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How do the morphologies of organisms affect their physical interactions with the environment and other organisms? My research in marine systems couples field studies of the physical habitats, life history strategies, and ecological interactions of organisms with laboratory analyses of their biomechanics. Here, I review how we pursued answers to three questions about marine organisms: ( a) how benthic organisms withstand and utilize the water moving around them, ( b) how the interaction between swimming and turbulent ambient water flow affects where small organisms go, and ( c) how hairy appendages catch food and odors. I also discuss the importance of different types of mentors, the roadblocks for women in science when I started my career, the challenges and delights of interdisciplinary research, and my quest to understand how I see the world as a dyslexic. 

ABSTRACT Organisms are subject to the laws of physics, so comparative biomechanics is a powerful approach for identifying basic principles that apply across taxa of how morphology affects performance of mechanical functions such as locomotion, feeding or resisting damage. Journal of Experimental Biology has been a leading journal for decades in publishing studies revealing such basic biomechanical principles. However, field studies of the physical environment, ecological interactions and life-history strategies of organisms reveal which aspects of their biomechanical performance are important to their success in different types of natural habitats, and thus enable us to design ecologically relevant laboratory experiments to understand biomechanical function. Because the fitness consequences of differences in morphology are affected by the biological and physical environment, biomechanics can be used to identify how physical constraints on the performance of organisms with different body plans in variable environments can affect evolution. I illustrate these points with examples from the literature that show how the biomechanical consequences of morphology depend on the ecology of the organisms. Knowledge of the temporal patterns of interactions of organisms with their physical and biological environments is essential for understanding their functional morphology as it changes during ontogeny, and it reveals constraints on their evolution. 

Locomoting organisms often carry loads such as captured prey or young. Load-carrying effects on high-Reynolds-number flight have been studied, but the fluid dynamics of load carrying by low-Reynolds-number microorganisms has not. We studied low-Reynolds-number load carrying using unicellular choanoflagellates, which wave a flagellum to swim and create a water current transporting bacterial prey to a food-capturing collar of microvilli. A regularized Stokeslet framework was used to model the hydrodynamics of a swimming choanoflagellate with bacterial prey on its collar. Both the model and microvideography of choanoflagellates showed that swimming speed decreases as number of prey being carried increases. Flux of water into the capture zone is reduced by bacteria on the collar, which redirect the water flow and occlude parts of the collar. Feeding efficiency (prey captured per work to produce the feeding current) is decreased more by large prey, prey in the plane of flagellar beating and prey near microvillar tips than by prey in other locations. Some choanoflagellates can attach themselves to surfaces. We found that the reduction in flux due to bacterial prey on the collars of these attached thecate cells was similar to the reduction in flux for swimmers.