Fitness costs of noise in biochemical reaction networks and the evolutionary limits of cellular robustness

Gene expression is inherently noisy, but little is known about whether noise affects cell function or, if so, how and by how much. Here I present a theoretical framework to quantify the fitness costs of gene expression noise and identify the evolutionary and synthetic targets of noise control. I find that gene expression noise reduces fitness by slowing the average rate of nutrient uptake and protein synthesis. This is a direct consequence of the hyperbolic (Michaelis-Menten) kinetics of most biological reactions, which I show cause \"hyperbolic filtering\", a process that diminishes both the average rate and noise propagation of stochastic reactions. Interestingly, I find that transcription