Darwinian evolution is being put to the test by a team from Michigan State University, the California Institute of Technology and the University of California in Los Angeles. Researchers hope that computer organisms will shed light on the most fundamental questions about life on Earth. The programme is designed to mimic life in the form of relatively simple organisms that can multiply and will randomly mutate. The computer organisms will be judged on their reproductive success, the key to survival in a Darwinian model of evolution. Professor Lenski, from MSU commented: "If we do see the same patterns [as in the world] this suggests that these patterns are general properties of life, be it organic or digital. And if we get strikingly different patterns, this raises interesting new questions, about why one self replicating system behaves this way, while another behaves some completely different way." The programme consists of two kinds of digital organism, a simple one whose role is only to reproduce, and a more complex one which must reproduce, but also perform some calculations along the way. The environment that the 'bugs' exist in can be changed by the team to see how they adapt. Successful species will be rewarded with more computer time. The experimental timescale offered by this programme is rather more convenient than waiting several millennia to test Darwin's ideas. ®