Digital Particle Image Velocimetry (DPIV) represents a significant advance for comparative experimental analysis of organismal function, and, in particular, opens up the field of experimental hydrodynamics of aquatic locomotion. The technique provides a powerful means of gaining insight into how animals swim, and I foresee its application being a central and fruitful component of my future research.

My primary near-term research goal is to use DPIV to study empirically, for the first time, the relationship between fin morphology and locomotor function in fishes. The evolution of bony fishes is characterized by major structural transformations of the locomotor system, including change in the shape, position and number of fins on the body. However, we presently understand very little about the connection between fin structure and locomotor force. In 2001 I received a National Science Foundation grant proposing explicit experimental tests of hypotheses regarding the functional consequences of evolutionary variation in fin design. The aim of the grant and, more generally, of my continuing work in biological fluid dynamics, is to compare patterns of fluid flow and wake-derived locomotor force among taxonomically diverse lineages of teleost fishes to allow functional interpretation of evolutionary trends in animal design. I am specifically interested in historical trends of elaboration and migration of the paired and median fins, and the implications of these trends for maneuverability. Two central questions I will pursue are as follows: (1) Does the location and orientation of the pectoral fin constrain the range of directions in which force may be applied on the fluid during turning? (2) Do fishes with both spiny and soft-rayed dorsal fins (the apomorphic teleost condition) exhibit enhanced maneuverability as compared to species lacking the spiny fin (the plesiomorphic condition)? Addressing these questions will shed light on how different species meet the locomotor demands of their varied habitats, and will help clarify the functional significance of observed evolutionary variation in propulsor design.

Over the long term, I will continue to explore the mechanics of behavior related to the ecological success of lower vertebrates. Development of interdisciplinary experimental approaches to the study of organismal function and evolution will remain a priority.