Deep in the open-chambered springs of Yellowstone National Park, life colorfully covers itself across the safety of secluded landscapes — an image I’m sure must haunt watercolorists who were never able to capture it in all of its magnificence. Behind billowing blankets of steam lifting skyward every morning, life truly lives on the edge of survival here. Or does it? Whether from a distance or nearby, it’s impossible not to see the conglomeration of hundreds of billions of seemingly ostentatious microorganisms, known as “extremophiles,” that line the hot spring’s runoff channels, filling them with extravagant colors in an environment that was once thought to be too extreme for life to grow, develop or reproduce. Ecologists now recognize that we are only just beginning to understand how these organisms have adapted to live in such harsh environments. I can’t help but to wonder whether the secret to the birth of life is encoded somewhere within these distantly related extremophiles.
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This past summer, while attending the University of Michigan’s western-most campus in the Rocky Mountain range of Jackson Hole, Wyo., 24 students and I learned a great deal about how the geology of a region shapes and modifies the ecology present. About halfway through the summer semester, our class traveled to Yellowstone National Park for three days of field observations. One morning we traveled to the Midway Geyer Basin. It was here that I found myself rapt in the spring’s warm veils of vapor as they erupted into the sky, as if the clouds themselves were generated on Earth in these open havens — a sight more marvelous than, dare I write, Old Faithful.
“To be honest,” Earth and Environmental Sciences Prof. Joel Blum stated with a sly smile, “There is no better place to study geology and ecology than right below your feet.” We had been walking on an elevated bridge as to not damage the fragile, yet smoldering, rock surface below, when I had noticed one hot spring in particular: the Grand Prismatic Spring. While the size alone is impressive (it is the largest hot spring in the United States), what sets this juggernaut of a spring apart from others is the array of life that clings to the spring’s fringe and surrounding, outflowing paths, as if the assortment of microorganisms were the white light cast by the refraction through an optical prism. Red, orange, yellow and green were the resulting shades of the residing extremophiles while at the center of the spring itself laid the sharpest and most contrasting blue I had ever seen.
Prof. Blum was right. I was only able to observe how captivating the landscape adjacent to the Grand Prismatic was when the sun rose, further increasing both the heat of the ground and the heat of the atmosphere. The haste of the climbing clouds eventually subsided, which in turn illuminated the ebb and flow of groundwater at the spring’s edge. Beating pulsations from under the gaping hole of the Earth flung water out and into the spectrum of life, and there was no immediate or apparent trend for the panorama presented in front of me. Magnificent reds swirled around orange and yellow blooms while dingy-brown and neon greens emptied into the river’s channels. I knew that what I was observing was a living mosaic of organisms suited to its particular environment; I just could not find the trend.
But there was a pattern. Minute differences in elevation at the foothold of the Grand Prismatic spring regulated which species of bacteria could outcompete and thrive best within equally minute differences in temperature. Where some extremophiles pooled in cool-temperature water, areas tended to be lush in emerald. In other areas where molten magma was just meters away from the Earth’s surface, hotter rock temperatures limited which bacteria could sustain populations. Where these extremophiles pooled in high-temperature water, areas tended to be set ablaze with fiery red. The happy medium extremophiles, represented by a stained deck of orange and yellow, found refuge underneath waters that filtered over the thick crust in areas ‘not too hot’ but ‘not too cold.’ The pattern was a highway-like construction of life that layered itself almost too perfectly between the surface of the ground and the surface of the water. It was another Earth.
I wrote in the beginning that I imagine there must be a haunted watercolorist somewhere out in the world that was never able to capture the Grand Prismatic’s decadence. I say this with confidence because to paint the landscape would be to gloss over the eccentricities of the magnificent showcase of life. If I were a painter, I would find frustration in even the smallest paintbrush I owned, for the bristles alone would be larger than an entire colony of red extremophiles fighting the battle to keep their home.