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heritability

heritability A measure of the degree to which the variance of a particular phenotype is caused by genetic factors. It is given by a value between 0 and 1 and effectively measures the extent to which offspring resemble their parents relative to the population mean. Estimates of heritability are important in applied genetics, especially in agriculture and horticulture, because they enable prediction of the response of a population to artificial selection. The higher the heritability value, the greater the response, although heritability declines after several generations of artificial selection due to increasing homozygosity. The term is used in two different ways. Heritability in the narrow sense is the proportion of phenotypic variance due only to the additive genetic effect of all the polygenes controlling a particular trait; hence it measures the proportion that is transmissible to offspring and therefore amenable to selection. Heritability in the broad sense considers other genetic but nontransmissible factors as well, including dominance and epistasis; it is used, for example, in psychology to quantify genetic and environmental influences.

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"heritability." A Dictionary of Biology. . Encyclopedia.com. 26 Sep. 2017 <http://www.encyclopedia.com>.

"heritability." A Dictionary of Biology. . Encyclopedia.com. (September 26, 2017). http://www.encyclopedia.com/science/dictionaries-thesauruses-pictures-and-press-releases/heritability-2

"heritability." A Dictionary of Biology. . Retrieved September 26, 2017 from Encyclopedia.com: http://www.encyclopedia.com/science/dictionaries-thesauruses-pictures-and-press-releases/heritability-2

heritability

heritability A measure of the degree to which a phenotype is genetically influenced and can be modified by selection. It is represented by the symbol h2: this equals Va/Vp where Va is the variance due to genes with additive effects (known as the additive genetic variance) and Vp is the phenotypic variance. The variance V may also be written as s2. Parent–offspring correlations are estimates of familiality and not of heritability: they cannot account for environmental correlations between relatives. This definition of heritability is a narrow one: heritability in the broad sense (represented by H2) is the fraction of total phenotypic variance that remains after exclusion of the variance resulting from environmental effects. Estimates of heritability are used widely by plant breeders to predict the likely effects of selection. If heritability estimates are low for a particular character, this indicates that the character is mainly influenced by the environment and suggests that the response to selection would not be rapid.

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"heritability." A Dictionary of Plant Sciences. . Encyclopedia.com. 26 Sep. 2017 <http://www.encyclopedia.com>.

"heritability." A Dictionary of Plant Sciences. . Encyclopedia.com. (September 26, 2017). http://www.encyclopedia.com/science/dictionaries-thesauruses-pictures-and-press-releases/heritability-0

"heritability." A Dictionary of Plant Sciences. . Retrieved September 26, 2017 from Encyclopedia.com: http://www.encyclopedia.com/science/dictionaries-thesauruses-pictures-and-press-releases/heritability-0

heritability

heritability A measure of the degree to which a phenotype is genetically influenced and can be modified by selection. It is represented by the symbol h2, which is equal to the additive genetic variance divided by the phenotypic variance. Parent–offspring correlations are estimates of familiality and not of heritability: they cannot account for environmental correlations between relatives. This definition of heritability is a narrow one: heritability in the broad sense (represented by H2) is the fraction of total phenotypic variance that remains after exclusion of the variance due to environmental effects. Estimates of heritability are used widely by plant breeders to predict the likely effects of selection. If heritability estimates are low for a particular character, this indicates that the character is mainly influenced by the environment and suggests that the response to selection would not be rapid. See also Fisher's fundamental theorem.

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"heritability." A Dictionary of Ecology. . Encyclopedia.com. 26 Sep. 2017 <http://www.encyclopedia.com>.

"heritability." A Dictionary of Ecology. . Encyclopedia.com. (September 26, 2017). http://www.encyclopedia.com/science/dictionaries-thesauruses-pictures-and-press-releases/heritability

"heritability." A Dictionary of Ecology. . Retrieved September 26, 2017 from Encyclopedia.com: http://www.encyclopedia.com/science/dictionaries-thesauruses-pictures-and-press-releases/heritability

heritability

heritability The measure of the degree to which a phenotype is genetically influenced and can be modified by selection. It is represented by the symbol h2: this equals Va/Vp where Va is the variance due to genes with additive effects (known as the additive genetic variance) and Vp is the phenotypic variance. The variance V may also be written as s2. Parent-offspring correlations, as used in studies of the heritability of human IQ, are estimates of familiality and not of heritability: they cannot account for environmental correlations between relatives. This definition of heritability is a narrow one: heritability in the broad sense (represented by H2) is the fraction of total phenotypic variance that remains after exclusion of the variance due to environmental effects.

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"heritability." A Dictionary of Zoology. . Encyclopedia.com. 26 Sep. 2017 <http://www.encyclopedia.com>.

"heritability." A Dictionary of Zoology. . Encyclopedia.com. (September 26, 2017). http://www.encyclopedia.com/science/dictionaries-thesauruses-pictures-and-press-releases/heritability-1

"heritability." A Dictionary of Zoology. . Retrieved September 26, 2017 from Encyclopedia.com: http://www.encyclopedia.com/science/dictionaries-thesauruses-pictures-and-press-releases/heritability-1