Preliminary modeling assessment of the efficacy of a suicide gene system to contain bacteria and plasmids in the environment

Abstract

Simulation models are rarely applied to the preliminary analysis of emerging environmental problems, because endpoints and behaviors of concern are not yet defined, or the principles and processes governing behaviors of concern are unknown. Nonetheless, environmental management decisions must be made based on inferences and beliefs about system behaviors and these inferences and beliefs form implicit models. As such, there may be benefits to be derived from modeling one's underlying perceptions as a way to expose flaws in reasoning, as well as insights and potential solutions that might otherwise be overlooked. This rationale was applied to the analysis of a suicide gene system that has been proposed for controlling environmental microbiotechnology products in the field. A simple simulation model was constructed to describe beliefs about the suicide gene system and an hypothesis about its effects presented by the developers of the control system. Analysis involved making plausible relaxations in modeling assumptions to test the robustness of model predictions about the control system's effects vis-a-vis the original hypothesis. Results provide a more thorough interpretation of current knowledge and perceptions about the control system's capabilities and limitations than previously reported in the literature, and offer suggestions for evaluating field test proposals. Institutional barriers to use of the methodology employed herein are discussed.