scholarly journals Neopanspermia – Evidence That Life Continuously Arrives at the Earth from Space

2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Milton Wainwright ◽  
◽  
N. Chandra Wickramasinghe ◽  
Gensuke Tokoro ◽  
◽  
...  
Keyword(s):  
Fungal Spores ◽  
Pollen Grains ◽  
Bilateral Symmetry ◽  
Primitive Earth ◽  
The Earth ◽  
Habitable Zones ◽  
Order Of Magnitude ◽  
Life On Earth ◽  
Biological Entities ◽  
Emergence Of Life

The theory of panspermia in a variety of forms remains an important theory to account for the origin of life on Earth and possibly also on other planetary bodies orbiting the “habitable zones” of stars. A form of panspermia we review here, that can be called neopanspermia, encapsulates the concept that a continuing infall of microbiota from space contributes both to the inception of life on Earth and its subsequent evolution. We discuss the development of the theory of panspermia and show how, over the past decade, we have used balloon-borne samplers (lofted to heights approaching 30km) to isolate unusual Biological Entities (BEs) which, we maintain, are continuously arriving at the Earth from space. These BEs are carbon-based, show bilateral symmetry, contain DNA and are in the range 10-40 micrometres in dimension. Their sizes are an order of magnitude higher than par-ticles (including bacteria and viruses) of terrestrial origin that are normally recovered in the strato-sphere. The fact that Earth-organisms (e.g. pollen grains, grass-shards and fungal spores) have not been found in our samples provides additional evidence that the isolated BEs originate from space and are of extraterrestrial provenance. We propose that such incoming microorganisms led to the emergence of life on the primitive Earth between 3.83 and 4 billion years ago and thereafter have continuously contributed to its evolution.

scholarly journals Viroids-First—A Model for Life on Earth, Mars and Exoplanets

Geosciences ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 241 ◽  
Author(s):  
Karin Moelling ◽  
Felix Broecker
Keyword(s):  
Early Life ◽  
Life Forms ◽  
Darwinian Evolution ◽  
Extraterrestrial Life ◽  
Cellular Life ◽  
Non Coding Rna ◽  
Virus Research ◽  
Life On Earth ◽  
Biological Entities ◽  
Emergence Of Life

The search for extraterrestrial life, recently fueled by the discovery of exoplanets, requires defined biosignatures. Current biomarkers include those of extremophilic organisms, typically archaea. Yet these cellular organisms are highly complex, which makes it unlikely that similar life forms evolved on other planets. Earlier forms of life on Earth may serve as better models for extraterrestrial life. On modern Earth, the simplest and most abundant biological entities are viroids and viruses that exert many properties of life, such as the abilities to replicate and undergo Darwinian evolution. Viroids have virus-like features, and are related to ribozymes, consisting solely of non-coding RNA, and may serve as more universal models for early life than do cellular life forms. Among the various proposed concepts, such as “proteins-first” or “metabolism-first”, we think that “viruses-first” can be specified to “viroids-first” as the most likely scenario for the emergence of life on Earth, and possibly elsewhere. With this article we intend to inspire the integration of virus research and the biosignatures of viroids and viruses into the search for extraterrestrial life.

scholarly journals LOUPE: observing Earth from the Moon to prepare for detecting life on Earth-like exoplanets

2020 ◽  
Vol 379 (2188) ◽  
pp. 20190577 ◽  
Author(s):  
D. Klindžić ◽  
D. M. Stam ◽  
F. Snik ◽  
C. U. Keller ◽  
H. J. Hoeijmakers ◽  
...  
Keyword(s):  
Direct Detection ◽  
Mission Design ◽  
The Moon ◽  
Weather Patterns ◽  
The Earth ◽  
Habitable Zones ◽  
Future Space ◽  
Earth Like Planets ◽  
Life On Earth ◽  
Phase Angles

