Chimpanzee

Chimpanzee, sometimes colloquially known as a chimp, is the common name for the genus Pan.

Chimpanzees are members of the Hominidae family, along with gorillas, humans, and orangutans. Chimpanzee are thought to have split from human evolution about 6 million years ago and thus 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.

Evolutionary relationships
The genus Pan is now considered to be part of the subfamily Homininae to which humans also belong. These two species are the closest living evolutionary relatives to humans, sharing a common ancestor with humans six million years ago. Research by Mary-Claire King in 1973 found 99% identical DNA between human beings and chimpanzees, although research since has modified that finding to about 94% commonality, with at least some of the difference occurring in non-coding DNA. It has even been proposed that troglodytes and paniscus belong with sapiens in the genus Homo, rather than in Pan. One argument for this is that other species have been reclassified to belong to the same genus on the basis of less genetic similarity than that between humans and chimpanzees.

Fossils
Many human fossils have been found, but chimpanzee fossils were not described until 2005. Existing chimpanzee populations in West and Central Africa do not overlap with the major human fossil sites in East Africa. However, chimpanzee fossils have now been reported from Kenya. This would indicate that both humans and members of the Pan clade were present in the East African Rift Valley during the Middle Pleistocene.