Abstracts (first author)
Varying patterns of genetic correlations between morphological traits along the ontogeny of blue tit nestlings
Morphological traits usually are strongly genetically determined, which results in relatively high heritabilities of such traits compared to life-history traits. However, apart from their genetic background, different phenotypic traits may be correlated at the genetic level with other traits. Such correlations - if strong - may hamper or strengthen evolution of pairs of traits, depending on the direction of genetic correlations. Here we analyse morphological traits such as body weight and structural body size from a long-term study of the wild population of blue tits. We measured morphological traits during the early development of nestlings at several points in time. By employing animal models we were able to estimate genetic and non-genetic sources of variance in these traits and covariances between different traits. We demonstrate that the magnitude of correlations between analogous traits expressed at different ages varies, indicating that different sets of genes influence expression of these traits at different ages. Our results indicate that traits expressed during development are not genetically uniform but have their internal, complex quantitative genetic architecture.