The contributions to this book aim at understanding, from an evolutionary perspective, the impact of stress on biological systems. Scientists, applying different approaches spanning from the molecular and the protein level to individuals, populations and ecosystems, explore how organisms adapt to extreme environments, how stress changes genetic structure and affects life histories, how organisms cope with thermal stress through acclimation, and how environmental and genetic stress induces fluctuating asymmetry, shapes selection pressure and causes extinction of populations. Finally, the book discusses the role of stress in evolutionary change, from stress-induced mutations and selection to speciation and evolution at the geological time scale.