Origin & Evolution of Life -- The Fact of Life -- Historical Review of the Origin of Life and Astrobiology -- In the Beginning -- The Standard Scenario -- The Chemistry of Life's Origins -- Prebiotic Amphiphilic Compounds -- Theoretical and Computational Approaches to the Study of the Origin of Life -- The HCN World -- The Possible Role of Volcanic Lightning in Chemical Evolution -- Chemistry in Prebiotic Aerosols: A Mechanism for the Origin of Life -- Alternatives to the Standard Scenario -- Prebiotic Interplay Between Fatty Acids and Amino Acids in Hydrothermal Environments -- The Role of Clays in the Origin of Life -- Organomineralization -- The First Steps of Biological Evolution -- Role of Nucleotide-Like Coenzymes in Primitive Evolution -- Cosmic Thermobiology -- Paradigm Completion for Generalized Evolutionary Theory with Application to Epistemology -- The First Cells -- The Outlines Of Bacterial Evolution -- Cell Wall Structures of Mesophilic, Thermophilic and Hyperthermophilic Archaea -- Potential Role of Dissimilatory Iron Reduction in the Early Evolution of Microbial Respiration -- The Evolution of Lipids in Prokaryotes -- Calcium Build-up in the Precambrian Sea -- The Viral Eukaryogenesis Theory -- Extremophiles & Biodiversity -- To The Extremophiles -- Alkalithermophiles: A Double Challenge From Extreme Environments -- Halophilic Microorganisms: Physiology and Phylogeny -- Adaptation of Bacteria to the Terrestrial Permafrost Environment -- Phototrophic Bacteria Under UV Stress -- Importance of Chemolithotrophy for Early Life on Earth: The Tinto River (Iberian Pyritic Belt) Case -- Glacial Periods on Early Earth and Implications for the Evolution of Life -- The Evolutionary Ecology of Species Diversity in Stressed and Extreme Environments -- Microbial Diversity in Meso-Neoproterozoic Formations, with Particular Reference to the Himalaya -- Microbial Biodiversity within the Vibrionaceae -- Distribution & Destiny of Life in the Universe -- Comets and the Origin of Life on the Primitive Earth -- Evaluating Comets as A Source of Earth's Water -- From Microbial Fossils to Astrobiology -- Organisms in Extreme Environments: From the Origin and Early Evolution of Life on Earth to Astrobiology -- A Brief Geological History of Water on Mars -- Evolution of the Martin Water Inventory -- Possible Biogeochemical Cycles on Titan -- Astrobiology's Last Frontiers. Origins: Genesis, Evolution and Biodiversity of Microbial Life in the Universe is the sixth unit of the book series Cellular Origins, Life in Extreme Habitats and Astrobiology (COLE) edited by Joseph Seckbach. In this book forty eminent scientists review their studies in the fields of Life from the beginning to the "Fact of Life". The history of Origin of Life and Astrobiology is well covered by these authors. Reviews cover the standard and alternative scenarios of the genesis of Life, while the chapters of "The First Cells" leading to the biodiversity and extremophiles of microbial Life. Among these extremophiles are the microbes living in the Life's limits, such as in high temperature, psychrophilic, UV radiation, and halophilic environments. The origin and history of Martian water is discussed followed by the possible biogeochemistry inside Titan. This new field of Astrobiology has been presented, from comets as a source of materials and Life on earth to the space for last Frontiers.