Figure 2. Apes Evolve Mutated Uricase and ADH4 Genes During the Miocene.
All the extant great apes (orangutans, gorillas, chimpanzees, and humans) exhibit the uricase mutation, which would have been advantageous during the Middle Miocene disruption in Europe. Only the African apes (gorillas, chimpanzees, and humans) also have the ADH4 mutation, which would have secondarily been useful during the late-Miocene aridification of East Africa.