The Relevance and Challenges of Studying Microbial Evolution

The evolution of microbes had been underway for about 3 billion years, covering much of the earlier evolutionary history of life. Many of the genes, molecular machines, regulatory, metabolic, and synthetic pathways found in all living organisms today evolved first in microorganisms. Even now, most of the biodiversity of life on Earth is microbial. The great diversity of microbes allows them to synthesize or break down a vast range of chemical substrates and govern biogeochemical cycles that make Earth a habitable planet. As such, microbes are essential to Earth’s functioning at every scale, and understanding them is essential for a complete understanding of life. As a brief introduction to this book, herein I highlight some of the reasons why understanding how microbes evolve is important to science and society and how challenging is to study microbial evolution.