From sciencedaily: "Compared with a chimpanzee hand, at left, the human hand, at right, has shorter fingers and palms and a longer, stronger more flexible thumb. That not only allows fine manipulation of tools and other objects, but allows humans to make a clenched fist, which apes cannot. A new University of Utah study argues that human hands evolved not only for manual dexterity, but for fighting." (Credit: Denise Morgan for the University of Utah)
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