Existence of a complexity threshold for mineral biosignatures and technosignatures

Determine whether a quantitative threshold in mineral complexity exists such that exceeding the threshold would classify a mineral as a biosignature or technosignature.

Background

Inspired by prior work using molecular assembly as a biosignature, the authors compute assembly indices for mineral unit cells and observe a continuum of values without an apparent threshold. They note that copy number and defects complicate direct interpretation of unit-cell complexity.

The unresolved issue is whether a clear complexity threshold can be defined for minerals that reliably distinguishes those produced by evolutionary or technological processes (biosignatures or technosignatures) from naturally formed materials.

References

It remains an open question whether there is a threshold in complexity above which a mineral might be considered a biosignature or technosignature.

— Quantifying the Complexity of Materials with Assembly Theory (2502.09750 - Patarroyo et al., 13 Feb 2025) in Section: Distribution of Assembly Indices of Known Minerals