It's easy to forget the marvel of human hands. Musicians' hands play masterful compositions on the piano; artists' hands paint timeless works; surgeons' hands save lives. The rest of us use our miraculous hands to get dressed, pour coffee, and type messages.
Like our big brains, our agile hands are part of what makes us human. The construction of nerves, tendons, and bones is a result of millions of years of evolution. But how exactly did they get that way? And when did hands emerge on our evolutionary timeline?