`In the beginning was the raw material of life: rocks and boiling, bubbling mud, small pools and puffs of subterranean steam ... all were features of an unstable world. They help to set the stark scene of 4,000 million years ago that greets you as you enter Evolution House.'The main problem for the Kew exhibit, and for all of the propounders of this scenario for the origin of life, is that it lacks any scientific support. It is completely hypothetical - but very few people seem to have noticed!
A modern advocate of this route to chemical evolution is Richard Dawkins. In his view, life is an amazingly lucky accident:
`...We go to a chemist and say...fill your head with formulae, and your flasks with methane and ammonia and hydrogen and carbon dioxide and all the other gases that a primeval nonliving planet can be expected to have; cook them all up together; pass strokes of lightning through your simulated atmospheres, and strokes of inspiration through your brain; bring all your clever chemist's methods to bear, and give us your best chemist's estimate of the probability that a typical planet will spontaneously generate a self-replicating molecule. Or, to put it another way, how long would we have to wait before random chemical events on the planet, random thermal jostling of atoms and molecules, resulted in a self- replicating molecule? ... we'd have to wait a long time by the standards of a human lifetime, but perhaps not all that long by the standards of cosmological time....even if the chemist said that we'd have to wait for a "miracle", have to wait a billion years - far longer than the universe has existed, we can still accept this verdict with equanimity. There are probably more than a billion available planets in the universe. If each of them lasts as long as Earth, that gives us about a billion planet-years to play with. That will do nicely! A miracle is translated into practical politics by a multiplication sum.' (Dawkins, R., The Blind Watchmaker, Penguin: London, 1991, page 145)
Modern theories of abiogenesis are traced back to the Russian biochemist Alexander Oparin who, in 1924, proposed a scheme of chemical evolution. Others picked up the theme: Haldane (1928), Bernal (1947) and Urey (1952). The latter's main contribution was to suggest an initial, hydrogen-rich, reducing atmosphere for the early earth.
Stanley Miller provided experimental data on the synthesis of organic materials which might be collected in a primeval pool. He worked initially (1952) with an atmosphere of methane, ammonia, hydrogen and water vapour (later experiments added other gases, notably carbon dioxide). Electrical discharges produced organic compounds. Numerous research investigations have taken place since Miller began, and in the products of the reaction, ten of the twenty amino acids found in living things have been synthesised naturally. Numerous other compounds were also detected, but these were not deemed so interesting as they do not occur in the proteins of life. It should perhaps be noted that these experiments have produced equal quantities of right-handed and left-handed organic molecules. This is quite different to the amino acids in living systems, where only left-handed molecules occur. The production of left-handed molecules is routine for living systems - but it is a fundamental problem to get them from a primeval soup.
Charles Darwin is often credited with having anticipated the modern chemical evolution scenario, based on ideas he expressed privately in a letter to Joseph Hooker in 1871.
`It is often said that all the conditions for the first production of a living organism are now present, which could ever have been present. But if (and oh! what a big if!) we could conceive in some warm little pond, with all sorts of ammonia and phosphoric salts, light, heat, electricity, &c., present, that a proteine (sic) compound was chemically formed ready to undergo still more complex changes, at the present day such matter would be instantly absorbed, which would not have been the case before living creatures were found.'Of course, this quotation is only from a private letter. In his public writings, Darwin made reference to the activity of the Creator initiating life. The general view seems to be that Darwin was making a public statement which he was not fully committed to. Thus, Orgel wrote:
`Darwin, bending somewhat to the religious biases of his time, posited in the final paragraph of The Origin of Species that "the Creator" originally breathed life "into a few forms or into one." Then evolution took over: "From so simple a beginning endless forms most beautiful and most wonderful have been, and are being evolved." In private correspondence, however, he suggested life could have arisen through chemistry, "in some warm little pond, with all sorts of ammonia and phosphoric salts, light, heat, electricity, etc. present".' (Orgel L.E., `The Origin of Life on the Earth', Scientific American, October 1994, p.53).This perception of the situation was shared by Carl Henry:
`But the closing paragraph of The Origin of Species offered a sop to the Christian tradition. There Darwin admits the possibility of a divine origination of the first living cells from whence all else came.' (Henry C.F.H., `Science and Religion', in Henry C.F.H., ed., Contemporary Evangelical Thought: A Survey, Baker: Grand Rapids MI, 1968, p.253)
The reality is that the `warm little pond' scenario should have been abandoned at least 20 years ago! There are three major lines of evidence against it, all of which are well documented in the academic literature:
1. There is no evidence for an early earth with a reducing atmosphere. The consensus now is that the early atmosphere was neutral: composed of carbon dioxide, nitrogen, water and perhaps 1% hydrogen. There is a strong case to be made for the presence of oxygen also. The neutral atmosphere makes the stability of organic molecules a matter of doubt - they would be degraded and lost very quickly.
2. Results from revised Miller-type experiments are quite different. With a neutral atmosphere of water, nitrogen and carbon dioxide, the reaction products are ammonia and nitric acid. Using the most favourable mix of gases, the yield is only about 0.01% amino acid, almost all lysine.
3. Biogenic carbon (derived from living cells) has been detected in the earliest rocks yet discovered in the earth -so there is no record of a time when life was not present! (This is why the date of 4,000 million years was used by John Lucas in his report of the Kew exhibition - there are no rocks known of this age). The origin of life has to be pushed back to where no data is available to constrain models.
Thaxton, Bradley & Olsen have a chapter entitled `The Myth of the Prebiotic Soup' in their book: The Mystery of Life's Origin. This summarises the evidence for the statements given above.
`Based on the foregoing geochemical assessment, we conclude that both in the atmosphere and in the various water basins of the primitive earth, many destructive interactions would have so vastly diminished, if not altogether consumed, essential precursor chemicals, that chemical evolution rates would have been negligible. The soup would have been too dilute for direct polymerization to occur. Even local ponds for concentrating soup ingredients would have met with the same problem. Furthermore, no geological evidence indicates an organic soup, even a small organic pond, ever existed on this planet. It is becoming clear that however life began on earth, the usually conceived notion that life emerged from an oceanic soup of organic chemicals is a most implausible hypothesis. We may therefore with fairness call this scenario "the myth of the prebiotic soup."' (Thaxton, C.B., Bradley, W.L. & Olsen, R.L., The Mystery of Life's Origin: Reassessing Current Theories, Lewis & Stanley: Dallas TX, 1992, p.66).
Why this persistent acceptance of a disproved scenario? The prebiotic soup provides a `creation myth' that is desperately needed by naturalistic scientists. Some have taken the plunge elsewhere and gone extraterrestrial -but few find this convincing either. Can this be science? The best that naturalists can legitimately say is that there is no model of chemical evolution which has survived critical scrutiny and there is no prospect of an imminent solution.
The naturalist rejects intelligent causation - but this explanation is exactly what Christians have come to expect from their reading of the Bible. The creation approach to origins explains why the earth carries evidence of life from its earliest history.
David J. Tyler (1996)