A zoogeographic model for the evolution of diversity and endemism in Madagascar

Abstract

The delineation of zoogeographic regions is essential for understanding the evolution of biodiversity. Madagascar, characterized by high levels of endemism and habitat diversity, presents unique challenges and opportunities for such studies. Traditional global zoogeographic classifications, largely based on vertebrates, may overlook finer‐scale patterns of diversity. This study employs comprehensive ant distribution and phylogenomic datasets to propose a refined zoogeographic model for Madagascar. Utilizing phylogenetic Simpson's turnover, we identified three primary regions – Eastern, Northern, and Western – each characterized by distinct environmental and phylogenetic profiles. Further subdivision revealed nine subregions, reflecting variations in elevation, net primary productivity, and terrain ruggedness. Our findings highlight the importance of topographical and environmental barriers in shaping phylogenetic diversity and endemism. Notably, we observed significant phylogenetic clustering in lowland areas and distinct differences in net primary productivity and elevation across regions. This study underscores the value of integrating phylogenetic data in zoogeographic analyses and provides a nuanced framework for investigating biodiversity patterns in Madagascar, offering insights into the processes driving speciation and endemism on the island.