LOUPE, the Lunar Observatory for Unresolved Polarimetry of the Earth, is a small, robust spectro-polarimeter for observing the Earth as an exoplanet. Detecting Earth-like planets in stellar habitable zones is one of the key challenges of modern exoplanetary science. Characterizing such planets and searching for traces of life requires the direct detection of their signals. LOUPE provides unique spectral flux and polarization data of sunlight reflected by Earth, the only planet known to harbour life. These data will be used to test numerical codes to predict signals of Earth-like exoplanets, to test algorithms that retrieve planet properties, and to fine-tune the design and observational strategies of future space observatories. From the Moon, LOUPE will continuously see the entire Earth, enabling it to monitor the signal changes due to the planet’s daily rotation, weather patterns and seasons, across all phase angles. Here, we present both the science case and the technology behind LOUPE’s instrumental and mission design. This article is part of a discussion meeting issue ‘Astronomy from the Moon: the next decades’.

scholarly journals Heterogeneous radiolysis of urea. Implications in astrobiology and prebiotic chemistry

2014 ◽  
Vol 13 (1) ◽  
Author(s):  
Abigail E. Abigail E. Cruz-Hernández, ◽  
Maria Colin-Garcia ◽  
Alejandro Heredia-Barbero ◽  
Alicia Negron-Mendoza ◽  
Sergio Ramos-Bernal
Keyword(s):  
Organic Molecule ◽  
Prebiotic Chemistry ◽  
Solid Surfaces ◽  
Mineral Surfaces ◽  
Primitive Earth ◽  
High Doses ◽  
Living Organisms ◽  
Life On Earth ◽  
Emergence Of Life

AbstractUrea is an organic molecule present in most living organisms. Historically, it was the first organic molecule synthesized in the laboratory. In prebiotic chemistry, urea readily forms in different laboratory simulations using different energy sources. Furthermore, the role of solid surfaces, particularly minerals, might have been crucial to increase the complexity of the organic matter which may have led to the subsequent emergence of life on Earth. In this work, the radiolysis of urea in presence of a clay is studied to determine to what extent the mineral surfaces influence the decomposition of organics. The results indicate that urea is relatively stable to ionizing radiation in aqueous solutions and up to 20 kGy no decomposition is observed. Moreover, the presence of sodium montmorillonite, by a mechanism until now unknown, affects the radiolytic behavior and urea remains in the heterogeneous solution without a change in concentration even at very high doses (140 kGy). These results indicate that solids could have protected some organics, like urea, from degradation enabling them to remain in the environment on the primitive Earth.

scholarly journals Autocatalytic and oscillatory reaction networks that form guanidines and products of their cyclization

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Alexander I. Novichkov ◽  
Anton I. Hanopolskyi ◽  
Xiaoming Miao ◽  
Linda J. W. Shimon ◽  
Yael Diskin-Posner ◽  
...  
Keyword(s):  
Chemical Cues ◽  
Native Chemical Ligation ◽  
Reaction Networks ◽  
Oscillatory Reaction ◽  
Experimental Conditions ◽  
Chemical Ligation ◽  
Chemical Systems ◽  
Life On Earth ◽  
Emergence Of Life ◽  
Equilibrium Chemical

AbstractAutocatalytic and oscillatory networks of organic reactions are important for designing life-inspired materials and for better understanding the emergence of life on Earth; however, the diversity of the chemistries of these reactions is limited. In this work, we present the thiol-assisted formation of guanidines, which has a mechanism analogous to that of native chemical ligation. Using this reaction, we designed autocatalytic and oscillatory reaction networks that form substituted guanidines from thiouronium salts. The thiouronium salt-based oscillator show good stability of oscillations within a broad range of experimental conditions. By using nitrile-containing starting materials, we constructed an oscillator where the concentration of a bicyclic derivative of dihydropyrimidine oscillates. Moreover, the mixed thioester and thiouronium salt-based oscillator show unique responsiveness to chemical cues. The reactions developed in this work expand our toolbox for designing out-of-equilibrium chemical systems and link autocatalytic and oscillatory chemistry to the synthesis of guanidinium derivatives and the products of their transformations including analogs of nucleobases.

