Can evolutionary potential help plants survive climate change? High variability in evolvability and G-matrix structure of Hypericum populations

2To predict the consequences of global change, we need knowledge of the ability of populations to evolve. On the short term, this is driven by the amount of standing genetic variation in the population. There is a pressing need for empirical data on evolutionary potential of natural populations, and on how evolutionary potential varies among species and across species distributions. Here, we evaluate and compare additive genetic variance-covariance matrices (G-matrices) and evolutionary potential in multiple populations of two Hypericum species, one of them a generalist perennial plant with a wide geographic distribution, and the other a rare habitat specialist. With these comparisons, we aim to evaluate the stability of the G-matrix within and among plant species, and whether the genetic architecture of some plant trait modules remains more stable than of others. We utilize manual crossing experiments in a nested half-sibling breeding design and quantitative genetic analyses to estimate evolvabilities (mean-scaled genetic variances) as a proportional measure of evolutionary potential. With such comparisons of evolvability in different types of species and populations, we can begin to understand general patterns in the variation of evolutionary potential in nature.