Colonization, diversification and speciation of the genus Hipparchia (Lepidoptera: Nymphalidae) in the Canary Islands

The Canary Islands harbor numerous endemic species, showcasing a wide array of colonization and diversification patterns. Butterflies belonging to the genus Hipparchia inhabit 5 of the 7 major islands in the archipelago, but their origin, colonization history, and taxonomic status are uncertain. In this study we contribute a molecular dataset representing the species of these butterflies on the 5 islands and all the related mainland taxa and provide insights on these questions. Our analysis points to an initial colonization of the Canary Islands circa 5.4 Mya, followed by a rapid expansion to the high-altitude islands then present or as soon as they emerged. The old age of the Canarian taxa and their position within the subgenus Pseudotergumia challenge previous hypotheses based on morphological characteristics or geographical proximity. Furthermore, our study underscores the pivotal role of founder-event speciation in driving the divergence of this taxon within the island complex. Finally, we show that each island harbors a unique and remarkably differentiated evolutionary lineage, without any hint of admixture. We conclude that these populations should be recognized as distinct species, endemic to each of the islands. Considering their notably limited ranges, this study amplifies the significance of each population in the context of forthcoming conservation efforts.