Olduvai Stone Chopping Tool

• The discovery of this stone tool helped to prove that humans evolved in Africa

By Professor Clive Gamble, Archaeologist, Royal Holloway University of London

This stone tells two stories: one about the fossil ancestor who made the tool and the other about the fossil hunter who found it. Is it having objects that makes us human?

The ancestor and the archaeologist are separated by almost two million years. They are similar because both walked upright and used tools. However, they differ greatly in the size of their brains and the sophistication of their technology. So are they both human?

Louis Leakey, the flamboyant Kenyan-born fossil hunter and champion of the importance of Africa for human evolution, was 28 when he found this stone tool. Not everyone believed that they were ancient artefacts and he had to wait another thirty years before it could be scientifically proven.

At the time, he claimed that these ancient Olduvai people, for whom 28 was a ripe old age, were our ancestors because they had things, like this tool. But crows, sea otters, monkeys and apes all make and use tools and we don’t call them human. In fact, these ancestors had brains not much larger than a chimpanzee – almost three times smaller than our own. So, if it wasn’t big brains that made us tool users or tools alone that made us human, was it our minds and imagination?

But how can a stone tool help us to understand the extent of the human mind? Certainly, it cannot tell us about a capacity for language or a passion of religious beliefs. However, the action of flaking the stone repeatedly to create a sharp-edged tool points to other imaginative powers - appreciating the properties of materials, predicting the outcome of physical actions, and understanding that an alternative point of view exists other than your own and acting accordingly. In other words our ancestors had an understanding of how other minds work, something no animal has and which children develop by the age of four.

To complete Leakey’s tale, his discoveries were questioned and his long search for our African origins, as predicted by Darwin, went on and on. His task was to convince others and eventually he triumphed. That was his story.

The toolmaker had other concerns to deal with. As this simple tool shows, he or she was just beginning to appreciate the potential of being human, moving beyond the mental ability of apes and crows and into the foothills of the human imagination. Brains are needed to make objects. But two million years ago a new story began that married brains to objects in such a way that together the human mind evolved.