Featured on the cover of the science journal Nature this week is an Acheulean handaxe, the earliest ever found anywhere. It was excavated from the Kokiselei complex of sites, out of the western shores of Lake Turkana's Nachukui geological formation in Kenya, and it reportedly dates to 1.76 million years ago (mya).
Acheulean axes are, really, the first recognizably-formed tool ever made by us and our ancestors. Its distinctive shape was so useful, in fact, that it remained in use for an incredible 1.6 million years, and it was used by Homo erectus, Neanderthals and early modern humans, all three of us. All that is really kind of amazing when you think about it.
But this handaxe isn't on the cover of Nature for its beauty or the earliness of its existence: well, clearly, it is partly on the cover for those reasons, but the real reason is that the authors of the article pose an interesting question about Acheulean handaxes that I've never seen before, but is definitely worth contemplating. Let me explain.
The very oldest stone tools ever found in the world, predating the Acheulean, are from the Gona and Bouri sites in Ethiopia. They date to roughly 2.5 million years ago and they're basically rough forms of tools you can think of as choppers. We call the stone tools Oldowan tradition, after the site where they were first discovered.
Helene Roche (at left) leading archaeological excavations in the west Turkana area. Photo credit: Rhonda Quinn>
Archaeologists believe that Oldowan tradition tools were made by Homo habilis, the "handy man" of our ancestors, and the first tool maker. The oldest fossil remains of early Homo species, however, only date to 2.38 mya: but that's not too surprising, because stone is much more likely to survive the dim march of millennia than bone. We also firmly believed, or did until recently, that Acheulean tools, the next step up in complexity from Oldowan, were invented by Homo erectus, "erect man", another of our direct ancestors and closer to us in appearance and behaviors than H. habilis.
The oldest Acheulean tradition tools in the world appear at Kokiselei, at 1.76 mya. The earliest Homo erectus remains appear outside of Africa at sites like Dmanisi in the Republic of Georgia beginning about 1.8 mya, but they appear to be using Oldowan tradition tools. Did a group of H. erectus leave Africa before Acheulean was, um, invented? Or was there another hominid, another as-yet-identified tool maker in Africa? Was Homo the only species with tool-making abilities?
This is not a completely new idea: when the early Oldowan site of Bouri was excavated, Australopithecus garhi was implicated as the tool-maker.
The human race has taken several hits lately concerning its status as the sole owners of the planet at any one time: we've learned in the last decade or so that we modern humans shared the world with Neanderthals and Denisovans. It may very well be that when we tie one stone tool type to one particular species of human we are jumping to unwarranted conclusions about that as well.
Here is some context, and some details in the site and its geological location in Kenya for them that wants them.
Here's a link to the article in Nature, and a link to John Hawk's blog, well worth reading among the other stuff out there.
Lepre CJ, Roche H, Kent DV, Harmand S, Quinn RL, Brugal J-P, Texier P-J, Lenoble A, and Feibel CS. 2011. An earlier origin for the Acheulian. Nature 477:82-85.
Digging deeper into the earliest Acheulean, John Hawks
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