First Steps: How Walking Upright Made Us HumanHumans are the only mammals to walk on two, rather than four, legs. From an evolutionary perspective, this is an illogical development, as it slows us down. But here we are, suggesting there must have been something tremendous to gain from bipedalism. First Steps takes our ordinary, everyday walking experience and reveals how unusual and extraordinary it truly is. The seven million year long journey through the origins of upright walking shows how it