In a recent ENV post, Stephen Meyer critiqued a May 2009 Nature paper co-authored by John D. Sutherland titled, “Synthesis of activated pyrimidine ribonucleotides in prebiotically plausible conditions.” The paper claimed to have produced RNA nucleobases under prebiotic conditions, but Meyer observed that it utterly failed to address the most crucial question in the origin of life (OOL): the origin of information, a topic Meyer addresses extensively in his new book Signature in the Cell.
Other scientists agree with Meyer. Organic chemist Dr. Charles Garner recently noted in private correspondence that “while this work helps one imagine how RNA might form, it does nothing to address the information content of RNA. So, yes, there was a lot of guidance by an intelligent chemist.”
Sutherland’s research produced only 2 of the 4 RNA nucleobases, and Dr. Garner also explained why, as is often the case, the basic chemistry itself also required the hand of an intelligent chemist:
As far as being relevant to OOL, the chemistry has all of the usual problems. The starting materials are “plausibly” obtainable by abiotic means, but need to be kept isolated from one another until the right step, as Sutherland admits. One of the starting materials is a single mirror image for which there is no plausible way to get it that way abiotically. Then Sutherland ran these reactions as any organic chemist would, with pure materials under carefully controlled conditions. In general, he purified the desired products after each step, and adjusted the conditions (pH, temperature, etc.) to maximum advantage along the way. Not at all what one would expect from a lagoon of organic soup. He recognized that making of a lot of biologically problematic side products was inevitable, but found that UV light applied at the right time and for the right duration could destroy much (?) of the junk without too much damage to the desired material. Meaning, of course, that without great care little of the desired chemistry would plausibly occur. But it is more than enough for true believers in OOL to rejoice over, and, predictably, to way overstate in the press.
Another anonymous pro-ID Ph.D. chemist privately wrote me similar criticisms of Sutherland’s paper:
They used pH manipulation, phosphate buffers and irradiation all at the correct times and amounts to achieve their goal, which was to produce “activated pyrimidine ribonucleotides.” Indeed, they could have shortened their title by chopping off the last four words and sent the paper to the Journal of Organic Synthesis and had a good chance of getting it accepted as a novel synthetic route with full credit to themselves for their clever manipulations. Certainly the fingerprints of several intelligent chemists are all over this pathway if not their rather ham fisted signatures.
Other control they exercised includes careful selection of the precursors, control of competing reactions by pH selection and the phenomenal phosphate concentration they used. Life in the modern ocean is phosphate limited as phosphate is generally about 0.5 micro-molar at the sea surface and only 2-4 micro-molar at depth. But what is a six order of magnitude enrichment among friends if it helps the cause!? Now they could argue that one gets that kind of enrichment in a tide pool but even that is a stretch.
Incidentally, now comes the hard parts: first, selectively hydrolyzing the cyclic 2′, 3′ phosphates to 3′- only, then getting them to polymerize ONLY at the 5′ position. And second, once you have a supply of various RNA molecules, spontaneously developing the required biochemical structure to convert the coded sequences into proteins. Of course, we have to hope that we get lucky and we guess the correct code on the first try. And all of this has to happen in the same tide-pool otherwise, well, you get the picture. It’s a bit of a stretch.
It is no wonder that whenever I see the word “plausible” in the title of an article, that I am reminded of the quote attributed to P.T. Barnum, “there is a sucker born every minute.”
“Plausible” is in the Eye of the Beholder
There are thus many instances in this research where the conditions they used were anything but, as the paper’s title claims, “prebiotically plausible conditions.” One such instance may have been the careful addition of the ‘just right’ quantity of UV light, where even the original Nature paper admits: “Although the issue of temporally separated supplies of glycolaldehyde and glyceraldehyde remains a problem, a number of situations could have arisen that would result in the conditions of heating and progressive dehydration followed by cooling, rehydration and ultraviolet irradiation.”
It’s no groundbreaking news story that there are potential sources of heat on the early earth. These “number of situations” referred to typically include proposals of heating and drying in intertidal pools or volcanic ridges where repeated cycles of heating and drying can take place. But mundane sources of heat are only a small part of the problem, which largely comes down to the fact that the proper amount of heat has to be carefully applied so as to not wipeout the desired molecular products. It’s quite easy to over-cook (or under-cook) the organic molecules, which tend to break down rapidly (i.e. cook) in the presence of heat.
This would have to be a fine balancing act that would also require just the right input of organic material, heat, and UV light, so as to avoid destroying the molecules. In other words, it’s a finely tuned system, the kind in which a successful scenario is very difficult to imagine without the input of intelligence. And of course, intelligently directed chemistry is exactly what provided the glycolaldehyde and glyceraldehydes in this recent research.
The Nature paper claims that the starting molecules are all “plausible prebiotic feedstock molecules,” but as Garner suggests, that claim turns on what we mean by “plausible.” In this case, the mechanisms of producing glycolaldehyde and glyceraldehyde are about as “plausible” as saying that if you have a pile of flour, baking powder, salt, butter, and eggs, you can produce a cake, given “the conditions of heating.” Any baker knows that the ingredients must be applied in the right quantities and the right order, and that “the conditions of heating” have to be applied at just the right level or you produce nothing worth eating. In the world of creating even the mere precursor molecules to ribonucleotides, it’s not just heating that’s necessary but also the proper amount and sequence of “the conditions of heating and progressive dehydration followed by cooling, rehydration and ultraviolet irradiation.”
As a third chemist put it to me, “The work was very carefully done. The problem is that it was very carefully done.” No kidding.
Of course, even some origin of life theorists recognize that this research is not relevant to plausible conditions on the early earth. A news article on the website of the Royal Chemistry Society stated:
However, Robert Shapiro, professor emeritus of chemistry at New York University disagrees. ‘Although as an exercise in chemistry this represents some very elegant work, this has nothing to do with the origin of life on Earth whatsoever,’ he says. According to Shapiro, it is hard to imagine RNA forming in a prebiotic world along the lines of Sutherland’s synthesis.
‘The chances that blind, undirected, inanimate chemistry would go out of its way in multiple steps and use of reagents in just the right sequence to form RNA is highly unlikely,’ argues Shapiro. Instead, he advocates the metabolism-first argument: that early self-sustaining autocatalytic chemosynthetic systems associated with amino acids predated RNA.
(Robert Shapiro quoted in James Urquhart, Insight into RNA origins, Royal Society of Chemistry (May 13, 2009).)
Of course Shapiro’s preferred “metabolism-first argument” has its own problems, but that’s a discussion for another day. Perhaps the most generous among the critical comments came from Albert Eschenmoser:
‘Of course, it is referring to an event of the past and therefore conclusions will never achieve a level of certainty as in other scientific fields,’ says renowned synthetic organic chemist Albert Eschenmoser. ‘But Sutherland’s work is a fundamental study referring to the problem of the origin of life. It is an exemplary piece of how to do synthetic organic chemistry research under very serious constraints of prebiotic chemistry,’ Eschenmoser adds.
(Albert Eschenmoser quoted in James Urquhart, Insight into RNA origins, Royal Society of Chemistry (May 13, 2009).)
Eschenmoser’s words are worth remembering next time someone objects to intelligent design on the grounds that it isn’t scientific because it pertains to events that took place in the deep past.