ARTICLE | doi:10.20944/preprints202201.0354.v2
Subject: Life Sciences, Biophysics Keywords: origin of life; disspative structuring; prebiotic chemistry; abiogenisis; non-equilibrium thermodynamics; thermodynamic dissipation theory
Online: 31 January 2022 (13:13:26 CET)
There is little doubt that life's origin followed from the known physical and chemical laws of Nature. The most general scientific framework incorporating the laws of Nature and applicable to most known processes to good approximation, is that of thermodynamics and its extensions to treat out-of-equilibrium phenomena. The event of the origin of life should therefore also be amenable to such an analysis. In this paper, I describe the non-equilibrium thermodynamic foundations of the origin of life for the non-expert. This ``Thermodynamic Dissipation Theory for the Origin of Life'' is founded on Classical Irreversible Thermodynamic theory developed by Lars Onsager, Ilya Prigogine, and coworkers.
ARTICLE | doi:10.20944/preprints202101.0500.v1
Subject: Life Sciences, Biochemistry Keywords: origin of life; disspative structuring; prebiotic chemistry; abiogenisis; adenine
Online: 25 January 2021 (13:57:05 CET)
I describe the non-equilibrium thermodynamics and the photochemical mechanisms which may have been involved in the dissipative synthesis, proliferation, and evolution of the fundamental molecules at the origin of life from simpler and more common precursor molecules such as HCN, H2O and CO2 under the impressed UVC photon flux of the Archean. The fundamental molecules absorb strongly in this UVC region and exhibit strong coupling between their electronic excited and ground states which endows them with efficient photon disipative capacity (broad wavelength absorption and rapid radiationless dexcitation) suggestive of dissipative structuring. The autocatalytic nature of the synthesized molecules in dissipating the same photochemical potential that directed their synthesis leads to their proliferation. The non-linearity in the photochemical and chemical reaction rates provides numerous stationary states which can be reached by amplification of a molecular concentration fluctuation near a bifurcation, promoting the system into states of generally higher photon disspative efficacy. An example is given of the UV photochemical dissipative structuring, proliferation, and evolution of molecules on route to the nucleobase adenine from the common precursor molecules HCN and H2O occurring within a fatty acid vesicle. The kinetic equations are resolved under different environmental conditions, providing a non-equilibrium thermodynamic analysis of the appearance of an early important molecule for the origin of life.
ARTICLE | doi:10.20944/preprints201909.0146.v1
Subject: Life Sciences, Biophysics Keywords: entropy; entropy production; non-equilibrium thermodynamics; information encoding; nucleic acids; DNA; RNA; origin of life; origin of codons; amino acids; stereochemical era; photon potential
Online: 14 September 2019 (19:44:54 CEST)
Ultraviolet light incident on organic material can initiate its spontaneous dissipative structuring into chromophores which can catalyze their own replication. This may have been the case for one of the most ancient of all chromophores dissipating the Archean UVC photon flux, the nucleic acids. Oligos of nucleic acids with affinity to particular amino acids which foment UVC photon dissipation would have been selected through non-equilibrium thermodynamic imperatives which favor entropy production. Indeed, we show here that those amino acids with characteristics most relevant to fomenting UVC photon dissipation are precisely those with greatest chemical affinity to their codons or anticodons. Entropy production could thus provide an explanation for the accumulation of information in nucleic acids relevant to the dissipation of the externally imposed thermodynamic potentials. The accumulation of information in this manner provides a link between evolution and entropy production.
ARTICLE | doi:10.20944/preprints202206.0287.v1
Subject: Life Sciences, Biochemistry Keywords: origin of life; disspative structuring; non-equilibrium thermodynamics; prebiotic chemistry; abiogenisis; adenine; guanine; hypoxanthine; xanthine; purines
Online: 21 June 2022 (05:14:12 CEST)
We have suggested that the abiogenisis of life around the beginning of the Archean may have been an example of microscopic dissipative structuring of UVC pigments (the fundamental molecules of life) under the prevailing surface UV solar spectrum. In a previous article in this series, we have describe the non-equilibrium thermodynamics and the photochemical mechanisms which may have been involved in the dissipative structuring of the purines adenine and hypoxanthine from the common precursor molecules of HCN and water under UVC light. In this article we extend our analysis to include the production of the other two important purines, guanine and xanthine, from these same precursors. The photochemical reactions are presumed to occur within a fatty acid vesicle floating on a hot ocean surface exposed to the prevailing UV light. Reaction-diffusion equations are resolved under different environmental conditions. Significant amounts of adenine (∼10−5 M) and guanine (∼10−6 M) are obtained within only a few months at 80 °C under plausible initial concentrations of HCN and cyanogen (a photochemical product of HCN).
ARTICLE | doi:10.20944/preprints202112.0440.v1
Subject: Physical Sciences, Other Keywords: disspative structuring; non-equilibrium thermodynamics; entropy production; origin of life; organic pigments; plants; ecosystems; evolution; chlorophyll; biosignatures
Online: 27 December 2021 (15:59:20 CET)
Through a modern derivation of Planck's formula for the entropy of an arbitrary beam of photons we derive a general expression for the entropy production due to the irreversible process of the absorption of an arbitrary incident photon spectrum in material and its dissipation into an infrared-shifted grey-body emitted spectrum, the rest being reflected or transmitted. Employing the framework of Classical Irreversible Thermodynamic theory, we define the generalized thermodynamic flow as the flow of photons from the incident beam into the material and the generalized thermodynamic force is then just the entropy production divided by the photon flow which is the entropy production per unit photon at a given wavelength. We compare the entropy production under sunlight of different inorganic and organic materials (water, desert, leaves and forests) and show that organic materials are the greater entropy producing materials. Intriguingly, plant and phytoplankton pigments (including chlorophyll) have peak absorption exactly where entropy production through photon dissipation is maximal for our solar spectrum $430<\lambda<550$ nm, while photosynthetic efficiency is maximal between 600 and 700 nm. These results suggest that the evolution of pigments, plants and ecosystems has been towards optimizing entropy production rather than photosynthesis. We propose using the wavelength dependence of global entropy production as a biosignature for discovering life on planets of other stars.