MATERIALS AND METHODS
Replication of analyses in Gomes et al. (2011)
Gomes et al. (2011) measured mean TL in kb in adult individuals using the telomere restriction fragment (TRF) method. Telomerase activity was measured in cultured fibroblasts relative to an adenocarcinoma cell line (%H1299). Following Gomes et al. (2011) we used the best species-level mammal supertree from Bininda-Emonds et al. (2007), which is available within the R package ‘PhyloOrchard’ (O’Meara et al., 2012). The phylogeny was pruned to match the dataset using the R package ‘ape’ (Paradis & Schliep, 2018). We used the phylogenetic generalized least squares method (Grafen, 1989) implemented as the ‘pgls’ function in the package ‘caper’ (Orme et al., 2018) to perform the phylogenetic regressions. Pagel’s λ was estimated with default bounds (0-1) using maximum likelihood. We used estimates of adult body mass (kg) and maximum lifespan (years) reported in Gomes et al. (2011), which were derived from the AnAge: The Animal Ageing and Longevity Database (Tacutu et al. 2018). Because some of these were different from current estimates in AnAge we compiled new values for a separate re-analysis (see Supporting Information Table S2). Following Gomes et al. (2011) TL, mass and lifespan were all log10-transformed. We performed two multivariate phylogenetic regressions (outlined in Fig. 2 in Gomes et al., 2011) of body mass (response variable) predicted by telomerase activity and TL, and of maximum lifespan (response variable) predicted by telomerase activity, TL and body mass. The phylogeny and TL evolution were visualized using the ‘phytools’ package (Revell, 2012) in which ancestral states were estimated following Felsenstein (1985) but using maximum likelihood with the function ‘fastAnc’.