Two-legged goats, conjoined twins, 'Cyclops' infants with a single eye in the middle of their forehead, double-headed snakes, and Laloo, a man with a partially formed twin attached to his chest... In Freaks of Nature, Mark S. Blumberg turns a scientist's eye on these unusual examples of humans and other animals, showing how a subject once relegated to the sideshow can help explain some of the deepest complexities of biology. These examples of extreme bodily anomalies are in fact the natural products of development, and it is through such developmental mechanisms that evolution works. And Blumberg shows how 'freak' deformities can provide valuable windows on the intimate connections between genetics, development, the environment, and evolution. In taking seriously a subject that has often been shunned as discomfiting and embarrassing, Freaks of Nature takes the perspective of evolutionary developmentalbiology to shed new light on how individuals--and entire species--develop, survive, and evolve.