Unsteady Mechanisms of Force Generation in Aquatic and Aerial Locomotion

tion. First, analyses have become much more comparative, both across and within species. The great diversity of teleost fishes provides one of the best backgrounds for exploring the evolution of locomotor sys? tems at both the physiological and anatomical levels (see papers by Fish 1996, Westneat 1996, Gillis 1996, and Lauder and Jayne 1996 in this volume). By doing so, researchers are discovering new and diverse patterns of locomotory behavior. In addition to cross species comparisons, researchers are attempting to focus on the more subtle but equally important changes in swimming behavior within the ontogeny of single spe? cies (see paper by Hale 1996 in this vol? ume). The second reason for an alteration in perspective is that researchers are not simply satisfied with treating locomotion as a means of getting efficiently from one point to another, but also as a complex and flexible system of behavior required for feeding, courtship, and escape. In this new perspective, maneuverability is often con? sidered a more important design criterion than energy efficiency. And finally, the availability of powerful desktop microcomputers makes it possible to develop more sophisticated mathematical models of aquatic locomotion (see papers by Jordan 1996 and Fauci 1996 in this volume). Whether focused on juvenile salmon or