highly significantp < 0.001
To test for phylogenetic signal in each of these thermal limit measures, Pagel's λ was calculated, which revealed a strong and highly significant phylogenetic signal for thermal scope ( λ = 0.99, p < 0.001) and CT max ( λ = 0.49, p < 0.001), suggesting that closely related species have a more similar thermal scope and CT max than more distantly related species.