Equilíbrio Mutação
- Created by
- Renato Passos, Eng. de Software
- Reviewed by
- Renato Passos, Eng. de Software
Last updated: Apr 18, 2026
About this calculator
The mutation-selection balance calculator estimates equilibrium frequency of deleterious alleles maintained by mutation using q = √(μ/s), where μ is mutation rate and s selection coefficient. This applies to recessive alleles with fitness costs, commonly used in population genetics to predict rare mutation persistence.
For example, in recessive diseases like sickle cell anemia, this tool helps quantify expected mutant allele frequencies. Assumes equilibrium between mutation rates and selection pressure. Typical μ values range from 10⁻⁵ to 10⁻⁸, while s varies with allele severity.
Important: this formula excludes dominant or codominant alleles. Accuracy requires small mutation rates and weak selection. In populations with gene flow or demographic shifts, results may vary. Strongly deleterious mutations require modified models.
Frequently asked questions
How does recessiveness affect equilibrium?
Recessive alleles only impact fitness when homozygous, allowing higher equilibrium frequencies compared to dominant alleles with same severity.
What do μ and s parameters represent?
μ is mutation rate (per generation) and s is selection coefficient (0 = no selection, 1 = lethal). Both determine the balance between mutation input and selection removal.
What happens with extremely rare mutations?
With very low μ, equilibrium frequency decreases, but the allele never disappears due to continuous new mutations.
Does this formula apply to dominant alleles?
No. For dominant alleles, use q ≈ μ/s since their impact is expressed even in heterozygotes.
When should this calculator be used?
In population genetics studies predicting frequencies of recessive deleterious alleles maintained by constant mutation.