Maggots, Mice, and…Stanley Miller?

 

—Biogenesis or the New Spontaneous Generation

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Sudarsana Srinivasan

STS—129: Artificial Life

Prof. Michael John Gorman

October 23, 2001

“If a dirty undergarment is squeezed…a ferment drained from the garments and transformed by the smell of grain, encrusts the wheat itself with its own skin and turns it into mice…And, what is more remarkable, the mice from corn and undergarments are neither weanlings or sucklings nor premature but they jump out fully formed.”[1]

                                —Jean Baptiste van Helmont

 

The “scientific” theories of spontaneous generation proponents are a ripe target for our ridicule. We feel free to malign them so, because they are our scientific kin. If one is unconvinced of our scientific lineage, a perfunctory perusal of a college level biology textbook will certainly clear up the confusion:

 

Sometime between the time the earth formed and the date of the earliest fossils discovered so far—an interval of 1 ½ billion years—life began. The chief raw materials for life were to be found in the atmosphere of the young earth. […] In order to break apart the simple gases of the atmosphere…energy was required. And energy abounded on the young earth. First there was heat, both boiling (moist) heat and baking (dry) heat. Water vapor spewed out of the primitive seas, cooled in the upper atmosphere, collected into clouds, fell back on the crust of the earth, and steamed up again. Violent rainstorms were accompanied by lightning, which provided electrical energy. The sun bombarded the earth’s surface with high-energy particles and ultraviolet light. Radioactive elements within the earth released particles into the atmosphere. These conditions can be simulated in the laboratory and scientists have now shown that under such conditions, organic molecules are produced.

 In the 1950s, Stanley Miller conducted such a series of experiments….[2]

                               

The passage above is Biological Genesis. It can be seen as the resurrection and reformulation of the antiquated notion of spontaneous generation. In biogenesis the forces of nature (so passionately described above) experiment (rather haphazardly) upon primordial earth to produce organic life (out of inorganic matter).  The four key principles that give this theory life are: 1) Reducing atmosphere 2) Energy sources 3) Chemical building blocks, and 4) Time for experimentation.  However, like any revenant, spontaneous generation in this new incarnation as the Oparin-Haldane hypothesis and the resultant Miller-Urey experiment on biogenesis, has its share of opponents and proponents who postulate theories that are biologically biased by their individual ideological agendas that can vary from general beliefs about the Continuity of Life to Spontaneous Generation, supernatural beliefs from Creationism to Panspermia, as well as to political beliefs such as Marxism.  Supporters, such as George Wald, as well as              detractors, such as Dean L. Overman and Robert Shapiro, have a great deal at stake—this particular hypothesis stands as the current scientific paradigm for the origin of life.

Before we can discuss what is possibly wrong with the current theory of biogenesis, we must be sure as to not merely ascribe it to the controversy over spontaneous generation, or autogenesis. There is a difference between the spontaneous generation of today and that of antiquity. The words “spontaneous generation” immediately invoke images of worms from waste, maggots in meat, and rodents from refuse. We then imagine this superstitious nonsense being swept away by the sanitizing influence of “real” science. St. Augustine, Newton, Descartes, and others were believers, until the likes of Francesco Redi in the seventeenth century and Lazzaro Spallanzi in the eighteenth century began to undermine the foundations of the notion that matter, especially putrefying matter, could instantly induce life. The issue was complicated by the beginnings of the Scientific Revolution and the invention of the microscope that revealed swarms of seemingly spontaneous micro organic life. In the end, Louis Pasteur was the one to land the decisive blow against spontaneous generation with his swan-neck experiments that proved that microorganisms came from the air and not from decaying substances. He predicted that spontaneous generation would never recover now that the paradigm had shifted to the belief that all life must come from previous life.[3]

