Homo ergaster was tall and muscular. Slim hips and long legs enabled this species to walk long distances. Their skin was smooth to cool themselves through sweating, meaning they no longer had to pant to keep cool.

Homo ergaster probably obtained food by scavenging or by chasing animals across the savannah until they died from exhaustion.

This species was amongst the first to leave Africa and colonize other continents. After ergaster leaves Africa, it becomes known as Homo erectus. In Asia, Homo erectus lived in the bamboo forests and may have made tools such as staffs and spears from this strong, versatile material.

Advance Use of Stone Tools

H. ergaster had a rounded cranium and a prominent browridge. Its teeth were much reduced in size, especially when compared to Australopithecus. Several features that distinguish H. ergaster from H. erectus are thinner bones of the skull and the lack of an obvious sulcus, or depression, just behind the browridge.

By 1.6 million years ago, an advance in stone tool technology is identified with H. ergaster. Known as the Achulean stone tool industry, it consisted of large cutting tools, primarily hand axes and cleavers. Originally thought to be responsible for the spread of early humans beyond Africa, it is now known that the migration out of Africa predates this tool industry.

Out of Africa

Shortly after Homo ergaster appeared 1.9 million years ago, humans began to leave Africa for the first time and migrate to other continents. Early humans reached Dmanisi in ex-Soviet Georgia around 1.8 million years ago. Here, they encountered cool, seasonal grasslands where African animals such as ostriches and giraffes mingled with Eurasian species such as wolves and the sabre-toothed cat Megantereon. Humans quickly spread east as far as the Indonesian island of Java. The hominids that inhabited subtropical Asia at this time belong to the species Homo erectus. This early human learned to survive in the bamboo forests that covered this region of Asia. The paucity of stone tools from Southeast Asian hominid sites suggests that erectus may have created a technology based on bamboo, a strong and versatile material.

Evidence:About a boy

One of the best sources of information about Homo ergaster is a skeleton discovered in 1984 by Alan Walker and Kamoya Kimeu at Nariokotome in West Turkana, Kenya. The remains were found to be those of a teenage boy between the ages of 11 and 13 when he died.

Around 1.5 million years ago, the boy’s body sank into the marsh where he died and became fossilised. His teeth show signs of an abscess where his milk teeth fell out, indicating that he may have died from septicaemia (blood poisoning).

Nariokotome boy, as he has been dubbed, was already developing a thick, bony ridge across his eyes. A pair of buck teeth stuck out from a large, projecting mouth below a long, wide nose.