Eastern gorilla
The eastern gorilla ("Gorilla beringei") is a critically endangered species of the genus "Gorilla" and the largest living primate. At present, the species is subdivided into two subspecies. Grauer's gorilla, formerly known as the eastern lowland gorilla ("G. b. graueri") is more populous, at about 3,800 individuals. The mountain gorilla ("G. b. beringei") has only about 1000 individuals. The International Union for the Conservation of Nature mentioned illegal hunting in its assessment of threats to the species.
Evolution of primates
Molecular evidence indicates that the lineage of gibbons (family Hylobatidae) diverged from Great Apes some 18-12 million years ago, and that of orangutans (subfamily Ponginae) diverged from the other Great Apes at about 12 million years; there are no fossils that clearly document the ancestry of gibbons, which may have originated in a so-far-unknown South East Asian hominoid population, but fossil proto-orangutans may be represented by "Sivapithecus" from India and "Griphopithecus" from Turkey, dated to around 10 million years ago.