Many factors have contributed to humanity's rise to domination over other species - most obviously opposable thumbs, mastery of fire and agriculture. However, arguably the most crucial is our capacity for specialization. Distinctively formed stone tools from Jordan suggest this had developed by 40,000 years ago
Plenty of animals use teamwork, and quite a few use tools. However, a team where every member is doing something similar will never be as effective as one where different members recognize and develop their strengths. For agricultural societies, specialization is essential, but it is also consistently demonstrated in nomadic peoples. However, knowing exactly when this developed is a challenge.
In the Journal of Human Evolution, Dr Aaron Stutz of Emory University reports on a study of thousands of tools found in the Mughr el-Hamamah cave, Jordan. "These toolmakers appear to have achieved a division of labor that may have been part of an emerging pattern of more organized social structures," Stutz says.
Stutz believes the tools support the theory that tribes that divided their labor were more successful and represented a major step forward for humanity. “The finds from Mughr el-Hamamah give us a new window onto a transitional time, on the cusp of modern human cultural behaviors, bridging the Middle and Upper Paleolithic."
Charcoal coinciding with the tools has been dated to at least 42,000 years ago, and Stutz suspects is at least 2000 years older than that. The timing coincides with the replacement of Neanderthals by modern humans.
The tools were clearly made for different purposes, including blades, scrapers, cutting flakes. Such diversity is nothing new. What is radical in Stutz's theory is the claim that they were made with differing techniques that speak of being made by different people. "These toolmakers appear to have achieved a division of labor that may have been part of an emerging pattern of more organized social structures," says Stutz.
The cave where the tools were found lies “midway between the Dead Sea and the Sea of Galilee,” says Stutz. “Each generation expanding into Eurasia would have foraged for food and made campsites” in the area.
Fragments of human bone at the site are inadequate to tell whether the toolmakers were Neanderthals or our direct ancestors, but the sheer volume of tools found there makes Stutz think the cave was inhabited by larger groupings than seen in either species previously. "We can speculate that several families shared the space and worked alongside one another," says Stutz. If the toolmakers were human, the authors consider that possible specialization was a key factor in our displacement of our nearest relatives.
Older tools often appear to have been designed to serve multiple uses, and where found together. they look to be made using the same techniques, and maybe the same hands. Mughr el-Hamamah contains examples of these older-style tools as well, along with flakes knocked off to form these tools, which co-author John Shea thinks may have been used like disposable cutlery, unlike the more long-lasting tools from which they were flaked.
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