Portland State Magazine Fall 2016

FALL 2016 PORTLAND STATE MAGAZINE 11 “The origin of life was almost certainly something like that,” he says. “You had the right conditions for molecules to start aggregating and reacting, causing more reactions and leading to a runaway event. In the case of a tornado, it’s a wind funnel. In the case of life, it’s a replicative system.” Lehman, who has been working on the science behind the origins of life for nearly 20 years, recently received a $600,000 grant from the John Templeton Foundation as part of its mission to answer “Big Questions” in science—the basic forces, concepts, and realities governing the universe and humankind’s place in the universe. Lehman’s approach is different from conventional thinking about life origins in which a single molecular accident became the spark from which all subsequent life flowed. Lehman believes that multitudes of events happened, all involving chemical attractions and the networks they formed. “My approach is new, which is why I got funded,” Lehman says. “I think the key is network cooperation. The question is when and how do these chemicals become life?” Lehman is testing his theory on RNA molecules, which play an essential role in life, but only if they’re paired with other molecules. His previous work demonstrated that RNA molecules can form simple triangles. His newest research will build on that to see if they can create complex networks. Doing so involves the daily pipetting of solutions containing strands of RNA from one test tube to another, week in and week out, and measuring how they react with each other. The process is unglamorous, says Lehman, but that’s what you have to do to answer the question mankind has been asking itself for millennia: where did we come from? THE ORIGIN and evolution of genetic code has been an interest of Lehman’s since he was a chemistry undergrad at University of California – Berkeley in the early 1980s. “How did organisms settle on this one particular genetic code? The fact that every living thing uses the same code is strong evidence that all life shared a common ancestry,” he says. His other inspiration was his mother, who was interested in the creation myths of different cultures and shared that interest with her son. Just about every culture has a creation myth. Adam and Eve and the Garden of Eden is just one of hundreds. “If you think about it, the creation myth that we scientists think about is the chemical origins of life,” Lehman says, explaining that in the beginning there was just chemistry, and at some point chemistry became biology. “Once I thought of it in that way, I thought I’d be pretty lucky to study that,” he says. MUCH OF Lehman’s research during his career has been funded by NASA, which began a broad-based effort to learn about life beyond Earth soon after it was established in 1958. Space has been a factor in the origins of life discussion for decades. Scientists believe that much of the Earth’s water could have come from passing near the tails of comets, which are essentially big balls of ice. And, Lehman says, organic materials—the building blocks of life— may have been delivered by meteorites. “People have detected amino acids and nucleotides on meteorites, as well as sugars, lipids and all kinds of things we associate with life,” he says. If life originated once that organic material reached Earth, it could have easily been snuffed out by the bombardment of more meteorites, which happened constantly in the planet’s early existence. What most likely happened, he says, is that life started and was exterminated several times before it finally took hold. “That’s why I always say the ‘origins’ of life rather than the ‘origin’ of life, because it probably happened multiple times. That’s not to say life itself came from outer space, just some of the building blocks. But the idea was batted around with some seriousness in the 1960s, when scientists found themselves stumped by the chemistry of life puzzle. One theory, espoused by Nobel Prize-winning scientist Francis Crick, proposed that life originated elsewhere and was purposely spread by an advanced extraterrestrial civilization. “Nobody really knows if he was joking, but it came at a time when scientists were stuck,” Lehman says. “A lot of people still talk about it, but serious people in the origins field don’t.” For one thing, scientists are less stuck now. They’re closing in on what likely happened when the Earth was “only” about 500 million years old—a time when the atmosphere was made up of nitrogen, ammonia, carbon dioxide and methane. There’s considerable agreement about what happened, even among scientists who disagree about “how.” “We’re pretty close to having a unified theory. We’ll never know the answer for sure; you’d have to have a time machine for that,” he says. “The best we can do is come up with a plausible sequence of events. If we did, then I think we would have accomplished something very important for humanity.” John Kirkland is a staff member in the PSU Office of University Communications. Professor Niles Lehman’s new approach to the study of life’s origins earned him a Science and the Big Questions grant.