−4) |
| Directional | 2 | 10,000 | 2.0976 | 2.0989 (6.3 × 10−3) | −0.0149 (1.3 × 10−4) |
| Directional | 2 | 100,000 | 2.0976 | 2.1013 (6.2 × 10−4) | −0.0156 (2.7 × 10−5) |
| Directional | 3 | 100,000 | 2.0646 | 2.0681 (1.3 × 10−3) | −0.0115 (1.2 × 10−5) |
| Directional | 4 | 100,000 | 2.0482 | 2.0467 (2.6 × 10−3) | −0.0097 (9.4 × 10−6) |
Simulations were run for 100 generations and mean and variance of Φ were computed (with variance in observed Φ within parentheses). All alleles were equally frequent at the start of each simulation run. Fitnesses are as follows: overdominant selection (wij = 1.1, wii = 1.0), underdominant selection (wij = 0.9, wii = 1.0), stochastic fitness (fitnesses for each genotype were generated each generation from a Gaussian distribution with a mean of 1.0 and a standard deviation of 0.1), and directional selection (homozygotes and heterozygotes containing a favored dominant allele have a fitness of 1.1, while all other genotypes have a fitness of 1.0).