I just finished "Your Inner Fish: a journey into the 3.5-billion year history of the human body," by Neil Shubin. Shubin is provost of the fabulous Field Museum, as well as professor of anatomy at the University of Chicago, and a clear, lively writer. His thesis is this: it is possible to trace a common blueprint for life from human beings all the way back to primitive multi-cellular organisms. As Shubin writes, A subset of these multicellular animals have a body plan like ours, with a front and a back, a top and a bottom, and a left and a right.... A subset of multicellular animals that have ... a body plan like ours....also have skulls and backbones... A subset of multicellular animals that have ... skulls and backbones ... also have hands and feet ... A subset of multicellular animals that have ... hands and feet also have a three-boned middle ear ... A subset of multicellular animals that have ... a three-boned middle ear also have a bipedal gait and enormous brains. Shub...