Loss of genetic diversity in an outbreeding specie

Authors: Kellie A Leigh Kyall R Zenger Imke Tammen Herman W Raadsma

Publish Date: 2012/02/29

Volume: 13, Issue: 3, Pages: 767-777

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Abstract

Genetic studies on the endangered African wild dog Lycaon pictus have primarily focused on the few remaining large and viable populations However investigations on the many isolated small African wild dog populations might also be informative for species management because the majority of extant populations are small and may contain genetic variability that is important for population persistence and for species conservation Small populations are at higher risk of extinction from stochastic and deterministic demographic processes than larger populations and this is often of more immediate conservation concern than loss of genetic diversity particularly for species that exhibit outbreeding behaviour such as long distance dispersal which may maintain gene flow However the genetic advantages of outbreeding behaviour may be reduced if dispersal is compromised beyond reserve borders edge effects further weakening the integrity of small populations Mitochondrial DNA and 11 microsatellite genetic markers were used to investigate population genetic structure in a small population of outbreeding African wild dogs in Zambia which occupies an historical dispersal corridor for the species Results indicated the Zambian population suffered from low allelic richness and there was significant evidence of a recent population bottleneck Concurrent ecological data suggests these results were due to habitat fragmentation and restricted dispersal which compromised natural outbreeding mechanisms This study recommends conservation priorities and management units for the African wild dog that focus on conserving remaining levels of genetic diversity which may also be applicable for a range of outbreeding speciesWe would like to thank the Zambia Wildlife Authority for permission to carry out this research in Zambia Grateful thanks to D Girman for providing raw genotypic data and to De Wildt Cheetah and Wildlife Trust for additional DNA samples from other populations Thank you to A English for facilitating the research program and to M Jones for extensive advice on laboratory techniques for genetic analysis This research was funded by donations from a large collection of corporate and individual donors who supported the African Wild Dog Conservation project wwwzambiacarnivoresorg

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