by Merry Youle
Darwin focused his attention on visible life forms…and there the evolutionary focus remained until recent decades when the microbes seized the limelight. The American Academy of Microbiology (ASM’s honorific leadership group) acknowledged this overdue shift two years ago, on the 150th anniversary of publication of On the Origin of Species. The AAM brought together 34 microbiologists with diverse specialties to participate in a colloquium held in the Galapagos Islands (where else?). What, they collectively wondered, would Darwin have made of the microbial world?
Some answers are shared in the colloquium report recently published by the AAM. For readers of this blog, already among the converted, the report provides a cogent summary of the importance of microbial evolution for all life on Earth—past, present, and future. The report’s clear and attractive presentation makes it also well-suited for use when proselytizing to those who tend to ignore The Small Things. As you would expect, it reminds us that for billions of years, microbial evolution was the only evolution, and that today most of the extant biological diversity is microbial. Further, it points out that many of the mechanisms driving the evolution of both macrobes and microbes were discovered by studying the latter. Studying microbial evolution is also useful in a practical sense as we seek new ways to tailor microbes for our own purposes (e.g., controlling disease, biosynthesis of useful materials, bioremediation). Despite methodological advances, these studies remain challenging due to the vast diversity of the microbes, their rampant gene swapping, and their ability to adapt at both the individual and community level.
This research takes on an added importance today because of the key role of the microbes in modifying and maintaining the global systems that support life on Earth. As we go purblindly about perturbing environmental systems in countless ways, some are asking: How resilient are these systems? How will the microbes respond? In the tradition of these colloquia, the report concludes with well-founded recommendations for how to pursue the answers. Key current research questions are highlighted, as well as potentially fruitful research directions. In brief, the report reminds us that if you want answers to such questions, ask the microbes.