Homo Habilis 2.5 mya

Small intelligent apes which could walk on their back legs appeared in Southern Africa about the time the recent ice age started 3 mya. This freed their front feet which could then evolve into hands. At the same time their brains evolved so they became intelligent and were able to make and use tools. Their brains were about the same size as a modern chimpanzee.

Although called Homo habilis, meaning "handy man", these creatures were more like apes than men. Their ancestors, apes called Australopithecus, may also have used tools.

Image from Saurier Park courtesy of Frank Vincentz

Intelligence Enhanced by Genetic Mutation?

There is some evidence (although not conclusive) that a duplication of a gene in Homo habilis led to an increase in their intelligence by increasing the number of connections between the neurons in their brains.

Oldowan Tools

The types of stone tools which Homo habilis used were primitive. The perimeter of a river pebble was chipped away, by striking with another stone, to create a jagged sharp edge. The resulting tools are often simple and inelegant.

Image of Oldowan hand axe courtesy of José-Manuel Benito

The flakes which had been struck off also had sharp edges and were also used as tools.

Such primitive tools belong to the Lower Paleolithic period of technology and are called "Oldowan". This type of tool was first found about 2.6 mya and used until about 1.7 mya when they were replaced by Acheulian technology.