Quaternary History and Phylogeography of Three <i>Hamadryas</i> Butterflies

ABSTRACT Aim Understanding the evolutionary processes shaping species distributions requires an integrative approach encompassing phylogeographic and biogeographic perspectives. Hamadryas butterflies represent a good model for such research, due to their widely studied ecological and evolutionary characteristics and the availability of detailed data on their distribution and taxonomy. This study investigates the drivers of diversification in Hamadryas julitta , H. glauconome glauconome , and H. glauconome grisea , assessing the roles of geographic barriers and Pleistocene climatic fluctuations across Mesoamerica. Location Mesoamerica. Taxon Hamadryas glauconome glauconome , Hamadryas glauconome grisea , and Hamadryas julitta . Methods An analysis was conducted on mitochondrial DNA (COI) from populations across Mexico and Central America. Evolutionary patterns were reconstructed using haplotype networks, phylogenies, and divergence time estimates. The assessment of demographic changes was conducted through the utilization of Fu's Fs , Tajima's D , and mismatch distributions, alongside biogeographic interpretations of geological and climatic events. Results Our analyses revealed three genetically distinct lineages with no shared haplotypes, supporting their status as separate evolutionary units. Divergence between H. julitta and H. glauconome dates to approximately 3.1 Ma, associated with the uplift of the Sierra Madre de Chiapas and Maya Mountains, isolating H. julitta within the Yucatán Peninsula. The Trans‐Mexican Volcanic Belt appears to have shaped the distribution of H. g. glauconome . Demographic patterns suggest a post‐glacial expansion in H. g. glauconome , while H. g. grisea shows high haplotype diversity without evidence of recent expansion, indicating long‐term isolation. Divergence between H. g. glauconome and H. g. grisea around 1.7 Ma coincides with Pleistocene climatic shifts, and historical marine transgressions may have reinforced isolation in H. julitta . Main Conclusions This study highlights the crucial role of geographic barriers, marine transgressions, and Pleistocene climatic changes in shaping butterfly diversification in Mesoamerica. The patterns observed emphasize the dynamic history of the region and its importance in promoting genetic differentiation. Further genomic, ecological, and morphological studies will be essential to fully unravel the evolutionary history of Hamadryas butterflies.