Over evolution, protein genes acquire substitutions that alter their function. Powerful phylogenetic advancements such as ancestral sequence reconstruction have made it possible to resurrect and characterize functions of ancestral proteins. We seek to understand how amino acid changes result in the acquisition of novel protein function. To achieve this, we i) resurrect, then structurally and functionally characterize ancestral protein sequences; ii) characterize evolutionary trajectories that result in novel function; iii) determine how conformational dynamics are altered over evolution; and iv) elucidate the structural mechanisms that permit(ted) functional evolution.