Here is a list of people that bestselling author Walter Isaacson has written definitive biographies of: Leonardo da Vinci, Benjamin Franklin, Albert Einstein, Steve Jobs, and Jennifer Doudna. One historic artist, one visionary statesman, one world-changing genius, one prophetic technologist, and one woman whose discovery may eventually prove as — or more — meaningful than any of them.

In 2012, Doudna, then a relatively unknown biochemist at the University of California Berkeley, published a paper with Emmanuelle Charpentier of Umeå University proposing that the bacterial enzyme Cas9 could be used to edit genes through a method called CRISPR. They weren’t the first to demonstrate that gene editing could be done, but CRISPR was a revolutionary leap in its precise ability to manipulate genes.

It was like going from a hacksaw to a scalpel — and after CRISPR, biology would never be the same.

In the less than 10 years since that paper was published, scientists have harnessed CRISPR to edit genes that can cause hereditary diseases like sickle-cell anemia, tweaked plant genomes to create crops that are more tolerant to disease or drought, and studied the very evolution of the human brain.

In 2020, eight years after their original research was published, Doudna and Charpentier were awarded the Nobel Prize for Chemistry — a blindingly fast timeline for the field’s most prestigious award. (Feng Zhang, a biologist at the Broad Institute, published research on CRISPR slightly before Doudna and Charpentier, and his institution laid claims to patent rights over the invention. The legal battle has been fought for years, but whatever the final result, the Nobel Prize has been seen as proof by many that it is Doudna and Charpentier who deserve primary scientific credit.)

To her credit, Doudna has not been satisfied by mere discovery. From the start, she understood that precise gene editing would have enormous consequences for the entire species, and that scientists could not wait before grappling directly with those ethical questions.

In 2015, she led a group of scientists calling for a worldwide moratorium on the use of CRISPR to alter human genes in a way that could be inherited. Her 2017 book A Crack in Creation was concerned as much with the ethical questions surrounding CRISPR as it was with the revolutionary science that led to its discovery. In between her research and her role commercializing CRISPR at Mammoth Biosciences, a biotech startup she co-founded, she has continued to ask tough questions about gene editing applications. As she told the New York Times recently: “If we can do it, should we be doing it? If we are going to do it, in what circumstances, and who decides?”

Where the 21st century ends up will depend in large part on whether we can maximize the benefits of dual-use technologies like genetic engineering and AI while minimizing the catastrophic misuses. We need more scientists willing to scrutinize the ethical implications of their discoveries, scientists like Jennifer Doudna, who surely knows that how she will finally be remembered among that star-studded group of biographees will depend on whether her life’s work does more good than ill.