Calculating Fitness from Coefficient of Selection

If the coefficient of selection (S) is 0.1, then the fitness (F) of that genotype is:

Correct Answer: 0.9

Fitness (F) = 1 − S
F = 1 − 0.1 = 0.9

Key Terms

• Fitness / Adaptive Value / Selective Value: Contribution of offspring to the next generation. F = 1 − S or 1 − L (where L = load).
• Coefficient of Selection (S): Measure of relative disadvantage of a genotype. S = 1 − F.

Example: If a genotype has a coefficient of selection of 1.0 (lethal), its fitness = 0 (no contribution to next generation). If S = 0, fitness = 1 (maximum fitness).

Note: Inbreeding leads to reduced fitness; traits governing fitness/viability show the greatest inbreeding depression.