The Global Biosphere and Its Metaphysical Underpinnings: Ecumenical Alternatives in Animism and Astrobiology

Sociologus ◽  
2021 ◽  
Vol 71 (1) ◽  
pp. 55-72
Author(s):  
Istvan Praet
Keyword(s):  
Indigenous People ◽  
Home Environment ◽  
Ancient Greek ◽  
Extraterrestrial Life ◽  
Terrestrial Life ◽  
Familiar World ◽  
Life On Earth ◽  
Historical Accident

The term biosphere designates the “zone of life” on Earth. Outside this sphere, everything becomes “alien.” In this view of things, which I take to be canonical in the modern West, terrestrial life and biosphere overlap more or less neatly. Yet this idea of an almost perfect convergence is not the only view possible. This study presents two anthropological cases which demonstrate, a contrario, that the modern tendency to envisage the biosphere as “our home environment” or as “our familiar world” is in many ways a historical accident. Other ecumenical possibilities (by which I refer to the ancient Greek notion of the “inhabited world,” the oikumene) are by no means unthinkable. Examining the ecumenical originality of two communities that at first sight seem unrelated – Chachi indigenous people in Ecuador and scientists involved in the search for extraterrestrial life – will allow us to cast new light on the metaphysical underpinnings of the modern biosphere concept.

scholarly journals Estimating survival probability using the terrestrial extinction history for the search for extraterrestrial life

2020 ◽  
Author(s):  
Kohji Tsumura
Keyword(s):  
Probability Density Function ◽  
Probability Density ◽  
Survival Probability ◽  
Normal Function ◽  
Extraterrestrial Life ◽  
New Approach ◽  
Random Multiplicative Process ◽  
Log Normal ◽  
Life On Earth ◽  
Fitted Function

Several exoplanets have been discovered to date, and the next step is the search for extraterrestrial life. However, it is difficult to estimate the number of life-bearing exoplanets because our only template is based on life on Earth. In this paper, a new approach is introduced to estimate the probability that life on Earth has survived from birth to the present based on its terrestrial extinction history. A histogram of the extinction intensity during the Phanerozoic Eon is modeled effectively with a log-normal function, supporting the idea that terrestrial extinction is a random multiplicative process. Assuming that the fitted function is a probability density function of extinction intensity per unit time, the estimated survival probability of life on Earth is ~0.15 from the beginning of life to the present. This value can be a constraint on fi in the Drake equation, which contributes to estimating the number of life-bearing exoplanets.

Seeking the oldest evidence of life on Earth

2004 ◽  
Vol 25 (1) ◽  
pp. 8
Author(s):  
Abigail Allwood ◽  
Adrian Brown
Keyword(s):  
Naked Eye ◽  
Terrestrial Life ◽  
Planetary Processes ◽  
Life On Earth

The search for the oldest evidence of terrestrial life is a search for answers to some of mankind?s oldest questions. But do we really have a chance of finding unequivocal fossils of the simple, soft bodied microorganisms that were the first inhabitants of this planet if we consider their lack of hard parts, their concealment from the naked eye, their simple morphologies, the timeframes and planetary processes since their formation (perhaps more than 3 billion years ago), and the rarity of suitable ancient rocks?

scholarly journals Classification of the Biogenicity of Complex Organic Mixtures for the Detection of Extraterrestrial Life

Life ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 234
Author(s):  
Nicholas Guttenberg ◽  
Huan Chen ◽  
Tomohiro Mochizuki ◽  
H. James Cleaves
Keyword(s):  
Solar System ◽  
Extraterrestrial Life ◽  
Analytical Technique ◽  
Spectral Signatures ◽  
Organic Mixtures ◽  
Terrestrial Life ◽  
Algorithmic Analysis ◽  
In Situ Methods ◽  
Solar System Exploration ◽  
Near Future

