bottleneck

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A marked decrease in gene pool diversity due to a low number of genetically distinct individuals in the population, i.e., a population bred from 2 individuals has far fewer variables on the allelic loci—a bottleneck—than a second population bred from hundreds of individuals

bottleneck

a period in the history of a population during which the number of individuals is reduced to a low number, perhaps by disease or extreme environmental conditions. As a result RANDOM GENETIC DRIFT may occur in the population. See also FOUNDER EFFECT.
References in periodicals archive ?
occidentalis populations in Shandong Province would be much less than those of potential source populations because of the founder or bottleneck effects.
For instance, under the Two Phase Mutation and Stepwise Mutation models (Table 5), the number of populations that exhibited heterozygosity excess decreased, which indicated that the bottleneck effects within these populations is a transient feature, and can be expected to last only a few generations.
In addition, generalized genetic distances for the ancestor from its own mean over all bottleneck cycles provided a further basis to test bottleneck effects on phenotypic divergence, by assessing drift, selection, and resampling effects in the ancestor.
Our results are anomalous with these predictions, but are consistent with our previous work on bottleneck effects, where we found that heritabilities (and additive genetic variances) of morphometric traits obtained from parent - offspring covariances were the same (or higher) in bottlenecked versus nonbottlenecked lines (Bryant et al.