Genetic Equilibrium is when the allele frequencies in a population remain the same, which also means that the population is not evolving.

The following are conditions that can appear in a population. These conditions can lead to a change in allele frequencies which in turn disturbs genetic equilibrium.
  1. Genetic Drift - a random change in the allele frequencies
  2. Differential migration- individuals who join a population may introduce new alleles into the gene pool and individuals who leave take alleles out of the gene pool
  3. Mutations- mutations can introduce new alleles into a gene pool causing evolution to occur
  4. Random Mating- Many species select mates based on heritable traits such as size, strength, or coloration a practice known as sexual selection. When sexual selection appears genes and traits may appear that are not in the gene pool.
  5. Population size- genetic drift does not have much effect in large populations but can affect small populations greatly.
  6. Natural Selection- If different genotypes have different fitness, genetic equilibrium will be disrupted, and evolution will occur

A picture of a population that is not in genetic equilibrium


The disruption of genetic equilibrium is important because more species will be created and there will be more variety in the various ecosystems. Genetic equilibrium is an ideal state that provides a baseline against which to measure change and if all species were in genetic equilibrium, then evolution would not occur. It is because there are disruptions in genetic equilibrium that indicates that evolution is occurring as it means something is changing within species and populations in order to adapt to the ever-changing environment. Genetic equilibrium is important as it will indicate if a species is not changing, or if it is undergoing a change, which would result in evolution.