What It Means To Be Human Is Changing Thanks To Gene Editing

Near the end of a wide-ranging conversation about the complexity of the human genome and the history and future of genetics, Arizona State University President Michael Crow noted the almost inconceivably large number — “10 to the 14th” power — of microorganisms in our bodies. And then he turned to cancer researcher Siddhartha Mukherjee and posed what Crow called “a complicated question.”

“What the hell are we?”

Crow and Mukherjee, author of the new book “The Gene: An Intimate History” and the Pulitzer Prize-winning “The Emperor of All Maladies: A Biography of Cancer,” already had spent much of the evening — a Zócalo Public Square event in front of a full house at the Skirball Cultural Center — trying to answer that question.

One answer, said Mukherjee, is “a majestic formula” akin to e=mc102: “Genes plus environment plus genetic interactions plus chance” equals the human form.

But what it means to be human is also changing, he said, both biologically and culturally. Our increasing knowledge and ability to manipulate our genes — the fundamental units of heredity and the basic...