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RE: From Nonlife to Nonlife
How did life arise from nonliving chemicals? This is the most fundamental, yet sketchiest chapter of evolutionary theory.
One proposal is to start with seemingly lifelike chemicals. This is the approach taken by Julius Rebek and his coworkers (Hong, et al., 1992; Feng, et al., 1992). Like DNA, Rebek"s chemicals can make copies of themselves (i.e., replicate). Further, Rebek can make more efficient replicators by subjecting them to ultraviolet radiation. These new varieties outproduce other forms, eventually dominating their test-tube world. Supposedly, these chemicals could provide the missing link between nonlife and life.
Yet, the gap remains because Rebek"s system contains little information (see Hurst and Dawkins, 1992, 357:199). Life is defined by a set of elegant instructions recorded on the DNA molecule, and there is more to life than replication.
Another proposal tries to circumvent the famous chicken-and-egg problem of chemical evolution by starting with RNA. If we think of DNA as the "brain," then RNA is the "nervous system" carrying the message of protein formation to the rest of the cell. However, the whole process involves crucial enzymes (specialized proteins). So which came first, the protein or the DNA?
The answer, many evolutionists believe, lies in the discovery that a special part of RNA can act like an enzyme. This means it can carry information and do various jobs within the cell. If this is the case, then perhaps evolution worked both ways, turning RNA into DNA for better information storage, and into specialized enzymes for more efficient copying. Last year, the proponents of this RNA world received a boost from the work of Beaudry and Joyce (1992) who used selection and mutations to make a more efficient RNA enzyme.
Some journalists and scientists have made extraordinary claims about this new research. First, they described the techniques and chemical processes in evolutionary terms such as "selection" and "mutation." One newspaper article hailed Beaudry and Joyce"s work as the "first complete laboratory demonstration of evolution" (Graham, 1992). Second, they believe the experiments show that "darwinian selection is universal for all lifes" (Hurst and Dawkins, 1992, 357:198), not just for "life as we know it." And third, because this research has a practical application in biotechnology, they wish to promote evolution as a fundamental tool of science, and not a mere theory.
However, using terms such as selection, mutation, and evolution does not explain the origin of life. These experiments entail a great deal of design and technical innovation. The human experimenters are forcing or directing "evolution" to achieve goals they have set (Culotta, 1992). As Leslie Orgel noted, to really show how life could have evolved, we need to start with something that does not require the "intervention of organic chemists" (1992, 358:207).
Further, this research may come closer to Darwin"s arguments than they would really like. By showing that man can use artificial selection to change species dramatically, even within recorded history, Darwin hoped to establish his case for long-term, large-scale evolution by natural selection (1859, pp. 133,153). But this analogy breaks down because artificial selection, by definition, involves human intelligence. The same is true for this recent research. We are seeing nothing more than high-tech horse breeding. Actually, we may be seeing less, because the experiments do not deal with life at all. If anything, they resemble Edison"s efforts to find a better filament for his electric light bulb.
What we must emphasize is that an evolutionist can invent any theory about the origin of life, no matter how implausible it may sound. He might succeed in modeling that theory in the laboratory. However, a model is not necessarily the same as reality; he has not proved that life evolved in that way. Ultimately, all he would have displayed is his God-given intellectual and physical abilities.
REFERENCES
Beaudry, Amber A. and Gerald F. Joyce (1992), "Directed Evolution of an RNA Enzyme," Science, 257:635-641, July 31.
Culotta, Elizabeth (1992), "Forcing the Evolution of an RNA Enzyme in the Test Tube," Science, 257:613, July 31.
Darwin, Charles (1859), The Origin of Species (New York: Avenel Books, 1979 reprint of the 1968 Penguin edition).
Feng, Qing, Tae Kyo Park and Julius Rebek, Jr. (1992), "Crossover Reactions Between Synthetic Replicators Yield Active and Inactive Recombinants," Science, 256:1179-1180, May 22.
Graham, David (1992), "Evolution in the Lab at Scripps," San Diego-Union Tribune, July 31, pp. A1-A2, July 31.
Hong, Jong-In, Qing Feng, Vincent Rotello and Julius Rebek, Jr. (1992), "Competition, Cooperation, and Mutation: Improving a Synthetic Replicator by Light Irradiation," Science, 255:848-850, February 14.
Hurst, Lawrence D. and Richard Dawkins (1992), "Life in a Test Tube," Nature, 357:198-199, May 21.
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Originally published in Reason and Revelation, February 1993, 13[2]:15.
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