01247nas a2200133   4500008004100000245006700041210006700108260000800175300001400183490000800197520079200205100002300997856009301020       2001                        eng d00aCosts and the diversification of exaggerated animal structures0 aCosts and the diversification of exaggerated animal structures  cFeb  a1534-15360 v2913 aSexual selection can favor production of extravagant ornaments and weapons in the contest for access to the opposite sex. Existing explanations for the diversity of sexually selected structures focus on reproductive benefits con- ferred by particular ornament or weapon morphologies. Here, I show that costs of weapon production also may drive patterns of weapon evolution. In beetles, production of horns reduces the size of neighboring morphological structures (antennae, eyes, or wings, depending on the location of the horns), and these tradeoffs reveal unexpected functional associations between ecology and horn morphology. This study illustrates a critical but overlooked role of costs in sexual selection and has implications for understanding the evolution of animal morphology.1 aEmlen, Douglas, J.  uhttps://scarabnet.myspecies.info/costs-and-diversification-exaggerated-animal-structures