Meeting Abstract
The complex relationship between form and function provides the foundation for the generation of organismal diversity. Selection acts directly on performance, which is the product of interacting phenotypic components. Thus, the ability to predict how multiple phenotypic traits interact in determining performance is key to understanding the evolution of complex functional systems. Here, we demonstrate how performance landscapes, which map the performance consequences of different phenotypic combinations, can be used to understand adaptive evolution of suction feeding fishes. A hydrodynamic model of the suction forces exerted on the prey allows us to explore the complex performance space for aquatic predator-prey interactions, and enables us to predict prey capture performance for any given phenotype. Using this model, we generated performance landscapes for three prey types that pose different challenges to the predators, namely planktonic prey that senses the hydrodynamic disturbance generated by the predator, visually oriented prey that escapes the looming predator and attached prey that clings to its holdfast. We explored the topography of the multidimensional performance landscape and determined it to be rugged with multiple local performance peaks. We used the landscape to generate a-priori hypotheses regarding the position of extant species relative to the theoretical optima in this performance space, which we tested by mapping prey-capture kinematics of fishes from four radiations onto the three generated performance landscapes. Whereas previous research generally focused either on studying phenotypic diversification using morphological traits, or on the biomechanical basis of performance, we integrate these approaches using a detailed mechanistic model to explore how a highly nonlinear and multidimensional performance space shapes organismal diversity in suction feeding fishes.
