Book excerpt: Written by the leading experts in the field, this book examines the evolutionary advantages of gender dimorphism and sexual dimorphism in flowering plants. Divided into three sections: the first introduces readers to the tremendous variety of breeding systems and their evolution in plants and sets the stage for a consideration of the evolution of dimorphism in reproductive and non-reproductive characters. The second section deals with the evolution of secondary sexual characters, including the theory related to the evolution of sexual dimorphism and its empirical patterns, while the last section deals with the genetics of gender expression and of secondary sexual characters.