Fig. 1

Correlations (Spearman’s rho) among variables related to local adaptation (left). Abbreviations are reported in Table 1 and Table 2. Additional file 3: Table S3 reports details of the correlation analysis. Asterisks (*) indicate correlations surviving Bonferroni multiple testing correction. Yellow, purple, and cyan colors indicate variables related to geo-climate, pathogen diversity, and language phonological complexity, respectively. Hierarchical clustering based on Spearman’s rho was generated considering absolute correlation distances