Sex, Time and Power: How Women's Sexuality Shaped Human Evolution

Leonard Shlain From the best selling author of Art and Physics and The Alphabet Versus the Goddess comes a provocative new book that will change our views of human sexuality and evolution. According to Leonard Shlain there is no clear and compelling explanation for the sudden emergence of glib, big-brained Homo sapiens 150,000 years ago. In his latest book, he proposes an original thesis that variations in female sexuality changed the course of human evolution. Due to the narrowness of her bipedal pelvis and the increasing size of her infant's head, the human female began to experience high childbirth death rates. Natural selection adapted her to this environmental stress by drastically reconfiguring her hormonal cycles. Her estrus with its external signal that she was ovulating disappeared as her menses became the most florid of any mammal and it mysteriously entrained with the periodicity of the moon. These interlocking adaptations led the first women to grasp the concept of a month and make the connection between sex and pregnancy. Upon learning the immense secret of time, early females became empowered to refuse sex when they were ovulating. The first males faced women who had a mind of their own. Men used the knowledge of the future acquired from women to become the planet's most fearsome predator. But soon, a man discovered that he was mortal and, then, when he belatedly understood the function of sex, he grasped that he could have an heir. These three insights concerning sex, death, and paternity structured all subsequent human culture. Throughout Sex, Time & Power , Shlain offers carefully reasoned, and certain to be controversial discussions on such subjects as menstruation, orgasm, puberty, circumcision, male aggression, menopause, baldness, left-handedness, the evolution of language, homosexuality, and the origin of marriage. Written in a lively and accessible style, Sex, Time & Power is certain to generate heated debate in the media and among readers interested in human evolution and the history of sexuality.