Molecular assembly indices of mineral heteropolyanions: some abiotic molecules are as complex as large biomolecules.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 38378136.
- Also identified by DOI 10.1098/rsif.2023.0632 and PMC identifier 10878807.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
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 H<sub>2</sub>CO<sub>3</sub> or Si(OH)<sub>4</sub> 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.
Medical subject headings
- Minerals
- Water