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V. Life's Corporeal Evolution Develops, Encodes and Organizes Itself: An Earthtwinian Genesis Synthesis1. The Origins of Life Ogata, Norichika. Quantitative Measurement of Heritability in the Pre-RNA World. arXiv:1901.07400. We cite this entry by a Nihon BioData Corp., Japan researcher, formerly at Kawasaki Medical University, as a 2019 example of how origin of life studies have moved beyond biomolecules (RNA) or metabolism alone to include the generative presence of nature’s universal independent generative propensities. Before assembly with nucleotides, in the pre-RNA era, what system dominated heredity? Self-organized complex systems are hypothesized to be a primary factor of the origin of life and to dominate heritability, mediating the partitioning of an equal distribution of structures and molecules at cell division. The degree of strength of self-organization would correlate with heritability; self-organization is known to be a physical basis of hysteresis phenomena, and the degree of hysteresis is quantifiable. However, there is no argument corroborating the relationship between heritability and hysteresis. Here, we show that the degree of cellular hysteresis indicates its heritability and daughter equivalence at cell division. Our results demonstrate that self-organized complex systems contribute to heredity and are still important in mammalian cells. Discovering ancient and hidden heredity systems enables us to study our own origin, to predict cell features and to manage them in the bio-economy. (Abstract excerpt) Papastavrou, Nikolaos, et al.. RNA-catalyzed evolution of catalytic RNA. PNAS. 121/11, 2024. Salk Institute of Biological Studies geneticists including its director Gerald Joyce are now able to discern a pathway by which this crucial nucleotide molecule could shape up, have the necessary capacities so as to propel living systems going on their evolutionary way. See also Prebiotic Astrochemistry from Astronomical Observations and Laboratory Spectroscopy by Lucy Ziurys in the Annual Review of Physical Chemistry (Volume 75, 2024.) An RNA polymerase ribozyme obtained by directed evolution can propagate a functional RNA through repeated rounds of replication and selection. Earlier versions did not have sufficient copying fidelity, but an improved variant can now replicate the hammerhead ribozyme through a reciprocal synthesis. Two evolutionary lineages were carried out using either the prior low-fidelity or the newer high-fidelity polymerase. Deep sequencing followed the course of evolution, revealing variants that diverged from as fitness increased. This study demonstrates the critical importance of replication fidelity for maintaining heritable information in an RNA-based evolving system, such as is thought to have existed during the early history of life on Earth. (Abstract) Pargellis, Andrew. Self-organizing Genetic Codes and the Emergence of Digital Life. Complexity. 8/4, 2003. Computer-based studies illuminate the role of complex system dynamics at life’s origin which served to organize the various molecular and protocell components. A major observation is that self-organization of the genetic code can greatly increase the probability of emergence of self-replicators from the primordial soup. (69)
Pascal, Robert.
A Possible Non-Biological Reaction Framework for Metabolic Processes on Early Earth.
Nature.
569/47,
2019.
The University of Montpellier biochemist comments on a paper, Synthesis and Breakdown of Universal Metabolic Precursors Promoted by Iron, in the same issue (569/104) by Kamila Muchowaka, et al (University of Strasbourg) which reports how a network of reactions for converting carbon dioxide into organic compounds could have fostered the advent and advance of original life. Pascal, Robert, et al. Towards an Evolutionary Theory of the Origin of Life Based on Kinetics and Thermodynamics. Open Biology. Online November, 2013. In this new Royal Society web journal, prime theorists Pascal, Institut des Biomolecules, Montpellier, France, with Addy Pross, Ben-Gurion University of the Negev, and John Sutherland, MRC Laboratory of Molecular Biology, Cambridge, combine their prebiotic chemistry and energetic drive studies to achieve a unitary synthesis of regnant living systems with a conducive cosmos. On page 2, per the quote, the issue of whether life’s occasion is an improbable rarity, or arises due to intrinsic properties is put To wit, in addition to biochemical pathways, there must be some nonequilibrium creative force, which much evidence now implicates. See also The Nature and Mathematical Basis for Material Stability in the Chemical and Biological Worlds by Pascal and Pross in the Journal of Systems Chemistry, online March 2014. This work is a significant coalescence and contribution to explain a natural organic genesis. A sudden transition in a system from an inanimate state to the living state — defined on the basis of present day living organisms — would constitute a highly unlikely