This article corresponds to Lowry, D. B., D. Popovic, D. J. Brennan, and L. M. Holeski. 2019. Mechanisms of a locally adaptive shift in allocation among growth, reproduction, and herbivore resistance in Mimulus guttatus. Evolution. https://doi.org/10.1111/evo.13699.Local adaptation in plants often requires coordinated shifts among resources. Lowry et al. provide evidence for physiological and genomic mechanisms underpinning adaptive shifts in yellow monkeyflower (Mimulus guttatus), such as the transition between annual and perennial life histories. In M. guttatus, differential activity of gibberellins, governed partially by a chromosomal inversion, is responsible for shifts between growth, reproduction, and herbivore defense (secondary compound production)