balanced polymorphism

(redirected from stable polymorphism)
Also found in: Medical.

balanced polymorphism

[′bal·ənst ¦päl·i′mȯr‚fiz·əm]
(genetics)
Maintenance in a population of two or more alleles in equilibrium at frequencies too high to be explained, particularly for the rarer of them, by mutation; commonly due to the selective advantage of a heterozygote over both homozygotes.
Mentioned in ?
References in periodicals archive ?
Beyond these two major factors, we also identified two other factors that may have contributed to the stable polymorphism, although to a lesser degree: (3) [Lac.
In apparent violation of this simple model leading to competitive exclusion, the evolution of stable polymorphisms in laboratory populations of bacteria has been clearly demonstrated.
It will be interesting to examine those asexual populations more thoroughly to discern whether some stable polymorphisms might have been overlooked.
We have here: (a) a stable polymorphism (initial point {[x.
Therefore, it does not necessarily produce sign-concordant environment, and we can not exclude the possibility of stable polymorphism even in case of additive genes with equal effects.
It was shown earlier that stabilizing selection in constant environment for a trait controlled by equal genes with dominant effect or nonequal additive genes may result in stable polymorphism (e.
Let F(z) = 1/{1 + [(z - Z)/[Sigma]]2 Provided selection is intense enough, stable polymorphism is possible in this case even for [d.