by Dr. Hugh Ross and Dr. Fazale ("Fuz") Rana
Some scientists’ commitment to finding a naturalistic explanation for the (basically miraculous) origin of life on this Earth remains firm – but the demands of that commitment are becoming much higher. It requires "blinder" faith than ever, in light of recent findings.
Since the early 1950s, when Stanley Miller claimed to have established an experimental foundation for doing naturalistic origin-of-life research, 1, 2 one group in particular has made that inquiry their main focus.
This past July, the most distinguished members of this coterie gathered at the University of California San Diego for ISSOL ’99, a gathering that combined the 9th meeting of the International Society for the Study of the Origin of Life (ISSOL) with the 12th International Conference on the Origin of Life.
FACTS for FAITH sent us to that conference to learn more (than we can see in print) about the latest ideas and efforts in the naturalistic-origin-of-life community, as well as its current personalities, interactions, and overall mood.
Despite international publicity, an attractive venue, and the infrequency of these meetings (held only every three years), attendance seemed surprisingly low – about 300. The content was limited to 90 talks and about 150 poster displays, also low for a conference of this magnitude.
A greater surprise was the dearth of "rising stars," that is, up-and-coming researchers. Most participants were origins-of-life veterans, accompanied by a few graduate students, most all funded by NASA’s Specialized Center for Research and Training (NSCORT) in "exobiology" (outer-space life).
The prevailing mood of the week-long conference contrasted starkly with the usual excitement of scientific meetings. Typically at such meetings, the atmosphere crackles with joy and anticipation; as participants hear about breakthroughs large and small, hopes for profound progress soar.
In San Diego, though, the mood was grim. We sensed frustration, pessimism, and desperation. Some 45 years of well-funded investigation have led to one dead end after another. The same intractable problems still remain, with no glimmerings of resolution in sight.
Midway through the first presentation – at 9:30 in the morning on the first day of the meeting – the doom and gloom descended. A solid report (detailed in the technical second half of this article) showed that the most-probable atmosphere for the primitive Earth (CO 2 + N 2 + H 2O) would not have supported any possible nonbiological synthesis of biotic molecules. 3
With that point conceded, origin-of-life researchers were left only to hope for tiny, localized sources of the all-important reducing gas (rich in hydrogen, with no oxygen present), which would have been essential for the production of such molecules.
Progress or regress?
Such hope rested in the possibility that exhalations from ancient volcanoes contained reducing gas. But it dimmed to the vanishing point by mid-afternoon of the meeting’s first day, when a researcher presented potent evidence against this scenario. 4
So what next? When all else fails, look to outer space – to other solar system bodies and beyond – for the origin of prebiotic molecules and life itself. Meaning that naturalists have moved to a fall-back position: Prebiotic molecules were long ago delivered to Earth by comets and meteorites. 5
Yet this hope, too, was soon dashed. Before the end of the conference’s second day, researchers had to agree that extraterrestrial delivery could not have supplied all the needed prebiotic molecules. 6 Moreover, any prebiotic molecules delivered to Earth via comets and meteorites would not have been properly homochiral (as in "right-handed" or "left-handed") – and proper homochirality is an essential condition for life. 7
Then New York University’s Robert Shapiro further took the life out of meteorites. Using the chemical classes of compounds found in the Murchinson meteorite, Shapiro showed that side reactions would effectively prevent any prebiotic molecules in the meteorite from ever spontaneously forming life molecules. 8
The meeting closed on Friday with a number of papers dashing hopes for a Martian origin of life. 9, 10, 11 Worse yet, these papers undermine the observational foundations for the formation of life anywhere in our solar system when it was young.
Considering the many scientific problems presented at ISSOL ’99 (more details in the paragraphs that follow), we must conclude that the pursuit of a naturalistic model for life’s origin is driven by something more than a commitment to truth.
