In this lively and controversial book, Elaine Morgan presents a challenging interpretation to the question of human evolution. With brilliant logic she argues that our hominid ancestors began to evolve in response to an aquatic environment.

Millions of years ago something happened that caused our ancestors to walk on two legs, to lose their fur, to develop larger brains and learn how to speak. Elaine Morgan discovers what this event was by studying the many incongruous flaws in the physiological make-up of humans. The human body is liable to suffer from obesity, lower back pain and acne. In support of her aquatic ape hypothesis she points out the flaws in our physiological make-up: the difficulties of erect bipedalism, our hairlessness and fat-layers, our preference for face to face sex and the way we breathe. Are these flaws a record of the history of the species, the 'scars' of evolution that are clues to earlier stages of evolution? Morgan establishes the origins of the evolutionary path that separated humans from other animals and questions the theories currently accepted by science. Did our ancestors adapt to an aquatic environment that subsequently dried out?