scholarly journals Origins of Life

2020 ◽  
pp. 2-7
Author(s):  
Hannah Mahoney
Keyword(s):  
Origin Of Life ◽  
Hydrothermal Vents ◽  
Rna World ◽  
Relevant Information ◽  
Future Research ◽  
Specific Chemical ◽  
Scientific Disciplines ◽  
Earth Environment ◽  
The Origin Of Life ◽  
Life On Earth

When, where, and how did life on Earth originate? The origin of life problem involves multiple scientific disciplines and has spanned multiple decades. It can be summarized into three stages: (1) the origin of biological monomers, (2) the origin of biological polymers, and (3) the emergence and evolution of cells. While highly speculative, the connections between these stages are theorized by attempting to determine the geochemical situations which could have driven chemical evolution and allow for the emergence of specific chemical functions of biological systems. This review summarizes reported findings relevant to the early Earth environment and the main theories in the origin of life subject. Specific focus is placed on the metabolism first, RNA world, and compartmentalization first theories as they are involved in the origin of life paradox. The review then discusses submarine hydrothermal vents as a possible location for which life could have occurred. Understanding of information pertaining to the origin of life is important as it allows for advancement and discoveries in other fields of science and medicine. Overall, the aim of this review is to display the relevant information about the origin of life theory and highlight the importance of future research.

A symbiotic view of the origin of life at hydrothermal impact crater-lakes

2016 ◽  
Vol 18 (30) ◽  
pp. 20033-20046 ◽  
Author(s):  
Sankar Chatterjee
Keyword(s):  
Origin Of Life ◽  
Early Life ◽  
Hydrothermal Vents ◽  
Impact Crater ◽  
Crater Lakes ◽  
Origin And Evolution ◽  
The Origin Of Life ◽  
Life On Earth

Submarine hydrothermal vents are generally considered as the likely habitats for the origin and evolution of early life on Earth.

The Chemical Origin of Life

1997 ◽  
Vol 161 ◽  
pp. 391-399
Author(s):  
Christian de Duve
Keyword(s):  
Origin Of Life ◽  
Scientific Research ◽  
Relevant Information ◽  
Astronomical Observations ◽  
Life Itself ◽  
Laboratory Investigations ◽  
The Origin Of Life ◽  
Life On Earth ◽  
Considerable Detail

AbstractFifty years ago, the problem of the origin of life was largely inaccessible to scientific research. Not only was almost nothing known of the conditions that surrounded the appearance of life on Earth, but there was so little understanding of life itself that the problem could not even be defined in concrete terms. The situation is very different today. Astronomical observations, geochemical findings, and laboratory investigations have illuminated the problem with much relevant information. Especially, the basic mechanisms of life are now understood in considerable detail. We know what to look for. Some important notions that have emerged in this way will be briefly surveyed in this essay, which summarizes views presented in two recent books (de Duve, 1991, 1995).

The Origin of Life

2014 ◽  
Author(s):  
S. Blair Hedges
Keyword(s):  
Origin Of Life ◽  
Hydrothermal Vents ◽  
Biological Evolution ◽  
Early Time ◽  
Molecular Clocks ◽  
Time Period ◽  
A Cell ◽  
The Origin Of Life ◽  
Successive Generations ◽  
Life On Earth

Biological evolution begins with the origin of life, but the subject is the perhaps the most interdisciplinary of any in science. Understanding how life began on Earth requires knowledge of the astronomical, geological, and atmospheric settings. However, those settings are in turn dependent on knowing the time period when life arose, which comes from the fossil and molecular records, including molecular clocks based on genetic mutations. Interrelated with the setting is the chemistry that generates the organic molecules used to assemble the first cells and carry the genetic information to successive generations of cells. But holding the chemical reactions and products together in a cell requires a membrane, and the assembly of that involves biophysics. Thus, we have all of the fields of science coming together to understand a single event that happened about four billion years ago and initiated the Tree of Life on Earth. Because little evidence of anything has remained from this early time, there have been enormous amounts of published speculation on this subject. Narratives on how life originated can be grouped by location (surface versus submarine hydrothermal vents), temperature (cold versus hot), source of energy (heterotrophic versus autotrophic), and evolutionary order (genetics-first versus metabolism-first). I use the last dichotomy here, only because it has a long history and renewed focus in recent years. Currently there is no consensus on any one theory for the origin of life, but this is an active field that has made great strides in recent decades.

scholarly journals Toy trains, loaded dice and the origin of life: dimerization on mineral surfaces under periodic drive with Gaussian inputs

2017 ◽  
Vol 4 (11) ◽  
pp. 170141 ◽  
Author(s):  
Rowena Ball ◽  
John Brindley
Keyword(s):  
Origin Of Life ◽  
Chemical Evolution ◽  
Rna World ◽  
Mineral Surfaces ◽  
Dynamical Equations ◽  
Output Fluctuations ◽  
New Information ◽  
The Origin Of Life ◽  
Set Up ◽  
Life On Earth

