Computerized mass extinction.

Computerized mass extinction 

Paleontologist James W. Valentine of the University of California at Santa Barbara used his computer to create and then kill off hundreds of animal species. Valentine wasn't just pretending to be a supreme being. He wanted to figure out whether the five great mass extinctions have been random or whether they affected some geographic areas or some kinds of animals more than others. From Valentine's results, it appears that mass extinctions have been random, he says.

Valentine first created in his computer an imitation world of species in various taxonomic groups, and then he performed three kinds of mass extinctions--one in which he killed off 85 percent of the species at random, one in which he hit 85 percent in a contiguous region, and a third in which he killed half of all the species in the four oldest taxa (which amounted to about 79 percent of all his species). He then looked at the profile of species left over after each trial and compared them with the real species profiles at the end of each of the five mass extinctions. "We found that the real events closely resemble random treatment profiles, and not the other two,' he reports.