Human evolution is the evolutionary process within the history of primates that led to the emergence of Homo sapiens as a distinct species of the hominid family, which includes the great apes. This process involved the gradual development of traits such as human bipedalism and language, as well as interbreeding with other hominins, which indicate that human evolution was not linear but a web.

The study of human evolution involves several scientific disciplines, including physical anthropology, primatology, archaeology, paleontology, neurobiology, ethology, linguistics, evolutionary psychology, embryology and genetics. Genetic studies show that primates diverged from other mammals about 85 million years ago, in the Late Cretaceous period, and the earliest fossils appear in the Paleocene, around 55 million years ago.

Within the superfamily Hominoidea, the family Hominidae (great apes) diverged from the family Hylobatidae (gibbons) some 15–20 million years ago; subfamily Homininae (African apes) diverged from Ponginae (orangutans) about 14 million years ago; the tribe Hominini (including humans, Australopithecus, and chimpanzees) parted from the tribe Gorillini (gorillas) between 8–9 million years ago; and, in turn, the subtribes Hominina (humans and extinct biped ancestors) and Panina (chimpanzees) separated 4–7 million years ago.

 

Note:   The above text is excerpted from the Wikipedia article Human evolution, which has been released under the GNU Free Documentation License.