Press Release

Recooking the Recipe for Prebiotic Soup: Scripps Professor Revisits the Miller Experiment and the Origin of Life

By SpaceRef Editor

May 19, 2003

Filed under Astrobiology, Scripps Research Institute, US

Fiftieth anniversary of famous experiment commemorated with June 10 public symposium

In the fall of 1952, Stanley Miller, now a chemistry professor emeritus
at the University of California, San Diego (UCSD), began simulating
primitive earthly conditions in an experiment that produced the basic
building blocks of life. When he published the results in Science on May
15 the following year, he kick-started research on the origin of life
and transformed modern thinking on a dormant area of science.

Jeffrey Bada, a professor of marine chemistry at Scripps Institution of
Oceanography, UCSD, and an expert on origin of life processes, revisits
the famous "Miller experiment" in a report published in the May 2 issue
of Science.

"Up to Miller’s experiment there was a large vacuum in our understanding
of how life began on the earth," said Bada, who coauthored the report
with Antonio Lazcano, a scientist at the Universidad Nacional AutÛnoma
de MÈxico, and is a visiting scholar at UCSD in Miller’s laboratory. "Up
to that point no one had demonstrated how compounds like amino acids
could be synthesized under possible early Earth conditions."

Bada and Lazcano’s essay traces the history of the Miller experiment,
which originated when the late Nobel Laureate and UCSD Chemistry
Professor Harold Urey discussed the idea behind the experiment in a
lecture at the University of Chicago. Miller, then a graduate student in
the audience, eventually presented Urey the idea of a prebiotic
synthesis experiment applying an electric discharge to a mixture of
methane, ammonia, water vapor, and hydrogen. Urey eventually agreed to
the idea.

Results of the famous Miller experiment, which used the glass apparatus
pictured, were published by Science 50 years ago. The lower flask was
designed to simulate the oceans and the upper flask the atmosphere. The
energy was supplied by sparking between two wire electrodes.

During Miller’s experiment, the mixture of gases was circulated through
a liquid water solution and continuously zapped with the electric spark,
which substituted for lightning. The surprising products of the process
were "biochemically significant" compounds such as amino acids, hydroxy
acids, and urea. Thus, with Urey’s guidance, Miller had produced the
basic building blocks of contemporary life forms on Earth.

"In the early 1950s, several groups were attempting organic synthesis
under primitive conditions," Bada and Lazcano note in their essay. "But
it was the Miller experiment, placed in the Darwinian perspective
provided by Oparin’s ideas and deeply rooted in the 19th century
tradition of synthetic organic chemistry, that almost overnight
transformed the study of the origin of life into a respectable field of
inquiry."

Bada and Lazcano also note that Miller’s study was published only a few
weeks after Watson and Crick’s landmark paper on the DNA double-helix
model and the authors highlight the important link between the two young
fields in the years that followed.

EVENT NOTE: Bada will be giving a public lecture on the 50th anniversary
of the Miller experiment at 3 p.m. on Tuesday, June 10, 2003, during
"Celebrating 50 Years of Prebiotic Chemistry," a public event at the
Robinson Building Complex Auditorium, Graduate School of International
Relations & Pacific Studies (IR/PS), Thurgood Marshall College, UCSD
campus. The event, which also features Gerald Joyce of the Scripps
Research Institute, is sponsored by the NASA Specialized Center of
Research and Training (NSCORT) in Exobiology, the UCSD Dean of Physical
Sciences, the Department of Chemistry and Biochemistry at UCSD, and the
National Aeronautics and Space Administration.