Chimpanzees are members of the Hominidae family, along with gorillas, humans, and orangutans. Chimpanzees split from the human branch of the family about 4 to 6 million years ago. The two chimpanzee species are the closest living relatives to humans, all being members of the Hominini tribe (along with extinct species of Hominina subtribe). Chimpanzees are the only known members of the Panina subtribe. The two Pan species split only about one million years ago.