Which Came First, the Tool or the Hand Size?

Did Technology Drive Human Evolution?

140 years ago Charles Darwin speculated that tool use may have influenced the evolution of the human hand. Now, in "Technology Based Evolution? A Biometric Test of the Effects of Handsize Versus Tool Form on Efficiency in an Experimental Cutting Task," in-press at the Journal of Archeological Science, two anthropologists at the University of Kent in Canterbury are investigating the particulars of that idea. Through a series of experiments with stone flake tools (similar to the those used by African hominids 2.6 million years ago) and un-handled steel blades, they have shown that bigger hands use those tools more efficiently. The scientists speculate that just as opposable thumbs may have enabled tool use, tool use may have influenced the biological evolution of hand size—and of musculature and bone structure in the hand. As eons ticked on, it was the hominids with genes coding for hands adept at tool use that survived.