Searching for life in the Universe depends on unambiguously distinguishing biological features from background signals, which could take the form of chemical, morphological, or spectral signatures. The discovery and direct measurement of organic compounds unambiguously indicative of extraterrestrial (ET) life is a major goal of Solar System exploration. Biology processes matter and energy differently from abiological systems, and materials produced by biological systems may become enriched in planetary environments where biology is operative. However, ET biology might be composed of different components than terrestrial life. As ET sample return is difficult, in situ methods for identifying biology will be useful. Mass spectrometry (MS) is a potentially versatile life detection technique, which will be used to analyze numerous Solar System environments in the near future. We show here that simple algorithmic analysis of MS data from abiotic synthesis (natural and synthetic), microbial cells, and thermally processed biological materials (lab-grown organisms and petroleum) easily identifies relational organic compound distributions that distinguish pristine and aged biological and abiological materials, which likely can be attributed to the types of compounds these processes produce, as well as how they are formed and decompose. To our knowledge this is the first comprehensive demonstration of the utility of this analytical technique for the detection of biology. This method is independent of the detection of particular masses or molecular species samples may contain. This suggests a general method to agnostically detect evidence of biology using MS given a sufficiently strong signal in which the majority of the material in a sample has either a biological or abiological origin. Such metrics are also likely to be useful for studies of possible emergent living phenomena, and paleobiological samples.

From the Moon to Mars: The Search for Extraterrestrial Life

2008 ◽  
Author(s):  
Susan M. Gaines ◽  
Geoffrey Eglinton ◽  
Jürgen Rullkötter
Keyword(s):  
Organic Compounds ◽  
Live Cells ◽  
The Moon ◽  
Extraterrestrial Life ◽  
Biological Origin ◽  
Inorganic Substances ◽  
Carbon Compounds ◽  
Sterile Medium ◽  
Carbonaceous Meteorite ◽  
Life On Earth

“But did anyone really expect to find anything?” I ask Geoff, as he shows me the canister that had contained his sample of moon dust from the 1969 Apollo 11 mission. “Well, no,” he replied, “we didn’t think there’d ever been life on the moon. But we didn’t know. We thought there might be organic compounds.” And why not? People had been finding organic compounds in meteorites for more than a century, and no one was quite sure where they’d come from or how they’d formed. In 1834, the Swedish chemist Jöns Jakob Berzelius noted the high carbon content of a meteorite that had fallen in southern France a couple of decades earlier. Meteor showers in Europe were described as early as 1492, and their extraterrestrial provenance had been documented in 1803, when the distinguished French physicist Jean-Baptiste Biot featured among the scores of citizens who witnessed the stones falling from the sky above the village of l’Alsace. But the source of the carbon compounds Berzelius and others found in meteorites would remain controversial far into the next century. Another carbonaceous meteorite fell in Hungary in 1857, and the eminent chemist Frederick Wöhler—Berzelius’s student, and the first to show that one could create carbon compounds like those made by organisms from inorganic substances in the lab—found organic compounds that he was convinced were of extraterrestrial biological origin. A decade later, Marcellin Berthelot found what he called “petroleum-like hydrocarbons” in a meteorite that had fallen near Orgueil, France, in 1864. He postulated that the hydrocarbons had formed abiotically from reaction of metal carbides with water, but in the next few years there was a spate of meteorite treatises in which the fossils of an astounding assortment of exotic extraterrestrial creatures were described in minute detail. Louis Pasteur had just presented his famous experiment showing that a protected, sterile medium remained devoid of life ad infinitum and debunked the popular theory that life could burst spontaneously into being from nonliving matter, but now the debate shifted to the possibility that life on Earth had originated with live cells or spores delivered by meteorites from space.

Leaves, genes, and greenhouse gases

2007 ◽  
Author(s):  
David Beerling
Keyword(s):  
Solar System ◽  
Liquid Water ◽  
Natural Radioactivity ◽  
Extraterrestrial Life ◽  
Left Behind ◽  
Direct Observations ◽  
Solar System Exploration ◽  
Life On Earth ◽  
The Universe ◽  
Modern Astronomy

