Predicting the Deleterious Effects of Mutation Load in Fragmented Populations
Résumé
Human-induced habitat fragmentation constitutes a major threat to biodiversity. Both genetic and
demographic factors combine to drive small and isolated populations into extinction vortices. Nevertheless, the
deleterious effects of inbreeding and drift load may depend on population structure, migration patterns, and
mating systems and are difficult to predict in the absence of crossing experiments. We performed stochastic
individual-based simulations aimed at predicting the effects of deleterious mutations on population fitness
(offspring viability and median time to extinction) under a variety of settings (landscape configurations,
migration models, and mating systems) on the basis of easy-to-collect demographic and genetic information.
Pooling all simulations, a large part (70%) of variance in offspring viability was explained by a combination
of genetic structure (FST) and within-deme heterozygosity (HS). A similar part of variance in median time to
extinction was explained by a combination of local population size (N) and heterozygosity (HS). In both cases
the predictive power increased above 80% when information on mating systems was available. These results
provide robust predictive models to evaluate the viability prospects of fragmented populations.
Origine : Fichiers éditeurs autorisés sur une archive ouverte
Loading...