Problems with Chemical Origins of Life Theories

PROBLEMS WITH CHEMICAL ORIGINS OF LIFE THEORIES

Based on talks at the University of South Carolina, 16 April 93 and 3 April 95

Copyright 1998 by Emerson Thomas McMullen

(Approximately 11 double-spaced pages long)

Abstract

The ultimate question concerning the origin of life is whether it happened naturalistically or as the result of a creator. In the twentieth century, A.I. Oparin and J.B.S. Haldane supplied a theoretical basis for the naturalistic origin of life. The supposed experimental evidence, the Miller experiment dominated discussions for decades, but has many weaknesses. One problem for all naturalistic explanations is the source of the information in DNA (deoxyribonucleic acid). Whatever the proposed pathway, mathematical calculations indicate that it is impossible for life to occur naturalistically. The best explanation for the origin of life, as well as its detailed genetic information stored in complex molecules, is a creator.

Background

Louis Pasteur's experiments, and those of others, seemed to end altogether the ancient idea of life appearing spontaneously. However, after the turn of this century, spontaneous generation started to make a comeback as a scientific theory. This was because of discoveries in biochemistry, especially proteins and viruses. (Most of the biologists today say that the virus is not true life because it has to have a cell in order to live. "On the border of the living and nonliving" is how some describe it.) One person inspired by these biochemistry discoveries and also driven by a materialist worldview was Alexander Ivanovich Oparin (1894-1980), a Soviet biologist. In the 1920's and 30's, he developed the idea of the chemical emergence of life. Oparin argued that, as chemicals mixed together over time, they formed more complex chemicals. With longer periods of time, they formed even more complex organic chemicals. Eventually, life emerged, but at no point along this development could one say where there was an abrupt change from nonliving to living. Life was a gradual emergence, over a long period of time, from a chemical beginning. A British scientist, J. B. S. Haldane, came up with a similar idea independently and thought the origin of life occurred in a hot, dilute soup.

Oparin was aware that his theory is not falsifiable. Therefore, according to the thinking of the late Karl Popper, it cannot be considered scientific. At best we can say that he was offering a guiding idea, since it is not testable (at problem, by the way, with most origins theories). There was not even a hint of scientific support for the chemical emergence of life theory until 1953. Then a graduate student, Stanley Miller, published the results of an experiment that seemed to support Oparin's ideas. Miller's experiment dominated the chemical origins of life discussions for three decades.

The Miller Experiment

Miller's professor, Harold Urey, had been lecturing about how the earth could have had a different atmosphere, and that perhaps life formed because of that atmosphere. Miller investigated the idea in the laboratory. A diagram of his apparatus is shown in Figure 1. He generated water flow around a glass loop by heating it until vapors were given off (B) and then cooling it (D). To the water vapor he added ammonia, methane, and hydrogen, (E) and electrically sparked this gaseous mixture (A). One product of the resulting reaction was a yellowish mixture that coated the glass. When he removed a sample from the water at the bottom of the loop (tapped off at C) and examined it, Miller found another product: amino acids. Amino acids are found in our bodies, and are the building blocks for other more complex organic materials. Some interpreted this experiment as supporting Oparin's idea of the chemical emergence of life. It appeared that Miller had shown the first step in Oparin's emergence theory, which went from chemicals to simple organics. Now in one sense, that's not so earthshaking because, beginning in 1828 with Friedrich Wohler, chemists had been synthesizing organic compounds from inorganics. In this sense, all Miller did was to synthesize an organic compound - there was nothing sensational about that. However, what is unique is the claim made for this experiment, that it supports Oparin's theory. In a sense, this is one strength of the Miller experiment.

Another strength is that a story can be inferred from the Miller experiment: The amino acids, mixing in the oceans create what has been termed an organic soup. From this organic soup, some thought that the next steps in Oparin's theory also occurred until life eventually emerged. A third strength of the Miller experiment is that it is easy to understand and explain. It is a simple experiment and a simple analogy: The early earth had an atmosphere of hydrogen, methane, ammonia, and water vapor. Lightning formed amino acids, and thus occurred the first step in the emergence of life here on earth. The experiment encourages belief in the plausibility of such a scenario. That was back in 1953. A lot has happened since then, and it hasn't been good for the naturalistic origins story.

