From Pleistocene Corridors to Isolated Peaks and Back: Biogeography of Afrocarduus (Compositae) in the Afromontane Archipelago

作者：Lucía D. Moreyra, Cristina Roquet, Alfonso Susanna, Siri Birkeland, Carme Blanco‐Gavaldà, Christian Brochmann, Desalegn Chala, Mercè Galbany‐Casals, Abel Gizaw, Juan Antonio Calleja · 发表于：Journal of Biogeography · 年份：2025 · DOI：10.1111/jbi.70045 · 被引用次数：3 · 研究领域：Ethnobotanical and Medicinal Plants Studies、Plant Diversity and Evolution、African Botany and Ecology Studies

ABSTRACT Aim We investigated the biogeographic history and diversification dynamics of Afrocarduus , an Afromontane–Afroalpine genus endemic to eastern Africa. We aimed to assess the roles of geographic isolation, habitat transitions, and ecological speciation in shaping current diversity. Location The Afromontane and Afroalpine regions of East Africa and Ethiopia are situated along the Great Rift Valley system. Taxon Afrocarduus (Compositae: Carduinae), a genus comprising 18 endemic species. Methods We conducted a comprehensive taxonomic and geographic sampling of Afrocarduus , generating data from 489 nuclear loci. Phylogenomic and biogeographic ancestral estimation analyses were performed to infer the evolutionary history and historical biogeography of the genus. Results Afrocarduus originated in the Afromontane zone of eastern Africa during the Late Miocene (~10.7 Ma), with major diversification events occurring in the Early Pleistocene (~2.3 Ma). Most dispersal events occurred between neighbouring massifs, though occasional long‐distance dispersal between disjunct mountain systems was detected. The Turkana Depression and the Great Rift Valley have acted as major biogeographic barriers. Phylogenetic structure shows distinct clades occupying different regions. Ecological divergence between Afromontane and Afroalpine environments contributed to speciation, with at least six independent adaptations to Afroalpine conditions and multiple cases of ecological reversal. Stem loss...