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Digital Life and Evolution
mrivorey writes "Discover Magazine has a story about The Digital Evolution Lab at Michigan State University. Scientists there have created virus-like computer programs that replicate, mutate randomly, and compete with each other... in other words, they evolve. Among such feats as learning to add and compare numbers, these digital life forms also once avoided scientists attempts at "killing" them, by playing dead.
You can download the project yourself from SourceForge." We first mentioned this in early 2003, but it appears to have developed a good deal since then.
TESTING DARWIN DISCOV ER, FEBRUARY 2005 (Cover story)If you want to find alien life-forms, hold off on booking that trip to the moons of Saturn. You may only need to catch a plane to East Lansing, Michigan. The aliens of East Lansing are not made of carbon and water. They have no DNA. Billions of them are quietly colonizing a cluster of 200computers in the basement of the Plant and Soil Sciences building at Michigan State University. To peer into their world, however, you have to walk a few blocks west on Wilson Road to the engineering department and visit the Digital Evolution Laboratory. Here you'll find a crew of computer scientists, biologists, and even a philosopher or two gazing at computer monitors, watching the evolution of bizarre new life-forms. These are digital organisms-strings of commands-akin to computer viruses. Each organism can produce tens of thousands of copies of itself within a matter of minutes. Unlike computer viruses, however, they are made up of digital bits that can mutate in much the same way DNA mutates. A software program called Avida allows researchers to track the birth, life, and death of generation after generation of the digital organisms by scanning columns of numbers that pour down a computer screen like waterfalls. After more than a decade of development, Avida's digital organisms are now getting close to fulfilling the definition of biological life. "More and more of the features that biologists have said were necessary for life we can check off," says Robert Pennock, a philosopher at Michigan State and a member of the Avida team. "Does this, does that, does this. Metabolism? Maybe not quite yet, but getting pretty close." One thing the digital organisms do particularly well is evolve." Avida is not a simulation of evolution; it is an instance of it," Pennock says. "All the core parts of the Darwinian process are there. These things replicate, they mutate, they are competing with one another. The very process of natural selection is happening there. If that's central to the definition of life, then these things count." It may seem strange to talk about a chunk of computer code in the same way you talk about a cherry tree or a dolphin. But the more biologists think about life, the more compelling the equation becomes. Computer programs and DNA are both sets of instructions. Computer programs tell a computer how to process information, while DNA instructs a cell how to assemble proteins. The ultimate goal of the instructions in DNA is to make new organisms that contain the same genetic instructions. "You could consider a living organism as nothing more than an information channel, where it's transmitting its genome to its offspring," says Charles Ofria, director of the Digital Evolution Laboratory. "And the information stored in the channel is how to build a new channel." So a computer program that contains instructions for making new copies of itself has taken a significant step toward life. A cherry tree absorbs raw materials and turns them into useful things. In goes carbon dioxide, water, and nutrients. Out comes wood, cherries, and toxins to ward off insects. A computer program works the same way. Consider a program that adds two numbers. The numbers go in like carbon dioxide and water, and the sum comes out like a cherry tree. In the late 1990s Ofria's former adviser, physicist Chris Adami of Caltech, set out to create the conditions in which a computer program could evolve the ability to do addition. He created some primitive digital organisms and at regular intervals presented numbers to them. At first they could do nothing. But each time a digital organism replicated, there was a small chance that one of its command lines might mutate. On a rare occasion, these mutations allowed an organism to process one of the numbers in a simple way. An organism might acquire the ability simply to read a number, for example, and then produce an identical output. Adami rewarded the digital organisms by speeding up the time it took them to reproduce. If an organism could read two nu
I, for one, welcome our new digital masters...