What is the Difference Between Gene Frequency and Genotypic Frequency?

Gene frequency and genotypic frequency are both measures used to determine genetic relationships within a population, but they differ in what they specifically measure and how they evolve within the gene pool. Here are the key differences between the two:

Gene Frequency: This refers to the relative frequency of a particular allele (a specific version of a gene) within a population. It is a measure of how common a specific gene or allele is within a population and can be either dominant or recessive.
Genotypic Frequency: This refers to the proportion of a specific genotype (a combination of alleles) within a population. It is a measure of how common a particular genotype, such as AA or Aa, is within a given population.

The main difference between gene frequency and genotypic frequency lies in the factor that determines the frequency. In gene frequency, it is a gene or an allele that determines the frequency, while in genotypic frequency, it is a genotype that determines the frequency. Additionally, gene frequency evolves faster within a gene pool, while genotypic frequency evolves at a slower rate.

On this page

What is the Difference Between Gene Frequency and Genotypic Frequency?

Comparative Table: Gene Frequency vs Genotypic Frequency

Gene frequency and genotypic frequency are related but distinct concepts in population genetics. Here is a table summarizing the differences between the two:

Feature	Gene Frequency	Genotypic Frequency
Definition	Gene frequency is the proportion of a specific allele in a population. It is a measure of the relative frequency of an allele at a genetic locus in a population.	Genotypic frequency is the proportion of a particular genotype amongst all the individuals in a population at a specific point in time.
Calculation	Gene frequency can be calculated by dividing the number of copies of a specific allele by the total number of alleles in the population. It is expressed as a decimal between 0 and 1.	Genotypic frequency can be calculated by dividing the number of individuals with each genotype by the total sample population, and then multiplying the result by 100. It is expressed as a percentage.
Relationship to Hardy-Weinberg Principle	Gene frequency is the basis for the Hardy-Weinberg principle, which states that allele frequencies in a population will not change from generation to generation unless certain conditions are met (e.g., natural selection, genetic drift, or migration).	Genotypic frequency is derived from gene frequency, as the frequencies of all the alleles of a gene must add up to one, or 100%. The expected genotype frequencies in a population with two alleles at a locus are p^2, 2pq, and q^2, where p and q are the frequencies of the two alleles.
Application	Gene frequency is used to study the evolution and distribution of specific alleles within a population and to understand the genetic diversity of a species.	Genotypic frequency is used to analyze the distribution of genotypes in a population, which can provide insights into the population's genetic structure, evolution, and potential for adaptation to changing environments.

In summary, gene frequency focuses on the proportion of specific alleles in a population, while genotypic frequency concentrates on the proportion of individuals with a particular genotype within a population. Both concepts are essential for understanding the genetic structure and evolution of populations.

Guilherme Mazui

Guilherme Mazui is graduated in journalism from the Federal University of Minas Gerais (UFMG) and a master's degree in Communication from the University of São Paulo (USP). In addition, he has experience in advertising writing and has worked as a content editor in several companies.