Ponnamperuma, Cyril (1923-1994)

Sri Lankan-born American chemist

Cyril Ponnamperuma, an eminent researcher in the field of chemical evolution, rose through several National Aeronautics and Space Administration (NASA) divisions as a research chemist to head the Laboratory of Chemical Evolution at the University of Maryland, College Park. His career focused on explorations into the origin of life and the "primordial soup" that contained the precursors of life. In this search, Ponnamperuma took advantage of discoveries in such diverse fields as molecular biology and astrophysics.

Born in Galle, Ceylon (now Sri Lanka) on October 16, 1923, Cyril Andres Ponnamperuma was educated at the University of Madras (where he received a B.A. in Philosophy, 1948), the University of London (B.Sc., 1959), and the University of California at Berkeley (Ph.D., 1962). His interest in the origin of life began to take clear shape at the Birkbeck College of the University of London, where he studied with J. D. Bernal, a well-known crystallographer. In addition to his studies, Ponnamperuma also worked in London as a research chemist and radiochemist. He became a research associate at the Lawrence Radiation Laboratory at Berkeley, where he studied with Melvin Calvin, a Nobel laureate and experimenter in chemical evolution.

After receiving his Ph.D. in 1962, Ponnamperuma was awarded a fellowship from the National Academy of Sciences, and he spent one year in residence at NASA's Ames Research Center in Moffet Field, California. After the end of his associate year, he was hired as a research scientist at the center and became head of the chemical evolution branch in 1965.

During these years, Ponnamperuma began to develop his ideas about chemical evolution, which he explained in an article published in Nature. Chemical evolution, he explained, is a logical outgrowth of centuries of studies both in chemistry and biology, culminating in the groundbreaking 1953 discovery of the structure of deoxyribonucleic acid (DNA) by James Watson and Francis Crick. Evolutionist Charles Darwin's studies affirming the idea of the "unity of all life" for biology could be extended, logically, to a similar notion for chemistry: protein and nucleic acid, the essential elements of biological life, were, after all, chemical.

In the same year that Watson and Crick discovered DNA, two researchers from the University of Chicago, Stanley Lloyd Miller and Harold Urey , experimented with a primordial soup concocted of the elements thought to have made up Earth's early atmosphere—methane, ammonia, hydrogen, and water . They sent electrical sparks through the mixture, simulating a lightning storm, and discovered trace amounts of amino acids.

During the early 1960s, Ponnamperuma began to delve into this primordial soup and set up variations of Miller and Urey's original experiment. Having changed the proportions of the elements from the original Miller-Urey specifications slightly, Ponnamperuma and his team sent first high-energy electrons, then ultraviolet light through the mixture, attempting to recreate the original conditions of the earth before life. They succeeded in creating large amounts of adenosine triphosphate (ATP), an amino acid that fuels cells. In later experiments with the same concoction of primordial soup, the team was able to create the nucleotides that make up nucleic acid—the building blocks of DNA and ribonucleic acid (RNA).

In addition to his work in prebiotic chemistry, Ponnamperuma became active in another growing field: exobiology, or the study of extraterrestrial life. Supported in this effort by NASA, he was able to conduct research on the possibility of the evolution of life on other planets. Theorizing that life evolved from the interactions of chemicals present elsewhere in the universe, he saw the research possibilities of spaceflight. He experimented with lunar soil taken by the Apollo 12 space mission in 1969. As a NASA investigator, he also studied information sent back from Mars by the unmanned Viking, Pioneer, and Voyager probes in the 1970s. These studies suggested to Ponnamperuma that Earth is the only place in the solar system where there is life.

In 1969, a meteorite fell to Earth in Muchison, Australia . It was retrieved still warm, providing scientists with fresh, uncontaminated material from space for study. Ponnamperuma and other scientists examined pieces of the meteorite for its chemical make-up, discovering numerous amino acids. Most important, among those discovered were the five chemical bases that make up the nucleic acid found in living organisms. Further interesting findings provided tantalizing but puzzling clues about chemical evolution, including the observation that light reflects both to the left and to the right when beamed through a solution of the meteorite's amino acids, whereas light reflects only to the left when beamed through the amino acids of living matter on Earth.

Ponnamperuma's association with NASA continued as he entered academia. In 1979, he became a professor of chemistry at the University of Maryland and director of the Laboratory of Chemical Evolution—established and supported in part by the National Science Foundation and by NASA. He continued active research and experimentation on meteorite material. In 1983, an article in the science section of the New York Times explained Ponnamperuma's chemical evolution theory and his findings from the Muchison meteorite experiments. He reported the creation of all five chemical bases of living matter in a single experiment that consisted of bombarding a primordial soup mixture with electricity .

Ponnamperuma's contributions to scholarship include hundreds of articles. He wrote or edited numerous books, some in collaboration with other chemists or exobiologists, including annual collections of papers delivered at the College Park Colloquium on Chemical Evolution. He edited two journals, Molecular Evolution (from 1970 to 1972) and Origins of Life (from 1973 to 1983). In addition to traditional texts in the field of chemical evolution, he also co-authored a software program entitled "Origin of Life," a simulation model intended to introduce biology students to basic concepts of chemical evolution.

Although Ponnamperuma became an American citizen in 1967, he maintained close ties to his native Sri Lanka, even becoming an official governmental science advisor. His professional life has included several international appointments. He was a visiting professor of the Indian Atomic Energy Commission (1967); a member of the science faculty at the Sorbonne (1969); and director of the UNESCO Institute for Early Evolution in Ceylon (1970). His international work included the directorship of the Arthur C. Clarke center, founded by the science fiction writer, a Sri Lankan resident.

Ponnamperuma was a member of the Indian National Science Academy, the American Association for the Advancement of Science, the American Chemical Society, the Royal Society of Chemists, and the International Society for the Study of the Origin of Life, which awarded him the A. I. Oparin Gold Medal in 1980. In 1991, Ponnamperuma received a high French honor—he was made a Chevalier des Arts et des Lettres. Two years later, the Russian Academy of Creative Arts awarded him the first Harold Urey Prize. In October 1994, he was appointed to the Pontifical Academy of Sciences in Rome. He married Valli Pal in 1955; they had one child. Ponnamperuma died on December 20, 1994.

See also Evolutionary mechanisms; Miller-Urey experiment