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Proposal Description download pdf

     A simple query, back in 1997, from my then graduate student Brian Enquist, "Why is it 3/4-power?" led to a multifaceted body of research which is answering a decades-old question. Scientists have realized for a long time that size and temperature affect metabolic rate in proportion to an organism's mass, but they haven't known exactly how.

     Brian and I put our heads together to devise a model, but soon realized we needed a mathematician. In stepped Geoffrey West, a physicist from the Santa Fe Institute and our trio devised a model to predict more precisely how metabolic rates increase as body size increases. That model uses the fractal geometry of circulatory networks, such as the vascular system to explain the quarter-power scaling law: the idea that metabolic rates vary in proportion to 3/4-power of an organism's mass - biological scaling laws which I call the fourth dimension of life.

     Scaling laws describe how different parts and characteristics of living organisms vary or scale in proportion to changes in body size. For more information is available about scaling (click here).

     NSF recently awarded our group a $2.5 million grant to collaborate with other researchers and organizations to look at how scaling relationships, which appear to be universal, occurring in virtually all taxa of organisms and all kinds of environments, offer clues to underlying mechanisms that powerfully contain biodiversity.

     We will use the interplay of mathematical models and empirical measurements to elucidate the physical and biological principles that determine how the life history, abundance, distribution, and species richness of organisms scale with body size, space, and time. Our program of research and education involves: i) collaborations among physicists, mathematicians, geologists/hydrologists, biologists, and ecologists; ii) interactions among scientists from seven institutions; iii) cooperation between the University of New Mexico, the Santa Fe Institute, and Los Alamos National Laboratory; and iv) interdisciplinary training for graduate students and postdocs. Our proposal is available for perusal.

Information contained in this document is © copyright James H. Brown, 2007. All rights reserved.

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