In this project, we will be presenting modeling approaches to study cellular signaling and the resulting physiological phenomena. We will study chemotaxis in dictyostelium discoideum, a model system in which single autonomous cells communicate with each other and aggregate into cellular mounds containing thousands of cells in response to starvation (chemotaxis quite literally implies “motion (taxis) in response to chemical substances (chemo)”). Here our focus will be on developing phenomenological models to describe cellular behavior; we will not detail the molecular machinery behind any cellular process (which is a complicated endeavor), but rather test the viability of simulating complex chemical networks with simple physical models. Secondly, we will focus on the Notch signaling pathway. This pathway is implicated in a diverse group of phenomena where cells pick a “fate” based on its neighbors. Here, signaling is mediated by contact with neighbors, as opposed to a diffusive signal in chemotaxis, as such we are focused closely on the dependence of outcome (patterns of cells with different fates) on network architecture (i.e. the types of players involved and types of interaction between chemical players) and cellular geometry. These projects exemplify the use of simple models and numerical algorithms to simulate biological processes to develop an understanding of how network architecture relate to cellular behavior. As we understand better how cells change fate and direct their motion, we can better understand such phenomena as immune responses, bacterial colony dynamics, inflammation and wound healing as well as cancer metastasis.