Fitness Values
Type of Selection A1A1 A1A2 A2A2 Change in q
Selection against a recessive trait 1 1 1 − s
Selection against a dominant trait 1 1 − s 1 − s
Selection against a trait with no dominance 1 1 − s 1 − s
Selection against both homozygotes (overdominance) 1 − s11 1 1 − s22
Table 25.5: Formulas for calculating change in allelic frequencies with different types of selection