Heterogeneity in ecological and evolutionary meta-analyses: its magnitude and implications

Abstract

...We reviewed 700 studies, finding 325 that used formal meta‐analysis, of which total heterogeneity was reported in fewer than 40%. We used second‐order meta‐analysis to collate heterogeneity statistics from 86 studies. Our analysis revealed that the median and mean heterogeneity, expressed as I 2, are 84.67% and 91.69%, respectively....