The Galileo spacecraft, named after the Italian astronomer Galileo Galilei (1564–1642), who launched modern astronomy with his observations of the heavens in 1610, plunged to oblivion in Jupiter’s crushing atmosphere on 21 September 2003. Launched in 1989, it left behind a historic legacy that changed the way we view the solar system. Galileo’s mission was to study the planetary giant Jupiter and its satellites, four of which Galileo himself observed, to his surprise, moving as ‘stars’ around the planet from his garden in Pardu, Italy. En route, the spacecraft captured the first close-up images of an asteroid (Gaspra) and made direct observations of fragments of the comet Shoemaker–Levy 9 smashing into Jupiter. Most remarkable of all were the startling images of icebergs on the surface of Europa beamed backed in April 1997, after nearly eight years of solar system exploration. Icebergs suggested the existence of an extraterrestrial ocean, liquid water. To the rapt attention of the world’s press, NASA’s mission scientists commented that liquid water plus organic compounds already present on Europa, gave you ‘life within a billion years’. Whether this is the case is a moot point; water is essential for life on Earth as we know it, but this is no guarantee it is needed for life elsewhere in the Universe. Oceans may also exist beneath the barren rocky crusts of two other Galilean satellites, Callisto and Ganymede. Callisto and Ganymede probably maintain a liquid ocean thanks to the heat produced by natural radioactivity of their rocky interiors. Europa, though, lies much closer to Jupiter, and any liquid water could be maintained by heating due to gravitational forces that stretch and squeeze the planet in much the same way as Earth’s moon influences our tides. To reach Jupiter, Galileo required two slingshots (gravitational assists) around Earth and Venus. Gravitational assists accelerate the speed and adjust the trajectory of the spacecraft without it expending fuel. The planets doing the assisting pay the price with an imperceptible slowing in their speed of rotation. In Galileo’s case, the procedure fortuitously permitted close observations of Earth from space, allowing a control experiment in the search for extraterrestrial life, never before attempted.

scholarly journals Commission 51: Bioastronomy – Search for Extraterrestrial Life

2005 ◽  
Vol 1 (T26A) ◽  
pp. 171-174
Author(s):  
Karen Meech ◽  
Alan Boss ◽  
Cristiano Cosmovici ◽  
Pascale Ehrenfreund ◽  
David Latham ◽  
...  
Keyword(s):  
Solar System ◽  
Origin Of Life ◽  
International Society ◽  
International Organizations ◽  
Extrasolar Planets ◽  
Extraterrestrial Life ◽  
Evolution Of Life ◽  
Formation And Evolution ◽  
The Origin Of Life ◽  
Life On Earth

Historically, there have been two main groups dealing with the investigation of extraterrestrial life and habitable worlds. The first is IAU Commission 51, composed of astronomers, physicists and engineers who focus on the search for extrasolar planets, formation and evolution of planetary systems, and the astronomical search for intelligent signals. The second group, the International Society for the Study of the Origin of Life (ISSOL), is composed largely of biologists and chemists focusing research on the biogenesis and evolution of life on Earth and in the solar system. There are now a variety of international organizations dedicated to this field, and this triennium has seen the beginnings of coordination and interaction between the groups through the Federation of Astrobiology Organizations, FAO.

Searching for a shadow biosphere on Earth as a test of the ‘cosmic imperative’

2011 ◽  
Vol 369 (1936) ◽  
pp. 624-632 ◽  
Author(s):  
P. C. W. Davies
Keyword(s):  
Origin Of Life ◽  
Observable Universe ◽  
The Galaxy ◽  
Terrestrial Life ◽  
The Origin Of Life ◽  
Absence Of Evidence ◽  
Life On Earth ◽  
Second Genesis

Estimates for the number of communicating civilizations in the galaxy, based on the so-called Drake equation, are meaningless without a plausible estimate for the probability that life will emerge on an Earth-like planet. In the absence of a theory of the origin of life, that number can be anywhere from 0 to 1. Distinguished scientists have been known to argue that life on Earth is a freak accident, unique in the observable universe and, conversely, that life is almost bound to arise in the course of time, given Earth-like conditions. De Duve, adopting the latter position, coined the phrase that ‘life is a cosmic imperative’. De Duve’s position would be immediately verified if we were to discover a second sample of life that we could be sure arose from scratch independently of known life. Given the current absence of evidence for life beyond Earth, the best way to test the hypothesis of the cosmic imperative is to see whether terrestrial life began more than once. If it did, it is possible that descendants of a second genesis might be extant, forming a sort of ‘shadow biosphere’ existing alongside, or perhaps interpenetrating, the known biosphere. I outline a strategy to detect the existence of such a shadow biosphere.

Life as a cosmic imperative?

