Life Beyond Sight: The microbial earth, brought into view

Jonathan Shaw in Harvard Magazine:

In rocks and soil, air, ponds and oceans, life is dominated by creatures that humans cannot see. Microbes thrive everywhere, from gardens and kitchens to the harshest environments on the planet: under polar ice, in hydrothermal vents at the bottom of the sea, in hot springs that spew acid. A single gram of soil teems with billions of them, and their genetic diversity is equally impressive, dwarfing that of all the plants and animals on Earth. Life at the Edge of Sight: A Photographic Exploration of the Microbial World (forthcoming from The Belknap Press of Harvard University Press), brings the planet-shaping diversity of these single-celled, microscopic organisms into view through stunning images. Co-authors Roberto Kolter, professor of microbiology and immunology, and Scott Chimileski, a research fellow in microbiology and immunology at Harvard Medical School, share their passion for the subject in part by magnifying what cannot be seen unaided, in part by revealing large-scale microbial impacts on the landscape. Kolter has long been a leader in microbial science at Harvard, while Chimileski brings to his scholarship a talent for landscape, macro, and technical photography.

Humanity, they note in the preface, is a fleeting presence in the four-billion-year-old story of life on the planet. Microbes, on the other hand—omnipresent and abundant beyond comprehension—have dominated that story for three billion years. In fact, microbes have written it, forming rocks and giving rise to the oxygen in the atmosphere, and underpinning many other atmospheric and geological processes that can span millennia. In crafting a human-scale narrative, the authors remind readers that the local ecology of microbes is closely tied to health: most germs protect people by keeping harmful microbes in check, boost access to nutrients in food, and only rarely cause disease—not surprising, because genus Homo evolved in a microbial world. Humans have even domesticated some microbes, albeit unwittingly for most of history: in the fermentation of wine, or the culturing of cheese. From these familiar examples, the authors pivot to specimens so bizarre that they seem almost extraterrestrial: single-celled intelligent slime molds (cabbage-sized, or larger) that can crawl along a decaying log at five centimeters an hour, or a “humongous fungus,” covering 10 square kilometers in Oregon, that lives in the soil and reaches up into trees, fruiting from under the bark as mushrooms each autumn. The mutability and generative force of microbes are so great, in fact, that Kolter and Chimileski assert that if life exists in distant galaxies, microbes are almost certainly involved.

More here.