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.
Farlex Partner Medical Dictionary © Farlex 2012

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.
The American Heritage® Medical Dictionary Copyright © 2007, 2004 by Houghton Mifflin Company. Published by Houghton Mifflin Company. All rights reserved.

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
Medical Dictionary for the Health Professions and Nursing © Farlex 2012

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.
Collins Dictionary of Biology, 3rd ed. © W. G. Hale, V. A. Saunders, J. P. Margham 2005
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.