scholarly journals Fundamental molecules of life are pigments which arose and co-evolved as a response to the thermodynamic imperative of dissipating the prevailing solar spectrum

2015 ◽  
Vol 12 (16) ◽  
pp. 4913-4937 ◽  
Author(s):  
K. Michaelian ◽  
A. Simeonov
Keyword(s):  
Cross Sections ◽  
Dissipation Rate ◽  
Solar Spectrum ◽  
Photochemical Process ◽  
Origin And Evolution ◽  
Organic Pigments ◽  
Early Atmosphere ◽  
Evolution Of Life ◽  
History Of ◽  
Uv C

Abstract. The driving force behind the origin and evolution of life has been the thermodynamic imperative of increasing the entropy production of the biosphere through increasing the global solar photon dissipation rate. In the upper atmosphere of today, oxygen and ozone derived from life processes are performing the short-wavelength UV-C and UV-B dissipation. On Earth's surface, water and organic pigments in water facilitate the near-UV and visible photon dissipation. The first organic pigments probably formed, absorbed, and dissipated at those photochemically active wavelengths in the UV-C and UV-B that could have reached Earth's surface during the Archean. Proliferation of these pigments can be understood as an autocatalytic photochemical process obeying non-equilibrium thermodynamic directives related to increasing solar photon dissipation rate. Under these directives, organic pigments would have evolved over time to increase the global photon dissipation rate by (1) increasing the ratio of their effective photon cross sections to their physical size, (2) decreasing their electronic excited state lifetimes, (3) quenching radiative de-excitation channels (e.g., fluorescence), (4) covering ever more completely the prevailing solar spectrum, and (5) proliferating and dispersing to cover an ever greater surface area of Earth. From knowledge of the evolution of the spectrum of G-type stars, and considering the most probable history of the transparency of Earth's atmosphere, we construct the most probable Earth surface solar spectrum as a function of time and compare this with the history of molecular absorption maxima obtained from the available data in the literature. This comparison supports the conjecture that many fundamental molecules of life are pigments which arose, proliferated, and co-evolved as a response to dissipating the solar spectrum, supports the thermodynamic dissipation theory for the origin of life, constrains models for Earth's early atmosphere, and sheds some new light on the origin of photosynthesis.

scholarly journals Fundamental molecules of life are pigments which arose and evolved to dissipate the solar spectrum

2015 ◽  
Vol 12 (3) ◽  
pp. 2101-2160 ◽  
Author(s):  
K. Michaelian ◽  
A. Simeonov
Keyword(s):  
Cross Sections ◽  
Dissipation Rate ◽  
Solar Spectrum ◽  
Photochemical Process ◽  
Physical Size ◽  
Origin And Evolution ◽  
Organic Pigments ◽  
Early Atmosphere ◽  
Evolution Of Life ◽  
History Of

Abstract. The driving force behind the origin and evolution of life has been the thermodynamic imperative of increasing the entropy production of the biosphere through increasing the global solar photon dissipation rate. In the upper atmosphere of today, oxygen and ozone derived from life processes are performing the short wavelength UVC and UVB dissipation. On Earth's surface, water and organic pigments in water facilitate the near UV and visible photon dissipation. The first organic pigments probably formed, absorbed, and dissipated at those photochemically active wavelengths in the UVC that could have reached Earth's surface during the Archean. Proliferation of these pigments can be understood as an autocatalytic photochemical process obeying non-equilibrium thermodynamic directives related to increasing solar photon dissipation rate. Under these directives, organic pigments would have evolved over time to increase the global photon dissipation rate by; (1) increasing the ratio of their effective photon cross sections to their physical size, (2) decreasing their electronic excited state life times, (3) quenching radiative de-excitation channels (e.g. fluorescence), (4) covering ever more completely the prevailing solar spectrum, and (5) proliferating and dispersing to cover an ever greater surface area of Earth. From knowledge of the evolution of the spectrum of G-type stars, and considering the most probable history of the transparency of Earth's atmosphere, we construct the most probable Earth surface solar spectrum as a function of time and compare this with the history of molecular absorption maxima obtained from the available data in the literature. This comparison supports the conjecture that many fundamental molecules of life are pigments which arose and evolved to dissipate the solar spectrum, supports the thermodynamic dissipation theory for the origin of life, constrains models for Earth's early atmosphere, and sheds some new light on the origin of photosynthesis.

