Until recently, it might have seemed impossible. Some scientists estimate that 90 percent of Earth’s species have not yet been identified; you’d need an enormous army of well-equipped biologists working night and day to even make a dent in that figure. But evolutionary biologist Paul Hebert of the University of Guelph in Ontario believes that he has found a way of accelerating the process. He has discovered a “bar code” embedded in the DNA of all animal life, from bacteria to monkeys, that functions like a fingerprint.