Identifying agnostic biosignatures without assuming specific metabolisms or Earth-like traits

Identify measurable biosignatures of life that can be sought without assuming specific metabolic processes, morphology, chirality, or other Earth-centric characteristics, under the premise that arbitrary measurements are possible.

Background

A central challenge in life detection is to find signals that do not rely on Earth-specific biological assumptions. The authors note that despite interest in agnostic biosignatures, proposed candidates typically depend on specific metabolic or structural features, leaving ambiguous what measurements should be pursued when such assumptions are removed.

This paper addresses the challenge by proposing energy-ordered resource stratification as a candidate signature arising from ecosystem-level dynamics, but the broader task of systematically identifying other agnostic biosignatures remains unresolved.

References

Even setting aside the technological challenges of remote sensing, and assuming we could perform arbitrary measurements (e.g., to detect ancient signatures of life on Earth, which is also an active field of research), it is not clear what to look for without making such assumptions.

— Energy-ordered resource stratification as an agnostic signature of life  (2403.18614 - Goyal et al., 2024) in Introduction, preceding Results