Possible evolutionary paths of our targets, assuming a simple evolutionary model with a constant star formation and a final stage in which all the molecular gas has been transformed into stars. The uncertainties are considered through a Monte Carlo integration. The color map is the same as employed for Fig. 6, For reference, the shaded red stars report the stellar mass and the redshifts for the massive and passive galaxies at z ∼ 3 discovered by Schreiber et al. (2018).