Fig. 5: Estimates on the availability of orthophosphate based on genomic records.
From: Timing the evolution of phosphorus-cycling enzymes through geological time using phylogenomics
Geochemical estimates of marine phosphate concentrations (vertical black bars) for the Archean and Proterozoic are indicated alongside phosphate concentrations most likely to have driven the evolution of the phosphate transport enzymes PstS and PNaS (vertical yellow arrows) and the phosphonate-metabolising enzymes PhnJ and PhnM (pink bars) according to divergence time estimates made with the CIR clock model and event costs of 3:2:1:0 for transfer, duplication, loss and speciation (a). Coloured horizontal lines in panel (b) represent the time since enzymes involved in the microbial utilisation of phosphate (yellow), hypophosphite (black), phosphite (blue) and phosphonate (pink) are estimated to have existed when using different reconciliation parameters. Green horizontal lines represent the time since enzymes which produce phosphonates have existed. Each line spans the period since the first gene encoding an enzyme in the metabolism evolved, with the earliest estimates for pnas (yellow circle), pstS (yellow square), phnJ (pink triangle) and phnM (pink diamond) highlighted with coloured shapes. GOE, Great Oxygenation Event.