2011 ◽  
Vol 369 (1936) ◽  
pp. 620-623 ◽  
Author(s):  
Christian de Duve
Keyword(s):  
Origin Of Life ◽  
Extrasolar Planet ◽  
Second Stage ◽  
Physical Chemical ◽  
Terrestrial Life ◽  
Probable Site ◽  
The Origin Of Life ◽  
Chemical Conditions ◽  
Life On Earth ◽  
Two Stages

The origin of life on Earth may be divided into two stages separated by the first appearance of replicable molecules, most probably of RNA. The first stage depended exclusively on chemistry. The second stage likewise involved chemistry, but with the additional participation of selection, a necessary concomitant of inevitable replication accidents. Consideration of these two processes suggests that the origin of life may have been close to obligatory under the physical–chemical conditions that prevailed at the site of its birth. Thus, an extrasolar planet in which those conditions were replicated appears as a probable site for the appearance of extra-terrestrial life.

scholarly journals Microbial life in oceanic crust

2020 ◽  
Author(s):  
Beth Orcutt ◽  
Timothy D'Angelo ◽  
Sean P. Jungbluth ◽  
Julie A. Huber ◽  
Jason B. Sylvan
Keyword(s):  
Oceanic Crust ◽  
Chemical Reactions ◽  
Environment Impact ◽  
Ocean Crust ◽  
Extraterrestrial Life ◽  
Microbial Life ◽  
The Past ◽  
New Synthesis ◽  
Life On Earth ◽  
Dissolved Chemicals

Oceanic crust comprises a vast but virtually unexplored habitat for life on Earth, characterized by massive global flows of water, heat, and dissolved chemicals. Uncovering where and how life exists in oceanic crust is important because chemical reactions occurring in this environment impact broader ocean systems and also because it is an earth analog for considering the possibility of extraterrestrial life on other ocean worlds. Over the past decade, several major oceanographic expeditions focused on characterizing the ocean crust microbiome, enabled by advances in seafloor drilling and observatory technologies. Here we review what is known about the crustal ocean microbial biosphere, focusing on a new synthesis of recent studies on the diversity of microbial life in oceanic crust to reveal common and unique taxa in this environment.

scholarly journals From climate models to planetary habitability: temperature constraints for complex life

2016 ◽  
Vol 16 (3) ◽  
pp. 244-265 ◽  
Author(s):  
Laura Silva ◽  
Giovanni Vladilo ◽  
Patricia M. Schulte ◽  
Giuseppe Murante ◽  
Antonello Provenzale
Keyword(s):  
Climate Models ◽  
Climate Model ◽  
Habitable Zone ◽  
Ambient Conditions ◽  
Thermal Thresholds ◽  
Planetary Evolution ◽  
Thermal Limits ◽  
Terrestrial Life ◽  
Earth Like Planets ◽  
Life On Earth

AbstractIn an effort to derive temperature-based criteria of habitability for multicellular life, we investigated the thermal limits of terrestrial poikilotherms, i.e. organisms whose body temperature and the functioning of all vital processes is directly affected by the ambient temperature. Multicellular poikilotherms are the most common and evolutionarily ancient form of complex life on earth. The thermal limits for the active metabolism and reproduction of multicellular poikilotherms on earth are approximately bracketed by the temperature interval 0°C ≤ T ≤ 50°C. The same interval applies to the photosynthetic production of oxygen, an essential ingredient of complex life, and for the generation of atmospheric biosignatures observable in exoplanets. Analysis of the main mechanisms responsible for the thermal thresholds of terrestrial life suggests that the same mechanisms would apply to other forms of chemical life. We therefore propose a habitability index for complex life, h050, representing the mean orbital fraction of planetary surface that satisfies the temperature limits 0°C ≤ T ≤ 50°C. With the aid of a climate model tailored for the calculation of the surface temperature of Earth-like planets, we calculated h050 as a function of planet insolation, S, and atmospheric columnar mass, Natm, for a few earth-like atmospheric compositions with trace levels of CO2. By displaying h050 as a function of S and Natm, we built up an atmospheric mass habitable zone (AMHZ) for complex life. At variance with the classic habitable zone, the inner edge of the complex life habitable zone is not affected by the uncertainties inherent to the calculation of the runaway greenhouse limit. The complex life habitable zone is significantly narrower than the habitable zone of dry planets. Our calculations illustrate how changes in ambient conditions dependent on S and Natm, such as temperature excursions and surface dose of secondary particles of cosmic rays, may influence the type of life potentially present at different epochs of planetary evolution inside the AMHZ.

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