An inverse relationship between moisture and grazing intensity in an arid mountain-basin system

2021 ◽  
pp. 030913332110600
Author(s):  
Jun Zhang ◽  
Xiao-zhong Huang ◽  
Jia-le Wang ◽  
Richard HW Bradshaw ◽  
Tao Wang ◽  
...  
Keyword(s):  
Arid Region ◽  
Influencing Factor ◽  
Regional Climate ◽  
Fungal Spores ◽  
Grazing Intensity ◽  
Pollen Grains ◽  
High Mountains ◽  
Spores And Pollen ◽  
The North ◽  
Basin System

Precipitation has been suggested as a crucial influencing factor in the primary productivity in arid and semi-arid regions, yet how moisture fluctuation in an arid mountain-basin system of the north Qinghai–Tibetan Plateau has affected human activities is poorly understood. Here, we reconstruct the variations of grazing intensity in high elevations and regional humidity based on independent and high-resolution records of Sporormiella-type coprophilous fungal spores and pollen grains in the same well-dated sediment core from Lake Tian’E in the western Qilian Mountains over the past 3500 years. We find that stronger grazing activity was associated with low regional effective moisture, and propose that the drier regional climate pushed people and their livestock into the mountainous areas. A notable exception was a reduction of human and grazing activities in arid region with high mountains during 380–580 CE caused by centennial-length dry and cold conditions. In addition, it is also noteworthy that intensified grazing activity occurred during 580–720 CE and after ∼1920 CE, corresponding to a warmer and wetter climate and diverse subsistence strategies with social developments in the lowlands of the Hexi Corridor. Our findings potentially provide a historical reference for understanding how ancient people adapted to the climate change in arid region with high mountains.

scholarly journals The formation of the building blocks of peptides on interstellar dust grains

2019 ◽  
Vol 15 (S350) ◽  
pp. 216-219
Author(s):  
N. F. W. Ligterink ◽  
J. Terwisscha van Scheltinga ◽  
V. Kofman ◽  
V. Taquet ◽  
S. Cazaux ◽  
...  
Keyword(s):  
Interstellar Dust ◽  
Reaction Network ◽  
Building Blocks ◽  
Dust Grains ◽  
Reaction Products ◽  
Experimental Conditions ◽  
Interstellar Dust Grains ◽  
Temperature Programmed ◽  
Life On Earth ◽  
Emergence Of Life

AbstractThe emergence of life on Earth may have its origin in organic molecules formed in the interstellar medium. Molecules with amide and isocyanate groups resemble structures found in peptides and nucleobases and are necessary for their formation. Their formation is expected to take place in the solid state, on icy dust grains, and is studied here by far-UV irradiating a CH4:HNCO mixture at 20 K in the laboratory. Reaction products are detected by means of infrared spectroscopy and temperature programmed desorption - mass spectrometry. Various simple amides and isocyanates are formed, showing the importance of ice chemistry for their interstellar formation. Constrained by experimental conditions, a reaction network is derived, showing possible formation pathways of these species under interstellar conditions.

scholarly journals Ecosystem Services and Disservices of Vegetation in Recreational Urban Blue-Green Spaces—Some Recommendations for Greenery Shaping

Forests ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 1077
Author(s):  
Agata Ćwik ◽  
Tomasz Wójcik ◽  
Maria Ziaja ◽  
Magdalena Wójcik ◽  
Katarzyna Kluska ◽  
...  
Keyword(s):  
Ecosystem Services ◽  
Positive Impact ◽  
Fungal Spores ◽  
Pollen Grains ◽  
Plant Composition ◽  
Artificial Lake ◽  
Negative Effect ◽  
Multi Media ◽  
The City ◽  
Main Attraction

Urban water bodies are an important asset in terms of climate change. The accompanying vegetation is an integral part of the waterside space system and a source of ecosystem services and disservices. The composition of greenery in waterside spaces should therefore be preceded by detailed research. This research would be the basis for the development of recommendations for enhancement of the positive impact of vegetation on humans and minimisation of its negative effect. The aim of the study was to identify ecosystem services and disservices of vegetation in the four most important waterside recreation spaces in the city of Rzeszów, Poland, and to develop plant composition guidelines. A detailed inventory of vegetation and aerobiological monitoring of the presence of airborne allergenic pollen grains and fungal spores were carried out. Next, the ecosystem services and disservices of the vegetation were determined based on literature data and on our expert judgement. Additionally, a counting of the number of visitors to waterside areas was conducted. All these steps were used to develop recommendations for shaping the vegetation of study areas. The results of the investigations show that the boulevards along the artificial lake function completely differently than other investigated places as the area resembles an urban park, and the water is not the main attraction in this space. The vegetation of the boulevards and the nearby gravel-pit bathing area has mostly a spontaneous character and offers the widest range of ecosystem services and disservices. The management of the vegetation should focus on its health-enhancing values. The vegetation growing near the outdoor swimming pools has been designed by man. Nevertheless, it requires recomposing and is targeted specifically at the enhancement of the visual attractiveness. Additionally, there is a need for planting compact deciduous trees that will provide shade at the multi-media fountain.

