Human evolution. Illustration showing stages in the evolution of humans. At left, proconsul (23-15 million years ago) is depicted hypothetically as an African ape with both primitive and advanced features. From it Australopithecus afarensis (>4- 2.5 Myr BP) evolved and displayed a bipedal, upright gait walking on two legs. Homo habilis (2.5 Myr BP) was truly human (“homo”) resembling Australopithecus but also used stone tools. About 1.5 Myr BP Homo erectus (at centre) appeared in Africa, used fire, wooden tools, and migrated from Africa into Eurasia. Homo neanderthalensis (200,000 years BP) lived in Europe and Middle East and was closely related to modern humans (right).