The miracle of human life is not that we are endowed with some frailties but that we aren't swamped with them. Don't forget that your genes come from ancestors who most of the time weren't even human. Some of them were fish. Lots more were tiny and furry and lived in burrows. These are the beings from whom you have inherited your body plan. You are the product of three billion years or evolutionary tweaks. We would all be a lot better off if we could just start fresh and give ourselves bodies built for our particular Homo sapiens needs - to walk upright without wrecking our knees and backs, to swallow without the heightened risk of choking, to dispense babies as if from a vending machine. But we weren't built for that. We began our journey through history as unicellular blobs floating about in warm, shallow seas. Everything since then has been a long and interesting accident, but a pretty glorious one, too, as I hope the following pages make clear. Adapted from back of book. .