The evolution of local adaptation in long-lived species

Abstract

Many species experience heterogeneous environments and adapt genetically to local conditions. The extent of such local adaptation has been shown to depend on a balance between divergent selection and gene flow, but also on other factors such as phenotypic plasticity or the genetic architecture of traits. Here, we explore the role of life history in this process. We develop a quantitative genetics model and run individual-based simulations to contrast the evolution of local adaptation between short- and long-lived species. We show that life history does not have a unidirectional effect on local adaptation. Instead, local adaptation varies with a species life cycle and how this cycle modulates the scheduling of selection and dispersal among stage classes. When a longer generation time is associated with more frequent events of selection than dispersal, local adaptation is more pronounced in long-lived than in short-lived species. If otherwise dispersal occurs more frequently than selection, long-lived species evolve weaker local adaptation. Our simulations confirm these findings and further highlight how the scheduling of selection and dispersal shape additive genetic variance, effective dispersal between patches, and the genetic response at quantitative trait loci. Taken together, our results suggest that the effect of longevity on local adaptation depends on the specifics of a species life cycle, potentially explaining why current meta-analyses have not consistently detected this effect.