Fluctuating asymmetry and individual variation in the skull shape of the common wall lizard (Podarcis muralis Laurenti, 1768) estimated by geometric morphometrics

Abstract

We explored individual variation and asymmetry in the skull shape of the common wall lizard (Podarcis muralis Laurenti, 1768) across four populations representing different habitats, by employing geometric morphometrics. We found directional and fluctuating asymmetry across the analysed populations, without differences in fluctuating asymmetry among populations. Patterns of individual variation and fluctuating asymmetry were highly correlated within and among populations. Asymmetric skull shape variation was similar in all populations, and was mostly related to the jaw adductor muscle chamber. Our results imply that the uniform pattern of skull fluctuating asymmetry results from a high level of canalisation. Directional asymmetry can be related to anatomical and behavioural lateralisation.