A prominent oxygenation event in the late Mesoproterozoic broke the calm of the second half of the “Boring Billion”

Palaeogeography Palaeoclimatology Palaeoecology, Год журнала: 2025, Номер unknown, С. 112752 - 112752

Опубликована: Янв. 1, 2025

Язык: Английский

---

Persistence selection between simulated biogeochemical cycle variants for their distinct effects on the Earth system

Proceedings of the National Academy of Sciences, Год журнала: 2025, Номер 122(7)

Опубликована: Фев. 12, 2025

The average long-term impact of Darwinian evolution on Earth’s habitability remains extremely uncertain. Recent attempts to reconcile this uncertainty by “Darwinizing” nonreplicating biogeochemical processes subject persistence-based selection conform with the historicity geochemical record but lack mechanistic clarity. Here, we present a theoretical framework showing how: 1) A “cycle-biota-variant” (CBV) can be defined non-arbitrarily as one biologically facilitated pathway for net recycling an essential element, plus genotypes driving relevant interconversion reactions. 2) Distinct CBVs individuated if they have climatic or side effects that feed-back relative persistence. 3) separation spatial/temporal scales between dynamics such and those conventional introduce degree randomness into relationship their Earth system properties, loosely analogous biochemical causes evolutionary genetic mutation. 4) Threshold behavior in climate feedback accentuate biotic impacts lead CBV-level “competitive exclusion”. 5) persistence is observationally distinguishable from genotype-level strong covariance “internal” CBV properties (genotypes reactions) “external” effects, which argue fitness traits under selection. These factors cannot circumvent basic fact local natural will often favor phenotypes ultimately destabilize large-scale geochemical/climatic properties. However, claim our results nevertheless demonstrate coherence persistence-selection non-replicating life–environment interaction patterns therefore broad applicability.

Язык: Английский

---

Decoupling microbial iron reduction from anoxic microsite formation in oxic sediments: a microscale investigation through microfluidic models

Frontiers in Microbiology, Год журнала: 2025, Номер 16

Опубликована: Янв. 28, 2025

Iron (Fe) reduction is one of the oldest microbial processes on Earth. After atmosphere and ocean became oxygenated, this anaerobic process was relegated to niche anoxic environments. However, evidence Fe in oxic, partially saturated subsurface systems, such as soils vadose zones, has been reported, with common explanation being formation microsites that remain undetected by bulk measurements. To explore how microscale oxygen concentrations regulate reduction, we cultivated a facultative Fe-reducing bacterium using microfluidic setup integrated transparent planar sensors. Contrary expectations, occurred under fully oxic conditions, without microsites. Our results suggest microbially mediated Fe-reduction could be more widespread environments than previously assumed. Moreover, our mathematical modeling dynamics around biomass-rich layers revealed onset anoxia mainly controlled biomass spatial organization rather conventionally used water saturation index. This opens new perspective proxies needed predict microsite Fe(III) occurrence.

Язык: Английский

---

The triple orogenic junction of central Gondwana

International Geology Review, Год журнала: 2025, Номер unknown, С. 1 - 28

Опубликована: Фев. 12, 2025

The Neoproterozoic tectonic evolution of central Gondwana involved three successive continental collisions, associated with the East African Orogeny (late Cryogenian), Kirwan (early Ediacaran), and Kuunga Ediacaran). interactions between these orogenies produced extensive reactivation Archean to Mesoproterozoic basement rocks, as well deformation metamorphism in cover sequences. To unravel geological history Gondwana, we compiled zircon monazite U-Pb ages (from igneous, detrital, metamorphic rock samples), Sm-Nd Lu-Hf isotope data, thermobarometric P-T peak estimates from 19 terranes. dataset, which encompasses regions eastern Africa, southern India, central-southern Madagascar, Sri Lanka, Antarctica, enables us reconstruct orogenies. analysis 2208 concordant ages, ranging 700 450 Ma, indicates that a event occurred at ~ 550 Ma. Our dataset allows identify records similar events amongst different terranes, thus demonstrating correlations multiple terranes Gondwana. A reassessment previous reconstructions is discussed based on geochronological isotopic data potentially contiguous province named TNASH (Trivandrum Nagercoil Androyen Anosyen southwestern Skallevikshalsen terrane Highland Province Lanka). These Paleoproterozoic exhibit comparable igneous signatures (Lu-Hf Sm-Nd), conditions. study provides an review into complex better understanding strengths limitations hypotheses.

