Darwin's concept of natural selection has been exhaustively studied, but his secondary evolutionary principle of sexual selection remains largely unexplored and misunderstood. Yet sexual selection was of great strategic importance to Darwin because it explained things that natural selection could not and offered a naturalistic, as opposed to divine, account of beauty and its perception.

Only now, with Darwin and the Making of Sexual Selection, do we have a comprehensive and meticulously researched account of Darwin's path to its formulation--one that shows the man, rather than the...