The distinction must now be drawn between the old notion of spontaneous generation and the new notion of autogenesis. Pasteur was correct that spontaneous generation as it was conceived of then, is an impossibility for the present Phanerozoic epoch we live in; however, his authority does not extend to preclude the more refined, scientific notion of spontaneous generation concerning chemical evolution of the past Archean epoch. The new conception of autogenesis began with the experiments of a German chemist named Friedrich Whole. In 1832, he managed to create the organic compound urea (the primary component of animal urine) from an inorganic compound. This shattered the scientific belief of the day that there was an essential difference between inorganic chemicals and organic nature. The gap had been bridged. The field of prebiotic chemistry, those reactions conducted in the lab “with the intention of simulating processes that occurred on the primitive earth,” had been unwittingly launched.[4]

The Oparin-Haldane hypothesis is the very basis of the prebiotic chemical theory of biogenesis. J.B.S. Haldane, a British physiologist, produced his theory in 1929, after, yet independently of Oparin. Though his theory is not as detailed as Oparin’s, Haldane is responsible for giving us the notion of a hot, primordial soup.[5] It was formulated first and most thoroughly in 1924 by the Russian biochemist Alexander Ivanovich Oparin. (A simple summary of the Oparin-Haldane theory will suffice for now, and the details will be teased out during the contra-arguments.) Oparin believed that there was a gradual evolution of organic molecules to greater and greater levels of complexity. He pictured the origins of life in an organic solution rich with carbon compounds leached from the earth’s crust, surrounded by an atmosphere of hydrogen, ammonia, and methane, and supplied with the solar energy of the sun.  Eventually, these “coacervates,” (the complex droplets) would develop the power to grow by becoming “…adapted for absorption and for the chemical transformation of the absorbed materials.”[6] The pre-requisites required for this hypothetical process were that, first, the primitive earth had to lack oxygen (the atmosphere had to be of a reducing nature, that is, donate electrons) otherwise it would destroy any newly formed organic molecules, secondly, that there needed to be an abundance of ultraviolet radiation to provide the energy necessary for the chemical transformations, and lastly, there must be an absence of life for life to develop, because a living organism with its “perfected metabolisms” would “draw varied organic compounds into its sphere of influence.”[7]

                J.B.S. Haldane and A.I. Oparin, despite being co-progenitors of this biogenesis paradigm, disagreed on the specific order of events in the origin of life. Oparin postulated that cells were created first, then enzymes, and then genes last. The first two steps logically follow one another. As the coacervate droplet increased in complexity and size, it would eventually close itself off from the rest of the organic solution and becomes a cell. Secondly, the random amalgamation of molecules trapped within the cell would be forced to produce the enzymes necessary to organized for metabolic activity and further growth. The placement of genes was problematic for Oparin. He placed them last because he had very little interest in them and had only a vague idea of their function.[8] Oparin’s sequence can be thought of as the position of the chemical evolutionists. Their position defies the Central Dogma of biology, the chain of command runs in reverse: protein > RNA > DNA. This would require a system that would directly duplicate protein without the translation of RNA to protein, a clunky “protein genome” that could code for protein.[9]

Haldane, on the other hand, believed that genes came first, then enzymes, and lastly came cells. Leslie E. Orgel and Manfred Eigen explain the sequence as follows: self-replicating RNA would be followed shortly by enzymes that with the RNA produced a primitive transcription system, that would eventually be enclosed by a cell for “physical cohesion.” Genes also seem structurally simpler than enzymes. With Crick and Watson’s elucidation of the structure of DNA it became “…natural to think of the nucleic acids as primary and of the proteins as secondary….[10] This sequence of events that places genes first can be thought of as the “naked gene” position.

