Meeting Abstract
Response to selection require traits to be heritable, but maternal effects, or the effects of parent’s phenotypes on their offspring phenotypes, can also influence the evolutionary process. Therefore, for a complete understanding of evolution, it is essential to understand how both genetic additive and maternal effects contribute to phenotypic variation. For example several studies of squamate reptiles present high broad-sense heritability (i.e., total genetic variation/ phenotypic variation) in performance-related and morphological traits. Nevertheless, this high heritabilities could be attributable to maternal effects since broad-sense estimations of heritability includes maternal effects in addition to common environmental effects. We took advantage of a seminatural breeding experiment and measured sprint speeds and several morphological traits in an Australian agamid lizard (Amphibolurus muricatus) parents and offsprings to understand the role of maternal and additive genetic effects in driving variation in offspring traits. Our data was collected when both parent and offspring were still hatchlings. Maternal and paternal identity of offspring were established and we then used animal models in order to partition phenotypic variance between maternal and additive genetic effects in traits that are believed to be under selection in many lizard species. We used a half-sibs design, which allowed us to better partition variance between additive genetic and maternal effects in comparison with full-sibs design and traditional parent-offspring regressions. We compare our results to published reports of heritabilities for squamates and other animals, and discuss the implications of our findings as well as future prospectives for research.
