The Origins of Life- page 2 | Science | Smithsonian
A fossil collector since childhood, Bob Hazen has come up with new scenarios for life's beginnings on earth billions of years ago. (Amanda Lucidon)

The Origins of Life

A mineralogist believes he's discovered how life's early building blocks connected four billion years ago

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Rocks have texture, whether shiny and smooth or craggy and rough. Molecules on the surface of minerals have texture, too. Hydrogen atoms wander on and off a mineral’s surface, while electrons react with various molecules in the vicinity. An amino acid that drifts near a mineral could be attracted to its surface. Bits of amino acids might form a bond; form enough bonds and you’ve got a protein.

Back at the Carnegie lab, Hazen’s colleagues are looking into the first step in that courtship: Kateryna Klochko is preparing an experiment that—when combined with other experiments and a lot of math—should show how certain molecules stick to minerals. Do they adhere tightly to the mineral, or does a molecule attach in just one place, leaving the rest of it mobile and thereby increasing the chances it will link up to other molecules?

Klochko gets out a rack, plastic tubes and the liquids she needs. “It’s going to be very boring and tedious,” she warns. She puts a tiny dab of a powdered mineral in a four-inch plastic tube, then adds arginine, an amino acid, and a liquid to adjust the acidity. Then, while a gas bubbles through the solution, she waits...for eight minutes. The work may seem tedious indeed, but it takes concentration. “That’s the thing, each step is critical,” she says. “Each of them, if you make a mistake, the data will look weird, but you won’t know where you made a mistake.” She mixes the ingredients seven times, in seven tubes. As she works, “The Scientist” comes on the radio: “Nooooobody saaaaid it was easyyyy,” sings Coldplay vocalist Chris Martin.

After two hours, the samples go into a rotator, a kind of fast Ferris wheel for test tubes, to mix all night. In the morning, Klochko will measure how much arginine remains in the liquid; the rest of the amino acid will have stuck to the mineral powder’s tiny surfaces.

She and other researchers will repeat the same experiment with different minerals and different molecules, over and over in various combinations. The goal is for Hazen and his colleagues to be able to predict more complex interactions, like those that may have taken place in the earth’s early oceans.

How long will it take to go from studying how molecules interact with minerals to understanding how life began? No one knows. For one thing, scientists have never settled on a definition of life. Everyone has a general idea of what it is and that self-replication and passing information from generation to generation are key. Gerald Joyce, of the Scripps Research Institute in La Jolla, California, jokes that the definition should be “something like ‘that which is squishy.’”

Hazen’s work has implications beyond the origins of life. “Amino-acids-sticking-to-crystals is everywhere in the environment,” he says. Amino acids in your body stick to titanium joints; films of bacteria grow inside pipes; everywhere proteins and minerals meet, amino acids are interacting with crystals. “It’s every rock, it’s every soil, it’s the walls of the building, it’s microbes that interact with your teeth and bones, it’s everywhere,” Hazen says.

At his weekend retreat overlooking the Chesapeake Bay, Hazen, 61, peers through binoculars at some black-and-white ducks bobbing around in circles and stirring the otherwise still water. He thinks they’re herding fish—a behavior he’s never seen before. He calls for his wife, Margee, to come take a look: “There’s this really interesting phenomenon going on with the buffleheads!”

Living room shelves hold things the couple has found nearby: beach glass, a basketful of minerals, and fossilized barnacles, coral and great white shark teeth. A 15-million-year-old whale jawbone, discovered on the beach at low tide, is spread out in pieces on the dining room table, where Hazen is cleaning it. “It was part of a living, breathing whale when this was a tropical paradise,” he says.

Hazen traces his interest in prehistory to his Cleveland childhood, growing up not far from a fossil quarry. “I collected my first trilobite when I was 9 or 10,” he says. “I just thought they were cool,” he says of the marine arthropods that went extinct millions of years ago. After his family moved to New Jersey, his eighth-grade science teacher encouraged him to check out the minerals in nearby towns. “He gave me maps and he gave me directions and he gave me specimens, and my parents would take me to these places,” says Hazen. “So I just got hooked.”

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