01301nas a2200121   4500008004100000245003600041210003200077300001200109490000700121520098600128100001801114856004701132       2008                        eng d00aThe evolution of animal weapons0 aevolution of animal weapons  a387-4130 v393 aMales in many species invest substantially in structures that are used in combat with rivals over access to females. These weapons can attain extreme proportions and have diversified in form repeatedly I review empirical literature oil the function and evolution of sexually selected weapons to clarify important unanswered questions for future research. Despite their many shapes and sizes, and the multitude of habitats within which they function, animal weapons share many properties: They evolve when males are able to defend spatially restricted critical resources, they are typically the most variable morphological structures of these species, and this variation honestly reflects among-individual differences in body size or quality. What is not clear is how, or why, these weapons diverge in form. The potential for male competition to drive rapid divergence in weapon morphology remains one of the most exciting and understudied topics in sexual selection research today.1 aEmlen, D., J.  uhttps://cephaloleia.myspecies.info/node/12