The work on which this review article is based has been funded by grants from the Research Council of Norway [Gram Nos. 133553, 146744, 166596, and 178444], the Norwegian University of Science and Technology, the Norwegian Academy of Science and Letters, the Royal Swedish Academy of Sciences, the Nordic Marine Academy, the EU Transnational Access to Research Infrastructures Scheme, the Nordic Council program NORDFORSK, and the National Science Foundation [USA, Grant No. OISE/0701086].
Our understanding of sexual selection has greatly improved during the last decades. The focus is no longer solely on males, but also on how female competition and male mate choice shape ornamentation and other sexuall...