Table 3 AIC scores and ω estimates for various branch-based selection models for the 13 PCGs (one ω for all branches (M0), two-ratio model with background (surface) ω and single ω for subterranean branches (M1), two-ratio model with background (surface) ω and single ω for subterranean branches fixed at neutral evolution (ω = 1) (M1fixed), six-ratio model with background (surface) ω and a single ω for each subterranean lineage, B. brachycaudus (C1), Stygobromus clade (C2), B. jaraguensis (C3), Metacrangonyx clade (C4), P. daviui (C5) (M1a), and ω for each branch (M2)). The best-fit model(s) for each PCG is highlighted in red color
