At the end of August, I got a press release saying that a chemist named Steven Benner was going to deliver a lecture in Italy in which he broached the idea that we might descend from Martians.

I met Benner ten years ago. He was sitting in a coffee shop in Cambridge, Massachusetts, working out what it would take to make life from scratch. Helping him in this exercise was Jack Szostak, a Nobel-prize winning Harvard biochemist whom he had known for years. In the midst of their conversation, Dr. Benner abruptly turned to me and asked, “How much do you think it would cost to create a self-replicating organism capable of Darwinian evolution?”

As a journalist, I’m not accustomed to