Extended Data Fig. 3: Thiols are required for autotrophic expansion and fatty acid production.

(a) We grouped the n=672 geochemical scenarios into whether a source of fixed carbon and thiols was provided in the seed set. We then plotted the empirical cumulative distributions for each group of scenarios. Notably, when thiols and fixed carbon are not supplied in the seed set, the networks are always below 100 metabolites, indicating that expansion is prohibited without either fixed carbon or thiols in the seed set. (b) We determined what geochemical parameters (x-axis) were essential for the production of important biomolecules (y-axis). For example, palmitate, a long chain fatty acid, is producible only if thiols and reductant below 400 mV is provided in the seed set.