scholarly journals Biological Implications of Organic Compounds in Comets

1989 ◽  
Vol 116 (1) ◽  
pp. 439-462
Author(s):  
Joseph N. Marcus ◽  
Margaret A. Olsen
Keyword(s):  
Origin Of Life ◽  
Catalytic Rna ◽  
Organic Chemicals ◽  
Substantial Fraction ◽  
Volatile Elements ◽  
The Earth ◽  
The Origin Of Life ◽  
Cometary Panspermia ◽  
Life On Earth ◽  
The Universe

AbstractOrganic chemicals — compounds that contain carbon — are the substance of life and pervade the universe. Is there a connection between comets, which are rich in prebiotic organics, and the origin of life? Current concepts of biomolecular evolution are first reviewed, including the important paradigm of catalytic RNA. At the very least, impacting comets appear to have supplied a substantial fraction of the volatile elements required for life shortly after the Earth formed. Some impacting material may even have survived chemically intact to directly provide necessary complex prebiotic organic chemicals. For life to originate and evolve in comets themselves, liquid H2O would be absolutely required: arguments for and against 26Al radiogenic melting of cometary cores are presented. Cometary panspermia, if theoretically possible, is not necessary to explain the origin of life on Earth. The Halley spacecraft provide evidence against Earth-type microorganisms in this comet’s dust.

The Origin of Life on Earth and in the Universe

2006 ◽  
pp. 147-198
Author(s):  
Jordi Llorca ◽  
Malcolm E. Schrader ◽  
Pasquale Stano ◽  
Francesca Ferri ◽  
Pier Luigi Luisi
Keyword(s):  
Origin Of Life ◽  
The Origin Of Life ◽  
Life On Earth ◽  
The Universe

Testing the universality of biology: a review

2007 ◽  
Vol 6 (3) ◽  
pp. 241-248 ◽  
Author(s):  
J. Chela-Flores
Keyword(s):  
Environmental Conditions ◽  
Common Ancestor ◽  
Seminal Contribution ◽  
The Earth ◽  
Molecular Events ◽  
The Origin Of Life ◽  
The Right ◽  
Life On Earth ◽  
Cosmic Convergence ◽  
The Universe

AbstractWe discuss whether it is possible to test the universality of biology, a quest that is of paramount relevance for one of its most recent branches, namely astrobiology. We review this topic in terms of the relative roles played on the Earth biota by contingency and evolutionary convergence. Following the seminal contribution of Darwin, it is reasonable to assume that all forms of life known to us so far are not only terrestrial, but are descendants of a common ancestor that evolved on this planet at the end of a process of chemical evolution. We also raise the related question of whether the molecular events that were precursors to the origin of life on Earth are bound to occur elsewhere in the Universe, wherever the environmental conditions are similar to the terrestrial ones. We refer to ‘cosmic convergence’ as the possible occurrence elsewhere in the Universe of Earth-like environmental conditions. We argue that cosmic convergence is already suggested by observational data. The set of hypotheses for addressing the question of the universality of biology can be tested by future experiments that are feasible with current technology. We focus on landing on Europa and the broader implications of selecting the specific example of the right landing location. We have previously discussed the corresponding miniaturized equipment that is already in existence. The significance of these crucial points needs to be put into a wider scientific perspective, which is one of the main objectives of this review.

scholarly journals The origin of life from primordial planets

2010 ◽  
Vol 10 (2) ◽  
pp. 83-98 ◽  
Author(s):  
Carl H. Gibson ◽  
Rudolph E. Schild ◽  
N. Chandra Wickramasinghe
Keyword(s):  
Origin Of Life ◽  
Big Bang ◽  
Space Telescopes ◽  
The Origin Of Life ◽  
Primordial Planets ◽  
Life On Earth ◽  
The Big Bang ◽  
Primordial Soup ◽  
The Universe ◽  
Origin Of The Universe