scholarly journals Energy, genes and evolution: introduction to an evolutionary synthesis

2013 ◽  
Vol 368 (1622) ◽  
pp. 20120253 ◽  
Author(s):  
Nick Lane ◽  
William F. Martin ◽  
John A. Raven ◽  
John F. Allen
Keyword(s):  
Environmental Changes ◽  
Evolutionary Synthesis ◽  
Past Century ◽  
Major Transitions ◽  
Life On Earth ◽  
Energy Harnessing ◽  
Emergence Of Life ◽  
The Universe ◽  
Planetary Habitability ◽  
Origin Of Eukaryotes

Life is the harnessing of chemical energy in such a way that the energy-harnessing device makes a copy of itself. No energy, no evolution. The ‘modern synthesis’ of the past century explained evolution in terms of genes, but this is only part of the story. While the mechanisms of natural selection are correct, and increasingly well understood, they do little to explain the actual trajectories taken by life on Earth. From a cosmic perspective—what is the probability of life elsewhere in the Universe, and what are its probable traits?—a gene-based view of evolution says almost nothing. Irresistible geological and environmental changes affected eukaryotes and prokaryotes in very different ways, ones that do not relate to specific genes or niches. Questions such as the early emergence of life, the morphological and genomic constraints on prokaryotes, the singular origin of eukaryotes, and the unique and perplexing traits shared by all eukaryotes but not found in any prokaryote, are instead illuminated by bioenergetics. If nothing in biology makes sense except in the light of evolution, nothing in evolution makes sense except in the light of energetics. This Special Issue of Philosophical Transactions examines the interplay between energy transduction and genome function in the major transitions of evolution, with implications ranging from planetary habitability to human health. We hope that these papers will contribute to a new evolutionary synthesis of energetics and genetics.

Airborne fungal spores, pollen grains, and vegetable cells in routine Papanicolaou smears

2004 ◽  
Vol 30 (6) ◽  
pp. 381-385 ◽  
Author(s):  
Rafael Martínez-Girón ◽  
Andrés Ribas-Barceló ◽  
M Teresa García-Miralles ◽  
Dolores López-Cabanilles ◽  
M Luisa Tamargo-Peláez ◽  
...  
Keyword(s):  
Fungal Spores ◽  
Pollen Grains ◽  
Airborne Fungal Spores ◽  
Papanicolaou Smears

Environmentally Responsible Behaviour for a Sustainable Future

2021 ◽  
Vol 10 (1) ◽  
pp. 21-27
Author(s):  
Rasna Sehrawat ◽  
◽  
Anshu Mathur
Keyword(s):  
Biological Diversity ◽  
Earth Systems ◽  
Responsible Behavior ◽  
Environmental Deterioration ◽  
The Earth ◽  
Environmentally Responsible ◽  
Ecological Culture ◽  
The Individual ◽  
Life On Earth ◽  
Threat To Life

Humans are the only species on the planet Earth who do not contribute in the natural environmental cycle but has always been the exploiter of the limited resources. Tecer (2007) told that Environmental deterioration, extinction, or pollution in many vital earth systems, such as air, water, soil, forest, and biological diversity have required countries to develop policies for protecting and developing the earth and promoting global cooperation on these issues. Atasoy (2005) concluded in his study that Environmental problems have become globalized and have reached the stage where they present a threat to life on Earth. This situation has led to the review of people's relationships with nature, their attitudes and behaviors towards the environment, the duties and responsibilities assumed by the individual towards nature, and the redefinition of ecological culture and environmental awareness. It is imperative to be Environmentally Responsible in the present scenario where awareness on the effect of responsible behavior already exists in abundance through media, curriculum, and social activities.

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