TRANSCRIPTION FACTORS. “Throughout evolution, regulatory networks need to expand and adapt to accommodate novel genes and gene functions. Recent studies demonstrate that changes in transcription factors contribute to the evolution of regulatory networks. In particular, duplication of transcription factors followed by specific mutations in their DNA-binding or interaction domains propels the divergence and emergence of new networks.”
http://www.sciencedirect.com/science/article/pii/S0958166915000208