Textbook evolutionary theory holds that evolutionary change occurs gradually. It may speed up or slow down but change, when it occurs, takes small steps. But from the fossil record to observed adaptations in the field, biological data do not always cooperate with theory. In fact, populations do respond dramatically to environmental challenges in a time window measured in years—not millions of years—and single mutations or the management of existing genes effect such responses. A review from last week, entitled Revenge of the hopeful monster, summarized the situation as follows: Read more