Overdominance

Overdominance is a phenomenon when a heterozygous individual for a gene in one population has greater fitness than two homozygous individuals for the same gene. This phenomenon was first described in 1969 by Erwin Myroux and Gottlieb Jacomb, who showed that in Escherichia coli bacteria, under certain conditions, a heterozygote for the invE- (c) mutation is considered more viable than its two homozygous states +/– or –/–.

Overdominance is a phenomenon in which a heterozygote (an organism having different alleles of the same gene) produces a more pronounced phenotype than homozygous individuals. This phenomenon is often observed in plants and animals and is the result of genetic mutations that lead to an increase or decrease in gene expression.

For example, if in a population there were individuals A and B whose dominant gene allele was homozygous, that is, AA and BB, they would produce the same phenotype. However, if one of the individuals had a heterozygous AA genotype, its phenotype will be more striking, in contrast to individuals with the BB genotype. This is explained by the fact that a heterozygote has two copies of the dominant alleles, while a homozygote has only one.

Overdominance can occur in a variety of situations. For example, if it concerns living beings, their ability to survive in environmental conditions. For example, people who have different alleles for a gene that causes allergies will exhibit different symptoms of the disease, even if they have the same alleles for that gene. This may be due to environmental factors such as pollution, allergens or temperature.

In the case of plants, overdominance can manifest itself in various aspects. For example, some species may

Overdominance is a genetic phenomenon in which a heterozygote (a hybrid with a trait) has higher fitness than homozygous individuals, dominant or recessive. In this case, the heterozygote may have some hidden advantages over the homozygote