Despite of the fact that the name Microbial genome plasticity was coined 80 years ago by Conrad Waddington and that nucleoid associated proteins have been known since the 80s, epigenetics is still less familiar than genetics, especially among microbiologists. Although excellent books are already available on molecular and genome evolution, of both eukaryotes and bacteria, there is no published book on how global or segmental mutations, epigenetic mechanisms and symbiosis change prokaryotic chromatin and how these changes may allow prokaryotes to survive. Microbial genome plasticity narrates through a colloquial style and "real life" examples how microorganisms cope with environmental changes including unanticipated ones. Although it does comprise eukaryotes, it focuses on bacteria and (as much as possible) on archaea, and on the genetic and epigenetic strategies they evolved to endure environmental instability and the attacks of alien nucleic acids. While reading Microbial Genome Plasticity: A Microscopic Look at the Modern Synthesis , the reader will growlingly realize that the environment not only selects genetic variants, but it also contributes to their generation in a way that is not always random. Therefore, they will come to appreciate the role of the environment in biological evolution is greater than the one envisioned by what is still the most successful theory of evolution, the Modern Synthesis.