The two gorilla species diverged approximately two million years ago (perhaps with subsequent gene flow between the western and eastern populations), based on analyses of mitochondrial and nuclear DNA ( Jensen-Seaman et al., 2003 Scally et al., 2012) this genetic difference is similar in magnitude to that observed between chimpanzees and bonobos ( Jensen-Seaman et al., 2003). beringei beringei) and Grauer's gorillas ( G. The latter includes two subspecies, mountain gorillas ( G. Gorillas are diverse and widespread African great apes that include two geographically distinct species: western gorillas ( Gorilla gorilla) and eastern gorillas ( G.
In addition, they tend to eat more fruit and have larger home ranges and consequently might depend more on spatial mapping functions of the hippocampus. gorilla engage in more arboreal locomotion and thus may rely more on cerebellar circuits. These anatomical differences may relate to divergent ecological adaptations of the two species. Among the species differences, the volumes of the hippocampus and cerebellum were significantly larger in G. Stereologic methods were used to measure volumes of brain structures, including left and right frontal lobe gray and white matter, temporal lobe gray and white matter, parietal and occipital lobes gray and white matter, insular gray matter, hippocampus, striatum, thalamus, each hemisphere and the vermis of the cerebellum, and the external and extreme capsules together with the claustrum. Postmortem magnetic resonance images were obtained of brains from 18 captive western lowland gorillas ( Gorilla gorilla gorilla), 15 wild mountain gorillas ( Gorilla beringei beringei), and 3 Grauer's gorillas ( Gorilla beringei graueri) (both wild and captive). This study examines neuroanatomical variation between gorilla species using structural neuroimaging. Although anatomical, genetic, behavioral, and socioecological differences have been noted among gorilla populations, little is known about variation in their brain structure.
Gorillas include separate eastern ( Gorilla beringei) and western ( Gorilla gorilla) African species that diverged from each other approximately 2 million years ago.