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’.