Academic journals are not the places to find fundamental critiques of Origins of Life (OOL) research. In most cases, publications are reports of research funded to advance knowledge of how life emerged from precursor chemical mixtures. Nevertheless, academic critiques of OOL research do exist, and one recent example is “Time Out” by Professor James Tour, a synthetic organic chemist from Rice University, USA. Tour’s research involves synthesizing complex organic molecules from simple precursors, so he is well equipped to understand what the OOL researchers are doing, and to evaluate the merits of their claims about what has been achieved.
Tour recognizes that the Miller/Urey research of 1952 was “electrifying”, because it seemed fair to say that the discipline of synthetic chemistry was beginning to provide answers to our questions about OOL. He writes these cautionary words:
“The excitement was justified, but premature. Origins of life (OOL) research has, to be sure, become progressively more sophisticated, but its goal—to explain the origins of life—remains as distant today as it was in 1952. This is not surprising. The protocols in use have remained unchanged: buy highly purified chemicals; mix them together in high concentrations and in a specific order under carefully devised laboratory conditions; derive a mixture of compounds; and publish a paper making bold claims about OOL. These protocols are as unrealistic as they are unimproved.”
Tour goes on to substantiate these comments about inflated claims. He refers to recent publications of OOL scientists to point out their blind spots and their substitution of hype for reasoned argument.
After this, he addresses an even more fundamental question: is life just an issue for of chemists to address, or are there other aspects that require our attention? The problem for many readers is that the terminology gets complicated and it is difficult for non-chemists to follow the argument. However, it is important to realise that James Tour is writing to professional colleagues, and he uses language they can understand. Tour moves on from the synthesis of the complex molecules of life to their interactions. This is how he introduces the “Interactome”:
“A functioning cell contains a complex non-covalent interactive system. Nobody knows how a cell emerges from its molecular components. An interactome is the set of molecular interactions in a given cell. Interactions may be between proteins, genes, or molecules. Information is transferred within the cell through these molecular interactions. Electrostatic potentials permit information to flow through non-covalent molecular arrays, but these arrays require specific orientation. The interactome defines these intermolecular orientations, alignments that are unattainable through random mixing.”
Most OOL research does not get beyond the chemistry: the building blocks of the cell or letters of the alphabet that could be turned into a poem. Those few researchers that write about the origins of cell communication realize quickly they are out of their depth! Tour draws attention to a paper in Protein Science that recognizes the challenge of assembling the cell’s control infrastructure:
“[t]he inability of the interactome to self-assemble de novo imposes limits on efforts to create artificial cells and organisms, that is, synthetic biology. In particular, the stunning experiment of “creating” a viable bacterial cell by transplanting a synthetic chromosome into a host stripped of its own genetic material has been heralded as the generation of a synthetic cell (although not by the paper’s authors). Such an interpretation is a misnomer, rather like stuffing a foreign engine into a Ford and declaring it to be a novel design. The success of the synthetic biology experiment relies on having a recipient interactome … that has high compatibility with donor genetic material. The ability to synthesize an actual artificial cell using designed components that can self-assemble spontaneously still remains a distant challenge.
The more we learn about the complexity of cells and the way information is communicated incessantly, the more absurd it appears for anyone to use the word “simple” when describing cellular mechanisms and information channels. This is a major weakness of OOL research; it consistently underplays both complexity and information.
Tour quotes a 2018 paper in Progress in Biophysics and Molecular Biology, which concedes the following:
“The transformation of an ensemble of appropriately chosen biological monomers (e.g. amino acids, nucleotides) into a primitive living cell capable of further evolution appears to require overcoming an information hurdle of super-astronomical proportions, an event that could not have happened within the time frame of the Earth except, we believe, as a miracle. All laboratory experiments attempting to simulate such an event have so far led to dismal failure.”
These astronomically low probabilities of life emerging have led these authors, along with others, to postulate an extra-terrestrial source of life. However, although they often provide valid critiques of the OOL literature, their cosmological origin alternative does not add anything to our understanding of causation. Despite their “black box” approach to OOL, it does enable them to live with the “dismal failure” of efforts to create “life in the lab”.
Some take-home messages:
- OOL research has hit a brick wall, and the finding of science is that life does not spontaneously emerge from a primordial mix of chemicals.
- The information hurdle faced by OOL researchers is one of super-astronomical proportions.
- Hype is pervasive. (Finding water on astronomical bodies, and detecting simple carbon-based molecules in space are not signs that life is there and waiting to be discovered.)
- Be alert to hype parading itself as science – hype has many blind spots and does not follow the evidence wherever it leads.
Tompa, P. and Rose, G.D. 2011, The Levinthal Paradox of the Interactome. Protein Science, 20, No. 12, 2074-2079.
Tour, J. 2019. Time Out. Inference, Vol. 4, No. 4, (July).