Enzymes are a class of proteins that catalyze, or facilitate, chemical reactions. In directed evolution, new and better enzymes are created in labs by artificial selection, similar to the way that breeders modify corn or cows. In this new study, scientists at Caltech have “bred” a bacterial protein with the ability to make silicon-carbon bonds, thus not just improving an enzyme’s biological function but actually persuading it to do something that it had not done before. Molecules with silicon-carbon compounds are found in agricultural chemicals, paints, semiconductors, and computer and TV screens. Currently, these products are made synthetically, since silicon-carbon bonds are not found in nature. Until now, that is.