Frances Arnold: This is an old idea. Cars were run on wood in the old days. They could burn wood, gasify wood. Cars were run on ethanol. I mean oil is a new phenomenon. That didn’t become widely available until the ‘30s and ‘40s. So the original fuels were — a lot of them were bio-based. We lost that when it became so easy to pump oil out of the ground. But we all know that biology stores solar energy in all sorts of forms, and one of those forms is plants. So these ideas had been around for a long time, that you could convert plants into fuels.

I wanted to do that when I went to graduate school in the 1980s, but we were not ready for that then. And that’s when I got caught up in this whole new revolution, that we could manipulate the code of life, that we could cut and paste DNA. These brand-new companies — Genentech, Amgen — they were just being formed, out of this revolution in the technology. Now they’re mega-companies today, but this was a whole nascent set of ideas. And here I was, a young graduate student learning biochemistry, and learning chemistry for the first time, from the people who started this revolution. So I looked at the biological world and said, “That’s what I want to engineer — not nuclear power plants, not rocket ships, not airplanes.” I thought maybe it would be fun to work on spaceships.

I said, “No, look at the biological world. Here is the most beautiful, intricate, functional, capable set of engineering things that have ever been devised. And it was all devised by the biological world, by evolution — not by human beings, not by human engineers.” And I said, “I want to engineer that. I want to go in and modify DNA to solve human problems” — to solve the same problems that I saw in my previous career. There were lots of problems to solve, but I didn’t have the tools. I said, “Now I’m going to take these brand-new tools and apply them to looking at some of these things.”