A lifelong reptile enthusiast, Jonathan Losos is driven in part by his passion for a group of lizards called anoles, which thrive in South and Central America and throughout the Caribbean. He also views them as an opportunity. Almost half of the 400 anole species live on islands, and their diverse lifestyles, habitats, and histories have proved to be a vehicle for exploring some of evolution’s biggest questions. “Jonathan’s islands are like giant test tubes, and he is the ultimate tinkerer,” says Martha Muñoz, an evolutionary biologist at Yale University. Losos’s research on anoles has shown that evolution can happen faster than most scientists had assumed, and that — contrary to what some leading thinkers have proposed — it is often predictable. Faced with similar challenges, separate populations often evolve similar solutions.