Weaknesses of the Miller Experiment

Initially, the Miller experiment gained acceptance because of the strengths mentioned above. As research continued, however, weaknesses arose. First, no one could come up with a good naturalistic explanation for the tap where Miller removed the amino acids from the loop. If someone does not tap off the amino acids they flow back around the loop to the spark, which then destroys them. Miller could not leave the amino acids in the loop; the rate of destruction in the spark is greater than the rate of formation, and the organics would never accumulate. He had to remove them; but what is the analog in nature for this?

A bigger weakness is the assumption that the early atmosphere consisted of hydrogen, methane, ammonia, and water. There's no proof of that. As a matter of fact, what evidence that does exist (oxidized rocks, for example) indicates that the early earth had an oxygen atmosphere. This fact is bad news for the naturalistic scenario because if there is oxygen in Miller's loop, the experiment does not go at all. Oxygen stops it cold. Even though we need oxygen to live today, oxygen in the past would have prevented the formation of amino acids. Also, atmospheric oxygen today forms the protective ozone layer. If there was no oxygen in the early earth's atmosphere, then there would have been no ozone layer and ultraviolet rays would have poured in, destroying any life that did exist. These harmful rays would also destroy any life that arrived from space.

Another weakness of the Miller experiment is that hydrogen is the lightest molecule and therefore has a high diffusion capability. The earth's gravitational field is not strong enough to hold hydrogen and it would have diffused easily out of our atmosphere. So it would not have been around to help form amino acids. (Only on the bigger planets, like Jupiter and Saturn, is there is enough gravity to hold the hydrogen in, but this is not so on the smaller planets.) Additionally, ammonia and methane in the atmosphere would not have lasted. In a few thousand years they would have been destroyed by chemical reaction caused by sunlight. So they would not have been around to form the hypothesized organic soup either. Sunlight in the hypothesized Miller-type of atmosphere is like a bull in a china shop - there is a lot of energy there, but most of it is destructive.

If there were an organic soup, then the next weakness would be the extremely low probability of formation for DNA (deoxyribonucleic acid) and other large, complex molecules from the soup. Figure 2 depicts the DNA molecule. (For more details on DNA see the DNA part of my article Science and Abortion). In more than 40 years, further experiments have not shown that amino acids naturally form anything more complex. (I will give the exact calculations for these probabilities at the end of this paper.)

Associated with this formation of complex molecules is the information content in our DNA. Where did the genetic codes come from that generate us? Also, this genetic code operates only in the presence of ribosomes, activating enzymes, transfer RNA (ribonucleic acid), etc. How all this happened naturalistically is a major unsolved problem.

One of the greatest weaknesses of the Miller experiment (and other naturalistic explanations) is that it does not explain the fact that only L-amino acid is found in our bodies. Most amino acids can appear in two different forms, "L" and "D." There is a left-handed form of an amino acid, "L", and a right-handed one, "D." One form rotates polarized light left, the other rotates it right. They are mirror images of each other. If you look in the mirror and raise your right hand, the image in the mirror raises its left hand. It is you in the mirror, but there is a difference - there is a "handedness" to our mirror images. It is the same thing with these amino acids. Of the twenty commonly occurring amino acids, nineteen have this mirror image capability: They are called optical isomers. The exception is glycine - it's symmetrical no matter which way you look at it, mirror image or straight on.

As mentioned, our bodies don't have the D-amino acids. This is true for all living beings. The only exception is the exoskeleton of insects, which have "D" in them. Otherwise, all living things have "L." The claim for the Miller experiment and similar naturalistic ideas is that they offer an analogy of how life could have occurred. But the Miller experiment gives D- and L-amino acids in roughly a 50-50 ratio. As a matter of fact, any way that we synthesize amino acids gives a 50-50 ratio. If we went into a lab and started mixing chemicals together, we would get a 50-50 mixture. The analogy breaks down.

