Biosignatures & Paleobiology

Energy-ordered Resource Stratification As An Agnostic Signature Of Life

By Keith Cowing
Status Report
April 4, 2024
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Energy-ordered Resource Stratification As An Agnostic Signature Of Life
Energy-ordered resource stratification as an observable signature of life. (a) Stratified profiles of chemical resources layered by energy content are commonly observed on Earth, e.g., microbial mats, early Earth fossils (stromatolites), Winogradsky columns, and in marine environments. (b) Such profiles are generally understood to be shaped by biotic species (typically microbes) that metabolize these resources for energy. Here, we propose that energy-ordered resource stratification is a robust signature of biotic action. — q-bio.PE

The search for extraterrestrial life hinges on identifying biosignatures, often focusing on gaseous metabolic byproducts as indicators. However, most such biosignatures require assuming specific metabolic processes.

It is widely recognized that life on other planets may not resemble that of Earth, but identifying biosignatures “agnostic” to such assumptions has remained a challenge.

Here, we propose a novel approach by considering the generic outcome of life: the formation of competing ecosystems. We use a minimal model to argue that the presence of ecosystem-level dynamics, characterized by ecological interactions and resource competition, may yield biosignatures independent of specific metabolic activities.

Specifically, we propose the emergent stratification of chemical resources in order of decreasing energy content as a candidate new biosignature. While likely inaccessible to remote sensing, this signature could be relevant for sample return missions, or for detection of ancient signatures of life on Earth itself.

Akshit Goyal, Mikhail Tikhonov

Comments: 5 pages, 3 figures
Subjects: Populations and Evolution (q-bio.PE); Biological Physics (
Cite as: arXiv:2403.18614 [q-bio.PE] (or arXiv:2403.18614v1 [q-bio.PE] for this version)
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Submission history
From: Akshit Goyal
[v1] Wed, 27 Mar 2024 14:29:36 UTC (440 KB)

Explorers Club Fellow, ex-NASA Space Station Payload manager/space biologist, Away Teams, Journalist, Lapsed climber, Synaesthete, Na’Vi-Jedi-Freman-Buddhist-mix, ASL, Devon Island and Everest Base Camp veteran, (he/him) 🖖🏻