highly significantp ≈ 5.0 × 10−5
To further avoid approximation error, we additionally conducted a permutation test (randomly shuffling the Core/Dispensable labels 20,000 times and recalculating χ2), which remained highly significant ( p ≈ 5.0 × 10−5) (Fig. 4 C, Table S14), supporting that “the distribution of core/dispensable genes changes significantly across subfamilies”.