Reply to 'Experimental measurement of assembly indices are required to determine the threshold for life'

We clarify misunderstandings of Walker et al. (Walker et al. 2024 J. R. Soc. Interface 21, 20240367 (doi:10.1098/rsif.2024.0367)) related to studies of the assembly pathways of molecular subunits in minerals. The finding that these subunits have calculated assembly pathways less than approximately 25 informs a central premise of Assembly Theory-that only life can produce numerous copies of molecules with assembly indices above a threshold value. What that threshold value might be, and whether the same value applies to chemical systems as different as organic and inorganic molecules, are questions deserving of additional study.