Magnitude gap distribution of the remnant groups at z = 0 for the halos that are selected as fossil, control, and random groups at z = 1 and traced to z = 0. The blue dashed, green dotted and red solid histograms show a gap distribution for traced fossil, control, and random groups within SI (top panel), SII (middle panel), and SIII (bottom panel). It appears that ≈ 40% of fossils with M₂₀₀> 10¹⁴ M_⊙h^-1 survive their gap after evolving between z = 1 and z = 0.