Interdisciplinary Search for Early Life Forms and for the Beginning of Life on Earth

1976 ◽  
Vol 1 (4) ◽  
pp. 291-310 ◽  
Author(s):  
Bartholomew Nagy ◽  
Lois Anne Nagy
Keyword(s):  
Early Life ◽  
Life Forms ◽  
Life On Earth

Co-evolution of trace elements and life in Precambrian oceans: The pyrite edition

Geology ◽  
2020 ◽  
Vol 48 (10) ◽  
pp. 1018-1022
Author(s):  
Indrani Mukherjee ◽  
Ross R. Large
Keyword(s):  
Trace Elements ◽  
Early Life ◽  
Redox State ◽  
Major Change ◽  
Life Forms ◽  
Biological Responses ◽  
Evolution Of Life ◽  
Marked Decline ◽  
Life On Earth ◽  
Middle Proterozoic

Abstract The significance of trace elements in initiating origins and driving evolution of life on Earth is indisputable. Trace element (TE) trends in the oceans through time broadly reflect their availability and allow speculation on all possible influences on early life. A comprehensive sedimentary pyrite–TE database, covering 3000 m.y. of the Precambrian, has improved our understanding of the sequence of bio-essential TE availability in the ocean. This study probed how changing availability (and scarcity) of critical TEs in the marine environment influenced early life. The pyrite-shale matrix TE sequence shows relatively elevated concentrations of Ni, Co, Cu, and Fe, Cr, respectively, in the Archean and Paleoproterozoic. Abundances of these elements in the Archean potentially facilitated their widespread utilization by prokaryotes. The Paleoproterozoic–Mesoproterozoic saw increases in Zn and Mo but a marked decline in Ni, Co, Cu, Se, and Fe. Our data suggest the evolution of the first complex cell in the Paleoproterozoic was probably triggered by this major change in TE composition of the oceans. A decline of elements prompted alternative utilization strategies by organisms as a response to TE deficits in the middle Proterozoic. An overall increase in a multitude of elements (Ni, Co, Cu, Cr, Se, V, Mo, and P) in the Neoproterozoic and Cambrian was highly advantageous to the various micro– and macro–life forms. Without questioning the importance of macronutrients and atmosphere-ocean redox state, multi-TE availability would have induced substantial heterogenous biological responses, owing to the effects of optimal, deficient, toxic, lethal, and survival levels of TEs on life.

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.

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.

3.43 billion-year-old stromatolite reef from the Pilbara Craton of Western Australia: Ecosystem-scale insights to early life on Earth

2007 ◽  
Vol 158 (3-4) ◽  
pp. 198-227 ◽  
Author(s):  
Abigail C. Allwood ◽  
Malcolm R. Walter ◽  
Ian W. Burch ◽  
Balz S. Kamber
Keyword(s):  
Western Australia ◽  
Early Life ◽  
Life On Earth ◽  
Pilbara Craton

scholarly journals Novel water source for endolithic life in the hyperarid core of the Atacama Desert

2012 ◽  
Vol 9 (6) ◽  
pp. 2275-2286 ◽  
Author(s):  
J. Wierzchos ◽  
A. F. Davila ◽  
I. M. Sánchez-Almazo ◽  
M. Hajnos ◽  
R. Swieboda ◽  
...  
Keyword(s):  
Liquid Water ◽  
Capillary Condensation ◽  
Extreme Environments ◽  
Atacama Desert ◽  
Water Source ◽  
Life Forms ◽  
Alternative Source ◽  
Biological Adaptation ◽  
Salt Flats ◽  
Life On Earth

Abstract. The hyperarid core of the Atacama Desert, Chile, is possibly the driest and most life-limited place on Earth, yet endolithic microorganisms thrive inside halite pinnacles that are part of ancient salt flats. The existence of this microbial community in an environment that excludes any other life forms suggests biological adaptation to high salinity and desiccation stress, and indicates an alternative source of water for life other than rainfall, fog or dew. Here, we show that halite endoliths obtain liquid water through spontaneous capillary condensation at relative humidity (RH) much lower than the deliquescence RH of NaCl. We describe how this condensation could occur inside nano-pores smaller than 100 nm, in a newly characterized halite phase that is intimately associated with the endolithic aggregates. This nano-porous phase helps retain liquid water for long periods of time by preventing its evaporation even in conditions of utmost dryness. Our results explain how life has colonized and adapted to one of the most extreme environments on our planet, expanding the water activity envelope for life on Earth, and broadening the spectrum of possible habitats for life beyond our planet.

