Asymmetry as a predictor of growth, fecundity and survival

Measures of developmental stability such as fluctuating asymmetry have been assumed to predict individual performance because asymmetry reflects an in ability to cope with stressful situations, and because asymmetry hampers lo comotion. However, the magnitude of this relationship between important fit ness components (growth, fecundity, survival) and asymmetry has never been assessed. Based on a literature survey, estimates of the correlation betwee n asymmetry and the three fitness components are presented. Pearson's corre lation coefficients weighted for sample size between asymmetry and growth, fecundity, and survival, respectively, were -0.15, -0.35, and -0.25, respec tively, with all three coefficients being highly significant. All three rel ationships were extremely robust given very large fail-safe numbers. The re sults were independent of whether studies or species were used as units of analysis. Hence asymmetry is a robust predictor of performance in fitness d omains such as growth, fecundity, and survival, although only accounting fo r 2.1%, 12.3%, and 6.0% of the variance. This may be of importance for stud ies of sexual selection, but also for ecological and conservation biologica l studies, where the performance of individuals or groups of individuals ar e assessed.