Evolution of <em>Homo sapiens</em>
The evolution of Homo sapiens: evidence from Africa
Note:
In more advanced tutorials, you will study the course of human evolution in great detail to gain a firm understanding of how we evolved. For now, we will learn some of the significant changes that have occurred in our species in Africa over the last four million years.
Humans are thought to have evolved from their ape-like ancestor over the last 6 million years. Human evolution has involved changes in physical appearance and behavioural traits. Some important physical developments include bipedalism, and a larger, more complex brain. Bipedalism is the ability to stand upright on two legs; it was an important adaptation as it freed the hands to be used in other tasks. Developments in behavioural characteristics include the ability to use fire, the ability to make and use tools, and the ability to communicate by means of language.
The most widely accepted theory of how anatomically modern humans evolved, suggests that Homo sapiens evolved in Africa approximately \(\text{200 000}\) to \(\text{150 000}\) years ago in what has now become known as the "Out of Africa" theory. Some of the evidence for the key events as found in Africa is shown in the table below.
Human ancestors evolved and migrated out of Africa in a series of 'waves'.
| Event in human evolutionary history | Evidence of event from Africa |
| Hominins and chimpanzees diverge from a common ancestor. | The earliest known human ancestor after the chimpanzee/ human separation is Orrorin tugenensis (Millenium Man, Kenya, around 6 million years ago). |
| Evidence of development of bipedalism in humans in Australopithecus afarensis. | Human-like footprints discovered on volcanic ash in Laetoli, Tanzania from \(\text{3.9}\)–\(\text{2.9}\) million years ago. |
| Bipedal austrolopithecines lose body hair \(\text{3}\)–\(\text{2}\) million years ago. | Loss of body hair occurs in parallel with the development of bipedalism. |
| Homo habilis is able to make and use tools \(\text{2.3}\)–\(\text{1.4}\) million years ago. | Fossil tools discovered in Olduvai Gorge, Tanzania and at Lake Turkana, Kenya. |
| Approximately \(\text{200 000}\) years ago, anatomically modern humans evolved. | The earliest fossil evidence found is near Omo river in Ethiopia. |
Fossil sites from South Africa providing evidence for pre-humans and humans
South Africa has been the site of various fossil discoveries and has been home to some of the world's leading paleoanthropologists such as Robert Broom, Raymond Dart and Phillip Tobias. Fossils of pre-humans and humans found across the country have contributed significantly to our understanding of human history on Earth. The table below shows some of the evidence and where it is located in South Africa.
The 'Taung Child'.
| Fossil Evidence and Age | Location in South Africa | Importance |
| Australopithecus africanus (the "Taung Child") (approximately \(\text{2.5}\) million years ago) | North West Province | Most direct ancestor of modern humans |
| Australopithecus sediba (approximately \(\text{2}\) million years ago) | Malapa Nature Reserve, Cradle of Humankind | First evidence of transition to tool-making in humans |
| Homo sapiens (approximately \(\text{75 000}\) years ago) | Klasies River Caves, Eastern Cape | Discovery of earliest anatomically modern humans |
Did You Know?
Philip Tobias (October 1925–June 2012) was a South African palaeoanthropologist at the University of Witwatersrand, whose work has contributed enormously to our understanding of how humans evolved. He is best known for his work with fellow palaeoanthropologist Louis Leakey. He identified the ancestral species of human beings known as Homo habilis. His work at the Sterkfontein caves in Gauteng has led to it becoming a World Heritage site. He was also famous for his opposition to apartheid and gave speeches condemning apartheid at protest rallies and also to academic audiences.
This lesson is part of:
History of Life on Earth