9423446 MORAN It is well established that a character of an organism can chanee in response to different environmental conditions, even though the underlying genetic composition of the organism is the same. This ability to respond to different environmental condition is termed phenotypic plasticity. Recent theoretical work suggests that phenotypic plasticity is favored by natural selection in variable environments as an evolutionary mechanism for coping with environmental variability. As such, phenotypic plasticity may affect evolutionary change and biodiversity in the broad sense. The purpose of this study is to test empirically the prediction made by the theoretical models, by comparing the levels of morphological phenotypic plasticity along precipitation and temperature variability gradients. This can increase our understanding of the importance of phenotypic plasticity in evolutionary change. In addition, this study may help conservation biologists understand the effects of environmental change on populations, as these are determined in part by their level of phenotypic plasticity. The study species, the pallid-wing grasshopper (Trimerotropis pallidipennis), is considered an agricultural pest in outbreak years. Knowledge of the importance of the environment on the genetics of this species may help us understand the evolution of insect outbreaks.
