The role of environmentally triggered genetic and epigenetic changes in microbial adaptation and evolution is still not broadly appreciated. Brave Genomes: Microbial Genome Plasticity in the Face of Environmental Challenge narrates how microorganisms cope with environmental changes including unanticipated ones. Although it does comprise eukaryotes, it focuses on bacteria and – whenever possible – on archaea.Among the environmentally sensitive sources of genome plasticity, the book treats tandem repeats, mutagenic break repair, transcription-associated mutagenesis and transposable elements. Additionally, it deals with epigenetic mechanisms such as DNA methylation and regulatory RNA-based systems. These not only regulate the activity of mobile DNA, they can also synergize with it. In closing, symbiosis and genetic noise are also discussed as possible sources of phenotypic plasticity.Brave Genomes emphasizes the role of the environment in generating genotypic and phenotypic diversity. This emerges, in turn, as the most efficient response to challenging conditions. - Compares environmentally sensitive genetic systems across the three kingdoms of life (bacteria, archaea, eukaryotes) - Compares environmentally sensitive epigenetic systems across the three kingdoms of life - Brings together insights of illustrious scientists including Josep Casadésus, Remus Dame, Cedric Feschotte, William Martin, Eva Jablonka, Eugen Koonin - Microbial symbioses and genetic noise are also treated as potential sources of phenotypic plasticity and adaptability together with more traditional sources - Familiarizes biologists with this discipline by using a colloquial style