Stanley Miller
Stanley Lloyd Miller, born on March 7, 1930, in Oakland, California, was a renowned American chemist best known for his groundbreaking work on the origins of life. He completed his undergraduate studies at the University of California, Berkeley, and pursued graduate studies at the University of Chicago, where he was influenced by physicist Edward Teller and Nobel laureate Harold C. Urey. Miller's most notable experiment, conducted in collaboration with Urey, simulated early Earth's reducing atmosphere, leading to the synthesis of amino acids, which are fundamental building blocks of life. This research provided significant insights into prebiotic chemistry and sparked interest in the conditions that may have led to life on Earth and beyond.
In 1960, he helped establish the Chemistry Department at UC San Diego, where he continued to explore exobiology, studying life on other planets. Miller published influential works, including a book on the origins of life, and received recognition such as the Oparin Medal in 1983. His ideas, while influential, were met with alternative theories regarding the origins of life, particularly from chemist Günter Wächtershäuser. Miller's legacy persists through ongoing research that builds upon his findings, including recent discoveries of additional amino acids in his original samples. He passed away on May 20, 2007, leaving a lasting impact on the fields of chemistry and astrobiology.
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Stanley Miller
American chemist
- Born: March 7, 1930; Oakland, California
- Died: May 20, 2007; National City, California
American chemist Stanley Miller opened new avenues of inquiry into the origins of life when he published the results of a groundbreaking experiment showing how amino acids, the building blocks of life, could have formed on primitive Earth.
Primary field: Chemistry
Specialty: Organic chemistry
Early Life
Stanley Lloyd Miller was born on March 7, 1930, in Oakland, California. His mother, Edith, was a teacher, and his father, Nathan, was a lawyer who worked in the district attorney’s office of Alameda County. Miller’s older brother, Donald, also became a chemist.
Miller earned his bachelor’s degree in 1951 from the University of California, Berkeley, which was known for its strong chemistry department. He continued on to graduate school at the University of Chicago, where he studied under physicist Edward Teller, known as the father of the hydrogen bomb. Miller was interested in the chemistry of stars, an area of study that would be the focus of much of his later work—although, due to Teller’s departure from the university, it would not be his thesis topic.
In 1951, Miller attended a lecture given by physical chemist Harold C. Urey, who had won the Nobel Prize in Chemistry in 1934. In the lecture, Urey posited the idea that early Earth had a reducing, rather than oxidizing, atmosphere and suggested that someone might experiment with prebiotic chemistry under those conditions. Having been suddenly left without a thesis adviser, Miller approached Urey, suggesting an experiment based on the ideas in Urey’s lecture. Urey was skeptical, but he agreed to work with Miller on the project for six months to a year.
Life’s Work
The experiment Miller designed while working with Urey operated on the assumption that early Earth had a reducing atmosphere composed of methane, ammonia, hydrogen, and water. An oxidizing atmosphere is what exists on Earth today, and it produces familiar chemical reactions, such as the rusting of metal, in which organic compounds are broken down when oxygen is added to them. In a reducing atmosphere, there is little to no oxygen, which means that organic compounds can build up instead of being destroyed.
Miller built an apparatus to circulate the gases thought to have been present in this reducing atmosphere past an electrical discharge, simulating the hypothetical ocean-atmosphere system of early Earth and the lightning storms thought to be common at the time. After a period of days, he took samples of the substances that had been created and ran a paper chromatography test, which identified the substances as various amino acids, including glycine. Samples taken after a longer period of time showed even more amino acids. From inorganic substances, Miller had created the building blocks of life.
He received his PhD in 1954 but continued his research, first as a Frank B. Jewett Fellow at the California Institute of Technology and then as a postdoctoral researcher and instructor at Columbia University from 1955 to 1960. In 1959, he published a paper discussing the strength of the reducing-atmosphere hypothesis for early Earth conditions and the process of transitioning to an oxidizing atmosphere through a higher rate of hydrogen escape. The paper includes a particularly notable section devoted to the possibility of life on other planets. In this section, Miller discusses shifts in colors on Mars as possible evidence of organic compounds and frames his work as a way of thinking about the conditions needed to produce life, whether on Earth or on another planet. He uses the examples of other planets to show what Earth’s primitive atmosphere might have been like.