event hardly predictable from physical laws. From this uncontroversial idea, a self-consistent representation of the origin of life process is built up, which is based on the possibility of a series of intermediate stages. This approach requires a particular kind of stability for these stages — dynamic kinetic stability (DKS) — which is not usually observed in regular chemistry, and which is reflected in the persistence of entities capable of self-reproduction. The necessary connection of this kinetic behaviour with far-from-equilibrium thermodynamic conditions is emphasized and this leads to an evolutionary view for the origin of life in which multiplying entities must be associated with the dissipation of free energy. Any kind of entity involved in this process has to pay the energetic cost of irreversibility, but, by doing so, the contingent emergence of new functions is made feasible. The consequences of these views on the studies of processes by which life can emerge are inferred. (Abstract) Patel, Bhavesh, et al. Common Origins of RNA, Protein and Lipid Precursors in a Cyanosulfidic Protometabolism. Nature Chemistry. 7/4, 2015. A team from John Sutherland’s (coauthor) laboratory at the MRC Laboratory of Molecular Biology, Cambridge describe for the first time how the essential classes of nucleic acids, amino acids, and lipids could have all formed at once. The work is noted as a breakthrough in an editorial A Primordial Soup that Cooks Itself, and by the Nobel chemist and origin of life researcher Jack Szostak in the journal Science (347/1298). As a result of this advance, it is said a singular environment can be identified which gave rise to diverse molecules that could store information, administer metabolism, and form bounded units, the three prime traits of life. A minimal cell can be thought of as comprising informational, compartment-forming and metabolic subsystems. To imagine the abiotic assembly of such an overall system, however, places great demands on hypothetical prebiotic chemistry. The perceived differences and incompatibilities between these subsystems have led to the widely held assumption that one or other subsystem must have preceded the others. Here we experimentally investigate the validity of this assumption by examining the assembly of various biomolecular building blocks from prebiotically plausible intermediates and one-carbon feedstock molecules. We show that precursors of ribonucleotides, amino acids and lipids can all be derived by the reductive homologation of hydrogen cyanide and some of its derivatives, and thus that all the cellular subsystems could have arisen simultaneously through common chemistry. The key reaction steps are driven by ultraviolet light, use hydrogen sulfide as the reductant and can be accelerated by Cu(I)–Cu(II) photoredox cycling. (Abstract) Pearce, Ben, et al. Origin of the RNA World: The Fate of Nucleobases in Warm Little Ponds. Proceedings of the National Academy of Sciences. 114/11327, 2017. Origins Institute, McMaster University and MPI Astronomy astrophysicists expand considerations of how living systems came to form on Earth, quite akin to Charles Darwin’s imagination of conducive baths. A commentary by David Deamer, Darwin’s Prescient Guess, in this issue commends their 2010s insight into life’s watery, and astral occasion. There are currently two competing hypotheses for the site at which an RNA world emerged: hydrothermal vents in the deep ocean and warm little ponds. Because the former lacks wet and dry cycles, which are well known to promote polymerization (in this case, of nucleotides into RNA), we construct a comprehensive model for the origin of RNA in the latter sites. Our model advances the story and timeline of the RNA world by constraining the source of biomolecules, the environmental conditions, the timescales of reaction, and the emergence of first RNA polymers. (Significance) Phillips, Melissa Lee. The Origins Divide: Reconciling Views on How Life Began. BioScience. October, 2010. A science writer seeks to report upon and review pathways toward a synthesis of various scientists and schools that, for example, favor metabolism or replication first, come from a systems chemistry, emphasize autocatalytic processes, and so on. Pratt, Andrew. Prebiological Evolution and the Metabolic Origins of Life. Artificial Life. 17/3, 2011. As this section reports, researchers of life’s origins tend to emphasize a certain aspect, often due to education or experience, which then beg assembly into a composite theory. In this extensive paper, a University of Canterbury biochemist cites Tibor Ganti’s chemoton to propose an early rudimentary phase driven by complex, self-organizing, autocatalytic networks. From this basis, key components such as phosphates, iron and sulfur and the “RNA-first” approach can be linked through a sorting out of when each chemical came into play. The chemoton model of cells posits three subsystems: metabolism, compartmentalization, and information. A specific model for the prebiological