Abstract
Local adaptation is pervasive. It occurs whenever selection favors different phenotypes in different environments, provided that there is genetic variation for the corresponding traits and that the effect of selection is greater than the effect of drift and migration. In many cases, ecologically relevant traits are quantitative and controlled by many genes. It has been repeatedly proposed that the within genome localization of these genes may not be random, but could be an evolved feature. In particular, the clustering of local adaptation genes may be theoretically expected and has been observed in several situations. Previous theory has focused on two-patches or island-continent models to investigate this phenomenon, reaching the conclusion that such clustering could evolve, but in relatively limited conditions. In particular, it required that migration rate was neither too low nor too large and that the full optimization of trait values could not be eventually achieved by a mutation at a single locus. Here, we investigate this question in spatially continuous space with distance-limited dispersal. We find that clustering of local-adaptation genes is pervasive within clines during both the establishment phase of local adaptation and the subsequent “reconfiguration” phase where different architectures compete with each other. We also show that different fitness functions relating trait to fitness have a strong impact on the overall dynamics and resulting architecture.
Competing Interest Statement
The authors have declared no competing interest.