Genotyping Contemporary Captive and Historical Wild Western Lowland Gorillas Indicates Captive Breeding Is Maintaining Genetic Diversity in a Critically Endangered Primate

ABSTRACT Genetic diversity is a fundamental component of biodiversity and a conservation priority. Genetic studies on captive populations, vulnerable to genetic erosion, are therefore needed for long‐term conservation of threatened species. The western lowland gorilla ( Gorilla gorilla gorilla ) is considered Critically Endangered, but no major conservation genetic studies have been published on the captive gorilla population in the European Ex situ Programme (EEP). Here, using 10 microsatellite loci and mitochondrial DNA (mtDNA), we investigated the genetic diversity, genetic structure, signatures of inbreeding and taxonomic affinities of captive gorillas at Howletts and Port Lympne (HPL), conservation zoos holding ~10% of the EEP population and compared this with historical wild gorillas from the Powell‐Cotton Museum. High heterozygosity values and similar allelic richness were found in contemporary captive and historical wild populations, with no evidence of nuclear genetic diversity loss or inbreeding. However, contemporary captive gorillas had lower effective population size and mtDNA diversity than the historical wild population, and weak genetic differentiation from historical wild gorillas. All HPL gorillas showed expected taxonomic affinities to the subspecies G. g. gorilla . Our results demonstrate that captive breeding has successfully maintained heterozygosity and allelic richness (i.e., genetic diversity) as compared with a historical wild population, crucial for the evolutionary potential of this endangered primate. However, genetic differentiation between contemporary captive and historical wild gorillas likely reflects ~50 years of captive breeding starting from a small founder population sourced from various locations. The HPL population is genetically well placed to sustain future generations in captivity and the wild through conservation translocations, contributing to biodiversity goals.