                The explanation for the disparity in Haldane and Oparin’s ordering of events can be explained in terms of their particular beliefs. Both were, strangely enough ideological comrades—they began as Marxists. This may explain why both were so open to this modified version of spontaneous generation. Oparin, in the officially atheistic Soviet Union, and Haldane as the political outsider in Great Britain, were free to posit about the origin of life in contradiction to the belief in the continuity of life. Life did not exist forever, but since it does exist, it had a beginning. Together, Haldane and Oparin, seemingly produced the only other validated option to Biblical Creation. Haldane eventually broke with the Marxists over scientific practices promulgated by the Party.  This break in thought correlates with the discontinuity in sequencing between Haldane and Oparin. The “Marxist science” that Haldane disagreed with was the product of Trofim D. Lysenko, who dominated discourse in Soviet biology. He was essentially a Lamarckian who believed in the inheritance of acquired characteristics, rather than “bourgeois” notions of genetic inheritance. Lysenko ignored evidence in favor of the Mendel-Morganist view of inheritance, because he felt it did not adequately address the needs of the Soviet state.[11] Oparin was a Lysenkoist. It was therefore easier for Oparin, in the Soviet state, to dismiss the notion of genes, and place them last, whereas for Haldane, the dominant theory (the Mendel-Morganist view) made it “natural” to think of nucleic acids as primary over amino acids.

Marxist ideology had a further affect upon Oparin. An extension of Lysenkoism was dialectical materialism, a topic that dominates the introduction to his later work, The Origin and Initial Development of Life. According to dialectical materialism, matter was reaching higher and higher levels of development and progress. The political nature of the work is revealed when Oparin discusses humans who “…represent the creation not of a biological, but of a higher social form of the motion of matter—the social life of the people.”[12]  Dialectic materialism also excluded the belief in the spontaneous generation of the “naked gene,” in favor of the more gradual approach of chemical evolution. Oparin even explicitly cites Engels as the basis of his theory with

Life, according to Engels, does not exist forever nor does it suddenly generate spontaneously; it arises in the evolution of matter everywhere and at all times when the necessary conditions are created for this type of evolution.[13]

                                                                                                                                                                                                                                         This then is the theoretical origin of Oparin’s fallacious belief that natural selection could operate at the prebiological level with organic molecules that were incapable of reproducing. Oparin wrote these words during the 1930s when the intelligentsia was being closely scrutinized for anti-Marxists sentiments. Though, of course, Oparin could have to some degree been both politically savvy and a true espouser. 

                The biology textbook’s dramatic presentation of primitive earth seems firmly based on the Oparin-Haldane hypothesis, but now let us turn to the casual aside made in the textbook about some experiments run in 1950s by Stanley Miller—experiments that are the strongest empirical evidence in favor of the Oparin-Haldane hypothesis. The Oparin-Haldane remained just a theory until Stanley L. Miller and his mentor H.C. Urey took it as the hypothesis for an experiment in 1953. Miller’s “apparatus for the electric discharge synthesis of amino acids” had three essential components to simulate, in miniature, the primitive earth ambience of particular gasses, heat, rain, and flashes of lightning. The first component was a small flask of boiling water. The water vapor from this flask would then enter the second compartment that had two electrodes with sufficient voltage to generate a spark. After passing through the charge, the water vapor would enter the third compartment, the condenser, where it was cooled, returned to liquid, and sent back to the boiling flask for the cycle to repeat. The initial ingredients were water, and a mixture of ammonia, methane, and hydrogen gas. The system ran for a week, after which the contents were analyzed by paper chromatography.[14]

                The results were more than satisfactory. Just as Wohler had produced urea without a kidney, it was once again proven that organic molecules (the building blocks of life) could be produced without the agency of living things. The visible products were an insoluble tar-polymer that coated the apparatus, and a red condensed liquid.[15] Miller was expecting to find that an analysis of the liquid would reveal a complex mixture containing small amounts of a random assortment of organic compounds, but this was not the case. The surprising breakthrough was the high yields of the two amino acids glycine and alanine, and to a lesser degree, glutamic acid and aspartic acid. The spontaneous synthesis of amino acids had been achieved![16] The mechanical-materialist mindset of western science allowed the experiment to be viewed as part of the grander evolutionary scheme.