Earth was no incubator
Now for a more-technical presentation of the problems shown with naturalistic origin-of-life proposals – for one, the absence of reducing gases on early Earth. First we should note that the volcanic exhalations we observe today are composed of H 2O, CO 2 and SO 2 (the three Os mean these exhalations contain lots of oxygen). Given that prebiotic synthesis of organic molecules requires an environment free of both molecular oxygen and reactive oxygen, the presence of these oxides argues against spontaneous synthesis – unless volcanic exhalations in the past were different.
If they were different – specifically if they were reducing by some as-yet-unknown natural means – then volcanic lightning theoretically could have supplied the energy needed to drive prebiotic molecule synthesis. Yet before the end of the first day of ISSOL ’99, that hope was shot down by John Delano, of NSCORT-NY and the University of Albany (SUNY). Delano reported firmly that chromium-oxygen barometry greatly limited the type of gaseous emissions possible from volcanoes on the primitive Earth. As far back as 4 billion years ago, Delano assured conferees, the volatiles released from volcanoes were identical to those exhaled today. 12
Further reducing the hope of finding reducing gases on the primitive Earth was the report by Ivan Draganic, of the Institute of Nuclear Sciences, Vinca (formerly part of Yugoslavia). Draganic has been researching radiation levels, specifically ionizing radiation levels, in the ancient Earth’s crust and oceans (the hydrosphere). He determined these levels from 40K and 235U decay.
At ISSOL ’99, Draganic declared that researchers have too-long ignored the impact of this radiation, which would promote production of certain oxygen "species" ( species here meant in a chemical rather than a biological sense) by breaking down water molecules.
Modern tests confirm that as ionizing radiation comes in contact with water, it yields, through standard reaction pathways, molecular oxygen, hydrogen peroxide and other high-energy oxygen species. We can conclude, then, based on the ubiquitous presence of radioactive decay, which is unaffected by other environmental factors, that the early Earth did indeed produce these oxygen species over its entire surface, uninterrupted and undisturbed throughout its early history. Earth’s ancient hydrosphere was undoubtedly oxidizing.
Since even the smallest amounts of molecular oxygen or reactive oxygen prove devastating to any naturalistic pathway to life assembly, Draganic’s research only adds to the accumulating evidence that the hydrosphere (not to mention the atmosphere) of primitive Earth thwarts rather than supports the case for spontaneous self-assembly of life-essential molecules .13
The implications of Draganic’s report provoked a minor furor. Several conferees rushed to the platform microphone to propose ways around the (lethal-to-prebiotic-molecules) oxygen problems. Yet none of their suggestions were convincing.
For even if there were a mechanism to remove that troublesome oxygen, the continuous production of oxygen species through the irradiation of the planet’s water would result in at least some steady-state level of oxygen in Earth’s hydrosphere – and quite likely in its atmosphere too.
Life on Earth too quick
This lack of a route for the prebiotic synthesis of biotic molecules did, of course, pose a big problem to the goals of ISSOL ’99. This problem worsened with a presentation on the solid evidence for the very early appearance of life on Earth. While paleogeochemistry debunks the notion of a prebiotic soup, 14 it does provide strong evidence that life existed on Earth as much as 3.86 billion years ago.
This finding comes from study of the 12C to 13C ratio of carbon deposits in the earliest Earth rocks. 15, 16 Those who challenged this finding, claiming that 12C to 13C ratios result from crustal changes rather than from biochemical processes, also saw their hopes dashed.
Manfred Schidlowski, of the Max Plank Institut für Chemie, demonstrated that even if geometamorphosis does occur, it consistently alters the 12C to 13C ratios in a counterproductive direction. In other words, the paleogeochemical results are correct, indicating that life was here on Earth 3.86 billion years ago. 17 Since Earth was frequently sterilized by collision events prior to 3.5 billion years ago, this means several origins of life recurred, and at least a few must have happened rather quickly. 18
No sugar in meteorites
The strength of evidence against a naturalistic life origin on Earth has been turning scientists’ attention outward, to the solar system and beyond. The most widely publicized current explanation for life’s early, quick appearance on Earth is that comets and meteorites carried prebiotic molecules here. 19
This scenario requires that sugars be among the molecules carried to Earth from space. So meteorite researchers have looked long and hard for traces of sugars in meteorite samples.
