Joshua Weitz
Adjunct Assistant Professor

Ph.D., Physics, Massachusetts Institute of Technology, 2003

Research Interests

Theoretical ecology. Viral-host interactions. Biological networks.

Evolutionary ecology of bacterial viruses
Evolutionary ecology of bacterial virusesBacterial 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.

Other Publications:

Mileyko, Y, Weitz JS. In Press. Bifurcation analysis of gene regulatory circuits subject to copy number variation. SIAM Journal on Applied Dynamical Systems.

Boettiger, C, Dushoff J, Weitz JS. 2010. Fluctuation domains in adaptive evolution. Theoretical Population Biology. 77:6-13.

Iyer-Pascuzzi, AS, Symonova O, Mileyko Y, Hao Y, Belcher H, Harer J, Weitz JS, Benfey PN. 2010. Imaging and Analysis Platform for Automatic Phenotyping and Trait Ranking of Plant Root Systems. Plant Physiology.

Ballantyne, F, Menge D, Weitz JS. 2010. A discrepancy between Michaelis-Menten based nutrient uptake model predictions and nitrogen to phosphorus stoichiometry in the surface ocean. Limnology and Oceanography. 55:997-1008.

Menge, DN, Weitz JS. 2009. Dangerous nutrients: evolution of phytoplankton resource uptake subject to virus attack.. Journal of Theoretical Biology. 257:104-115.

[Additional Publications]