Genetically modified

Genetic variance refers to the diversity in the genetic makeup of individuals within a population. It is a fundamental concept in genetics and evolutionary biology, as it is the raw material upon which natural selection acts. Genetic variance can be partitioned into different components, including additive genetic variance, dominance genetic variance, and interaction variance.

Overview

Genetic variance is the variation in the genetic makeup of individuals within a population. It is caused by differences in the genotypes of individuals, which can result from mutation, gene flow, genetic drift, and natural selection. Genetic variance is a key component of the genetic diversity of a population, and it is crucial for the survival and evolution of species.

Causes of Genetic Variance

Mutation

Mutation is a primary source of genetic variance. It introduces new alleles into a population, which can increase the genetic diversity of the population.

Gene Flow

Gene flow is the transfer of genetic variation from one population to another. It can increase the genetic variance within a population by introducing new alleles.

Genetic Drift

Genetic drift is a random change in allele frequencies in a population. It can increase or decrease genetic variance, depending on the specific alleles that increase or decrease in frequency.

Natural Selection

Natural selection can increase or decrease genetic variance, depending on whether it favors or disfavors certain alleles.

Components of Genetic Variance

Additive Genetic Variance

Additive genetic variance is the component of genetic variance that is due to the additive effect of different alleles. It is the portion of genetic variance that can be passed from parents to offspring.

Dominance Genetic Variance

Dominance genetic variance is the component of genetic variance that is due to the interaction between alleles at the same locus. It is the portion of genetic variance that cannot be passed from parents to offspring.

Interaction Variance

Interaction variance is the component of genetic variance that is due to the interaction between alleles at different loci. It is also known as epistatic variance.

Importance of Genetic Variance

Genetic variance is crucial for the survival and evolution of species. It provides the raw material upon which natural selection can act, allowing populations to adapt to changing environments. Without genetic variance, populations would be unable to evolve and could potentially go extinct.