Sex-specific evolution of bite performance in Liolaemus lizards (Iguania: Iguanidae): the battle of the sexes.

B. VANHOOYDONCK; F. B. CRUZ; C. S. ABDALA; D. L. MORENO AZOCAR; M. F. BONINO; A. HERREL.

BIOLOGICAL JOURNAL OF THE LINNEAN SOCIETY

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2010 p. 461 - 475

0024-4066

Although differential selective pressures on males and females of the same species may result in sex-specific evolutionary trajectories, comparative studies of adaptive radiations have largely neglected within-species variation. In this study, we explore the potential effects of natural, sexual selection, or a combination of both, on bite performance in males and females of 19 species of Liolaemus lizards. More specifically, we study the evolution of bite performance, and compare evolutionary relationships between the variation in head morphology, bite performance, ecological variation and sexual dimorphism between males and females. Our results suggest that in male Liolaemus, the variation in bite force is at least partly explained by the variation in the degree of sexual dimorphism in head width (i.e. our estimate of the intensity of sexual selection), and neither bite force or the morphological variables were correlated to diet (i.e. our proxy for natural selection). On the contrary, in females, the variation in bite force and head shape can, to a certain extent, be explained by variation in diet. These results suggest that whereas in males, sexual selection seems to be operating on biteperformance, in the case of females, natural selection seems to be the most important selective pressure.