Coevolution of primitive methane cycling ecosystems and early Earth atmosphere and climate. (arXiv:2006.06433v1 [q-bio.PE])
<a href="http://arxiv.org/find/q-bio/1/au:+Sauterey_B/0/1/0/all/0/1">Boris Sauterey</a>, <a href="http://arxiv.org/find/q-bio/1/au:+Charnay_B/0/1/0/all/0/1">Benjamin Charnay</a>, <a href="http://arxiv.org/find/q-bio/1/au:+Affholder_A/0/1/0/all/0/1">Antonin Affholder</a>, <a href="http://arxiv.org/find/q-bio/1/au:+Mazevet_S/0/1/0/all/0/1">Stéphane Mazevet</a>, <a href="http://arxiv.org/find/q-bio/1/au:+Ferriere_R/0/1/0/all/0/1">Régis Ferrière</a>
The history of the Earth has been marked by major ecological transitions,
driven by metabolic innovation, that radically reshaped the composition of the
oceans and atmosphere. The nature and magnitude of the earliest transitions,
hundreds of million years before photosynthesis evolved, remain poorly
understood. Using a novel ecosystem-planetary model, we find that
pre-photosynthetic methane-cycling microbial ecosystems are much less
productive than previously thought. In spite of their low productivity, the
evolution of methanogenic metabolisms strongly modifies the atmospheric
composition, leading to a warmer but less resilient climate. As the abiotic
carbon cycle responds, further metabolic evolution (anaerobic methanotrophy)
may feed back to the atmosphere and destabilize the climate, triggering a
transient global glaciation. Although early metabolic evolution may cause
strong climatic instability, a low CO:CH4 atmospheric ratio emerges as a robust
signature of simple methane-cycling ecosystems on a globally reduced planet
such as the late Hadean/early Archean Earth.
The history of the Earth has been marked by major ecological transitions,
driven by metabolic innovation, that radically reshaped the composition of the
oceans and atmosphere. The nature and magnitude of the earliest transitions,
hundreds of million years before photosynthesis evolved, remain poorly
understood. Using a novel ecosystem-planetary model, we find that
pre-photosynthetic methane-cycling microbial ecosystems are much less
productive than previously thought. In spite of their low productivity, the
evolution of methanogenic metabolisms strongly modifies the atmospheric
composition, leading to a warmer but less resilient climate. As the abiotic
carbon cycle responds, further metabolic evolution (anaerobic methanotrophy)
may feed back to the atmosphere and destabilize the climate, triggering a
transient global glaciation. Although early metabolic evolution may cause
strong climatic instability, a low CO:CH4 atmospheric ratio emerges as a robust
signature of simple methane-cycling ecosystems on a globally reduced planet
such as the late Hadean/early Archean Earth.
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