Eastern gorilla
Grauer's gorillas and mountain gorillas were previously thought to be two of the three subspecies of one single species, the gorilla ("Gorilla gorilla"). However, genetic research has shown that the two eastern subspecies are far more closely related than the western subspecies: the western lowland gorilla ("G. gorilla gorilla"), which justified the separate classification. The two eastern subspecies are now classified as "G. beringei".
Deme (biology)
Primates, for example, have the second highest speciation rate among mammals, with one speciation event per lineage every 3 million years. However, not all primate species have a high speciation rate and this is seen back in there deme size and social structure. Geunons ("Cercopithecus"), for example, live together in small polygynous troops and are a quite diverse genus. On the other hand, baboons ("Papio") have a much lower speciation rate. Baboons have larger deme sizes because they live in polygynous multi-male troops. These baboon demes are usually allopatric but gene-flow still exists between demes with hybridization being common.