The general selection model (GSM) is a model of population genetics that describes how a population's allele frequencies will change when acted upon by natural selection.

Equation

The General Selection Model applied to a single gene with two alleles (let's call them A1 and A2) is encapsulated by the equation:

1. where:

   1. is the frequency of allele A1

   2. is the frequency of allele A2

   3. is the rate of evolutionary change of the frequency of allele A2

   4. are the relative fitnesses of homozygous A1, heterozygous (A1A2), and homozygous A2 genotypes respectively.

   5. is the mean population relative fitness.

In words:

is proportional to the genetic variation.

—i.e. when the population is maximally fit, no further change can occur.

, refers to the mean effect of an allele substitution. In essence, this term quantifies what effect genetic changes will have on fitness.

See also

• Darwinian fitness

• Hardy–Weinberg principle

• Population genetics

References