This result, however, was a prebiotic chemical synthesis, that is, it was produced by an experiment conducted under laboratory settings, not randomly by natural causes. There is an implicit critique of the scientific process when one draws this distinction. The criticism is that prebiotic chemists have the option to run as many reactions as they would like until they achieve the desired product and can claim success, regardless of how many trials it took or how minuscule the desired product yields were. They then go on to the next step in their particular sequence of the chemical evolution of life where they use mass quantities of the purified organic compounds that their previous experiment may have only produced minute traces of![17] Their justification is that they must replicate in mere weeks what nature had billions of years to accomplish. This is a common objection of biblical creationists, but even supporters of the Miller-Urey experiment take exception to the belief in the absolute objectivity of the scientist. George Wald, a staunch believer in the Oparin-Haldane hypothesis, scoffs that such experiments definitively show that organic compounds could be produced without a living organism, because “organic chemists are alive….”[18]

                There are four flawed key elements, as previously mentioned, that are essential to the tenability of the Oparin-Haldane hypothesis and the resultant Miller-Urey experiment. The first of these crucial, yet controversial, issues is the composition of the primitive atmosphere, specifically its composition and reducing ability (ability to donate electrons). There is no way for scientists to directly sample the primitive atmosphere, so discussions of what gases were present are conjectures based on knowledge of volcanic gasses, and the composition of elements present in interstellar space. Chemical evolutionists have favored a reducing atmosphere that lacked any free oxygen. There are two mechanisms for producing oxygen naturally; one is the photo-dissociation of water molecules by ultraviolet light that splits the hydrogen from the oxygen molecule, or two, there is photosynthesis.[19] On the primitive earth, before life, we are left with the first option. Most scientists believe that it would take a very long time for a substantial amount of oxygen to accumulate in the atmosphere this way, yet Dean L. Overman cites a scientist from the Australian National University, J.H. Carver, as having calculated that photo-dissociation could have produced nearly 10% of the present level of oxygen in the early atmosphere.[20] That amount of oxygen in the environment would have oxidized the molecules present in the primordial stew, as well as decompose the fragile, new organic molecules such as amino acids. Wickramasinghe and Hoyle support the view of a less reducing atmosphere due to geological data that shows the earliest rocks show signs of oxidation.[21]  A second, minor point concerning the atmosphere involves the delicate balance between hydrogen and carbon dioxide required by the Urey-Miller experiment. If the ratio between hydrogen and carbon dioxide dropped below 1, only glycine would be produced. Methane and other reducing gasses would be required.[22]

                The second of the crucial, yet controversial, issues are the energy sources that are both necessary and yet dangerous to organic molecules and early life. If life began in the ocean that was essentially a gigantic chemical experiment, than that vast body of water would require a constant input of energy to prevent an equilibrium state from occurring (where the rate of organic molecules formed equaled the rate of organic molecules dissociated). Chemical equilibrium would mean the end of chemical evolution. Ultraviolet light would be an abundant and therefore ideal energy source for fueling the constant chemical reactions; however, ultraviolet light would also subject the organic molecule to mutation, damage, and complete destruction. If the atmosphere did lack free oxygen, as is accepted, then there would not be a protective ozone layer on primitive earth to shield the early precursors to life.[23]  Wald insists that the molecules were able to find shelter from solar radiation by remaining in the depths of the ocean until the ozone layer had formed. Solar radiation was only one of the constant energy sources that bombarded primitive earth. The constant stream of energy in the form of ultraviolet radiation, heat, and lightning, would force organic chemicals to form chemical bonds until they become the insoluble tar-polymer that was produced in the Miller-Urey experiment.[24] Organic molecules, once formed, needed protection from the environment..

                The third issue, that of a primordial soup containing the necessary building blocks for life, is the theory most widely accepted by the general public. If the protected molecules somehow managed to survive the ceaseless energy assault, they would still have to fight the tendency towards equilibrium in the liquid medium that they lived in.  As molecules grew and became more concentrated in relation to the soup around them, the forces of hydrolysis that they would have to overcome would be enormous.[25] Evidence points to the fact that life in the hypothetical primordial soup would have been very difficult, but it does not point to the existence of a rich organic soup. If such a prebiotic soup existed, and if there was a reducing atmosphere, then the ultraviolet rays would have caused the formation of heavy hydrocarbons that would have sank to the bottom of the primordial soup and formed sedimentary layers. There is however, nothing of this sort in the geological record.[26]