In a major extension of previous work, we model the putative hydrothermal rock pore setting for the origin of life on Earth as a series of coupled continuous flow units (the toy train ). Perfusing through this train are reactants that set up thermochemical and pH oscillations, and an activated nucleotide that produces monomer and dimer monophosphates. The dynamical equations that model this system are thermally self-consistent. In an innovative step that breaks some new ground, we build stochasticity of the inputs into the model. The computational results infer various constraints and conditions on, and insights into, chemical evolution and the origin of life and its physical setting: long, interconnected porous structures with longitudinal non-uniformity would have been favourable, and the ubiquitous pH dependences of biology may have been established in the prebiotic era. We demonstrate the important role of Gaussian fluctuations of the inputs in driving polymerization, evolution and diversification. In particular, we find that the probability distribution of the resulting output fluctuations is left-skewed and right-weighted (the loaded dice ), which could favour chemical evolution towards a living RNA world. We tentatively name this distribution ‘Goldilocks’. These results also vindicate the general approach of constructing and running a simple model to learn important new information about a complex system.

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 ‘Whole Organism’, Systems Biology, and Top-Down Criteria for Evaluating Scenarios for the Origin of Life

Life ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 690
Author(s):  
Clifford F. Brunk ◽  
Charles R. Marshall
Keyword(s):  
Origin Of Life ◽  
Top Down ◽  
Chemical Systems ◽  
Biochemical Pathways ◽  
The Origin Of Life ◽  
Energy And Material Flows ◽  
Complex Scenario ◽  
Life On Earth ◽  
Physical Laws ◽  
Equilibrium Chemical

While most advances in the study of the origin of life on Earth (OoLoE) are piecemeal, tested against the laws of chemistry and physics, ultimately the goal is to develop an overall scenario for life’s origin(s). However, the dimensionality of non-equilibrium chemical systems, from the range of possible boundary conditions and chemical interactions, renders the application of chemical and physical laws difficult. Here we outline a set of simple criteria for evaluating OoLoE scenarios. These include the need for containment, steady energy and material flows, and structured spatial heterogeneity from the outset. The Principle of Continuity, the fact that all life today was derived from first life, suggests favoring scenarios with fewer non-analog (not seen in life today) to analog (seen in life today) transitions in the inferred first biochemical pathways. Top-down data also indicate that a complex metabolism predated ribozymes and enzymes, and that full cellular autonomy and motility occurred post-LUCA. Using these criteria, we find the alkaline hydrothermal vent microchamber complex scenario with a late evolving exploitation of the natural occurring pH (or Na+ gradient) by ATP synthase the most compelling. However, there are as yet so many unknowns, we also advocate for the continued development of as many plausible scenarios as possible.

What is life?

1997 ◽  
Author(s):  
John Maynard Smith ◽  
Eors Szathmary
Keyword(s):  
Natural Selection ◽  
Origin Of Life ◽  
Definition Of Life ◽  
The Sun ◽  
Physical Processes ◽  
Living Things ◽  
Survival And Reproduction ◽  
The Origin Of Life ◽  
Definition Of ◽  
Life On Earth

Imagine that, when the first spacemen step out of their craft onto the surface of one of the moons of Jupiter, they are confronted by an object the size of a horse, rolling towards them on wheels, and bearing on its back a concave disc pointing towards the Sun. They will at once conclude that the object is alive, or has been made by something alive. If all they find is a purple smear on the surface of the rocks, they will have to work harder to decide. This is the phenotypic approach to the definition of life: a thing is alive if it has parts, or ‘organs’, which perform functions. William Paley explained the machine-like nature of life by the existence of a creator: today, we would invoke natural selection. There are, however, dangers in assuming that any entity with the properties of a self-regulating machine is alive, or an artefact. In section 2.2, we tell the story of a self-regulating atomic reactor, the Oklo reactor, which is neither. This story can be taken in one of three ways. First, it shows the dangers of the phenotypic definition of life: not all complex entities are alive. Second, it illustrates how the accidents of history can give rise spontaneously to surprisingly complex machine-like entities. The relevance of this to the origin of life is obvious. In essence, the problem is the following. How could chemical and physical processes give rise, without natural selection, to entities capable of hereditary replication, which would therefore, from then on, evolve by natural selection? The Oklo reactor is an example of what can happen. Finally, section 2.2 can simply be skipped: the events were interesting, but do not resemble in detail those that led to the origin of life on Earth. There is an alternative to the phenotypic definition of life. It is to define as alive any entities that have the properties of multiplication, variation and heredity. The logic behind this definition, first proposed by Muller (1966), is that a population of entities with these properties will evolve by natural selection, and hence can be expected to acquire the complex adaptations for survival and reproduction that are characteristic of living things.

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