Redshift evolution of the zero point of the size–stellar mass relation (i.e., log(R_e/1 kpc) at the reference stellar mass of 10¹¹ M_⊙) as a function of D_n4000. The top and bottom panels show the results in the UV and red rest frames, respectively. Black points show the median size of the total sample of galaxies, and the sets of colder and warmer points show the zero points for the subpopulations of newcomers and aging galaxies, respectively. The colors of symbols for the two subpopulations correspond to their median D_n4000. The error bars denote the 25th–75th percentile range of the distribution. The dashed blue and dash-dotted orange lines are power law fits to the evolution of the zero point of the subpopulations of newcomers and aging galaxies, respectively.