Albert Farrell Bennett

My research concerns the interaction of living systems with their environments, particularly in regard to temperature and energy exchange. Temperature controls nearly all rate processes in organisms, including their metabolism, locomotion, growth and reproduction, and thus governs all aspects of their lives. All these processes are likewise limited by energy intake and its subsequent partitioning into maintenance, thermoregulation, synthesis, and activity. I study these factors in very diverse kinds of organisms. Much of my earlier research involved comparative and experimental studies on vertebrates, particularly reptiles, which have limited capacities of oxygen uptake and are consequently very reliant on anaerobic metabolism to sustain vigorous activity. These physiological constraints, coupled with variable body temperatures, create interesting adaptive patterns in behavior and energy allocation that are quite distinct from those of homeothermic animals. Much of this work was undertaken in an attempt to understand the evolution of endothermy (“warm-bloodedness”) in mammals and birds, both in regard to the alterations entailed in physiology and morphology and also in the selective factors that promoted its development. In order to study evolution in different environments experimentally, I use populations of bacteria which can be cultured for thousands of generations in the laboratory and measure changes in their adaptive fitness and underlying genetics. This research has involved nearly 100 populations which have adapted to different thermal and acid environments, some of them constant and some variable. Experimental evolution provides an important tool for testing evolutionary hypotheses and determining the diversity of adaptive responses to novel environments.