Writing in Z+Blog, Andrew Zolli describes a circuit developed an unorthodox way. Rather than devising it from scratch, researchers "simulated biological evolution by testing, mating and mutating more than 4000 generations of circuit designs. A set of instructions called a 'fitness function' killed off inefficient designs and mated efficient ones, mimicking the effects of natural selection."
One side effect of the method: It took months for the team to figure out how the resulting mechanism worked. "The evolutionary approach exploited what was there in ingenious and intricate ways," Zolli notes, "including properties of the chip its inventor couldn't even measure at the time of the experiment. Ultimately, to figure out what was going on, he had to use the kinds of techniques that biologists use to understand the nervous systems of simple animals."
Programmers have been generating software this way for years. Now, apparently, evolution is coming to hardware. "As engineers act less on planning the specifics of the design," Zolli writes, "and more as artificial selectors of the end product, engineering begins to look less and less like architecture, where one designs from the foundation up, and more and more like gardening, where one directs forces only partially under one?s direct control."