Fraction of old stellar populations (D_n(4000) ≥ 1.6) as a function of the stellar mass. Vertical error bars are obtained by using the bootstrap resampling technique. Filled black circles and dotted lines represent the galaxies in CGs, low-mass LGs objects are shown as filled squares and solid blue lines; high mass LGs sample are shown as filled triangles and solid red lines. Galaxies in the field are represented as filled diamonds and solid violet lines. The left panel considers the whole sample, central panel the early-type galaxies, and right panel late types. The binsizes in stellar mass are 0.5 dex for LGs, 0.4 dex for CGs, and 0.3 dex for the field. Abscissas are the medians of the mass within each bin. Bins with fewer than 10 galaxies were excluded.