A fun and informative book that answers the “why?” of an assortment of bodily functions — sure to capture the curiosity of many elementary school students.  The table of contents lists all the questions the book addresses, from “Why do you get hiccups?” to “Why do you throw up?” and “Why do you yawn?”  One to two pages answer each question with clear and complete explanations, including both the physical mechanics part of the why and the evolutionary advantages offered by each human trait.  Be prepared for protests from any parents who are of an anti-evolutionary mind-set, as the book explains that humans are not only evolutionarily related not only to chimpanzees and other primates, but all other animals including fish and bacteria.