Lowly Origin: Where, When, and Why Our Ancestors First Stood UpOur ability to walk on two legs is not only a characteristic human trait but one of the things that made us human in the first place. Once our ancestors could walk on two legs, they began to do many of the things that apes cannot do: cross wide open spaces, manipulate complex tools, communicate with new signal systems, and light fires. Titled after the last two words of Darwin's Descent of Man and written by a leading scholar of human evolution, Lowly