2009/03/30 by JERRY F. HUSAK, Jerry F. Husak, A. KRISTOPHER LAPPIN +3 · 90 citations
Agricultural and Biological Sciences · Environmental Science · #Animal Behavior and Reproduction #Animal Ecology and Behavior Studies #Biology #Evolutionary biology #Plant and animal studies
paper · pdf · doi:10.1111/j.1095-8312.2008.01176.x
published in Biological Journal of the Linnean Society 96(4), 840-845 (Oxford University Press)
openalex publication_date 2009/03/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Weapons used in combat between males are usually attributed to sexual selection, which operates via a fitness advantage for males with weapons of better ‘quality’. Because the performance capacity of morphological traits is typically considered the direct target of selection, Darwin's intrasexual selection hypothesis can be modified to predict that variation in reproductive success should be explained by variation in performance traits relevant to combat. Despite such a straightforward prediction, tests of this hypothesis are conspicuously lacking. We show that territorial male collared lizards with greater bite-force capacity sire more offspring than weaker biting rivals but exhibit no survival advantage. We did not detect stabilizing or disruptive selection on bite-force capacity. Taken together, these results support the hypothesis that superior weapon performance provides a fitness advantage through increased success in male contests. Sexual selection on weapon performance therefore appears to be a force driving the evolution and maintenance of sexual dimorphism in head shape.