SALT LAKE CITY, UTAH—Researchers from the University of Utah have determined that the ability to make a clenched fist offers some protection to the bones of the human hand during a fight, and therefore may have been just as important as the ability to manipulate objects as a shaping force in the evolution of the human hand. “Ultimately, the evolutionary significance of the human hand may lie in its remarkable ability to serve two seemingly incompatible, but intrinsically human, functions,” they wrote in the Journal of Experimental Biology. Apes are not able to form a clenched fist.