Equilibrium Population

When a population is in equilibrium, both genotype and allele frequencies remain constant from one generation to the next. If a population satisfies the conditions necessary to ensure that genotypes are in Hardy-Weinberg proportions, it follows that it is also in equilibrium. Even if a population does not satisfy the Hardy-Weinberg conditions, however, it may still be in equilibrium. The frequency of recessive alleles preventing individual monkey flower plants from producing pollen, for example, is likely to represent a balance between the tendency of natural selection to eliminate the recessive allele and recurrent mutation that tends to increase its frequency. A population in which such forces are balanced might be said to be in dynamic equilibrium. Two dynamic equilibrium points in a gene regulatory network correspond to biological switch to a gene circuit.