The development of bipedalism, in the human species, has left several fossils remains that led us have a fairy exact chronology about the anatomical changes.

However, variations in the use of the hands present some dating difficulties as it not only involves bony anatomical modifications, but also involves the development of the central nervous system related to mobility and in the neocortex, in order to imagine the use of hand objects.

But the central nervous system, as other organs, does not fossilize. That’s why many of the geological remains allow us to know the evolution of the use of the hands are based on the tools found.

It is considered that 3,3 million years ago tools began to be made, in the northwest of present-day Kenya, in the form of scales suitable for cutting. This is 500,000 years before the oldest Homo fossil.

For this reason, it is considered that these first instruments were built by Kenyanthropus platyops, which could be at the root of the separation between Paranthropus and Homo that began 3.6 million years ago.

It seems that in early times there were hominin species with sufficient cranial capacity to design tools, but with anatomically incapable hands and that it was not until the appearance of Homo ergaster, 1.7 million years ago, that both conditions occurred in the same species.