George Cooper, of the NASA-Ames Research Center, has been fine-tooth combing the Murchinson meteorite. 20 At the conference, he reported that his team found small amounts of ethylene glycol and glycerol, and vanishing trace levels of C3 and C4 polyols – but they were not able to find any sugars. Which means that even if, on the long shot, comets and meteorites did transport some prebiotic molecules to Earth, they certainly did not bring an adequate variety to produce life.
Another proposed starting place for life is Mars. Evidence affirms that in its early history Mars was indeed a warm, wet planet – and thus, according to this theory, a suitable locale for life’s origin.
Near the close of ISSOL ’99, Michael Carr contradicted that idea with findings from the U.S. Geological Survey. Carr’s modeling studies indicated that warm, early Mars was dramatically transformed into cold, arid Mars about 3.8 billion years ago. This aridization occurred soon after a period of heavy meteor bombardment – bombardment sufficient to "sterilize" the planet. In other words, Mars seems a less likely cradle for life than Earth. 21 Also note that the bombardment of Mars occurred at a time when life on Earth was already flourishing .
In the face of such findings, researchers have begun scouring the dust of far-distant, newly-forming solar systems (proto-solar systems) for any "signs of life." In the nearest-to-us proto-solar systems, astronomers have found hydrogen cyanide (HCN) and some polyaromatic hydrocarbons (PAHs). 22 But such findings far from prove any case for life-formation elsewhere; that remains an open question, plagued with obvious problems.
For example, HCN will not, on its own, produce organic molecules that can convert to useful biological molecules. In fact, in the presence of water HCN gets quickly converted to formic acid. 23 As for PAHs, their chemical stability argues against them ever converting to useful prebiotic molecules.
That tough homochirality hand
ISSOL ’99 presenters also reported on the latest attempts to account for homochirality, the amazing consistency and necessity of life forming with amino acids that are exclusively left-handed and with sugars that are exclusively right-handed (with reference to the configuration of their chemical bonds). To their credit, these scholars acknowledged they have made no significant progress in accounting for this pattern.
Arizona State University’s John Cronin and Sandra Pizzarello reported the detection of a slight chiral excess of ±-methyl, ±-amino acids in the Murchinson meteorite. 24 To explain this chiral excess, they suggested we look at the circularly polarized ultraviolet (UV) light present in a proto-solar system, which would preferentially destroy only certain amino acids.
Yet Jeremey Bailey, of the Anglo-Australian Observatory, cautioned that we must use quite-challenging criteria before accepting the above UV scenario: We would have to find a reflection nebulae in just the right location to generate and reflect circularly polarized light, without any additional sources of UV light nearby 25 – for any such source would indiscriminately destroy all organic and prebiotic molecules present.
To date, astronomers’ observations of reflection nebulae show only a 17% excess of circularly polarized light in the nebulae’s infrared region, an insufficient quantity to account for the 100% chiral excess. And though model calculations suggest this circularly polarized light may extend somewhat into the UV region, no one has yet made any direct observation of this phenomenon.
And there’s another problem, too: If the intensity of the circularly polarized light is too great, it will increase the chiral excess, but it will also destroy the organics overall. Obviously, these offsetting parameters severely limit the possibilities for chiral excess.
A further problem: Selective destruction of organics (the ones with the "wrong-handed" configuration) within circularly polarized light requires that the light be monochromatic. 26 Reflection nebulae cannot provide such light.
Eventually, frustration over the homochirality problem grew so extreme that one ISSOL ’99 speaker suggested we "pass the problem to others." He asked biologists and biochemists to look into showing that homochirality is not essential to life’s formation. In other words, if we can’t get around it, let’s get rid of it, regardless of the chemical consequences!
Ideology vs. truth
The ISSOL ’99 conference suggested to us that origin-of-life research is a waning discipline. Few qualified scholars are preparing and seeking to become active participants in it. NASA’s recent focus on the search for extraterrestrial life has for a time bolstered the inquiry – although shifting it from an Earth-based focus to a somewhere-out-there focus.
