8.6: Tool Use
- Page ID
- 62185
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Fossil hand bones show greater potential for evidence of tool use. Although no stone tools are recognizable in an archaeological context until 2.5 million years ago (mya), we can infer nevertheless their existence for the earliest stage of human evolution. The tradition of making and using tools almost certainly goes back much earlier to a period of utilizing unmodified stones and tools mainly of organic, perishable materials (wood or leaves) that would not be preserved in the fossil record.
How can we tell a hominin-made artifact from a stone generated by natural processes? First, the manufacturing process of hitting one stone with another to form a sharp cutting edge leaves a characteristic mark where the flake has been removed. Second, the raw material for the tools often comes from some distance away and indicates transport to the site by hominins.
Modification of rocks into predetermined shapes was a technological breakthrough. Possession of such tools opened up new possibilities in foraging: for example, the ability to crack open long bones and get at the marrow, to dig, and to sharpen or shape wooden implements.
Even before the fossil record of tools around 2.5 mya, australopithecine brains were larger than chimpanzee brains, suggesting increased motor skills and problem solving. All lines of evidence point to the importance of skilled making and using of tools in human evolution.