The importance of genetic factors to the short-term survival of natural populations is not known. Small populations lose genetic variation due to genetic drift (random loss) more quickly than large populations, and may experience inbreeding depression. However, the relationship between inbreeding, genetic variation, and population survival is unclear. The first part of this proposal research project will examine the importance of genetic variation on the immediate survival of small populations. The PIs will test whether populations founded with greater initial genetic variation are more likely to persist, as measured by smaller fluctuations in population size and larger mean size, than populations founded with lower amounts of genetic variation. Secondly, the PIs propose to examine the effectiveness of migration in reducing the potentially detrimental effects of inbreeding and genetic drift. The effect of different levels of migration on population fecundity will be assessed. Information regarding the minimum rates of migration needed to balance the detrimental effects of inbreeding and drift is necessary for prescribing management procedures on isolated, small populations of rare species.
