Functional loss of yeast detectors parallels transition to herbivory

Herbivorous insects are extraordinarily successful. Half of the world’s extant insects and one quarter of all living metazoan species belong to herbivorous insect lineages (1, 2). Although feeding on living plant tissue is an evolutionarily difficult transition, herbivorous insect lineages are more diverse than their nonherbivorous relatives (3, 4). In PNAS, Goldman-Huertas et al. (5) present both the underlying genetic basis and the resulting physiological changes that led to the evolution of herbivory in the fly Scaptomyza flava (Fig. 1).