In nature, enzymes are the catalysts that make much of biology work. They jumpstart chemical reactions that either wouldn’t happen, or would happen super slowly. They break down food, build other molecules, extract energy, and more. What if we could harness evolution to engineer designer enzymes that do other specific jobs that benefit us?  Putting that idea into practice changed the game for chemistry, and earned Frances Arnold the Nobel Prize prize in 2018. She called it “directed evolution.” Today, thousands of labs use her methods to coax enzymes into doing things no one ever thought of. She joins Host Flora Lichtman to talk about where she sees this approach going in the future, and the personal evolution that brought her into science. Guest: Dr. Frances Arnold is the Linus Pauling Professor of Chemical Engineering, Bioengineering and Biochemistry at the California Institute of Technology in Pasadena, California. Transcripts for each episode are available within 1-3 days at sciencefriday.com