scholarly journals The Origin of Life on Earth and the Design of Alternative Life Forms

2017 ◽  
Vol 01 (02) ◽  
pp. 121-131 ◽  
Author(s):  
Jack W. Szostak
Keyword(s):  
Nucleic Acids ◽  
Origin Of Life ◽  
Artificial Life ◽  
Building Blocks ◽  
Life Forms ◽  
Chemical Energy ◽  
Synthetic Chemistry ◽  
Broad Scope ◽  
The Origin Of Life ◽  
Life On Earth

To understand the origin of life on Earth, and to evaluate the potential for life on exoplanets, we must understand the pathways that lead from chemistry to biology. Recent experiments suggest that a chemically rich environment that provides the building blocks of membranes, nucleic acids and peptides, along with sources of chemical energy, could result in the emergence of replicating, evolving cells. The broad scope of synthetic chemistry suggests that it may be possible to design and construct artificial life forms based upon a very different biochemistry than that of existing biology.

scholarly journals BUILDING BLOCKS OF LIFE IN METEORITES MAY LEAD TO PANSPERMIA ORIGIN OF LIFE

2021 ◽  
Vol 9 (11) ◽  
pp. 235-251
Author(s):  
Y. V. Subba Rao
Keyword(s):  
Origin Of Life ◽  
Electromagnetic Force ◽  
Building Blocks ◽  
Life Forms ◽  
Biological Molecules ◽  
Evolution Of Life ◽  
Living Organisms ◽  
Definition Of ◽  
Life On Earth ◽  
The Universe

              The current hypothesis leads to the panspermia origin of life, which is based on the scientific principle of electromagnetic force interaction with matter. Electromagnetic force (Sunlight) interacts with inorganic chemistry available to us given out by the stars in the universe plausibly triggers the formation of extra-terrestrial biological molecules of proto cells under abiotic conditions, as evidenced by their presence in meteorites.' Proto cells’ might theoretically give rise to living organisms with a manifested soul, allowing 'Ribose' to be formed from ice grains hit by sunlight for RNA and DNA at the same time. The presence of life's building blocks and other important organic chemicals like ribose in meteorites, including some microscopic life forms that aren't native to Earth, may have led to the 'Panspermia Origin of Life' and the 'Evolution of Life on Earth' which is evidenced by the definition of 'Meteorites' in Vedic Scriptures, such as the "Bhagavad Gita" (3000 BC) and "Brihat Samhita" (520 AD) that they are the souls of righteous people who have returned to earth to be reborn.

scholarly journals The Generalized Definition of Life

2021 ◽  
Author(s):  
vivek kumar
Keyword(s):  
Origin Of Life ◽  
Life Forms ◽  
Living Systems ◽  
Definition Of Life ◽  
The Origin Of Life ◽  
Definition Of ◽  
Life On Earth

In this article, I propose and discuss a new definition of life. This new definition considers reproduction and evolution as major aspects of life. It brings into consideration a variety of other life forms like inorganic life, etc. In this study, I aim to present the possibility of various life forms and some of their properties, which might help understand the origin of life on earth and the existence of life in other parts of the cosmos. This new proposed definition of life is independent of the mode of evolution and general enough to consider all potential life forms. This article uses NASA’s definition of life as a structure to derive this generalized definition of life. Finding and exploring new living systems will definitely be very helpful in understanding the aspects of life. In order to explain some complex life forms, a new concept of addition of living systems is introduced in this article. This study underscores the need for further work to understand the origin and properties of living systems.

scholarly journals Defining the envelope for the search for life in the Universe

2009 ◽  
Vol 5 (H15) ◽  
pp. 697-698
Author(s):  
Lynn J. Rothschild
Keyword(s):  
Origin Of Life ◽  
Life Forms ◽  
Chemical Parameters ◽  
Theoretical Possibility ◽  
Origin And Evolution ◽  
Set Constraints ◽  
The Origin Of Life ◽  
Life On Earth ◽  
Physical And Chemical ◽  
The Universe

AbstractThe search for life in the universe relies on defining the limits for life and finding suitable conditions for its origin and evolution elsewhere. From the biological perspective, a conservative approach uses life on earth to set constraints on the environments in which life can live. Conditions for the origin of life, even on earth, cannot yet be defined with certainty. Thus, we will describe what is known about conditions for the origin of life and limits to life on earth as a template for life elsewhere, with a particular emphasis on such physical and chemical parameters as temperature, pH, salinity, desiccation and radiation. But, other life forms could exist, thus extending the theoretical possibility for life elsewhere. Yet, this potential is not limitless, and so constraints for life in the universe will be suggested.

