Evolution of metal and dust masses. M_Z/M_star (blue dots) and M_dust/M_star (red dots) both regularly increase with the age of the Universe (top); more metals and dust grains are formed as the Universe ages. We note that even for galaxies (blue symbols) in the early Universe (age_Universe≲600 Myr or z ≳ 9), M_Z/M_star never goes below a few 10⁻³, possibly suggesting a fast rise of metals that produces the observed threshold. M_Z/M_star increases faster than M_dust/M_star, with a much larger dispersion for M_dust/M_star. The light blue and red areas show the mean and 2σ confidence interval of the distribution within several bins. At the bottom, same as aboce a function of sSFR. M_Z/M_star (in blue) and M_dust/M_star (in red) decrease from high to low sSFR (bottom), as also shown in, e.g. Palla et al. (2024) and Shivaei et al. (2022). We also note a larger dispersion at lower sSFR for M_dust/M_star, but only for M_dust/M_star.