Connecting weathering, entropy and the search for life

Elements, 2005

This paper has integrated the latest achievements of lithostratigraphy, biostratigraphy and geochemical survey in China. Research indicates, the directionality, staged, and irreversibility of biological evolution can all be reflected in the time evolution of rock geochemistry. The outbreak and extinction of biological population correspond to the lithostratigraphic geochemical interfaces .Between the number of biological species, and the rock elemental content, existed a significant correlation. The fractal distribution of rock geochemistry reflects the basic structural features of life on the earth, just like a human body meridian acupuncture point map. In the long-term formation and evolution process, the biological chain system is always in a dynamic equilibrium with the global ecological environment. The abundance and lack of certain elements in the environment, has important influence on the physiological and biochemical processes of plants and animals, thus restricting the regional ecological structure. At last, the authors propose geochemical view point of the origin and evolution of life: Life is the essential characteristic of the universe, the adaptation and coordinated development of biological systems and their living ecological environment, is the fundamental causes and driving forces of biological evolution. Biological evolution is the inevitable result of the interaction of the Earth's lithosphere, hydrosphere, atmosphere and biosphere. Scientists found 37.7-43 billion years of microbial fossils on the Canadian coast, indicating that the earliest life entity on Earth are close to the time of Earth's formation (AFP, 2017). Spencer regards evolution as a process that is solemnly revealed, and the therein program is embedded in the structure of the universe. Darwin proceed from the origin of species, discussed the horizontal evolution or diversity sources. Wallace argues that natural selection is difficult to explain the emergence of human advanced capabilities. Gould and Eldredge proposed theory of punctuated equilibrium (Chen, 1996). Manfred Eigen's the hypercycle theory think, there is a molecular self-organization stage. Kenneth J. Hsu believes that, the catastrophes of nature have contributed to the tremendous changes in biological evolution (Kenneth, 1986). Stephen Meyer wisdom design theory very well explained the necessary information that form the first living cell (Huang,2009,Meyer,2009).From the view point of life elements geochemistry, the history of the origin of life is how the atoms of life elements are combined into complex chemical substances, which in turn form the process of life. (Feng,1980). 2 Relationship between Earth life and rock geochemistry 2.1 Biological fossil assemblage and rock geochemistry Rock strata as the biological fossil 's carrier, its geochemical time evolution also shows directionality, staged periodicity, and irreversibility. Between rock types geochemical and fossil distribution has the correspondence and correlation. The correlation analysis shows that between the strata age and the elemental content, there is a significant linear correlation. There was a significant negative correlation between the number of species and the geological age, γ=-0.4818，n=80, γ 0.05 =0.2172. In general, the more new the eras, the more the species tend to be richer. The biological population outbreak and extinction, correspond to the lithostratigraphic geochemical interface. Chemical elements content high and low become the threshold of the emergence or absence of biological fossils. Xu et al. analyzed the profiles of the Sinian and Cambrian boundary sections, found Ni-Ir-δ 13 C double anomalies in the black shale layer. (Wang, 1999).

Elements, 2016

Life, 2018

In 2001, the first author (S.N.) led the publication of a book entitled “Geochemistry and the origin of life” in collaboration with Dr. Andre Brack aiming to figure out geo- and astro-chemical processes essential for the emergence of life. Since then, a great number of research progress has been achieved in the relevant topics from our group and others, ranging from the extraterrestrial inputs of life’s building blocks, the chemical evolution on Earth with the aid of mineral catalysts, to the fossilized records of ancient microorganisms. Here, in addition to summarizing these findings for the origin and early evolution of life, we propose a new hypothesis for the generation and co-evolution of photosynthesis with the redox and photochemical conditions on the Earth’s surface. Besides these bottom-up approaches, we introduce an experimental study on the role of water molecules in the life’s function, focusing on the transition from live, dormant, and dead states through dehydration/hy...

