Do population size bottlenecks reduce evolutionary potential?

Single locus neutralist models predict that population size bottlenecks will reduce genetic variation and increase inbreeding, thereby reducing evolutionary potential. However, experimental evaluations of the effects of bottlenecks on quantitative genetic variation do not always follow predictions, especially for characters related to reproductive fitness. Populations of Drosophila melanogaster were subjected to population bottlenecks of a single pair for one or three generations, and their ability to tolerate increasing concentrations of NaCl was compared with those of their outbred base populations, and related highly inbred lines. Bottlenecked populations became extinct at significantly lower concentrations of NaCl than their non-bottlenecked base populations. Population bottlenecks should be avoided in managing species of conservation concern.