Molecular assembly indices, which measure the number of unique sequential steps theoretically required to construct a three-dimensional molecule from its constituent atomic bonds, have been proposed as potential biosignatures. A central hypothesis of assembly theory is that any molecule with an assembly index ≥15 found in significant local concentrations represents an unambiguous sign of life. We show that abiotic molecule-like heteropolyanions, which assemble in aqueous solution as precursors to some mineral crystals, range in molecular assembly indices from 2 for H2CO3 or Si(OH)4 groups to as large as 21 for the most complex known molecule-like subunits in the rare minerals ewingite and ilmajokite. Therefore, values of molecular assembly indices ≥15 do not represent unambiguous biosignatures. © 2024 The Authors.
Original languageEnglish
Article number20230632
JournalJournal of the Royal Society Interface
Issue number211
StatePublished - Feb 2024

    Research areas

  • assembly theory, heteropolyanion, mineral evolution, molecular complexity, Titan, Minerals, Silicon compounds, Assembly theory, Atomic bonds, Biosignatures, Heteropoly anions, Large biomolecules, Mineral crystals, Mineral evolutions, Molecular assembly, Molecular complexity, Molecules, mineral, aqueous solution, article, Molecular Conformation, Water, Minerals/chemistry

ID: 117319092