We know more about our bodies than ever before, but there remain many unanswered questions. Accessible and endlessly fascinating, this discussion of evolution and the human body reveals which features humans have inherited from fish, amphibian, reptile, four-legged mammal, and primate ancestors; while also exploring how the human body is likely to evolve in the future. Such questions as Why do our elbows and knees bend in opposite directions? Why do men and women walk differently? Why do men have nipples? Why is childbirth so painful? Why do we sleepwalk? and Why do so many of us suffer from back pain and dental problems? have fascinating answers rooted in human evolution from fish.