Pyrite and the Origins of Life

Pyrite ◽  
2015 ◽  
Author(s):  
David Rickard
Keyword(s):  
Origin Of Life ◽  
Early Life ◽  
Life Forms ◽  
Origins Of Life ◽  
Sources Of Information ◽  
Ancient India ◽  
Pyrite Formation ◽  
The Origin Of Life ◽  
Life On Earth ◽  
The Relationship

If you have been reading this book since the beginning, you will not be surprised by now to find that you have come across a chapter documenting the involvement of pyrite in the origin of life. This is because you will have read in this book how pyrite has been at the root of many fundamental discoveries about the nature of our world. So you do not suffer more than eyebrow-raising surprise and maybe a gentle throat-clearing in learning that pyrite is contributing to our current understanding of the origins of life. By contrast, if you have dived in at Chapter 9 you probably look at the title of this chapter with disbelief. After all, what could be the connection between a common glitzy mineral and the origin of life? The more diligent reader will have already learned that pyrite formation is intimately associated with biology because most of it is produced by bacteria that extract their oxygen from sulfate and produce hydrogen sulfide. This relationship is so overweening today that pyrite formation controls many fundamental aspects of the Earth’s environment. So what happens if we extend this line of inquiry back to the beginnings of geologic time? We have already seen that the characteristics of ancient pyrite are one of the main sources of information about the nature of the early Earth. The consequence of this is that we know quite a bit about the relationship between pyrite and early life on Earth. In this chapter, we further explore this and review the laboratory work that implicates pyrite itself in the original syntheses of the self-replicating biomolecules that assembled to produce Earth’s first life forms. The thesis that life developed from nonbiological chemistry is a very old idea stretching back through Anaximander in 6th-century BCE Greece to the Vedic writings of ancient India around 1500 BCE and is often called abiogenesis.

scholarly journals The chemical origins of life and its early evolution: an introduction

2011 ◽  
Vol 366 (1580) ◽  
pp. 2853-2856 ◽  
Author(s):  
David M. J. Lilley ◽  
John Sutherland
Keyword(s):  
Nucleic Acids ◽  
Origin Of Life ◽  
Chemical Reactions ◽  
Rna World ◽  
Building Blocks ◽  
Transferase Activity ◽  
Peptidyl Transferase ◽  
Self Assembling ◽  
The Earth ◽  
The Origin Of Life

Can we look at contemporary biology and couple this with chemical insight to propose some plausible mechanisms for the origin of life on the planet? In what follows, we examine some promising chemical reactions by which the building blocks for nucleic acids might have been created about a billion years after the Earth formed. This could have led to self-assembling systems that were based on an all-RNA metabolism, where RNA is both catalytic and informational. We consider the breadth of RNA enzymes presently existing in biology, and to what extent these might have covered a wider range of chemistry in the RNA world. Ultimately, the RNA world would probably have given way to protein-based life quite quickly, and the origins of peptidyl transferase activity are discussed below.

Photochemical Evolution of Interstellar/Precometary Organic Material

1997 ◽  
Vol 161 ◽  
pp. 23-47 ◽  
Author(s):  
Louis J. Allamandola ◽  
Max P. Bernstein ◽  
Scott A. Sandford
Keyword(s):  
Origin Of Life ◽  
Building Blocks ◽  
Complex Species ◽  
Infrared Observations ◽  
Interstellar Ice ◽  
Polycyclic Aromatic ◽  
Ultraviolet Photolysis ◽  
The Origin Of Life ◽  
Simple Molecules ◽  
Complex Organic

AbstractInfrared observations, combined with realistic laboratory simulations, have revolutionized our understanding of interstellar ice and dust, the building blocks of comets. Since comets are thought to be a major source of the volatiles on the primative earth, their organic inventory is of central importance to questions concerning the origin of life. Ices in molecular clouds contain the very simple molecules H2O, CH3OH, CO, CO2, CH4, H2, and probably some NH3and H2CO, as well as more complex species including nitriles, ketones, and esters. The evidence for these, as well as carbonrich materials such as polycyclic aromatic hydrocarbons (PAHs), microdiamonds, and amorphous carbon is briefly reviewed. This is followed by a detailed summary of interstellar/precometary ice photochemical evolution based on laboratory studies of realistic polar ice analogs. Ultraviolet photolysis of these ices produces H2, H2CO, CO2, CO, CH4, HCO, and the moderately complex organic molecules: CH3CH2OH (ethanol), HC(= O)NH2(formamide), CH3C(= O)NH2(acetamide), R-CN (nitriles), and hexamethylenetetramine (HMT, C6H12N4), as well as more complex species including polyoxymethylene and related species (POMs), amides, and ketones. The ready formation of these organic species from simple starting mixtures, the ice chemistry that ensues when these ices are mildly warmed, plus the observation that the more complex refractory photoproducts show lipid-like behavior and readily self organize into droplets upon exposure to liquid water suggest that comets may have played an important role in the origin of life.

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.

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