"Experiments on the escape from extinction: Lessons from the common housefly."
Conflicts and gaps in our understanding of the genetics of inbreeding call for comprehensive examinations of how populations can escape imminent extinction. Artificial selection projects, such as in agricultural programs, commonly reveal catastrophic effects of inbreeding. In theory and in practice, immigration should rescue such endangered populations. This basic assumption, however, has not been tested in an evolutionarily relevant context. Moreover, many natural populations appear to have adapted to high levels of inbreeding, without requiring such rescue processes. In lieu of tests on these glaring conflicts in inbreeding effects, conservation programs for endangered species must assume that maximum outbreeding promotes the genetic health of a population. This fundamental assumption influences irreversible policy decisions ranging from the design of migration corridors to the point of recommending the hybridization of different species. In general, the pervasive threat of inbreeding depression is well documented, but how natural or captive populations avoid or escape extinction trajectories remains unclear. I will give an overview of three large-scale experiments designed to investigate the intricacies of inbreeding and the escape from extinction, using the common housefly as a model organism. This work is critical for advancing evolutionary theory on inbreeding depression and population networks, with practical applications for agriculture and conservation biology.