We're History: Back to the Future: Revisiting the Chemical Origins of Life Experiment in Chemical Engineering Progress
Stanley Miller in the lab, 1953. Image: Dept. of Chemistry and Biochemistry, UCSD.
July 1, 2010 - New York, NY
By Neil Gussman
In the middle of the 20th century, chemistry was cool. In that era, when polymers were the promise of the future and the Chemist's Club of New York had more than 4,000 members, chemistry was also big news.
In 1953, James Watson and Francis Crick (together with Rosalind Franklin) discovered the double-helix structure of DNA - that is, the chemical structure of DNA. Although the greatest result from that experiment was the empire of biotechnology, the hero ofthat story was chemistry.
An even bigger chemical news story at the time was the Miller-Urey Experiment. In April 2006, this column discussed the iconic experiment performed by a graduate student named Stanley Miller, studying under Nobel laureate Harold Urey. In 1 952, reporters worldwide wrote about the discovery of "life in the lab." Miller and Urey had designed a simple apparatus and had a simple list of ingrethents for the prebiotic atmosphere: ammonia, hydrogen, methane, and water. The result: in less than a week, they had identified 13 of 20 amino acids found in proteins, with 4% of the mixture - 10% to 15% of the carbon in the methane - converted to amino acids.
This famous experiment is now back in the news. Jeffrey L. Bada, distinguished professor of marine chemistry at the Univ. of California, San Diego (UCSD), will be recreating the Miller-Urey experiment to study how life could arise from amino acids, and also to show that the 1953 experiment had better results than either Miller or Urey knew.
In a May 2010 interview published in the New York Times "Science Times," Bada said he changed his area of study when he met Stanley Miller. "When I started in graduate school in 1 965, 1 had ideas about becoming a theoretical chemist," Bada said. "But when I arrived at UCSD, I met Stanley Miller, who'd been a student of Harold Urey. They completed the classic experiment on the chemical origins of life. They'd taken gases present on the early Earth like methane, ammonia and hydrogen and applied a spark discharge to them, to mimic lightning. From that, they produced amino acids, the compounds that make up the proteins in all living organisms. It was a stunning discovery. So when I met Stanley, I was hooked. I switched my thesis to work with him."
Forty years later, a chance remark led Bada to a carefully labeled box that contained results of the 1952 experiment. Miller had a stroke in 1999 and had given everything in his lab to Bada. In 2006, said Bada, "1 was giving a talk in Texas and someone there told me that he'd once seen the extracts of the experiment in a cardboard box in Stanley's laboratory. When I got back to San Diego, I asked my staff, 'When we moved everything from Stanley's office, did we get a little cardboard box?' And someone said, 'Yeah, it's right over there.'"
"Inside were all these tiny glass vials carefully labeled, with page numbers referring Stanley's laboratory notes. I was dumbstruck. We were looking at history. It immediately hit me that when Stanley had first done the experiment, analytic tools were still very primitive. We have instruments today that are a billion times better. So, we reanalyzed the original materials with the modem tools. And, Io and behold, we found that the spark-discharge experiment had actually made about 30 compounds."
Bada and his team plan to recreate the Miller-Urey experiment and use the latest analytical tools to show exactly what Stanley Miller's apparatus created. According to Philip Ball, author of Elegant Solutions: Ten Beautiful Experiments in Chemistry, the experiment illustrates the "beauty of simplicity" in experimental chemistry. When Bada recreates the experiment, we will learn just how productive a beautiful experiment can be.
When I wrote about the Miller-Urey experiment in 2006 (April, p. 64), I got enough responses to devote the next column (June 2006, p. 64) to answering those readers who asserted that the experiment was flawed. These readers were not attacking the apparatus, but the entire idea that life could have evolved from amino acids in a reducing atomosphere, or that life evolved at all. In the June 2006 column, I reported searching the phrase "Miller-Urey discredited" in Google. At the time I got more than 300 hits. I just searched the same phrase and got 4,840 hits. So the critics have made their objections more prominent on the Web....
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