overdominance

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Related to Overdominance hypothesis: Outbreeding Enhancement

o·ver·dom·i·nance

(ō'vĕr-dom'i-năns),
That state in which the heterozygote has greater phenotype value and perhaps is more fit than the homozygous state for either of the alleles that it comprises. Compare: balanced polymorphism.

overdominance

(ō′vər-dŏm′ə-nəns)
n.
The condition of a heterozygote having a phenotype that is more pronounced or better adapted than that of either homozygote.

o′ver·dom′i·nant adj.

o·ver·dom·i·nance

(ō'vĕr-dom'i-năns)
That state in which the heterozygote has greater phenotype value and perhaps is more fit than the homozygous state for either of the alleles that it comprises.
Compare: balanced polymorphism

overdominance

a phenotypic condition in which the HETEROZYGOTE expresses a stronger manifestation of the trait than either HOMOZYGOTE. Overdominance produces heterozygous advantage that can maintain a GENETIC POLYMORPHISM in a population.
References in periodicals archive ?
Here, we report the results of a second test of the associative overdominance hypothesis examining the effects of heterozygosity at ten nuclear RFLP loci on growth rate in two Norwegian populations of the Atlantic cod, Gadus morhua.
In the absence of karyotypic information, heterosis associated with these loci would seem consistent with the overdominance hypothesis.
According to the partial dominance hypothesis, inbreeding depression is due to recessive deleterious alleles, while according to the overdominance hypothesis, inbreeding depression is due to heterozygote advantage at viability loci.