Biome conservatism prevailed in repeated long-distance colonization of Madagascar’s mountains by Helichrysum (Compositae, Gnaphalieae)

作者：Carme Blanco‐Gavaldà, Cristina Roquet, Genís Puig-Surroca, Santiago Andrés‐Sánchez, Sylvain G. Razafimandimbison, Rokiman Letsara, Nicola G. Bergh, G.V. Cron, Lucía D. Moreyra, Juan Antonio Calleja, Òscar Castillo, Randall J. Bayer, Frédérik Leliaert, Alfonso Susanna, Mercè Galbany‐Casals · 发表于：Molecular Phylogenetics and Evolution · 年份：2025 · DOI：10.1016/j.ympev.2024.108283 · 被引用次数：8 · 研究领域：Sesquiterpenes and Asteraceae Studies、Ethnobotanical and Medicinal Plants Studies、Plant Diversity and Evolution

• Helichrysum (Compositae) colonized Madagascar independently at least six times since the Pliocene. • Niche conservatism prevailed in dispersals to Madagascar and during species diversification for most Madagascan lineages. • Helichrysum underwent two recent and rapid radiations in Madagascar’s mountains. • In Madagascar’s mountains, shifts from high- to low-elevation habitats lead to ecological speciation during the Pleistocene. Colonization and diversification processes are responsible for the distinctiveness of island biotas, with Madagascar standing out as a biodiversity hotspot exceptionally rich in species and endemism. Regardless of its significance, the evolutionary history and diversification drivers of Madagascar’s flora remain understudied. Here we focus on Helichrysum (Compositae, Gnaphalieae) to investigate the evolutionary and biogeographic origins of the Malagasy flora. We inferred a highly resolved phylogeny based on target-enrichment data from 327 species (including 51 % of Malagasy endemics) and conducted ancestral range estimation analyses. Our results revealed at least six trans -oceanic dispersal events from different African regions to Madagascar during the Pliocene. In this process, biome conservatism prevailed, as evidenced by similarities between Malagasy lineages and their African relatives. The southern African grasslands, known to be the center of diversification and the main source of African Helichrysum lineages, played a key role in the coloniz...