scholarly journals Are Scientific Models of Life Testable? A Lesson from Simpson’s Paradox

Sci ◽  
2020 ◽  
Vol 2 (3) ◽  
pp. 73
Author(s):  
Prasanta S. Bandyopadhyay ◽  
Nolan Grunska ◽  
Don Dcruz ◽  
Mark C. Greenwood
Keyword(s):  
Origin Of Life ◽  
Rna World ◽  
Scientific Models ◽  
Scientific Model ◽  
Simpson’S Paradox ◽  
World Theory ◽  
Life Issues ◽  
The Origin Of Life ◽  
Logical Sense ◽  
Simpson's Paradox

We address the need for a model by considering two competing theories regarding the origin of life: (i) the Metabolism First theory and (ii) the RNA World theory. We discuss two inter-related points. (I) Models are valuable tools in understanding both the processes and intricacies of the origin of life issues. (II) Insights from models also help us to evaluate the core objection to origin of life theories called “the inefficiency objection” commonly raised by proponents of both the Metabolism First theory and the RNA World theory against each other. We use Simpson’s paradox as a tool for challenging this objection. We will use models in various senses ranging from taking them as representations of reality to treating them as theories/accounts that provide heuristics for probing reality. In this paper, we will frequently use models and theories interchangeably. Additionally, we investigate Conway’s Game of Life and contrast it with our Simpson’s Paradox (SP)-based approach to emergence of life issues. Finally, we discuss some of the consequences of our view. A scientific model is testable in three senses: (i) a logical sense, (ii) a nomological sense, and (iii) a current technological sense. The SP-based model is testable in the logical sense. It is also testable nomologically. However, it is not currently feasible to test it.

scholarly journals Are Scientific Models of Life Testable? A Lesson from Simpson’s Paradox

Sci ◽  
2019 ◽  
Vol 1 (2) ◽  
pp. 54
Author(s):  
Bandyopadhyay ◽  
Grunska ◽  
Dcruz ◽  
Greenwood
Keyword(s):  
Origin Of Life ◽  
Rna World ◽  
Scientific Models ◽  
Scientific Model ◽  
Simpson’S Paradox ◽  
World Theory ◽  
Life Issues ◽  
The Origin Of Life ◽  
Logical Sense ◽  
Simpson's Paradox

We address the need for a model by considering two competing theories regarding the origin of life: (i) the Metabolism First theory and (ii) the RNA World theory. We discuss two inter-related points. (I) Models are valuable tools in understanding both the processes and intricacies of the origin of life issues. (II) Insights from models also help us to evaluate the core objection to origin of life theories called “the inefficiency objection” commonly raised by proponents of both the Metabolism First theory and the RNA World theory against each other. We use Simpson’s paradox as a tool for challenging this objection. We will use models in various senses ranging from taking them as representations of reality to treating them as theories/accounts that provide heuristics for probing reality. In this paper, we will frequently use models and theories interchangeably. Additionally, we investigate Conway’s Game of Life and contrast it with our Simpson’s Paradox (SP)-based approach to emergence of life issues. Finally, we discuss some of the consequences of our view. A scientific model is testable in three senses: (i) a logical sense, (ii) a nomological sense, and (iii) a current technological sense. The SP-based model is testable in the logical sense. It is also testable nomologically. However, it is not currently feasible to test it.

scholarly journals Are Scientific Models of Life Testable? A Lesson from Simpson’s Paradox

Sci ◽  
2020 ◽  
Vol 3 (1) ◽  
pp. 2
Author(s):  
Prasanta S. Bandyopadhyay ◽  
Nolan Grunska ◽  
Don Dcruz ◽  
Mark C. Greenwood
Keyword(s):  
Origin Of Life ◽  
Rna World ◽  
Scientific Models ◽  
Scientific Model ◽  
Simpson’S Paradox ◽  
World Theory ◽  
Life Issues ◽  
Logical Sense ◽  
Simpson's Paradox ◽  
Emergence Of Life

We address the need for a model by considering two competing theories regarding the origin of life: (i) the Metabolism First theory, and (ii) the RNA World theory. We discuss two interrelated points, namely: (i) Models are valuable tools for understanding both the processes and intricacies of origin-of-life issues, and (ii) Insights from models also help us to evaluate the core objection to origin-of-life theories, called “the inefficiency objection”, which is commonly raised by proponents of both the Metabolism First theory and the RNA World theory against each other. We use Simpson’s Paradox (SP) as a tool for challenging this objection. We will use models in various senses, ranging from taking them as representations of reality to treating them as theories/accounts that provide heuristics for probing reality. In this paper, we will frequently use models and theories interchangeably. Additionally, we investigate Conway’s Game of Life and contrast it with our SP-based approach to emergence-of-life issues. Finally, we discuss some of the consequences of our view. A scientific model is testable in three senses: (i) a logical sense, (ii) a nomological sense, and (iii) a current technological sense. The SP-based model is testable in the first two senses but it is not feasible to test it using current technology.

