Origin of life : testing the isotopic resonance hypothesis

The Miller-Urey (MU) experiment provided evidence supporting the abiogenesis theory, and is considered to be the seminal experiment in the context of origin of life. The MU mixture produced in the experiment is assumed to be an essential raw material for life emergence on the primitive Earth or beyond. However, there was no direct experimental evidence that this primordial soup supports life. In this thesis, we provided a proof that the abiotically produced MU mixture can support the growth of primitive living organisms, such as bacteria Escherichia coli.

The recent Isotopic Resonance hypothesis suggests that the rates of chemical and biochemical reactions are not monotonous upon the enrichment degree of isotopic composition of reactants. Instead, at some “resonance” isotopic conditions with certain compositions of CHON, the kinetics increases or decreases compared to the “off-resonance” conditions. To test the predictions of this hypothesis, we designed a precise (standard error ±0.05%) method to explore the bacterial growth behaviour under different isotopic compositions. A number of predicted resonances including the terrestrial resonance and several other non-terrestrial resonances were tested, with significant enhancements in kinetics discovered at most of these conditions. The terrestrial resonance was intensively studied with multiple living organisms including prokaryotic bacteria Escherichia coli, eukaryotic yeast, mammalian RKO cells, grass seeds and shrimp. All obtained results strongly confirm the preference of living organisms for the terrestrial resonance and support the validity of isotopic resonance phenomena.

Our study confirmed that the MU-type process created hospitable environment for early life, which further benefited from the presence of the terrestrial isotopic resonance.

List of scientific papers

I. Xie, X., Backman, D., Lebedev, A. T., Artaev, V. B., Jiang, L., Ilag, L. L., Zubarev, R. A. Primordial soup was edible: abiotically produced Miller-Urey mixture supports bacterial growth. Sci Rep. 5, 14338.
https://doi.org/10.1038/srep14338

II. Xie, X., Zubarev, R. A. Effects of low-level deuterium enrichment on bacterial growth. PLoS One. 9, e102071, (2014).
https://doi.org/10.1371/journal.pone.0102071

III. Xie, X., Zubarev, R. A. Effects of low-level deuterium enrichment and depletion on yeast growth, seed germination and mammalian cell growth. [Manuscript]

IV. Xie, X., Zubarev, R. A. On the effect of planetary stable isotope compositions on growth and survival of terrestrial organisms. [Accepted]
https://doi.org/10.1371/journal.pone.0169296

V. Xie, X., Zubarev, R. A. Isotopic Resonance Hypothesis: experimental verification by Escherichia coli growth measurements. Sci Rep. 5, 9215, (2015).
https://doi.org/10.1038/srep09215