'One of the best books on evolutionary biology for a broad readership ever written' Edward O. Wilson

A dazzling tour of evolution in action that sheds light on one of the greatest debates in science

The natural world is full of fascinating instances of convergence: phenomena like eyes and wings and tree-climbing lizards that have evolved independently, multiple times. Convergence suggests that evolution is predictable, and if we could replay the tape of life, we would get the same outcome. But there are also many examples of contingency, cases where the tiniest change - a random mutation or an ancient butterfly sneeze - caused evolution to take a completely different course.