Amino acids have been found in some meteorites. A good question to ask would be about the L- and D-amino acids in these meteorites. What's the ratio of the L to D in them, as far as amino acids are concerned? The answer is roughly 50-50.⁽¹⁾

No one has come up with a good explanation of why we have only the "L" form in us when naturally occurring amino acids have roughly equal amounts of left-handed and right-handed amino acids. A possible one is that polarized light in the Orion nebula could have created L-amino acids. (See Science, 31 July 1998.) ⁽²⁾ One problem with this scenario is that huge amounts would have to be made for the earth to get enough. Another is exactly how this light makes "L"-amino acids only. Of course this extraterrestrial explanation undercuts the Miller experiment and any other terrestrial hypotheses.⁽³⁾

The last and most formidable weakness of the Miller experiment is Miller himself. He designed the experiment, hoping to produce amino acids, but the first run did not generate any. It was back to the drawing board. He changed certain experimental parameters and the second run did provide the desired results. Now a supposed strength of the experiment is that it is a possible naturalistic explanation of the origin of life. The methane, ammonia, water, and hydrogen in the Miller experiment, even though of an artificially high purity, could be the earth's early atmosphere. The electric spark could be analogous to lightning, and the liquid water, the oceans. If so, then what is the analogy for Miller, the designer and modifier of the experiment? The answer is an intelligence - a designer; God, if you will, is needed for life to occur. If one thought the earlier inferences from the Miller experiment was scientific, then one has to concede that this inference of a supernatural being is also scientific.

ETI

Some astronomers are searching the heavens with radiotelescopes, seeking a signal from an extraterrestrial intelligence (ETI). They think that such a signal would be non-random and therefore distinguishable from the random noise they now receive. Is this science, to search for a message with meaningful information? Is it scientific to infer, that if such information is found, there is another intelligence besides ourselves? The answer, from the scientists, seems to be yes. Well, we have found non-random and very meaningful information contained in our DNA codes. Where did this information come from? Following the exact same reasoning used in the search for ETI, one can argue that the fantastic amount of exceptionally detailed DNA information came from an intelligence, and a superior one at that.

Other Options

Because of the weakness of the Miller experiment, scientists have been proposing other theories for the naturalistic origin of life. One example is an article in Insight magazine, May 1987, entitled "Evolutionary Tail." Probes of the crust of Halley's comet have led a chemist to challenge the prevailing theory of the evolution of life. Cliford Matthews at the University of Illinois reasons that since Halley's comet had a lot of hydrogen cyanide in it, therefore the early earth had hydrogen cyanide in its atmosphere. He theorizes that sunlight triggered a chemical reaction to form clouds of hydrogen cyanide in the earth's atmosphere. The cyanide formed polymers that rained down into the oceans. These were converted to protein-like compounds, and from these, life developed.

The January 16, 1988 Science News carried an article proposing another idea for the formation of life on earth. James A. Lake, a molecular biologist at UCLA, proposed that all living things evolved from a single-celled organism which lived in boiling sulfur springs. Lake arrived at this conclusion from a new computerized method of analyzing bacteria genes. Yet another solution for the origin of life is that perhaps clays were involved in the formation of life, and another one is that maybe life formed in tidal pools.

Finally, as mentioned earlier, some scientists are hypothesizing that life originated extraterrestrially. However, whether on earth or somewhere else, we will find the naturalistic generation of life is mathematically impossible.

Mathematical Probabilities - Hoyle and Crick

I once entered the Sports Illustrated magazine sweepstakes. If I had won, they would have paid me one million dollars, tax-free, in twenty-five installments of $40,000. In the fine print, the magazine said the odds of winning that year were one in 1.2 x 10⁸. This means, on the average, I would win once every 120 million years. Let's say I happen to live for the next 120 million years and the contest is conducted each year. Normally I would expect to win just once. What do you think the chances are for me to win the grand prize each and every year for the next 120 million years? Sounds impossible? According to Sir Fred Hoyle and others, I have a fantastically better chance of winning the Sports Illustrated Sweepstakes 120 million years in a row, than of life forming on earth by naturalistic means. Hoyle and Wickramasinghe calculate an extremely low probability for the formation of an enzyme: one in 10^40,000 - that's 10 with 40,000 zeros behind it. Winning the Sports Illustrated contest 120 million years in a row has a probability of only 1.44 in 10¹⁶

Nobel Prize winner Francis Crick also arrived at an extremely low probability for life to have originated naturally. Hoyle and Wickramasinghe have come to the same conclusion as did Crick: the formation of life elsewhere is more probable than spontaneous generation on earth. It is extremely improbable for life to have originated here on earth and slightly less improbable for life to have occurred somewhere else.

Crick, Hoyle and Wickramasinghe are not alone in calculating very low mathematical probabilities for the formation life on earth. Others are Charles-Eugene Guye, Harold J. Morowitz, Frank B. Salisbury, and James F. Coppedge.

