Lack of evolutionary potential of developmental instability of front tibia length in the Indian meal moth (Plodia interpunctella)

The evolutionary potential of developmental instability (DI, defined as an individual's inability to buffer its development against random perturbations) as estimated by individual asymmetry (so-called fluctuating asymmetry, small random deviations from perfect symmetry), remains a controversial subject of research. Only if DI is heritable and if it is related with fitness, can evolution be expected to occur. In this study we find no evidence for evolutionary potential of DI of the front tibia in the Indian meal moth. The heritabilities of fluctuating asymmetry and DI were negative. Individual asymmetry was nor related to two fitness components: survival probability and body length. In contrast, both survival probability and body length were heritable. Body length increased with food quality but was not affected by density, whereas survival probability increased with food quality and decreased with density. Thus, effects of environmental stress and genetic background differed for fluctuating asymmetry on one hand and survival probability and body length on the other hand.