Redshift evolution of the characteristic acceleration scale. In each quantile-based z bin (blue bars), we fit the RAR with Eq. (1) to derive a₀, with uncertainties shown as grey error bars. The star marks the SPARC z = 0 value. The purple line shows the predicted evolution, using the best-fitting parameters from the global z-dependent fit to the RAR for the full sample (i.e. using Eq. (1) where a₀ was substituted with Eq. (3); see Eq. (4)). The red line shows the same, but including SPARC in the fit. The coloured shaded region shows the 1σ errors for the fits.