Guye, Morowitz and Salisbury

Guye was a Swiss physicist who, having died in 1942, made his calculations before the major biochemical breakthroughs such as the study of DNA. Based on the oversimplification of two kinds of atoms ordered in proteins, he arrived at a probability of 2.02 x 10^-321. This was reported by Pierre Lecomte du Noy in Human Destiny (1947) as requiring 10²⁴³ billions of years for one protein molecule to form from an earth being shaken at the speed of light. Since the longest proposed age of the earth is five billion years and life needs more than one protein, we are basically faced with an impossibility.

Morowitz's approach, in his Energy Flow in Biology (1968) was to calculate the probability of chance fluctuations generating enough energy for the bond formation that molecules needed for a living cell. For an ocean of the correct molecules needed to make a minimal cell, this would be one chance in 10^399,999,866, again, basically an impossibility.

Salisbury realized that genes appear to be too unique to have occurred by chance. He also realized that even if genes existed, at some point a certain enzyme would be needed. Evolutionary theory predicts that this early enzyme appeared due to chance mutations of existing genes. He generously assumed 10²⁰ planets with oceans containing small DNA genes of 1,000 nucleotides in length that replicated a million times a second with a mutation happening each time. He calculated the odds of getting the desired result was one in 10⁴¹⁵, which to him seemed too improbable if the earth was only 4 billion (4 x 10⁶) years old. This posed a dilemma since natural selection needs something to operate on.⁽⁴⁾

Coppedge's Calculations

Coppedge did several calculations, all showing the extreme improbability of life occurring by chance. For protein formation, he grants extreme conditions such as the rate of amino acids forming chains at one-third of a ten-million-billionth of a second. (This concession is 150 thousand trillions the normal speed.)⁽⁵⁾

He arrives at the probability of one protein forming from a chance arrangement of amino acids as one in 10²⁸⁷. For the minimum set of 239 protein molecules for the smallest theoretical life, the probability of chance formation is one in 10^119,879. This to him, is impossible.⁽⁶⁾

Coppedge realized that even with extreme probabilities of occurrences, one could always say that there is still a chance, no matter how slim the odds. His answer to this argument enlisted the work of the French probability expert Emile Borel. Borel introduced his "law of chance" in Elements of the Theory of Probability (1965). His law is that events whose probability is extremely small never occur. How small is small? In Probabilities and Life (1962) he calculates that a probability of one in 10¹⁵ as negligible on a terrestrial scale and one in 10⁵⁰ on a cosmic scale. The probabilities we have been discussing are all far greater than one in 10⁵⁰. If Borel's mathematics are correct, then it is impossible for life to occur naturalistically, both on earth and in the universe.

Conclusion

As Pasteur's and others' experiments indicate, life does not occur spontaneously anywhere. Also, they imply that life did not occur at any time past. Additionally, the mathematical approach eliminates the option of life naturally occurring, either terrestrially or extraterrestrially. That leaves only the supernatural option. Life had to be created. It could not have happened by chance.

Acknowledgments

Figures 1 (from S. Miller) and 2 (from J. Watson and F. Crick) are taken from S. Glasstone, The Book of Mars, published by NASA (1968). Sharon Ann McMullen did the word processing.

References

1. 1.J. G. Lawless and E. Peterson, "Amino Acids in Carbonaceous Chondrites," Origins of Life (1975) 6:3-8. There may be a slight (7 - 9%) excess of L amino acid in the Murchison meteorite but still not the 100% of "L" needed; see J. R. Cronin and S. Pizzarello, "Enantiometric Excesses in Meteoritic Amino Acids," Science (1997) 275:951-955.

2. J. Bailey, et. al., "Circular Polarization in Star-Formation Regions: Implications for Biomolecular Homochirality," Science(1998)281:672-674, and R. Stone. "Did Twisty Starlight Set Stage for Life?," Ibid:626-627.

3. 3.For a comprehensive analysis of theories of biochemical evolution see C.B. Thornton, WL. Bradley and R.L. Olsen, The Mystery of Life's Origin (New York: Philosophical Library, 1984).

4. F. B. Salisbury, "Natural Selection and the Complexity of the Gene," Nature, 1969, 224:342.

5. James F. Coppedge, Evolution, Possible or Impossible? Molecular Biology and the Laws of Chance in Nontechnical Language (Northridge, CA: Probability Research in Molecular Biology, 1993 reprint of Grand Rapids, Zondervan, 1973) p. 107.

6. Ibid, pp. 114-115.