scholarly journals Relaxed Substrate Specificity in Qβ Replicase through Long-Term In Vitro Evolution

Life ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 32
Author(s):  
Kohtoh Yukawa ◽  
Ryo Mizuuchi ◽  
Norikazu Ichihashi
Keyword(s):  
Substrate Specificity ◽  
Early Life ◽  
Evolutionary History ◽  
Rna Replication ◽  
Life Forms ◽  
In Vitro Evolution ◽  
Present Evidence ◽  
Major Transition

A change from RNA- to DNA-based genetic systems is hypothesized as a major transition in the evolution of early life forms. One of the possible requirements for this transition is a change in the substrate specificity of the replication enzyme. It is largely unknown how such changes would have occurred during early evolutionary history. In this study, we present evidence that an RNA replication enzyme that has evolved in the absence of deoxyribonucleotide triphosphates (dNTPs) relaxes its substrate specificity and incorporates labeled dNTPs. This result implies that ancient replication enzymes, which probably evolved in the absence of dNTPs, could have incorporated dNTPs to synthesize DNA soon after dNTPs became available. The transition from RNA to DNA, therefore, might have been easier than previously thought.

scholarly journals From cosmos to intelligent life: the four ages of astrobiology

2012 ◽  
Vol 11 (4) ◽  
pp. 345-350 ◽  
Author(s):  
Marcelo Gleiser
Keyword(s):  
Chemical Elements ◽  
Life Forms ◽  
Big Bang ◽  
Self Awareness ◽  
First Stars ◽  
History Of ◽  
Life On Earth ◽  
The Big Bang ◽  
The Universe ◽  
Intelligent Life

AbstractThe history of life on Earth and in other potential life-bearing planetary platforms is deeply linked to the history of the Universe. Since life, as we know, relies on chemical elements forged in dying heavy stars, the Universe needs to be old enough for stars to form and evolve. The current cosmological theory indicates that the Universe is 13.7 ± 0.13 billion years old and that the first stars formed hundreds of millions of years after the Big Bang. At least some stars formed with stable planetary systems wherein a set of biochemical reactions leading to life could have taken place. In this paper, I argue that we can divide cosmological history into four ages, from the Big Bang to intelligent life. The physical age describes the origin of the Universe, of matter, of cosmic nucleosynthesis, as well as the formation of the first stars and Galaxies. The chemical age began when heavy stars provided the raw ingredients for life through stellar nucleosynthesis and describes how heavier chemical elements collected in nascent planets and Moons gave rise to prebiotic biomolecules. The biological age describes the origin of early life, its evolution through Darwinian natural selection and the emergence of complex multicellular life forms. Finally, the cognitive age describes how complex life evolved into intelligent life capable of self-awareness and of developing technology through the directed manipulation of energy and materials. I conclude discussing whether we are the rule or the exception.

The Biography of the Earth

2021 ◽  
pp. 163-180
Author(s):  
Elisabeth Ervin-Blankenheim
Keyword(s):  
Early Life ◽  
Plate Tectonics ◽  
Life Forms ◽  
Snowball Earth ◽  
The Moon ◽  
Geologic Time ◽  
Earth Systems ◽  
Organic Life ◽  
The Earth ◽  
Geologic Record

The way the planet has changed through geologic time, and life on it, the account of the Earth, is the topic of this and the next three chapters, starting in this chapter with the Precambrian Supereon. The overarching principles of geologic time, plate tectonics, and evolution worked dynamically to create the biography of the planet. This chapter traces back to the recesses of the geologic record and early Earth, from its birth and the formation of the Moon through seven-eighths of its existence, a huge span of time. Early life forms emerged during this supereon in the Archean Eon and had a profound influence on other Earth systems. Life interacted and changed the chemistry of the atmosphere through photosynthesis, so much so that the changes are thought to have sent planetary systems over an edge into multiple “Snowball Earth” episodes when most of the planet froze over. In addition to the beginning of organic life and climate, the emergence and configuration of the continents during the Precambrian are covered. Events of this supereon set the stage for the burgeoning of life forms in the next eon, the Phanerozoic.

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