Meeting Abstract
Phenotypic plasticity is important for organisms facing heterogeneous environments because it can allow them to quickly respond to changing or novel conditions and persist. Thus, phenotypic plasticity can act as a bridge until adaptive genetic changes occur. However, this early, critical stage in the process of adaptation has been hard to identify. Patchy but widely distributed species are good candidates to study the process of adaptation. Developmental responses in mouthpart shape and size may allow immediate use and rapid, whole-organism adaptation to changing resource availability, but it may also lead to within species genetic differences across populations that use resources of varying sizes. Combining fieldwork with common garden/reciprocal transplant experiments, we examined the response of mouthpart length across a broad landscape in the leaf-footed cactus bug Narnia femorata. These insects feed with straw-like mouthparts (=beak) through the fruit wall to get to the seeds and pulp. Here, we present evidence of genetic and developmental plasticity in mouthpart length in response to food resources of different sizes. Bugs that locally feed on cacti species with thicker fruits have genetically longer mouthparts, but both populations studied in the common garden also exhibit patterns consistent with adaptive plasticity.