                Lastly, there is the issue of sufficient time.  One must remember that it is plausible that life would have formed given the right conditions during some time in the earth’s nearly five billion years—but this is incorrect way of viewing the situation. Time, is not as George Wald suggests, “the hero of the plot.”[27]

Between the stabilization of the earth, about 3.98 billion years ago, and the appearance of the first life form on the fossil record, about 3.85 billion years ago, there are only 130 million years for chemical evolution to occur.[28] 

Followers of both biblical creationism and panspermia share the critique that there was both a temporal and spatial insufficiency for the random and accidental creation of life. Even if reactions took only a few seconds and took up only a few square millimeters of primordial soup, most calculations seem to show the impossibility of the random creation of a viable protein or RNA strand. Creationists resent the notion that life is an accidental occurrence. Overman focuses on the nucleotide first scenario by pointing out in the Urey-Miller experiment, the amino acids were of both the left-handed (L-amino acids) and right-handed (D-amino acids) variety that will indiscriminately bond with each other, although biologically functional proteins are only composed of L-amino acids.[29] Overman cites a calculation by Walter L. Bradley and Charles B. Thaxton of the odds of the random production of a single protein. Bradley and Thaxton assumed that there was a 50% chance that the starting amino acid would be an L-amino acid, and a 50% chance that the amino acid would bond with another L-amino acid. They extended the amount of time available for experimentation to one billion years. Their end calculation for the probability of the random formation of amino acids into a simple protein was 4.9 x 10–191.[30]  Overman’s attempt to discredit the Oparin-Haldane theory of biogenesis is the result of his belief that a view that is dependent upon happenstance will lead to “relativistic ethics,” that is, will erode the Judeo-Christian code of morality.[31] But, if the theory of random causation persists, despite the evidence to the contrary, then “if life transcends the laws of physics and chemistry, then a rational conclusion is that a Person, not chance, and the laws of physics and chemistry, caused and is causing life.”[32]

                The panspermists, resent the notion that this was a random occurrence. Panspermia is made up of two notions concerning the extraterrestrial origins of life on earth. The older, more mystical version posits that a great race of extraterrestrial beings purposefully sent out microspores of chemical building blocks, and thus seeded the entire universe with life. The second, more modern notion takes into account the natural abundance of organic compounds that have been detected in interstellar space, and believes that asteroids and meteorites rich in organic compounds brought the precursors of life to earth. Their mathematical calculations show that the atmosphere of earth would have been capable of slowing down objects such as meteorites (thus preventing the destruction of the organic compounds during the high speed entry onto earth).[33] Some panspermists are compatible with the Oparin-Haldane hypothesis, such as Leslie E. Orgel, who worked closely with Miller, is a proponent of panspermia, as is George Wald. Others, such as Wickramasinghe and Hoyle completely reject the Oparin-Haldane hypothesis, saying that the random creation of life is as probabilistic as “…a typhoon blowing through a junkyard and constructing a Boeing 747.”[34] Panspermia is not grounded in any empirical science, but is merely the product of their optimistic faith. As Wold says “on this planet that is our home, we have every reason to wish it well. Yet should we fail, all is not lost. Our kind will try again elsewhere.”[35]

Each of the scientists involved in the origin of life have a small part of the puzzle, but none have attempted a synergy to find a new solution. Many are concerned with merely revealing the flaws evident in the arguments of others, and are as intent in disproving their opponents’ argument as their opponent was in producing their preconceived results.  Small degrees of success were lauded as fully plausible in prebiotic chemistry, thereby reducing stringent empirical science to blind religious faith.  The Oparin-Haldane and Urey-Miller paradigm is still in place, and there seems to be little else in the way of scientific theory to replace it. In 1871, Darwin wrote of a “warm little pond” with “light, heat, electricity, etc.” where life would originate.[36]  It is difficult to decide whether this is speaks of Darwin’s genius and foresight, or whether is speaks of our lack of progress. Let us revisit the primordial soup paradigm once more, but this time through its most famous proponent.

