Emergence of a global subterranean biodiversity hotspot – the origin of the Dinaric amphipod fauna

Teo Delić

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The Mediterranean region has been recognized as one of the global biodiversity hotspots. This pattern is explained as an effect of Pleistocene climatic shifts, that were explicitly linked with two mechanisms generating species richness: dispersal and extinction. However, a third mechanism, speciation, received far less attention and is poorly understood. Subterranean animals in the Western Balkan’s Dinaric Karst are an excellent model system for addressing the question on contribution of speciation to the emergence of a global subterranean hotspot for several reasons. First, subterranean species have lower dispersal abilities. Second, species richness of subterranean taxa deviates from a general species richness pattern on the surface and finally, subterranean habitats are buffered from short term environmental dynamics on the surface. Our aim is to explore how dynamic geological history affected the patterns of speciation in the subterranean amphipod genus Niphargus. The genus is the most suitable model system for addressing these questions for multiple reasons. First, it is the species richest genus of freshwater amphipods and it presents a substantial part of crustacean species diversity of European groundwaters. Next,  the majority of its evolutionary history entirely took place within the subterranean realm, reaching diversity peaks in the Western Balkan’s Dinaric Karst. Finally, previous analyses imply that the genus may be up to 100 MY old, indicating that evolution of the genus followed the formation of the European continent. As such, Niphargus can be used as a valuable model to investigate the importance of speciation in formation of a global subterranean hotspot. The specific focus of the project is the Dinaric Karst, the world hotspot of subterranean biodiversity, and critical evaluation of the major paleogeographic events on shaping the speciation and diversification patterns of the genus Niphargus.

Slovenian Research Agency, project number Z1-9164