Asymmetry as a predictor of growth, fecundity and survival

Abstract

Measures of developmental stability such as fluctuating asymmetry have been assumed to predict individual performance because asymmetry reflects an inability to cope with stressful situations, and because asymmetry hampers locomotion. However, the magnitude of this relationship between important fitness components (growth, fecundity, survival) and asymmetry has never been assessed. Based on a literature survey, estimates of the correlation between asymmetry and the three fitness components are presented. Pearson’s correlation coefficients weighted for sample size between asymmetry and growth, fecundity, and survival, respectively, were –0.15, –0.35, and –0.25, respectively, with all three coefficients being highly significant. All three relationships were extremely robust given very large fail‐safe numbers. The results were independent of whether studies or species were used as units of analysis. Hence asymmetry is a robust predictor of performance in fitness domains such as growth, fecundity, and survival, although only accounting for 2.1%, 12.3%, and 6.0% of the variance. This may be of importance for studies of sexual selection, but also for ecological and conservation biological studies, where the performance of individuals or groups of individuals are assessed.