 

“It must be admitted from the beginning that we do not know how life began. It is generally believed that a variety of processes led to the formation of simple organic compounds on the primitive earth. These compounds combined together to give more and more complex structures until one was formed that could be called living. No one should be satisfied with an explanation as general as this.”[37]

                                                                                                                —Stanley Miller

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Works Cited

 

 

Curtis, Helena. Biology. New York: Worth Publishers, 1968.

 

Dyson, Freeman. Origins of Life. New York: Cambridge University Press, 1985.

 

Margulis, Lynn, and Dorion Sagan. What is Life.  New York: Simon & Schuster, 1995.

 

Miller, Stanley L.,  and Leslie E. Orgel. The Origins of Life on the Earth. Englewood Cliffs: Prentice-Hall, 1974.

 

Oparin, A. I The Origin of Life. Trans. Sergius Morgulis. New York: The Macmillan Company, 1938.

 

Oparin, A. I The Origin and Initial Development of Life. Trans. Moscow: Publishing House, 1966.

 

Orgel, Leslie E. The Origins of Life: Molecules and Natural Selection. New York: John Wiley & Sons, 1973.

 

Overman, Dean L. A Case Against Accident and Self-Organization. Lanham: Rowman & Littlefield Publishers, 1997.

 

Shapiro, Robert. Origins: A Skeptic’s Guide to the Creation of Life on Earth . New York: Bantam, 1987.

 

Wald, George. “The Origin of Life.” Scientific American Aug. 1954. Reprinted in Life: Origin and Evolution. San Francisco: W.H. Freeman, 1979.

 



[1] Lynn Margulis and Dorion Sagan, What is Life (New York: Simon & Schuster, 1995), 50.

[2] Helena Curtis, Biology (New York: Worth Publishers, 1968), 21-2.

[3] Margulis, 55.

[4] Leslie E. Orgel, The Origins of Life: Molecules and Natural Selection (New York: John Wiley & Sons, 1973), 181-2.

[5] Margulis, 57.

[6] A.I. Oparin, The Origin of Life, trans. Sergius Morgulis (New York: The Macmillan Company, 1938), 249

[7] A. I. Oparin, The Origin and Initial Development of Life, trans. (Moscow: Publishing House, 1966), 57.

[8] Freeman Dyson, Origins of Life (New York: Cambridge University Press, 1985), 31.

[9] Robert  Shapiro, Origins: A Skeptic’s Guide to the Creation of Life on Earth (New York: Bantam, 1987), 295.

[10] Dyson, 31-2.

[11] Shapiro, 141.

[12] Oparin, The Origin and Initial Development of Life, 5.

[13] Oparin, The Origin and Initial Development of Life, 23.

[14] Stanley L. Miller and Leslie E. Orgel, The Origins of Life on the Earth (Englewood Cliffs: Prentice-Hall, 1974), 83.

[15] Dean L. Overman, A Case Against Accident and Self-Organization (Lanham: Rowman & Littlefield Publishers, 1997), 40.

[16] Miller, 84-5.

[17] Shapiro, 180.

[18] George Wald, “The Origin of Life,” Scientific American Aug. 1954. Rpt. in Life: Origin and Evolution (San Francisco: W.H. Freeman, 1979), 50.

[19] Orgel, 110.

[20] Overman, 41-2.

[21] F. Hoyle and N.C. Wickramasinghe, Astronomical Origins of Life: Steps Towards Panspermia (Boston: Kluwer Academic, 1999), 104.

[22] Shapiro, 112.

[23] Overman, 42.

[24] Shapiro, 113.

[25] Shapiro, 113.

[26] Overman, 45-6.

[27] Wald, 50,

[28] Overman, 51.

[29] Overman, 44.

[30] Overman, 62.

[31] Overman, 195.

[32] Overman, 197.

[33] James L. Gould and William T. Keeton, Biological Science, 6th ed. (New York: W.W. Norton & Company, 1996), 530.

[34] Overman, 60.

[35] Wald, 56.

[36] Margulis, 56.

[37] Miller, 1.