But in between the cell-on-silicon and the brain-on-silicon simulators lies a fascinating and strange new project to create a life-like simulation of Caenohabditis elegans, a roundworm. OpenWorm isn't like these other initiatives; it's a scrappy, open-source project that began with a tweet and that's coordinated on Google Hangouts by scientists spread from San Diego to Russia. If it succeeds, it will have created a first in executable biology: a simulated animal using the principles of life to exist on a computer.

"If you're going to understand a nervous system or, more humbly, how a neural circuit works, you can look at it and stick electrodes in it and find out what kind of receptor or transmitter it has," said John White, who built the first map of C. elegans's neural anatomy, and recently started contributing to the project. "But until you can quantify and put the whole thing into a computer and simulate it and show your computer model can behave in the same way as the real one, I don't think you can say you understand it."

For example, when researchers touch a worm on the head and it responds by turning and moving backwards, what exactly is happening there? What molecular mechanisms coordinate the firing of neural networks that initiate and complete this complex behavior? This month, a paper came out in PLOS Biology describing that exact sequence as recorded in live C. elegans. But it's one of very few studies like that.

More broadly, OpenWorm raises fascinating questions about what we mean when we say something is alive. If and when this project succeeds in modeling the worm successfully, we'll be faced with a new and fascinating concept to think with: a virtual organism. Imagine downloading the worm and running it in a virtual petri dish on your computer. What, exactly, will you be looking at? Will you consider it to be alive? What would convince you?

Perhaps creations like the digital C. elegans will start to break down our binary conception of the matter in the world as either living or not living. We'll discover that we can create systems that exist in-between these two spheres, or that certain aspects of life as we know it are not required to meet our definition of being alive.

"I suspect that we'll recognize that living systems are far-from-equilibrium molecular systems that are carrying out very specific sophisticated physical patterns and have some ability to sustain themselves over time," OpenWorm's organizer Stephen Larson wrote to me. "Thinking about it that way makes me go beyond a black and white notion of 'alive' to a more functional perspective -- living systems are those which self sustain. Our goal is to aggregate more of the biological processes we know that help the worm to self-sustain than have ever been aggregated before, and to measure how close our predictions of behavior match real living behavior, more than it is to shoot for some pre-conceived notion of how much 'aliveness' we need."