ENVIRONMENTAL MATERNAL EFFECTS ON LOCOMOTOR PERFORMANCE IN THE COMMONLIZARD (LACERTA-VIVIPARA)

Environmental (i.e. non-genetic) maternal effects have the potential t o associate the environmental conditions faced by mothers during gesta tion or before egg laying with the phenotype of their offspring. For t his reason, maternal effects may play a major role in determining offs pring phenotype independently of the genotype of the individuals, and can thus be considered a mechanistic basis of phenotypic plasticity. D espite the ecological and evolutionary implications of environmental m aternal effects, few studies have experimentally investigated this phe nomenon in reptiles. Here we report the results of an experimental lab oratory study on the effects of maternal feeding rate and density on o ffspring locomotor performance in the common lizard (Lacerta vivipara) . Lacerta vivipara is a viviparous lizard, and viviparity enhances the probability of a maternal influence on offspring phenotype. We focuse d on a particular phenotypic trait, maximal sprint running speed, beca use this trait is thought to be selectively important in squamates. Sp rint speed was a repeatable trait. and it varied significantly among f amilies. Maternal feeding rate significantly affected sprint speed, wh ereas density had no effect on this trait. The effect of maternal feed ing rate differed according to the sex of the offspring and their body size, resulting in significant two-way and three-way interactions amo ng these factors. In other words, the maternal feeding rate changed th e shape of the allometric relationship between speed and size, but dif ferently for males and females. The complexity of such effects makes i t extremely difficult to offer an adaptive interpretation, but emphasi zes the role played by the environment in shaping phenotypes among gen erations.