Joshua Weitz, Assistant Professor
Ph.D., Physics, Massachusetts Institute of Technology, 2003
Office: Cherry Emerson 219
Tel: 404-385-6169
Fax: 404-894-0519
Email: jsweitz at gatech.edu
Research Interests
Theoretical ecology; evolutionary ecology of microbial & viral communities; biological networks; vascular plants; scaling laws; disease dynamics; interacting particle systems.
Current Research
Evolutionary ecology of bacterial viruses
Bacterial viruses (bacteriophage) are the most abundant organisms on Earth. Typical densities of phage are approximately 10 billion per liter of seawater and even higher in soil samples. Despite their ubiquitous presence, we have only a limited understanding of the evolutionary ecology of bacteria and bacteriophage. I plan to begin a multidiscplinary research program on phage that includes the study of (i) the generation and maintenance of microbial and viral diversity; (ii) the evolution of life-history switches in phage; (iii) basic mechanisms of host-phage population dynamics; and (iv) the role of phage in altering infectious disease.
Scaling and biological networks
Networks are a central element in biological functioning that span gene regulation to resource delivery to ecosystem organization. Projects in the group include the use of empirical analysis with scaling theory to assess internal architecture of resource delivery networks from the xylem networks of vascular plants to the cardiovascular networks of mammals. In addition, I am interested in networks at the ecosystem scale, whether the emergence of size-structured food webs or the dynamics of riparian vegetation within river networks. Future work will include studies of competition and evolution of biological networks from a game-theoretic perspective.
Mathematical ecology
Analysis of biological systems depends on scale. I am interested in the foundations of two important approaches to study multi-scale phenomena in biological systems: (i) adaptive dynamics; and (ii) metabolic theory. I emphasize application of both theories to novel systems as well as the development of new methodologies, for example the extension of metabolic theory to predator-prey dynamics.
Selected Publications
Joshua S. Weitz, Philip N. Benfey, and Ned S. Wingreen. Evolution, interactions and biological networks. PLoS Biology (in press).
Rachata Muneepeerakul, Joshua S. Weitz, Simon A. Levin, Andrea Rinaldo, and Ignacio Rodriguez-Iturbe. A Neutral Metapopulation Model of Biodiversity in River Networks. Journal of Theoretical Biology (in press).
Joshua S. Weitz and Hyman Hartman. Phage in the time of cholera. The Lancet Infectious Diseases, 6, 257-258 (2006).
Joshua S. Weitz, Kiona Ogle, and Henry S. Horn. Ontogenetically stable hydraulic design in woody plants. Functional Ecology, 20, 191-199 (2006).
Joshua S. Weitz and Simon A. Levin. Size and scaling in predator-prey dynamics.. Ecology Letters, 9, 548-557 (2006).
Joshua S. Weitz, Hyman Hartman, and Simon A. Levin. Coevolutionary arms races between bacteria and bacteriophage. Proc. Natl. Acad. Sci. USA 102, 9535-9540 (2005).
Joshua S. Weitz and Daniel H. Rothman. Scale-dependence of resource-biodiversity relationships. J. Theor. Biol. 225, 205-214 (2003).
Peter S. Dodds and Joshua S. Weitz. Packing-limited growth. Phys. Rev. E 65, 056108 (2002).
Joshua S. Weitz and Hunter B. Fraser. Explaining mortality rate plateaus. Proc. Natl. Acad. Sci. USA 98(26), 15383-6 (2001).
Peter S. Dodds, Daniel H. Rothman, and Joshua S. Weitz. Re-examination of the 3/4-law of Metabolism. J. Theor. Biol. 209(1), 9-27 (2001).