Exploring the Complex Origin of Pantropical Diversity: Phylogenomics, Systematics, and Biogeography of Dichapetalaceae

• Applicant: Dr. Marie Claire Veranso-Libalah, Ph.D.
• Subject Area: Evolution and Systematics of Plants and Fungi
• Term: since 2026
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 578743323

Pantropical disjunctions—closely related taxa distributed across Africa, Asia, and the Americas—are striking macroecological patterns that provide a valuable framework for studying evolutionary and biogeographic processes. These patterns offer critical insights into dispersal, vicariance, and diversification mechanisms across vast ecological barriers. Despite their prevalence, these lineages remain understudied due to high species richness, complex evolutionary histories, and logistical challenges in tropical regions. The pantropical family Dichapetalaceae (Malpighiales) includes ~215 species across three genera: Dichapetalum, Tapura, and Stephanopodium. Exhibiting diverse morphologies and ecological adaptations as lianas, shrubs, and trees, this family is an ideal model to investigate pantropical evolutionary history. This project aims to reconstruct the first comprehensive, time-calibrated phylogeny of Dichapetalaceae, resolve ambiguous generic boundaries, and investigate diversification and biogeographic dynamics. By integrating nuclear, plastid, and mitochondrial datasets, we will estimate divergence times, reconstruct ancestral ranges, and assess diversification rates linked to ecological transitions and paleoclimatic changes. An integrative taxonomic revision will synthesize molecular, morphological, and geographic evidence to update species classifications. This study utilizes genome skimming, a cost-effective high-throughput sequencing approach, to recover extensive nuclear and organellar loci, complemented by transcriptomic resources for comprehensive phylogenomic inference. Preliminary data from ~ 50% of accepted species, reveal a monophyletic Dichapetalum, a polyphyletic Tapura, and Stephanopodium nested within Tapura, with evidence of cytonuclear discordance. By generating a robust phylogenetic framework, this research will elucidate the historical processes shaping pantropical plant diversity, emphasizing the roles of long-distance dispersal, vicariance, and ecological innovation. The outcomes will advance understanding of tropical evolution and the assembly of pantropical lineages.

• DFG Programme: Research Grants