evolution of a reproducing system with rudimentary versions of these three interdependent subsystems is presented. This is based on the initial emergence and reproduction of autocatalytic networks in hydrothermal microcompartments containing iron sulfide. The driving force for life was catalysis of the dissipation of the intrinsic redox gradient of the planet. The codependence of life on iron and phosphate provides chemical constraints on the ordering of prebiological evolution. (203) Preiner, Martina, et al. The Future of Origin of Life Research: Bridging Decades Old-Divisions. Life. 10/3, 2020. This is a conference summary by twenty five “early career” scientists as a unique retrospect of this field over its past decades, so that an integrative resolve going forward can be scoped out. The overview allows prior aspects such as prebiotic catalysis, thermal sea vents, mineral surfaces, first replicators, encapsulations, some 21 in all, to be gathered into a graphic display. A further issue has been a broad split between an RNA replicator or bounded metabolism preference, see Iris Fry 2011 herein. New synoptic pathways will involve better theories, common trends, and clever experiment. In this regard, this intentional project is a good example of an intentional shift to a coordinated, worldwide scientific pursuit. Research on the origin of life is highly heterogeneous. After a peculiar historical development, it still includes strongly opposed views which potentially hinder progress. In the 1st Interdisciplinary Origin of Life Meeting, early-career researchers gathered to explore the commonalities between theories and approaches, critical divergence points, and expectations for the future. We find that even though classical approaches and theories—e.g. bottom-up and top-down, RNA world vs. metabolism-first—have been prevalent in origin of life research, they are ceasing to be mutually exclusive and they can and should feed integrating approaches. Here we focus on pressing questions and recent developments that bridge the classical disciplines and approaches, and highlight expectations for future endeavours in origin of life research. (Abstract) Prosdocimi, Francisco, et al. The Theory of Chemical Symbiosis: A Margulian View for the Original Emergence of Biological Systems. Acta Biotheoretica. August, 2020. Universidade Federal do Rio de Janeiro, Universidad Nacional Autónoma de México, and Universidade Federal da Paraíba theoretical biologists proceed to expand the occurrence of mutually beneficial symbiotic unions, as long advocated by Lynn Margulis (1938-2011) and now well proven, deeply into life’s prior biochemical beginnings. So into 2020, along with self-organization and networking phenomena, still another innately procreative agency can be found at constant effect at each and every lively stage. The theory of chemical symbiosis (TCS) suggests that biological systems started with the collaboration of two polymeric molecules existing in early Earth: nucleic acids and peptides. Chemical symbiosis emerged when RNA-like nucleic acid polymers happened to fold into 3D structures capable of binding amino acids together. TCS suggests that there is no chicken-and-egg problem into the emergence of biological systems as RNAs and peptides were of equal importance to the origin of life. Life has initially emerged when these two macromolecules started to interact in molecular symbiosis. Further, we suggest that life evolved into progenotes and cells due to new layers of symbiosis. Mutualism is the strongest force in biology, capable to create novelties by emergent principles; on which the whole is bigger than the sum of the parts. TCS aims to apply the Margulian view of biology into the origins of life field. (Abstract excerpt) Purvis, Graham, et al. Generation of long-chain fatty acids by hydrogen-driven bicarbonate reduction in ancient alkaline hydrothermal vents. Communications Earth & Environment. 5/30, 2024. Newcastle University paleobiochemists quantify how another vital complexity stage came to readily occur. Once again our Earthuman retrospective scenario from prebiotic sources onto replicative protocells indeed takes on a robust guise of a natural endemic fertility. The origin of life at some point required membrane-bound compartments to foster the separation and concentration of internal biochemistry from the external environment. Long-chain amphiphilic molecules, such as fatty acids, appear good candidates to have formed the first cell membranes. Here we show that the reaction of dissolved hydrogen and bicarbonate with the iron-rich mineral magnetite under conditions of continuous flow, alkaline pH and simple low temperatures (90 °C) generate a range of long-chain aliphatic compounds. Readily generated membrane-forming amphiphilic organic molecules in the first cellular vesicles may have been driven by similar chemistry generated from the mixing of bicarbonate-rich water with alkaline hydrogen-rich fluids. (Abstract)
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