Meeting Abstract
Phenotypic plasticity is the capacity of an organism’s phenotype to vary depending on the conditions under which it develops. The ability of an individual to change its phenotype in response to environmental cues may increase its fitness in novel and/or fluctuating environments, which suggests that developmental plasticity may be adaptive and therefore subject to selection itself. While sufficient levels of genetic variation have been documented for plasticity to respond to selection, a strict genetic basis for this trait has remained elusive. Here we explore this question in cichlid fishes. We first document that cichlids reared under distinct kinematic conditions, whereby fish are made to feed with either a biting or sucking mode, vary in a way that mimics natural eco-morphological variation between species. Next, we show that different lineages vary in their ability to mount a plastic response when reared under unique trophic conditions. Finally, we document an explicit genetic basis for developmental plasticity by mapping jaw, skull and body shape under distinct trophic environments. These data advance our understanding of how the genotype-phenotype map is shaped by the environment, and provide insights into the “flexible stem” theory of adaptive radiation.
