Cellular automata (self-modifying software "robots") in an evolutionary computing simulation spontaneously began to exhibit altruism, sacrificing themselves for the good of their relations. The researchers were trying to confirm W. D. Hamilton's theory that altruism allows individuals to indirectly pass on their genes.

Once the team was comfortable with the virtual evolution environment it had set up, it added a new twist: It allowed the robots to share food disks with each other. If Hamilton's hypothesis was correct, "successful" virtual robots were likely to be those that were closely related and shared food with each other; that would help to ensure that at least one of them — and some of the genes of both–would make it to the next round. (Two robots with a modest amount of food disks would both be more likely to be cut from the simulation, but if one robot gave all of its food to a second robot, that second robot would likely make the next round.) And indeed, altruism quickly evolved in the simulation, with greater food-sharing in groups where robots were more related, the researchers report online today in PLoS Biology. The more closely related the robots, the quicker they cooperated. "It shows how general the [theory] is, whether you are an insect, a human or a robot," says Floreano.

For reasons I don't entirely understand, the researchers also used real robots and modified them periodically to match the mutations that emerged in the software simulation (don't get me wrong, building robots is its own justification, of course, but I don't understand the sciencey reasoning)

Even Robots Can Be Heroes

(via /.)