Integrating multiple evolutionary processes in models of captive breeding

Abstract

Models of captive breeding tend to come in two varieties: one type examines the potential for different strategies to preserve genetic diversity, while the other considers the impacts of many evolutionary processes but uses a simple mating system. This study presents an individual-based, stochastic simulation model that seeks to combine aspects of drift, mutation, selection, and gene flow with a breeding protocol similar to that used by captive population managers. It also tests a model of genetic adaptation to captivity, in which alleles are selected for in captivity that are deleterious in the wild. Both captive and wild fitness values are calculated. Results show that adaptation occurs rapidly and can lead to significant decline in wild fitness compared to the founding population. The most serious threats to captive fitness are the sensitivity of the species to inbreeding and the relative contribution of lethal and mildly deleterious alleles.