scholarly journals Microscopic Dissipative Structuring at the Origin of Life

2017 ◽  
Author(s):  
Karo Michaelian
Keyword(s):  
Radiative Decay ◽  
Double Helix ◽  
Solar Spectrum ◽  
Conical Intersection ◽  
Origin And Evolution ◽  
Physical Chemical ◽  
Evolution Of Life ◽  
The Origin Of Life ◽  
Uv C ◽  
Rna And Dna

AbstractFundamental molecules of life are suggested to be formed, proliferated, and evolved through microscopic dissipative structuring and autocatalytic replication under the UV-C solar spectrum prevalent at Earth’s surface throughout the Archean. Evidence is given in the numerous salient characteristics of these, including their strong absorption in this spectral region, their rapid non-radiative decay through an inherent conical intersection, UV-C activation (phos-phorylation) of nucleotides, and UV-C induced denaturing of double helix RNA and DNA. The examples of the dissipative structuring and dissipative proliferation of the purines and of single strand DNA are given. This provides a physical-chemical foundation for understanding the origin and evolution of life.

scholarly journals Comment on K. Michaelian and A. Simeonov (2015) “Fundamental molecules of life are pigments which arose and co-evolved as a response to the thermodynamic imperative of dissipating the prevailing solar spectrum”

2021 ◽  
Author(s):  
Lars Olof Björn
Keyword(s):  
Solar Radiation ◽  
Entropy Production ◽  
Driving Force ◽  
Dissipation Rate ◽  
Solar Spectrum ◽  
Origin And Evolution ◽  
Evolution Of Life

Abstract. This is a comment to: “Fundamental molecules of life are pigments which arose and co-evolved as a response to the thermodynamic imperative of dissipating the prevailing solar spectrum” by K. Michaelian and A. Simeonov, Biogeosciences, 12, 4913–4937, 2015. Michaelian and Simeonov formulate the leading thought in their article “The driving force behind the origin and evolution of life has been the thermodynamic imperative of increasing the entropy production of the biosphere through increasing the global solar photon dissipation rate”. I doubt that the reasoning that follows regarding the role of “pigments” (in which they include all substances able to absorb solar radiation) is correct.

scholarly journals Concurrent origins of the genetic code and the homochirality of life, and the origin and evolution of biodiversity. Part I: Observations and explanations

2015 ◽  
Author(s):  
Dirson Jian Li
Keyword(s):  
Genetic Code ◽  
Early History ◽  
Mass Extinctions ◽  
Genome Sequences ◽  
Origin And Evolution ◽  
New Methods ◽  
Evolution Of Life ◽  
History Of ◽  
Technical Details ◽  
Recruitment Order

The post-genomic era has brought opportunities to bridge traditionally separate fields on early history of life. New methods promote a deeper understanding of the origin of biodiversity. Relative stabilities of base triplexes are able to regulate base substitutions in triplex DNAs. We constructed a roadmap based on such a regulation to explain concurrent origins of the genetic code and the homochirality of life. Based on the recruitment order of codons in the roadmap and the complete genome sequences, we reconstructed the three-domain tree of life. The Phanerozoic biodiversity curve has been reconstructed based on genomic, climatic and eustatic data; this result supports tectonic cause of mass extinctions. Our results indicate that chirality played a crucial role in the origin and evolution of life. Here is Part I of my two-part series paper; technical details are in Part II of my paper (see “Concurrent origins of the genetic code and the homochirality of life, and the origin and evolution of biodiversity. Part II: Technical appendix” on bioRxiv).

