Table 2.

Estimates of phylogenetic signal in eggshell water vapour conductance (G_H2O) in all birds. Phylogenetic signal was analysed separately for log₁₀-transformed G_H2O (log(G_H2O)) and residual water vapour conductance (RG_H2O). The p-value tests the null hypothesis of no phylogenetic signal (λ = 0) and Brownian motion model (λ = 1) of evolution.

response variable	Pagel's λ	log-likelihood	log-likelihood for λ = 0	log-likelihood for λ = 1	p for λ = 0	p for λ = 1
log(GH2O)	0.96	−74.39	590.76	−125.64	<0.001	<0.001
RGH2O	0.55	27.20	258.50	−92.27	<0.001	<0.001