Fig. 4. Mass-specific basal metabolic rates (BMR_w), exceptional longevity (L_o/L_p), and lifetime expenditure of energy (LxBMR_w) are function of the rate of cytochrome b evolution. Data are from Table S2 in supplementary material. (A) Mass-specific basal metabolic rates (BMR_w) are function of both body mass (M) and the rate of cytochrome b evolution (Scytb) in the Fringillidae family. Multiple linear regression of lnBMR_w as a function of both lnM and Scytb: LnBMR_w=2.304–0.157xlnM+6.373xScytb (N=16, r²=0.706, P<0.001, VIF=1.07, P(lnM)<0.001, P(Scytb)=0.002). (B) L_o/L_p as function of Scytb. Open symbols indicate oscines (N=31), inverted triangles indicate Fringillidae (N=16), and solid symbols indicate all other birds (N=28). L_o/L_p (BMR_w), the residuals from power law 1, are indicated by squares; L_o/L_p (M), the residuals from power law (3) are indicated by circles. For oscine birds L_o/L_p(BMR_w)=–1.143+ 16.5xScytb (r²=0.170, P=0.021, and L_o/L_p(M)=–1.547+19.6xScytb (r²=0.243, P=0.005). For Fringillidae; L_o/L_p(M)=–3.964+36.2xScytb (r²=0.42, P=0.007); L_o/L_p(BMR_w)=–4.575+40.35xScytb (r²=0.489, P=0.003). For all other birds: L_o/L_p(BMR_w)=1.96–11.9xScytb (N=28, r²=0.300, P=0.003) and L_o/L_p(M)=1.676–8.37xScytb (r²=0.186, P=0.022). (C) LxBMR_w as a function of Scytb. Symbols are as in B. For oscine birds LxBMR_w=–213+2893xScytb (r²=0.171, P= 0.021); for Fringillidae LxBMR_w=–817+7079xScytb (r²=0.507, P=0.002); for all other birds LxBMR_w=164–778xScytb (r²= 0.104, P=0.095). The difference in LxBMR_w between oscines, 178.7±77, and all other birds 106±47 was significant (t=4.273, P<0.001).