AbstractThe origin of life and the origin of the Universe are among the most important problems of science and they might be inextricably linked. Hydro-gravitational-dynamics cosmology predicts hydrogen–helium gas planets in clumps as the dark matter of galaxies, with millions of planets per star. This unexpected prediction is supported by quasar microlensing of a galaxy and a flood of new data from space telescopes. Supernovae from stellar over-accretion of planets produce the chemicals (C, N, O, P, etc.) and abundant liquid-water domains required for first life and the means for wide scattering of life prototypes. Life originated following the plasma-to-gas transition between 2 and 20 Myr after the big bang, while planetary core oceans were between critical and freezing temperatures, and interchanges of material between planets constituted essentially a cosmological primordial soup. Images from optical, radio and infrared space telescopes suggest life on Earth was neither first nor inevitable.

scholarly journals Viroids and the Origin of Life

2021 ◽  
Vol 22 (7) ◽  
pp. 3476
Author(s):  
Karin Moelling ◽  
Felix Broecker
Keyword(s):  
Origin Of Life ◽  
Circular Rna ◽  
Essential Elements ◽  
Darwinian Evolution ◽  
Catalytic Rna ◽  
Current Evidence ◽  
Rna Molecules ◽  
Basic Functions ◽  
The Origin Of Life ◽  
Life On Earth

Viroids are non-coding circular RNA molecules with rod-like or branched structures. They are often ribozymes, characterized by catalytic RNA. They can perform many basic functions of life and may have played a role in evolution since the beginning of life on Earth. They can cleave, join, replicate, and undergo Darwinian evolution. Furthermore, ribozymes are the essential elements for protein synthesis of cellular organisms as parts of ribosomes. Thus, they must have preceded DNA and proteins during evolution. Here, we discuss the current evidence for viroids or viroid-like RNAs as a likely origin of life on Earth. As such, they may also be considered as models for life on other planets or moons in the solar system as well as on exoplanets.

scholarly journals Defining Lyfe in the Universe: From Three Privileged Functions to Four Pillars

Life ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 42 ◽  
Author(s):  
Stuart Bartlett ◽  
Michael L. Wong
Keyword(s):  
Origin Of Life ◽  
Classification System ◽  
Historical Narrative ◽  
New Classification ◽  
General Picture ◽  
Living State ◽  
The Origin Of Life ◽  
Life On Earth ◽  
The Universe ◽  
Dynamical Order

Motivated by the need to paint a more general picture of what life is—and could be—with respect to the rest of the phenomena of the universe, we propose a new vocabulary for astrobiological research. Lyfe is defined as any system that fulfills all four processes of the living state, namely: dissipation, autocatalysis, homeostasis, and learning. Life is defined as the instance of lyfe that we are familiar with on Earth, one that uses a specific organometallic molecular toolbox to record information about its environment and achieve dynamical order by dissipating certain planetary disequilibria. This new classification system allows the astrobiological community to more clearly define the questions that propel their research—e.g., whether they are developing a historical narrative to explain the origin of life (on Earth), or a universal narrative for the emergence of lyfe, or whether they are seeking signs of life specifically, or lyfe at large across the universe. While the concept of “life as we don’t know it” is not new, the four pillars of lyfe offer a novel perspective on the living state that is indifferent to the particular components that might produce it.

scholarly journals Chirality and the Origin of Life

Symmetry ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 2277
Author(s):  
Ferdinand Devínsky
Keyword(s):  
Origin Of Life ◽  
Information Transfer ◽  
Weak Interactions ◽  
Left Handed ◽  
The Earth ◽  
Natural Choice ◽  
The Origin Of Life ◽  
The Impact ◽  
Primordial Soup ◽  
The Universe

The origin of life, based on the homochirality of biomolecules, is a persistent mystery. Did life begin by using both forms of chirality, and then one of the forms disappeared? Or did the choice of homochirality precede the formation of biomolecules that could ensure replication and information transfer? Is the natural choice of L-amino acids and D-sugars on which life is based deterministic or random? Is the handedness present in/of the Universe from its beginning? The whole biosystem on the Earth, all living creatures are chiral. Many theories try to explain the origin of life and chirality on the Earth: e.g., the panspermia hypothesis, the primordial soup hypothesis, theory of parity violation in weak interactions. Additionally, heavy neutrinos and the impact of the fact that only left-handed particles decay, and even dark matter, all have to be considered.

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.

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