Gene regulatory networks (GRNs) are groups of interacting regulatory transcription factors (TFs) and their target genes. Environmental stimuli are propagated through signal transduction cascades. In response, TFs interacting within the GRN promote or inhibit RNA polymerase to differentially regulate the expression of genes encoding proteins which alter physiology. Hence, these GRNs are central to the process of dynamic, physiological responses to a variable environment in all organisms. Despite recent progress on archaeal GRNs, however, molecular functions of TFs in archaea are not well understood relative to the other domains of life. Based on our recent work with archaeal GRNs, we hypothesize that in archaea, extensive combinatorial control in transcription provides flexibility and robustness in response to extreme and variable environments. This project aims to test this hypothesis using a combination of genome-wide experimentation and statistical modeling.