SCIENTISTS HAVE FOUND The makeup and function of thousands of genes in creatures from bacteria to rats. And because evolution tends to preserve traits that work, many of these genes have human cousins. But identifying the human version isn't easy. Genes aren't an unbroken stretch of DNA text, like a movie. They're more like TV shows, with each segment of information surrounded by ads--what researchers call genetic garbage. Both the length of segments (called exons) and the amount of "trash" can vary dramatically from species to species.
Existing software programs already find human genes by looking for DNA sequences that are similar to those in animal genes. But Russian mathematicians, including one working at the University of Southern California, have devised a potentially better way. Their approach divides up strings of animal DNA many different ways, then looks for the combination of pages and surrounding garbage that produces the best fit with the unknown DNA. In some tests, the method's accuracy rate is near 100%.