Homininae - History of Discoveries and Classification

History of Discoveries and Classification

Until 1980, the family Hominidae contained only humans, with the great apes in the family Pongidae. Later discoveries led to a revision of classification, with Hominidae uniting the great apes (now in the sub-family Ponginae) and humans (in the sub-family Homininae). Further discoveries indicated that gorillas and chimpanzees are more closely related to humans than they are to orangutans, leading to their current placement in Homininae as well.

The subfamily Homininae can be further subdivided into three tribes, each with only a single living genus: Gorillini (gorillas), Panini (chimpanzees), and Hominini (humans and their extinct relatives). The early Late Miocene Nakalipithecus nakayamai, described in 2007, and perhaps also its contemporary Ouranopithecus, are basal members of this clade, not assignable to any of the three extant tribes. They suggest that the Homininae tribes diverged not earlier than about 8 million years ago (see Human evolutionary genetics).

Today, chimpanzees and gorillas live in tropical forests with acid soils that rarely preserved as fossils. No fossil chimpanzees or gorillas have been reported. However, four chimpanzee teeth, about 500,000 years old, have recently been discovered in the rift valley, where many fossils from the human lineage (hominins) have previously been found. This shows that some chimpanzees lived close to Homo (H. erectus or H. rhodesiensis) at the time; the same is likely true for gorillas.