Cold Spring Harbor Perspectives in Biology, 2010

Crystalline surfaces of common rock-forming minerals are likely to have played several important roles in life's geochemical origins. Transition metal sulfides and oxides promote a variety of organic reactions, including nitrogen reduction, hydroformylation, amination, and Fischer-Tropsch-type synthesis. Fine-grained clay minerals and hydroxides facilitate lipid self-organization and condensation polymerization reactions, notably of RNA monomers. Surfaces of common rock-forming oxides, silicates, and carbonates select and concentrate specific amino acids, sugars, and other molecular species, while potentially enhancing their thermal stabilities. Chiral surfaces of these minerals also have been shown to separate left-and right-handed molecules. Thus, mineral surfaces may have contributed centrally to the linked prebiotic problems of containment and organization by promoting the transition from a dilute prebiotic "soup" to highly ordered local domains of key biomolecules.

Frontiers in Microbiology

Rocks that react with liquid water are widespread but spatiotemporally limited throughout the solar system, except for Earth. Rock-forming minerals with high iron content and accessory minerals with high amounts of radioactive elements are essential to support rock-hosted microbial life by supplying organics, molecular hydrogen, and/or oxidants. Recent technological advances have broadened our understanding of the rocky biosphere, where microbial inhabitation appears to be difficult without nutrient and energy inputs from minerals. In particular, microbial proliferation in igneous rock basements has been revealed using innovative geomicrobiological techniques. These recent findings have dramatically changed our perspective on the nature and the extent of microbial life in the rocky biosphere, microbial interactions with minerals, and the influence of external factors on habitability. This study aimed to gather information from scientific and/or technological innovations, such as omi...

Treatise on Geophysics, 2007

Frontiers in Astronomy and Space Sciences

The origin of life is one of the most fundamental questions of humanity. It has been and is still being addressed by a wide range of researchers from different fields, with different approaches and ideas as to how it came about. What is still incomplete is constrained information about the environment and the conditions reigning on the Hadean Earth, particularly on the inorganic ingredients available, and the stability and longevity of the various environments suggested as locations for the emergence of life, as well as on the kinetics and rates of the prebiotic steps leading to life. This contribution reviews our current understanding of the geological scene in which life originated on Earth, zooming in specifically on details regarding the environments and timescales available for prebiotic reactions, with the aim of providing experimenters with more specific constraints. Having set the scene, we evoke the still open questions about the origin of life: did life start organically o...

Comptes Rendus …, 2009

The search for early Earth biological activity is hindered by the scarcity of the rock record. The very few exposed sedimentary rocks have all been affected by secondary processes such as metamorphism and weathering, which might have distorted morphological microfossils and biogenic minerals beyond recognition and have altered organic matter to kerogen. The search for biological activity in such rocks therefore relies entirely on chemical, molecular or isotopic indicators. A powerful tool used for this purpose is the stable isotope signature of elements related to life (C, N, S, Fe). It provides key informations not only on the metabolic pathways operating at the time of the sediment deposition, but more globally on the biogeochemical cycling of these elements and thus on the Earth's surface evolution. Here, we review the basis of stable isotope biogeochemistry for these isotopic systems. Rather than an exhaustive approach, we address some examples to illustrate how they can be used as biosignatures of early life and as proxies for its environment, while keeping in mind what their limitations are. We then focus on the covariations among these isotopic systems during the Archean time period to show that they convey important information both on the evolution of the redox state of the terrestrial surface reservoirs and on co-occurring ecosystems in the Archean.

Nature communications, 2017

The ca. 3.48 Ga Dresser Formation, Pilbara Craton, Western Australia, is well known for hosting some of Earth's earliest convincing evidence of life (stromatolites, fractionated sulfur/carbon isotopes, microfossils) within a dynamic, low-eruptive volcanic caldera affected by voluminous hydrothermal fluid circulation. However, missing from the caldera model were surface manifestations of the volcanic-hydrothermal system (hot springs, geysers) and their unequivocal link with life. Here we present new discoveries of hot spring deposits including geyserite, sinter terracettes and mineralized remnants of hot spring pools/vents, all of which preserve a suite of microbial biosignatures indicative of the earliest life on land. These include stromatolites, newly observed microbial palisade fabric and gas bubbles preserved in inferred mineralized, exopolymeric substance. These findings extend the known geological record of inhabited terrestrial hot springs on Earth by ∼3 billion years and...