The concept of randomness is caught up in evolution, in two broad ways. The first and most famous aspect is the oft-misunderstood randomness of mutation. The second aspect is the role of chance in the trajectory of evolution. It is this question—is evolution predictable, or is it a random "drunkard's walk"—that Conway Morris tackles in the second chapter of From Extraterrestrials to Animal Minds: Six Myths of Evolution.