Evolution Before Darwin

2019 ◽  
Author(s):  
Bill Jenkins
Keyword(s):  
Natural History ◽  
Charles Darwin ◽  
Natural World ◽  
Origin And Evolution ◽  
Evolutionary Theories ◽  
Evolutionary Thought ◽  
Evolution Of Life ◽  
History Of ◽  
New Ideas ◽  
The City

It was long believed that evolutionary theories received an almost universally cold reception in British natural history circles in the first half of the nineteenth century. But recently serious doubt has been cast on this assumption. This book will be the first major study of what was the most important centre or pre-Darwinian evolutionary thought in the British Isles. It shows that Edinburgh in the late 1820s and early 1830s was witness to a veritable ferment of radical new ideas on the natural world, including speculation on the origin and evolution of life, at just the time when Charles Darwin was studying medicine in the city. Those who were students in Edinburgh at the time could have hardly avoided coming into contact with these new ideas, espoused as they were by many of professors, fellow students and acquaintances in Edinburgh. This book sheds new light on the genesis and development of one of the most important scientific theories in the history of western thought.

scholarly journals Early evolution of purple retinal pigments on Earth and implications for exoplanet biosignatures

2018 ◽  
pp. 1-10 ◽  
Author(s):  
Shiladitya DasSarma ◽  
Edward W. Schwieterman
Keyword(s):  
Light Harvesting ◽  
Solar Spectrum ◽  
Halophilic Archaea ◽  
Oxygenic Photosynthesis ◽  
Chlorophyll Pigments ◽  
Evolution Of Life ◽  
Harvesting Systems ◽  
History Of ◽  
Life On Earth ◽  
Retinal Pigments

AbstractWe propose that retinal-based phototrophy arose early in the evolution of life on Earth, profoundly impacting the development of photosynthesis and creating implications for the search for life beyond our planet. While the early evolutionary history of phototrophy is largely in the realm of the unknown, the onset of oxygenic photosynthesis in primitive cyanobacteria significantly altered the Earth's atmosphere by contributing to the rise of oxygen ~2.3 billion years ago. However, photosynthetic chlorophyll and bacterio chlorophyll pigments lack appreciable absorption at wavelengths about 500–600 nm, an energy-rich region of the solar spectrum. By contrast, simpler retinal-based light-harvesting systems such as the haloarchaeal purple membrane protein bacteriorhodopsin show a strong well-defined peak of absorbance centred at 568 nm, which is complementary to that of chlorophyll pigments. We propose a scenario where simple retinal-based light-harvesting systems like that of the purple chromoprotein bacteriorhodopsin, originally discovered in halophilic Archaea, may have dominated prior to the development of photosynthesis. We explore this hypothesis, termed the ‘Purple Earth,’ and discuss how retinal photopigments may serve as remote biosignatures for exoplanet research.

Streptococcus pluranimalium meningoencephalitis in a horse

2021 ◽  
pp. 104063872110234
Author(s):  
Dah-Jiun Fu ◽  
Akhilesh Ramachandran ◽  
Craig Miller
Keyword(s):  
Ribosomal Rna ◽  
Cross Sections ◽  
Nucleotide Sequencing ◽  
Formalin Fixed Paraffin ◽  
Quarter Horse ◽  
Formalin Fixed Paraffin Embedded ◽  
History Of ◽  
The Brain ◽  
Gram Positive Cocci ◽  
Formalin Fixed

A 3-y-old, female Quarter Horse with a history of acute neurologic signs was found dead and was submitted for postmortem examination. Areas of petechial and ecchymotic hemorrhage were present on cross-sections of the cerebrum, cerebellum, and brainstem. Histologic examination of the brain revealed severe, purulent meningoencephalitis and vasculitis with a myriad of intralesional gram-positive cocci. Streptococcus pluranimalium was identified from formalin-fixed, paraffin-embedded tissue obtained from sites with active lesions by PCR and nucleotide sequencing of bacterial 16S ribosomal RNA. S. pluranimalium should be considered as a cause of meningoencephalitis in a horse.

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