Genetic and morphological analyses of historic and contemporary populations of western lowland gorilla: a multidisciplinary approach for the conservation of a critically endangered primate

This study investigates the morphology and genetic diversity of the critically endangered sub-species, the western lowland gorilla (Gorilla gorilla gorilla). Regional variation of a historic wild population was assessed morphologically and genetically, and genetic comparisons between this and a contemporary captive population were made to assess the genetic fitness of the contemporary population with the aim of assisting future conservation planning.

Geometric morphometric analyses were applied to skulls and mandibles of both sexes in the historic population of gorillas to assess regional variation in relation to size and shape. No significant difference was found for regional size comparisons but shape variation between regions did find significant variation in skull morphology, particularly for males.

MtDNA and nuclear markers were employed to detect regional differentiation in the historic population of gorillas, and to compare genetic diversity between historic and contemporary populations. The mtDNA results were hindered by nuclear insertions (numts) yet 30 sequences of the mitochondrial Control Region Hypervariable Region I (HVI) were obtained and haplogroups identified, which revealed potential differences in the historic distribution of haplogroups than current literature reports.

Nuclear analysis based on microsatellites confirmed that all the gorillas used in this study were western lowland gorillas. Furthermore, the paternity of individuals in the contemporary population was confirmed. Comparisons between the historical population and the captive US population showed that genetic diversity of the contemporary population had been retained at similar levels to wild populations and the US captive population thus concluding that the contemporary population is genetically sustainable for the foreseeable future.