Язык: Английский

---

Near-equilibrium kinetics in the Fe(II)-silicate system and the significance of nanoparticle greenalite in Archaean Iron Formations

Geochimica et Cosmochimica Acta, Год журнала: 2025, Номер unknown

Опубликована: Фев. 1, 2025

Язык: Английский

---

Biogenic pyrite and metastable iron sulfides: Emerging formation pathways and geological and societal relevance

Deleted Journal, Год журнала: 2025, Номер 2

Опубликована: Янв. 1, 2025

Abstract Iron sulfide (Fe-S) minerals such as mackinawite (FeS), greigite (Fe 3 S 4 ) and pyrite (FeS 2 are widespread on Earth, where their formation dissolution strongly linked to the biogeochemical cycles of iron, sulfur, carbon, oxygen, nutrients trace metals. Recent studies have shed light how microorganisms mediate formation, with breakthroughs biogenic pyrite. In this review, we highlight pathways Fe-S minerals, starting increasingly recognized roles Fe(III) intermediate sulfur species ( e.g. 0 polysulfides) during initial steps. The mechanisms by which affect mineral compiled discussed for low (25–35°C) high (≥ 80°C) temperatures, specific examples from experimental studies. morphology precipitation rates obtained experiments compared natural environments, similarities differences critically discussed. We then review current state art in context origin life environmental proxies biosignatures geological record using texture chemical isotopic compositions. end highlighting importance societal issues, sequestration organic acid drainages, metal recovery nitrate removal, potential use technological bio-materials future.

Язык: Английский

---

A geological timescale for bacterial evolution and oxygen adaptation

Science, Год журнала: 2025, Номер 388(6742)

Опубликована: Апрель 4, 2025

Microbial life has dominated Earth’s history but left a sparse fossil record, greatly hindering our understanding of evolution in deep time. However, bacterial metabolism signatures the geochemical most conspicuously Great Oxidation Event (GOE). We combine machine learning and phylogenetic reconciliation to infer ancestral transitions aerobic lifestyles, linking them GOE calibrate time tree. Extant phyla trace their diversity Archaean Proterozoic, families prior Phanerozoic. that were ancestrally anaerobic adopted lifestyles after GOE. cyanobacterial ancestor, likely predated GOE, which may have facilitated oxygenic photosynthesis.

Язык: Английский

---

Nitrogenase structural evolution across Earth’s history

Опубликована: Апрель 9, 2025

Life on Earth is more than 3.5 billion years old—nearly as old the age of planet. Over this vast expanse time, life and its biomolecules adapted to triggered profound changes Earth’s environment. Certain critical enzymes evolved early in history have persisted through planetary extremes. While sequence data widely used trace evolutionary trajectories, enzyme structure remains an underexplored resource for understanding how proteins evolve over long timescales. Here, we implement integrated approach study nitrogenase, ancient, globally essential nitrogen fixation. Despite ecological diversity host microbes, nitrogenase has strict functional limitations, including extreme oxygen sensitivity, energy requirements substrate availability. By combining phylogenetics, ancestral reconstruction, protein crystallography deep-learning based structural prediction, resurrected three history. We present first effort predict all extant structures along tree a total ∼5000 structures. Our lays foundation reconstructing key constraints that influence evolution studying ancient light phylogenetic environmental change.

Язык: Английский

---

Nitrogenase structural evolution across Earth’s history

Опубликована: Апрель 9, 2025

Life on Earth is more than 3.5 billion years old—nearly as old the age of planet. Over this vast expanse time, life and its biomolecules adapted to triggered profound changes Earth’s environment. Certain critical enzymes evolved early in history have persisted through planetary extremes. While sequence data widely used trace evolutionary trajectories, enzyme structure remains an underexplored resource for understanding how proteins evolve over long timescales. Here, we implement integrated approach study nitrogenase, ancient, globally essential nitrogen fixation. Despite ecological diversity host microbes, nitrogenase has strict functional limitations, including extreme oxygen sensitivity, energy requirements substrate availability. By combining phylogenetics, ancestral reconstruction, protein crystallography deep-learning based structural prediction, resurrected three history. We present first effort predict all extant structures along tree a total ∼5000 structures. Our lays foundation reconstructing key constraints that influence evolution studying ancient light phylogenetic environmental change.

Язык: Английский

---

Mo-Isotope Constraints on the Mid-Proterozoic Ocean Oxidation: Insights from the Black Shales of the ~ 1.64 Ga Chuanlinggou Formation, North China Craton

Опубликована: Янв. 1, 2025

Язык: Английский

---