The crucial insight came to me as I leisurely rode my bike home from work. It was Valentine's Day, 2008. While I cruised along, my mind mulled over a problem that had been preoccupying me and others in my field for more than a decade. Was there some way to simulate life—including all the marvelous, mysterious and maddeningly complex biochemistry that makes it work—in software?
A working computer model of living cells, even if it were somewhat sketchy and not quite accurate, would be a fantastically useful tool. Research biologists could try out ideas for experiments before committing time and money to actually do them in the laboratory. Drug developers, for example, could accelerate their search for new antibiotics by homing in on molecules whose inhibition would most disrupt a bacterium. Bioengineers like myself could transplant and rewire the genes of virtual microorganisms to design modified strains having special traits—the ability to fluoresce when infected by a certain virus, say, or perhaps the power to extract hydrogen gas from petroleum—without the risks involved in altering real microbes. Eventually, if we can learn to make models sophisticated enough to simulate human cells, these tools could transform medical research by giving investigators a way to conduct studies that are currently impractical because many kinds of human cells cannot be cultured.