On the one hand, our firm belief in the supernatural origin of life would seem to oppose this apparent waste of talent and tax dollars. However, we do not necessarily see this research as a waste.
If nothing else, it continues to strengthen our position, our conviction that life’s existence on Earth requires the intricate planning, indescribable power, and unswerving purpose of a divine Creator. Some people seem to need more "proof" than others, and God cares for them as much as for those who need less evidence – or evidence of a different kind.
1. Stanley L. Miller, "A Production of Amino Acids Under Possible Primitive Earth Conditions," Science 117 (1953), 528-529.
2. Stanley L. Miller, "Production of Some Organic Compounds Under Possible Primitive Earth Conditions," Journal of the American Chemical Society 77 (1955), 2351-2361.
3. Francois Raulin, "Atmospheric Prebiotic Synthesis," 12th International Conference on the Origin of Life and the 9th International Society for the Study of the Origin of Life meeting, San Diego, CA (1999). Hereafter referred to as ISSOL ’99.
4. John W. Delano, "Cr Oxygen Barometry: Oxidation State of Mantle-Derived Volatiles Through Time," ISSOL ’99.
5. Christopher F. Chyba et al. "Cometary Delivery of Organic Molecules to the Early Earth," Science 249 (1990), 366-373.
6. George Cooper et al., "Polyhydroxylated Compounds in Carbonaceous Meteorites," ISSOL ’99.
7. John Cronin et al., "Meteorite Amino Acids and the Origin of Homochirality," ISSOL ’99.
8. Robert Shapiro, "The Homopolymer Problem in the Origin of Life," ISSOL ’99.
9. Michael H. Carr, "The Habitability of Early Mars," ISSOL ’99.
10. Daniel P. Glavin et al., "Amino Acids in Martian Meteorite Nakhla," ISSOL ’99.
11. Daniel P. Glavin et al., "Amino Acids in the Martian Meteorite Nakhla," Proceedings of the National Academy of Sciences USA 96 (1999), 8835-8838.
12. John W. Delano, "Cr Oxygen Barometry: Oxidation State of Mantle-Derived Volatiles Through Time," ISSOL ’99.
13. Ivan G. Draganic, "Oxygen and Oxidizing Free-Radicals in the Hydrosphere of Early Earth," ISSOL ’99.
14. Hubert P. Yockey, "The Soup’s Not On," Facts & Faith , Vol. 10, No. 4 (1996), 10-11.
15. Minik T. Rosing, "13C Depleted Carbon Microparticles in >3700-Ma Sea-Floor Sedimentary Rocks from West Greenland," Science 283 (1999), 674-676.
16. S.J. Mojzsis, G. Arrhenius, K.D. McKeegan, T.M. Harrison, A.P. Nutman, and C.R.L. Friend, "Evidence for Life on Earth Before 3,800 Million Years Ago," Nature 384 (1996), 55-59.
17. Manfred Schidlowski, "Carbon Isotopes as a Biogeochemical Tool: Evolution of a Concept," ISSOL ’99.
18. Hugh Ross, The Genesis Question (Colorado Springs, CO: NavPress, 1998), 90.
19. Christopher F. Chyba, et al. "Cometary Delivery of Organic Molecules to the Early Earth," Science 249 (1990), 366-373.
20. George Cooper et al. "Polyhydroxylated Compounds in Carbonaceous Meteorite," ISSOL ’99.
21. Michael H. Carr, "The Habitability of Early Mars," ISSOL ’99.
22. David W. Koerner, "The Evolution of Early Solar System Analogs," ISSOL ’99.
23. Charles B. Thaxton et al., The Mystery of Life’s Origin. Reassessing Current Theories (Dallas, TX: Lewis and Stanley, 1984), 48-50.
24. John Cronin et al., "Meteorite Amino Acids and the Origin of Homochirality," ISSOL ’99.
25. Jeremey Bailey "Astronomical Sources of Circularized Polarization and the Origin of Homochirality," ISSOL ’99.
26. Stephen Mason, "Extraterrestrial Handedness," Nature 389 (1997), 804.