Evolution News has commented already on Rice University chemist James Tour’s video series on the origin of life, which details common misperceptions about the state of origin-of-life research (here, here, here, here, here). I watched the series in complete awe as Dr. Tour exposed how the vast majority of journal articles published under the rubric of origin-of-life research have no direct relevance to addressing the actual question of how a cell could have emerged on the early earth. The videos detail several of the monumental challenges that apply to all origins scenarios. The technical details can come across as quite daunting, but the problems addressed in each video can largely be summarizing in simple terms.
Exquisite Exactness of Protocols
Seemingly, the simplest task should be identifying how the building blocks for the first cell could have emerged. Yet, experiments over the greater part of the last century have consistently demonstrated that even this stage faces monumental challenges. In particular, the synthesis of complex amino acids, nucleotides, carbohydrates, and lipids all require exquisite exactness in the synthesizing protocols that include dozens, if not hundreds, of properly ordered steps.
Many steps entail precise adjustments in temperature, pH, the physical environment, and other conditions. In addition, chemicals must often be introduced that could not plausibly have existed on the early earth in non-trace quantities, and several physical conditions must be employed that could never have realistically existed in just the right locale at just the right time, or perhaps not at all (e.g., vacuum pressure). Such research has no direct bearing on what could have occurred in any setting at any time in earth’s history.
Requirement of Relay Synthesis
Moreover, the yields of intermediate molecules are often in very small quantities mixed with multiple other molecules, many of which are extremely similar to the biologically relevant ones. If the other products were not removed, interfering cross-reactions would block additional progress toward the target molecules. No natural process could have isolated and concentrated an intermediate sufficiently for the next step in any pathway to have commenced at a useful rate.
To make any semblance of progress, researchers must resort to relay synthesis where they constantly restart with intermediate molecules in sufficiently high concentrations and purity to force each step to proceed artificially. Even if the series of experimental conditions in a protocol corresponded to actual interlinked environments on the early earth, the requirement of such extreme intervention — what Dr. Tour labeled as “cheating” — would still completely disconnect the experiments from attempts to identify an undirected route to life’s origin.
The irrelevance of such research was perhaps best articulated by leading origins researcher Robert Shapiro:
The analogy that comes to mind is that of a golfer, who having played a golf ball through an 18-hole course, then assumed that the ball could also play itself around the course in his absence. He had demonstrated the possibility of the event; it was only necessary to presume that some combination of natural forces (earthquakes, winds, tornadoes and floods, for example) could produce the same result, given enough time. No physical law need be broken for spontaneous floods formation to happen, but the chances against it are so immense, that the suggestion implies that the non-living world had an innate desire to generate RNA. The majority of origin-of-life scientists who still support the RNA-first theory either accept this concept (implicitly, if not explicitly) or feel that the immensely unfavorable odds were simply overcome by good luck.
Tomorrow, “James Tour Video Series on the Origin of Life — Properly Combining Building Blocks.”