Jonathan B. Losos’s Improbable Destinies: Fate, Chance & the Future of Evolution is an expansive, experiment‑driven look at one of evolutionary biology’s biggest questions: is evolution predictable, or does it hinge on contingency and accident. Losos surveys decades of research—from classic natural experiments to modern lab‑based evolution studies—to show how both repeatability and randomness shape life. He explores lizards adapting on islands, microbes evolving in controlled environments, and species responding to rapid ecological change, arguing that evolution is neither wholly deterministic nor wholly chaotic but a dynamic interplay of constraint, opportunity, and chance. The book is both scientific and narrative, illustrating how experimental evolution is transforming our understanding of life’s pathways.