Résumé
The dynamics of speciation and extinction shape biodiversity over time. The Red Queen hypothesis attributes these dynamics to biotic factors, whereas the Court Jester hypothesis emphasizes abiotic drivers. We investigated how past environmental changes influenced ants (Formicidae) diversification using maximum-likelihood diversification models. We tested whether speciation and/or extinction rates were constant, time-dependent or shaped by variables such as angiosperm and gymnosperm diversities, temperature and sea level fluctuations. We expected biotic factors, particularly angiosperm diversity, to drive ant diversification. Through model selection across 22 diversification scenarios for 30 ant tribes, we found that the environment-dependent models explain nearly half (46%) of diversification patterns, providing comparable support for the Court Jester and Red Queen hypotheses. Angiosperm radiation was not the sole driver of ant diversification, acting as a key factor only for several ant tribes. Instead, temperature and sea level fluctuations often emerged as stronger drivers. These findings suggest abiotic environmental changes played a greater role in shaping ant evolution than previously thought. Comparisons across grafted and non-grafted phylogenies further revealed that taxon sampling can strongly influence diversification analyses. By identifying potential causes of rate variation, this study offers testable hypotheses for understanding the eco-evolutionary processes underlying ant biodiversity.