First Steps: How Upright Walking Made Us Human

Paleoanthropologist DeSilva (A Most Interesting Problem) takes readers on a brisk jaunt through the history of bipedalism. Humans are the only living mammals to walk upright, the author notes, and in exploring how and why, he reveals what the fossil record says about the history of human evolution, migration, and social organization. “Homo erectus almost certainly moved in and out of Africa in pulses” rather than in one big wave, for example, and he describes various primate fossils that led to new discoveries in bipedalism, including those of Lucy, a 3.2-million-year-old skeleton whose bones confirmed “bipedalism appeared early in our evolutionary history.” DeSilva argues bipedalism is a “prerequisite for changes that define our species” as it freed up hands for tool-making, and investigates its implications on modern human life, including the creative benefits of walking and the complications it introduces into giving birth. DeSilva’s love of fossil discovery and of collaborating with colleagues comes through in the wonder he experiences in examining bones firsthand: “Light reflected from it as if it were a geode, not an ancient human fossil. I hadn’t expected Taung to be so beautiful.” DeSilva’s ability to turn anatomical evidence into a focused tale of human evolution and his enthusiasm for research will leave readers both informed and uplifted. Agent: Esmond Harmsworth, Aevitas Creative Management. (Apr.)