BELIEVE IN EVOLUTION? Hell, I’ve seen it done! “In that time, the bacteria have changed significantly. For one thing, they are bigger — twice as big on average as their common ancestor. They are also far better at reproducing in these flasks, dividing 70 percent faster than their ancestor. These changes have emerged through spontaneous mutations and natural selection, and Dr. Lenski and his colleagues have been able to watch them unfold. When Dr. Lenski began his experiment 18 years ago, only a few scientists believed they could observe evolution so closely. Today evolutionary experiments on microbes are under way in many laboratories.”