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Explaining Life's Origins
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12034 |
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BOOK WORLD
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| Issue
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12 / 1987 |
3,170 Words |
| Author
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James G. Osborn
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ORIGINS
A Skeptic's Guide to the Creation of Life on Earth
Robert Shapiro
New York: Bantam Books, 1987
332 pp., $9.95 (paperback)
Where do we come from? The scientific community has given the difficult question of the origin of life less attention than perhaps any other. In fact, until 1953 the creation stories of the various religions held as much weight among scholars as any theory that chemists or biologists had come up with.
The origin of life is difficult to pursue because all life, even the most primitive, is so complex. To qualify as a living thing, a being must satisfy three basic criteria: It must be able to (1) trap and use energy from the environment; (2) reproduce; and (3) defend itself against attack. All organisms currently alive or ever found embedded in ancient rock have very sophisticated systems for accomplishing all three of these tasks. That this kind of life originated from the nonliving elements of our planet seems miraculous indeed. With this in mind, scientists who are searching for the way life first came into being are examining the most primitive systems that might qualify as living.
Ironically, since Stanley Miller and Harold Urey published their classic research findings in 1953, the popular press and many general science texts have assumed that science had the origin of life sewn up. Miller had assembled a flask containing what he considered the main constituents of primitive earth: methane, ammonia, hydrogen, and water. Sparks were jumped between two electrodes in the flask to stimulate lightning. When the apparatus was left to run for seven days, Miller found that the resulting "broth" contained two of the twenty amino acids essential to life. While Miller and Urey maintained an objective assessment of their results, other were extremely optimistic in their interpretations. Time magazine reported after the Miller-Urey results were published "If their apparatus had been as big as the ocean, and if it had worked for a million years instead of one week, it might have created something like the first living molecule." The bogeyman in this notion of "chemical evolution" is that in the thirty-five years since Miller's research, no one has come any closer to the synthesis of a simple microbe than that initial experiment.
Into this arena that pits exaggeration against true science comes Robert Shapiro, a professor of chemistry at New York University, who, in Origins: A Skeptic's Guide to the Creation of Life on Earth, presents a careful analysis of contemporary theories about life's origins in a manner that separates myth from experimental science. The author has created a delightful literary device, a character named the Skeptic who asks clarifying questions. Together, the author and the Skeptic explain in a highly readable and detailed fashion the Miller-Urey experiment, other theories concerning the first self-replicating molecule, the possible role of clay minerals in creating the first life, and extraterrestrial-origin theories.
The book begins with a clever prologue, designed to display the immense diversity of the ideas that have been proposed about the origin of life. In it the Skeptic, described as "our hero in this book," meets a Guru living upon the proverbial mountaintop and asks him
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