Divergence in evolutionary potential of life history traits among wild populations is predicted by differences in climatic conditions

Short-term adaptive evolution represents one of the primary mechanisms allowing species to persist in the face of global change. Predicting the adaptive response at the species level requires reliable estimates of the evolutionary potential of traits involved in adaptive responses, as well as understanding how evolutionary potential varies across a species' range. Theory suggests that spatial variation in the fitness landscape due to environmental variation will directly impact the evolutionary potential of traits. However, empirical evidence on the link between environmental variation and evolutionary potential across a species range in the wild is lacking. In this study, we estimate multivariate evolutionary potential (via the genetic variance-covariance matrix, or G-matrix) for six morphological and life history traits in 10 wild populations of great tits (Parus major) distributed across Europe. The G-matrix significantly varies in size, shape, and orientation across populations for both types of traits. For life history traits, the differences in G-matrix are larger when populations are more distant in their climatic niche. This suggests that local climates contribute to shaping the evolutionary potential of phenotypic traits that are strongly related to fitness. However, we found no difference in the overall evolutionary potential (i.e., G-matrix size) between populations closer to the core or the edge of the distribution area. This large-scale comparison of G-matrices across wild populations emphasizes that integrating variation in multivariate evolutionary potential is important to understand and predict species' adaptive responses to new selective pressures. Adaptive evolution of phenotypes is a key mechanism for species persistence in the face of global change, and predicting these responses is a major challenge to implementing biodiversity scenarios. The quality of these predictions relies notably on our estimates of evolutionary potential, and several questions need to be answered: How different is evolutionary potential across a species distribution? Will it change under new environmental conditions? Can we use information on evolutionary potential from one population to infer adaptive responses in another population? Here we address these questions in the great tit (Parus major) by evaluating how evolutionary potential is influenced by climatic conditions across the species' range. Our study is based on the long-term monitoring of 10 wild populations of great tits distributed across Europe for which information about life history and morphological traits have been collected. We find significant differences in evolutionary potential between populations for both categories of traits, and for life history traits, these differences are linked to population differences in climatic conditions. These results show that evolutionary potential is not a "one-size-fits-all" measure and that its variation needs to be taken into account when predicting adaptive responses to climate change.