This document summarizes a presentation on the evolution of symmetry in protein structures. It discusses how CE-Symm, a software tool, can accurately detect internal symmetry in proteins. The presentation finds that 18% of SCOP superfamilies exhibit symmetry, with β proteins having the highest percentage at 24.6%. It also discusses how identifying symmetric subdomains can help find "protodomains" that are building blocks of protein domains and have spread across evolution. The use of symmetry to study protein evolution is demonstrated through several examples.