Condensation Reactions Synthesize Random Polymers

2019 ◽  
Author(s):  
David Ross
Keyword(s):  
Origin Of Life ◽  
Rna World ◽  
Functional Polymers ◽  
Peptide Bonds ◽  
Individual Molecular Species ◽  
Condensation Reactions ◽  
Past Half Century ◽  
Working Together ◽  
The Origin Of Life ◽  
The Individual

Over the past half century of serious research on the origin of life, several schools of thought have emerged that focus on “worlds” and what came first in the pathway to the origin of life. One example is the RNA World, a term coined by Walter Gilbert after the discovery of ribozymes. Other examples include the Iron-Sulfur World of Günther Wächtershäuser and the Lipid World proposed by Doron Lancet and coworkers. Then we have a competition between “metabolism first” and “replication first” schools. The worlds and schools have the positive effect of sharpening arguments and forcing us to think carefully, but they also can lock researchers into defending their individual approaches rather than looking for patterns in a larger perspective. One of the main themes of this book is the notion that the first living cells were systems of functional polymers working together within membranous compartments. Therefore, it is best not to think of “worlds” and “firsts” as fundamentals but instead as components evolving together toward the assembly of an encapsulated system of functional polymers. At first the polymers will be composed of random sequences of their monomers, and the compartments will contain random assortments of polymers. Here, we refer to these structures as protocells which are being produced in vast numbers as they form and decompose in continuous cycles driven by a variety of impinging, free-energy sources. This chapter describes how thermodynamic principles can be used to test the feasibility of a proposed mechanism by which random polymers can be synthesized. There is a current consensus that early life may have passed through a phase in which RNA served as a ribozyme catalyst, as a replicating system, and as a means for storing and expressing genetic information. For this reason, we will use RNA as a model polymer, but condensation reactions also produce peptide bonds and oligopeptides. At some point in the evolutionary steps leading to life, peptides and RNA formed complexes with novel functional properties beyond those of the individual molecular species.

Understanding Life: A Bioinformatics Perspective

2016 ◽  
Vol 25 (2) ◽  
pp. 231-245 ◽  
Author(s):  
Natalia Szostak ◽  
Szymon Wasik ◽  
Jacek Blazewicz
Keyword(s):  
Origin Of Life ◽  
Rna World ◽  
Origins Of Life ◽  
Life Itself ◽  
Wet Lab ◽  
The Origin Of Life ◽  
To Come ◽  
World Hypothesis ◽  
Definition Of ◽  
Rna World Hypothesis

According to some hypotheses, from a statistical perspective the origin of life seems to be a highly improbable event. Although there is no rigid definition of life itself, life as it is, is a fact. One of the most recognized hypotheses for the origins of life is the RNA world hypothesis. Laboratory experiments have been conducted to prove some assumptions of the RNA world hypothesis. However, despite some success in the ‘wet-lab’, we are still far from a complete explanation. Bioinformatics, supported by biomathematics, appears to provide the perfect tools to model and test various scenarios of the origins of life where wet-lab experiments cannot reflect the true complexity of the problem. Bioinformatics simulations of early pre-living systems may give us clues to the mechanisms of evolution. Whether or not this approach succeeds is still an open question. However, it seems likely that linking efforts and knowledge from the various fields of science into a holistic bioinformatics perspective offers the opportunity to come one step closer to a solution to the question of the origin of life, which is one of the greatest mysteries of humankind. This paper illustrates some recent advancements in this area and points out possible directions for further research.

