selection coefficient (s) A measure of the relative excess or deficiency of adaptive value of a genotype compared with another genotype in the population. If s = 100 then one out of a hundred individuals of a given genotype fails to reproduce.

selection coefficient Symbol s or t. A measure of the sum of the forces acting to oppose the reproductive success of a particular organism, phenotype, or genotype. It varies between 0 and 1 and is related to fitness (W) by the equation: W = 1 – s. Hence, as the selection coefficient increases, fitness decreases.

selection coefficient (s) A measure of the relative excess of deficiency of fitness of a genotype compared with another genotype in the population. If s = 100, then 1 out of a 100 individuals of a given genotype fails to reproduce.

selection coefficient(s) A measure of the relative excess or deficiency of fitness of a genotype compared with another genotype in the population. If s = 100 then 1 out of a 100 individuals of a given genotype fails to reproduce.