Figure 5: Summary of meta-analyses and meta-syntheses that test the ERH or related sub-hypotheses. ‘Scope of meta-analyses’: Each coloured box represents an effect size and is positioned to reflect what factor of the ERH the meta-analysis tested, and what metric of that factor it examined. Multiple boxes per row indicate that the meta-analysis calculated different effect sizes for different metrics and/or factors – long boxes spanning multiple metrics indicate a single effect size that combined all those metrics. ‘Contexts’: Each box indicates whether the meta-analyses accounted for the seven key contexts of the ERH. Codes in boxes are as follows: Grey shading, the effect of that context was tested for; red star, the context was found to be significant; solid diagonal line, the context was controlled for in meta-analysis design (e.g. accounting for resource availability by only including common garden studies); dashed diagonal line, the context was controlled for in design for the process of host adaptation only; NA, the context is not applicable for the process that the meta-analysis tested.