Comment on "Evolutionary paths underlying flower color variation in Antirrhinum"

Although Whibley et al. (Reports, 18 August 2006, p. 963) argue for the presence of high-fitness ridges in the Antirrhinum floral-color adaptive landscape, their data are equally compatible with adaptive landscapes having a single peak and no ridges. Their demonstration of divergent selection across a hybrid zone argues against the presence of adaptive ridges.