Evolutionary capacitors are molecular mechanisms that are able to tap into stocks of cryptic genetic variation. Just as an electronic capacitor stores and releases charge, an evolutionary capacitor stores and releases genetic variation. We study the yeast prion [PSI+] as a model system for evolutionary capacitance, using both theoretical population genetic and comparative genomic / bioinformatic approaches. [PSI+] is an epigenetically inherited aggregate of the Sup35 protein, which is a release factor required for translation to terminate at stop codons. When [PSI+] appears, elevated readthrough occurs at every gene in the genome. A range of pre-existing genetic variation beyond stop codons then ceases to be cryptic, and is instead phenotypically revealed. Among a number of current studies, we are modeling the evolution of networks of transcriptional regulators in order to study emergent properties such as canalization (also known as robustness), genetic assimilation and evolutionary capacitance.