Amazon.com Product Description (ISBN 0316856150, Hardcover)

Men's beards grow faster when their bearers expect some sex. Fewer sperm cells are made in summer. Circumcised boys are more frightened of injections than boys who have not undergone the operation. And the average length of a man's penis is less than six inches, while that of a blue whale is ten feet.
These are only a few of the remarkable facts that spill out in Y: The Descent of Men. With marvelous literary flair, the acclaimed scientist and author Steve Jones offers a landmark exploration of maleness, based on today's explosion of biological research about what makes a male -- a topic of consuming interest to at least half the population. From what males consider to be the "prince of chromosomes" -- the Y -- to novel insights into men's hormones, hair loss, and the hydraulics of man's most intimate organ, Jones lays out the case for and against masculinity.
But the self-proclaimed "biologist in the bedroom" goes far beyond discussing straight science. He writes, for instance, of a meeting between Napoleon and Czar Alexander in which they discussed baldness cures rather than matters of state. And, as many angry males have found out, to the law fatherhood means more than genes. A father who is not a biological parent but who leaves a family with children still has responsibility for the offspring.
Steve Jones hints at a startling truth: men are the second sex. The Y chromosome is no longer an excuse for excess. Compared with their partners, men are in relative decline, whether in social status or in length of life. Both halves of the population have to learn to cope with the Y chromosome. This book helps show them how.