In 1960, the University of California, San Diego (UCSD) was established with an emphasis on science and engineering, and both Urey and Miller were recruited to teach there. Miller helped to found the Chemistry Department, directing it toward interdisciplinary research. In the ensuing years, his interest in exobiology, the study of life on other planets, led to research and publications on organic molecules in space and the chemical composition of other planets.
In 1973, Miller was elected to the National Academy of Sciences. The following year, he and biochemist Leslie E. Orgel published the book The Origins of Life on the Earth, in which they elucidate a broad range of topics related to the formation of life, including evidence leading to conclusions about the primitive atmosphere, synthesis of amino acids, and signs of life on other planets. For his work in the study of the origin of life, Miller was awarded the Oparin Medal in 1983. From 1986 to 1989, he served as president of the International Society for the Study of the Origin of Life (ISSOL), the organization that awards the Oparin Medal.
Miller’s ideas about the origins of life were not without detractors. In 1990, German chemist Günter Wächtershäuser published a paper promoting a different theory, one in which life arose in hydrothermal vents rather than shallow seas, as Miller had suggested. Wächtershäuser proposed that at the interface between vents and ocean, the reaction of hydrogen sulfide and iron released energy that could spur the creation of organic matter. This idea, advocated by Wächtershäuser and others, became known as the “metabolism-first”theory because it focuses on complex chemical reactions leading to the formation of genetic material. Miller, in contrast, believed that replication came first and subsequently allowed the development of metabolism, and in 1991 he published a paper refuting Wächtershäuser’s theories.
Miller retired in 1995, but he remained professor emeritus at UCSD for some years afterward. He died on May 20, 2007, in National City, California.
Impact
Miller was not the first scientist to attempt to create life in the laboratory; as early as 1828, German chemist Friedrich Wöhler had experimented with obtaining the organic compound urea from silver cyanate and ammonium chloride, and in the 1920s, Russian biochemist Alexander Oparin formulated ideas about the rise of life in a “primitive soup.” However, Miller was able to build on the work and theories of these scientists and produce significant results. What set Miller’s experiment apart was the quantity and variety of amino acids produced and the sheer simplicity of the experimental conditions, which made them plausible as a possible scenario for life’s beginnings. With his experiments, his subsequent work on stars and other planets, and his engagement with the theories of other scientists, Miller brought the relatively unknown field of exobiology, also known as astrobiology, into the mainstream.
Scientists continued to build on Miller’s research after his death. Jeffrey Bada, a former student of Miller who became a professor of marine chemistry, inherited the contents of Miller’s office, including samples from his experiments. In collaboration with colleagues from various institutions, Bada examined the samples with the more advanced technology of the early twenty-first century and discovered that the experiment had yielded a total of twenty-two amino acids, many more than Miller had been able to detect in the 1950s.
Bibliography
Ball, Philip. Elegant Solutions: Ten Beautiful Experiments in Chemistry. Cambridge: Royal Soc. of Chemistry, 2005. Print. Discusses why Miller’s findings were so important and shocking and why they had such a significant impact on the study of the origin of life.
Lane, Nick. Life Ascending: The Ten Great Inventions of Evolution. New York: Norton, 2009. Print. Contextualizes Miller’s work, discusses various theories about early Earth conditions and the rise of life, and explains why some scientists disagree with Miller.
Lazcano, Antonio, and Jeffrey L. Bada. “The 1953 Stanley L. Miller Experiment: Fifty Years of Prebiotic Organic Chemistry.” Origins of Life and Evolution of the Biosphere 33. 3 (2003): 235–42. Print. Surveys the events leading to Miller’s work with Urey, the specifics of the experiment itself, other attempts to synthesize amino acids, and the general scientific climate of the time.
Luisi, Pier Luigi. The Emergence of Life: From Chemical Origins to Synthetic Biology. New York: Cambridge UP, 2006. Print. Provides a comprehensive overview and detailed analysis of the development of organic life from inorganic matter.