Weitz Group @ Georgia Tech

Theoretical Ecology and Quantitative Biology

Army Research Office -- Coevolutionary complex networks: dynamical foundations, influence, and control (2014-2017)

  • The proposed research will develop theoretical methods, modeling approaches, and computational algorithms for coevolutionary network dynamics, influence, and control, and will be organized around the following research themes: (i)Dynamical foundations of coevolution; (ii) network influence and control; (iii) host-viral interactions.

National Science Foundation - Biological Oceanography (2012-2016)

  • Bacteria and their viruses (phages) make up two of the most abundant and genetically diverse groups of organisms in the oceans. However, the ongoing discovery of new taxonomic diversity has, thus far, out-paced gains in quantifying the function of and interactions among phages and bacteria. In this proposal, we will develop a theoretical framework for characterizing the e ffect of complex phage-bacteria interactions on marine ecosystem structure and function.

Dimensions: Costs and benefits of chronic viral infections in natural ecosystems (2013-2018)

  • This research project will investigate a new hypothesis about how viruses may control the structure and function of microbial communities. The traditional view of viruses is that they negatively impact the fitness of infected hosts. In other words, they are viewed strictly as pathogens, in which the host tries to eliminate the virus. This project will explore an alternative hypothesis: that chronic viral infections contribute positively to host fitness, increasing the success of the virus-host pair by protecting their hosts from infection by even more pathogenic viruses.

Physics of Living Systems Student Research Network (2012-2016)

  • Georgia Tech has joined the PoLS SRN. The founding PIs are Daniel Goldman (PI), Jennifer Curtis, David Hu, Harold Kim, Joshua Weitz, Kurt Wiesenfeld. New members of the community include Flavio Fenton, JC Gumbart and Simon Sponberg. The PoLS SRN meets regularly as a community and includes many cross-linking activities, including research in the physics of living systems across scales from molecules to ecosystems.

Simons Foundation: Viruses vs. zooplankton: quantifying the interplay between parasites and predators in the North Pacific Ocean (2014-2017)

  • Marine viruses affect microbial community structure and biogeochemical cycles in multiple ways: (i) by negatively affecting, and potentially limiting, the density of target populations; (ii) by modifying the metabolic activity of infected cells, including nutrient uptake rates; (iii) by stimulating production via the “viral shunt”, in which cellular lysates are released back into the environment and then re-assimilated by non-targeted cells. Yet inferring the relative importance of virus-induced modifications of microbes and microbial cell fate is difficult in the face of competing ocean processes, e.g., grazing by zooplankton. Here, I propose to leverage theory- and simulation-based approaches to quantify the relative importance of viruses relative to that of zooplankton in regulating microbial mortality and modifying ecosystem functioning in a model ocean environment: Station ALOHA. This work is part of a multi-PI project the "Simons Collaboration on Ocean Processes and Ecology" aka SCOPE.