What is the Difference Between Additive and Nonadditive Genetic Patterns?

Additive and nonadditive genetic patterns are the subject of quantitative genetics, which measures the influence of genes on phenotypes. The key difference between additive and nonadditive genetic patterns lies in the way alleles contribute to the phenotype:

Additive genetic patterns: In this case, both alleles contribute to the phenotype in measurable amounts. The total effect on a trait stemming from one or more gene loci is considered additive variation. Each locus contributes to the trait in a measurable way, and the combined effect of multiple genes is linear or additive.
Nonadditive genetic patterns: These patterns involve the interactive effects of different alleles and include genetic dominance (within locus interaction) and epistasis (across locus interaction). In this scenario, only one allele contributes to the phenotype through dominance or epistasis. Nonadditive genetic variation results from interactions between genes.

Both additive and nonadditive genetic patterns give rise to variations in populations and are important in understanding the genetic architecture underlying phenotypic variation.

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What is the Difference Between Additive and Nonadditive Genetic Patterns?

Comparative Table: Additive vs Nonadditive Genetic Patterns

Additive and nonadditive genetic patterns are both involved in the study of quantitative behavioral genetics, which focuses on the relative importance of genetic variation on phenotypic variation. Here is a table comparing the two patterns:

Feature	Additive Genetic Patterns	Nonadditive Genetic Patterns
Definition	Both alleles contribute to the phenotype in measurable amounts.	Only one allele contributes to the phenotype through dominance or epistasis.
Examples	1. Certainly, I'll add more later.	1. Texture of peas: smooth (S) or wrinkled (s), with the smooth allele being dominant.
		2. Human hair color.
Summary	Additive genetic patterns arise due to the additive effects of both alleles in a gene in measurable amounts.	Nonadditive genetic patterns explain the effect of a single allele on the phenotype through dominance or epistasis.

Both additive and nonadditive genetic patterns contribute to variation in organisms and 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.