This repository provides the complete data and code required to reproduce the analyses for the Biology Letters submission on mammalian pace-standardised lifespan (PSL) across 28 taxa (n = 28). Version note (v4)This is the fourth release of the replication package. Earlier versions (v1, v2, and v3) are superseded by v4. This update introduces a comprehensive README.txt to clarify nomenclature and ensures full alignment between internal data identifiers and the manuscript text. Please use v4 for all verification and reproducibility purposes. 1) Statistical analysis package (PSL_Analysis_v4.zip)- Contents: Core input data and R scripts for OLS and PGLS models evaluated across 100 posterior mammalian trees.- How to reproduce: Run source("run_all.R") in R, or execute Rscript run_all.R from the terminal.- Outputs: Results are written to the /results folder. Session information (including package versions) is saved to /docs/sessionInfo.txt.- Note: This package focuses on the core statistical outputs reported in the manuscript (e.g. slope, confidence interval, and R²) to ensure direct alignment with the text. 2) Figure generation package (PSL_Figure_v4.zip)- Contents: Python scripts (make_fig1.py–make_fig3.py), figure-specific Excel workbooks, and documentation for reproducibility.- How to reproduce (Windows): Double-click RUN_FIGURES_WINDOWS.bat.- Outputs: Figures are generated as Figure1.pdf, Figure2.pdf, and Figure3.pdf in the /figures directory.- Note: For internal consistency, PSL is labelled as “E” in the main workbook and “LEP” in the ANOVA workbook; these refer to the same values as the pace-standardised lifespan (PSL) reported in the manuscript.