What is the Difference Between Stabilizing and Balancing Selection?

The main difference between stabilizing and balancing selection lies in their effects on genetic diversity and the types of traits they act upon.

Stabilizing selection:

Favors average phenotypes within a population, eliminating both extreme phenotypes.
Applies to a phenotypic trait.
Results in a more uniform population with decreased genetic variation.
Occurs when the population stabilizes on a particular trait value.

Balancing selection:

Maintains advantageous genetic diversity within populations.
Applies to a gene locus.
Favors multiple alleles and non-uniform populations.
Contributes to increased genetic diversity via two key mechanisms: heterozygote advantage and frequency-dependent selection.

In summary, stabilizing selection favors average phenotypes and leads to a more uniform population with less genetic diversity, while balancing selection maintains genetic diversity by favoring multiple alleles and non-uniform populations.

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What is the Difference Between Stabilizing and Balancing Selection?

Comparative Table: Stabilizing vs Balancing Selection

The key difference between stabilizing and balancing selection lies in their effect on genetic diversity within a population. Stabilizing selection favors average phenotypes and eliminates extreme phenotypes, resulting in a uniform population and decreased genetic diversity. In contrast, balancing selection maintains genetic diversity by keeping multiple alleles of a gene within a population. Here is a table summarizing the differences between stabilizing and balancing selection:

Feature	Stabilizing Selection	Balancing Selection
Definition	A type of natural selection that favors average phenotypes and eliminates extreme phenotypes.	Several selective processes that maintain advantageous genetic diversity.
Effect on Phenotypes	Eliminates both extremes of phenotypes, resulting in a uniform population.	Maintains multiple alleles of a gene within a population, contributing to increased genetic diversity.
Mechanisms	Does not maintain multiple alleles of a gene.	Contributes to increased genetic diversity via two key mechanisms: heterozygote advantage and frequency-dependent selection.
Examples	A population of mice with brown fur would be favored in a forest environment, eliminating other shades of fur.	A heterozygote advantage example: a population of animals with two different alleles for a specific trait, such as the interbreedingischer coat color experiment in rabbits.

In summary, stabilizing selection favors average phenotypes and eliminates extreme phenotypes, while balancing selection maintains genetic diversity by keeping multiple alleles of a gene within a population. Both types of selection contribute to the balance and stability of populations, but they have different effects on genetic diversity.

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.