Overview

Biological systems are often celebrated for their tremendous complexity.  For example, the dynamics of metabolic networks in bacteria, the interplay between predators and prey in a large ecosystems, and the spread of epidemics in human populations all depend on interactions between the thousands, millions, or even billions of individual “parts” that make up the system. Despite this complexity, however, the behavior of these systems is often the result of relatively simple emergent properties that are shared by a large number of statistically similar, but microscopically distinct, systems.  Motivated by emergent phenomena across physical and biological disciplines, our group applies systems level approaches to the study of living systems, where biologically-relevant dynamics—for example, the evolution of drug-resistance in a population of cancer cells—emerge from interactions and competition between a large number of individual components.  While we study a wide range of biological systems, we are especially interested in multi-drug resistance in bacteria and cancer cells.  Our goal is the development of quantitative tools to measure and predict how interactions between cells and interactions between drugs contribute to large scale behavior of the population as a whole.  Our research is highly multidisciplinary and combines theoretical tools from physics, engineering, applied math, and computer science with experimental approaches from molecular biology, genetics, microbiology, and cancer biology.

Topics of current interest include:

• Evolution of microbial drug resistance in spatially heterogeneous environments;
• Single-cell spatial architecture in cooperative biofilms;
• Effects of coupling between population density and fitness in microbial populations;
• The interplay between multi-drug interactions, drug cycling, and ecological dynamics in bacteria and cancer;
  
• The role of network structure and critical dynamics in determining the responses of large statistical mechanical systems, including those close to and far from equilibrium, to single and combined perturbations.
• Synchronization phenomena in self-replicating populations of coupled oscillators