Self-Reproduction of Chemical Structures and the Question of the Transition to Life

1997 ◽  
Vol 161 ◽  
pp. 461-468 ◽  
Author(s):  
Pier Luigi Luisi
Keyword(s):  
Origin Of Life ◽  
Rna World ◽  
Natural Increase ◽  
Chemical Structures ◽  
Self Assembling ◽  
New Concepts ◽  
The Origin Of Life ◽  
Molecular Complexity ◽  
The One ◽  
Methodological Difficulties

AbstractThe principles which underlay the chemical approach to the origin of life are discussed, beginning with Oparin’s notion of molecular evolution, whereby the minimal living emerged from the non livingviaa natural increase of molecular complexity and organization. The philosophical and methodological difficulties inherent in such a view are briefly examined. The scenario of the origin of life provided by the RNA-world is then reviewed, and the great difficulties inherent in this view are emphasized, particularly the one according to which a RNA family is createdex-novoin an enzymefree world in a way which is capable to self-replicate, mutation is concluded that the view of the RNA world for the origin of life, despite its popularity, is not very realistic at all; however it has a great importance as it has introduced a series of fundamental new concepts into the field of origin of life. Particularly important is the notion of self-reproduction, and in the paper the self-reproduction of vesicles is reviewed, pointing to the fact that it is a thermodynamically driven process based on spontaneously self-assembling macromolecualr aggregates. The possible relevance of these experiments for assessing a prebiotic «pre-RNA» world is discussed.

Buds of the tree: the highway to the last universal common ancestor

2016 ◽  
Vol 16 (2) ◽  
pp. 105-113 ◽  
Author(s):  
Savio Torres de Farias ◽  
Francisco Prosdocimi
Keyword(s):  
Origin Of Life ◽  
Common Ancestor ◽  
Rna World ◽  
Biological Activities ◽  
Ribosomal Subunit ◽  
Life Forms ◽  
Point Of View ◽  
Last Universal Common Ancestor ◽  
Universal Common Ancestor ◽  
The Origin Of Life

AbstractThe last universal common ancestor (LUCA) has been considered as the branching point on which Bacteria, Archaea and Eukaryotes have diverged. However, the increased information relating to viruses’ genomes and the perception that many virus genes do not have homologs in other organisms opened a new discussion. Based on these facts, there has emerged the idea of an early LUCA that should be moved further into the past to include viruses, implicating that life should have originated before the appearance of cellular life forms. Another point of view from advocates of the RNA-world suggests that the origin of life happened a long time before organisms were capable of organizing themselves into cellular entities. Relevant data about the origin of ribosomes indicate that the catalytic unit of the large ribosomal subunit is what should actually be considered as the turning point that separated chemistry from biology. Other researchers seem to think that a tRNA was probably some sort of a strange attractor on which life has originated. Here we propose a theoretical synthesis that tries to provide a crosstalk among the theories and define important points on which the origin of life could have been originated and made more complex, taking into account gradualist assumptions. Thus, discussions involving the origin of biological activities in the RNA-world might lead into a world of progenotes on which viruses have been taken part until the appearance of the very first cells. Along this route of complexification, we identified some key points on which researchers may consider life as an emerging principle.

Can the RNA World Still Function without Cytidine?

2019 ◽  
Vol 37 (1) ◽  
pp. 71-83
Author(s):  
Andrew S Tupper ◽  
Ralph E Pudritz ◽  
Paul G Higgs
Keyword(s):  
Secondary Structure ◽  
Structure Formation ◽  
Origin Of Life ◽  
Rna World ◽  
Information Storage ◽  
Specific Site ◽  
Rna Sequences ◽  
Secondary Structure Formation ◽  
The Origin Of Life ◽  
Rule Out

Abstract Most scenarios for the origin of life assume that RNA played a key role in both catalysis and information storage. The A, U, G, and C nucleobases in modern RNA all participate in secondary structure formation and replication. However, the rapid deamination of C to U and the absence of C in meteorite samples suggest that prebiotic RNA may have been deficient in cytosine. Here, we assess the ability of RNA sequences formed from a three-letter AUG alphabet to perform both structural and genetic roles in comparison to sequences formed from the AUGC alphabet. Despite forming less thermodynamically stable helices, the AUG alphabet can find a broad range of structures and thus appears sufficient for catalysis in the RNA World. However, in the AUG case, longer sequences are required to form structures with an equivalent complexity. Replication in the AUG alphabet requires GU pairing. Sequence fidelity in the AUG alphabet is low whenever G’s are present in the sequence. We find that AUG sequences evolve to AU sequences if GU pairing is rare, and to RU sequences if GU pairing is common (R denotes A or G). It is not possible to conserve a G at a specific site in either case. These problems do not rule out the possibility of an RNA World based on AUG, but they show that it wouldbe significantly more difficult than with a four-base alphabet.

Sign in / Sign up

Export Citation Format

Share Document