Drift in the tropics: Phylogenetics and biogeographical patterns in Combretaceae

Aim: The aim of this study was to further advance our understanding of the species-rich, and ecologically important angiosperm family Combretaceae to provide new insights into their evolutionary history. We assessed phylogenetic relationships in the family using target capture data and produced a dated phylogenetic tree to assess fruit dispersal modes and patterns of distribution.Location: Tropical and subtropical regions.Time Period: Cretaceous to present.Major Taxa Studied: Family Combretaceae is a member of the rosid clade and comprises 10 genera and more than 500 species, predominantly assigned to genera Combretum and Terminalia, and occurring on all continents and in a wide range of ecosystems.Methods: We use a target capture approach and the Angiosperms353 universal probes to reconstruct a robust dated phylogenetic tree for the family. This phylogenetic framework, combined with seed dispersal traits, biome data and biogeographic ranges, allows the reconstruction of the biogeographical history of the group.Results: Ancestral range reconstructions suggest a Gondwanan origin (Africa/South America), with several intercontinental dispersals within the family and few transitions between biomes. Relative abundance of fruit dispersal types differed by both continent and biome. However, intercontinental colonizations were only significantly enhanced by water dispersal (drift fruit), and there was no evidence that seed dispersal modes influenced biome shifts.Main Conclusions: Our analysis reveals a paradox as drift fruit greatly enhanced dispersal distances at intercontinental scale but did not affect the strong biome conservatism observed.

Automated summary

The aim of this study was to enhance our understanding of the Combretaceae family and its evolutionary history. By analyzing phylogenetic relationships, fruit dispersal modes, and distribution patterns, the study revealed the Gondwanan origin of the family, as well as intercontinental dispersals and biome transitions. The results showed that drift fruit played a significant role in intercontinental colonization but did not influence biome shifts.