Fig. 3.

Comparative analysis of ln maximum lifespan vs residual ln rate of mitochondrial H₂O₂ production during succinate respiration using phylogenetic independent contrasts (PIC). a Construction of a phylogenetic “tree” for 12 mammalian and avian species results in 11 contrasts (nodes numbered 1–11) based on phylogenetic distance. The plot in b represents the PIC of residual ln maximum lifespan (corrected for body mass) vs PIC of residual ln H₂O₂ production rate (corrected for body mass) with the x-axis ‘positivized’ (Garland et al. 1992). For 10 of the 11 points in b, H₂O₂ production is negatively correlated with maximum lifespan, emphasized by the fact that 10 of the 11 points fall below the dashed line at y = 0. This relationship achieves significance in a sign test (P = 0.011; sign test), but not in a regression analysis due to the outlier at node 11 representing the contrast between two mole-rat species. Reprinted with permission from Lambert et al. 2007