What is the Difference Between Transient and Balanced Polymorphism?

The main difference between transient and balanced polymorphism lies in the behavior of alleles in a population over time. Both types of polymorphism give rise to phenotypic changes and affect gene expression. Here are the key differences between the two:

Transient Polymorphism:
Occurs when there are two alleles in the gene pool, and one allele is gradually replacing the other.
This type of polymorphism is temporary, as one form is being replaced by another.
It takes place when one allele is progressively replaced by another, causing a shift in the gene pool.
Balanced Polymorphism:
Occurs when there are two alleles in the gene pool, and the frequency of the two alleles remains constant over time.
This type of polymorphism is stable, as it involves the coexistence of two different alleles.
Balanced polymorphism is maintained at a fixed level by a balance of selective agencies.
An example of balanced polymorphism is the heterozygous advantage in sickle cell anemia, where heterozygotes do not develop anemia but have resistance to malaria.

In summary, transient polymorphism involves the progressive replacement of one allele by another, while balanced polymorphism involves the stable coexistence of two different alleles in a population.

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What is the Difference Between Transient and Balanced Polymorphism?

Comparative Table: Transient vs Balanced Polymorphism

Transient and balanced polymorphism are two types of genetic polymorphism that occur in populations. They differ in how the alleles behave and their frequency in the population. Here is a table comparing the two:

Feature	Transient Polymorphism	Balanced Polymorphism
Definition	Refers to the progressive replacement of one allele of a gene by another.	Refers to the maintenance of different phenotypes in the population, with both alleles maintained over time.
Occurrence	Occurs when two alleles in the gene pool, and one allele gradually replaces the other due to strong environmental pressure creating directional selection.	Occurs when two alleles in the gene pool, and the frequency of the two alleles is not changing, due to selective pressures promoting the coexistence of both alleles.
Example	Light vs. dark melanic variants of the peppered moth, where the darker form becomes more predominant.	Sickle cell anemia in African nations, where heterozygotes do not develop anemia but have resistance to malaria.
Advantage	The direction of selection is determined by the environment, leading to the gradual elimination of one allele.	Heterozygous advantage, where individuals carrying both versions of the gene have a relatively higher fitness.

In summary, transient polymorphism involves the gradual replacement of one allele by another, while balanced polymorphism results in the maintenance of both alleles in the population over time.

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.