Life in A Bubble

By | April 21, 2021

Excerpt from Environment by Rolf Halden

The odds of being alive are so incredibly slim. Humble beginnings some 3.8 billion years ago on a rocky planet that, ejected by the Big Bang, found its place just right in a Goldilocks distance from the sun, a location perfectly suitable for the miracle we call life.

Initially our planet’s chemical inventory was limited to elemental building blocks tallied on the periodic table and arranged into basic minerals—like the rock I was holding on to, part andesite, part dacite. But long before this, way back near the beginning, the random assortment of matter soon began to swell as a result of physical-chemical reactions, transformation, and weathering. Rocks dissolved into water and, by releasing carbon dioxide, sulfur, and nitrogen, formed a primordial stew—precursors to what we would come to call “life.”

Random electrical discharges on this barren planet’s surface gave rise to amino acids, short strings of carbon atoms that, decorated with hydrogen and nitrogen appendices, became simple three-dimensional structures. Soon, the stringy amino acids combined by chance to form more complex corkscrew helices and stacks of sheets, giving rise to the first proteins, the macromolecules that catalyze most reactions in what we recognize as the “environment.”

After enough amino acids formed and combined by chance, a miracle sprang from the dilute, primordial soup. So, “life” began, a rudimentary membrane, not yet fit to recreate itself, a first take on cellular life.

But it perished soon after birth. Like a spark unable to find kindling, unable to start the fire burning in each of us. It happened again. And again. Until futile bursts of randomness, ongoing maybe for millions of years, turned into self-replicating cells. A second miracle, capable of sustained life, commenced—and endured.

Initially, our cellular progenitors only managed to increase in abundance, occupying more and more of the habitable space. The tiny creatures clung to rocky surfaces on Earth—not so unlike hapless me, clinging to the vertical rock face in the icy Andes so many years later.

But then these tiny creatures started a revolution, driven by the opportunity to coexist, cohabitate, and cooperate.

They became one, a remarkable success and inspiration—something our species has yet to emulate. Here’s what happened: They were just two cells, primed to compete fiercely for limited resources and living space. But instead of competing, they took an alternative path, and by doing so, invented new possibilities in the adventure of survival. One swallowed the other—but without destroying it. Two monocellular organisms unexpectedly merged into a single living organism, in an instant.

Rather than fighting each other, they began to cooperate. They divided essential chores, the bigger one creating an internal habitat for the other; and the small intruder in turn becoming a biochemical energy plant, known as a mitochondrium, powering the newly sprung cellular union. Then it happened again, this time giving rise to chloroplasts, the locus of modern photosynthesis. This happened about 1.5 billion years ago.

The gamble of cellular cooperation and co-inhabitation paid off in multiple, unexpected ways, creating an explosion of new possibilities. The newly formed eukaryotic cells, containing first a single and soon multiple mitochondria, were compartmentalized by membranes and contained a nucleus harboring their genetic blueprint. They began to rule our early world. From singular to multicellular designs, one new model after another ran off this assembly line of life: molds, mollusks, mammals, monkeys, and mankind. And the factory work is not complete.

Our cellular forebears paved the way for a comfortable future for humans, by inventing a supportive machinery that harvests energy contained in sunlight, an essentially unlimited source of power that freely traverses outer space to visit and penetrate us.

This was and continues to be the good fortune of a planet bathing in seemingly eternal sunshine.

Harvesting light energy to split water made all the difference for the future of life. Bacteria deserve credit not only for inventing the process of photosynthesis but also for the art of harvesting the energy contained in light and directing it at, and splitting, water.

The water-busting process released oxygen into the atmosphere. One by one, each water molecule split into two hydrogen atoms and one oxygen atom. Two oxygen atoms held hands, forming molecular oxygen, or O2—the quintessence of our atmosphere, and what we breathe today. Algae swalled the photosynthetic bacteria and adopted the art of photosynthesis and water splitting to soon evolve into plants that perform these tasks both in water and on land.

Rolf Halden, PhD, PE, is Director of the Biodesign Center for Environmental Health Engineering, Biodesign Institute, Professor in the School of Sustainable Engineering and the Built Environment, and Senior Sustainability Scientist at the Global Institute of Sustainability at Arizona State University, USA. Professor Halden’s scientific discoveries and opinions have been covered in documentaries, radio shows, podcasts, and media outlets, including the New York Times,Wall Street JournalTime, Scientific American, and Forbes. He serves on the Expert Team of the American Chemical Society and has been invited repeatedly to brief decision-makers at the U.S. Environmental Protection Agency, the Food and Drug Administration, the National Academies, and members of U.S. Congress on issues pertaining to environmental health and sustainability. Environment is part of the Object Lessons series.

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