Humans are culture-bearing primates classified in the genus Homo, especially the species Homo sapiens. They are anatomically similar and related to the great apes (orangutans, chimpanzees, bonobos, and gorillas) but are distinguished by a more highly developed brain that allows for the capacity for articulate speech and abstract reasoning. Humans display a marked erectness of body carriage that frees the hands for use as manipulative members.
What is a human being?
When did humans evolve?
The answer to this question is challenging, since paleontologists have only partial information on what happened when. So far, scientists have been unable to detect the sudden “moment” of evolution for any species, but they are able to infer evolutionary signposts that help to frame our understanding of the emergence of humans. Strong evidence supports the branching of the human lineage from the one that produced great apes (orangutans, chimpanzees, bonobos, and gorillas) in Africa sometime between 6 and 7 million years ago. Evidence of toolmaking dates to about 3.3 million years ago in Kenya. However, the age of the oldest remains of the genus Homo is younger than this technological milestone, dating to some 2.8–2.75 million years ago in Ethiopia. The oldest known remains of Homo sapiens—a collection of skull fragments, a complete jawbone, and stone tools—date to about 315,000 years ago.