Molecular phylogenetics and trait-dependent biogeography offer insights on the dispersal of Meiogyne (Annonaceae) across the Australasia–Pacific region

Abstract

Meiogyne is a genus of shrubs, trees and treelets occurring in India, tropical Southeast Asia, and Australasia–Pacific, an unusually wide distribution across Australasia and the Western Pacific compared to other genera of Annonaceae. Previous chloroplast phylogenies of the genus offered poor resolution and support. Here, a molecular phylogeny was reconstructed based on 27 described Meiogyne species (ca. 70% sampling) using seven chloroplast and 11 nuclear markers. The combined data set generated a well-resolved and well-supported phylogeny. Estimation of divergence time utilized two fossil calibrations and an uncorrelated log-normal relaxed clock model. Trait-dependent and trait-independent biogeographical models in BioGeoBEARS were compared using corrected Akaike information criterion weight and the likelihood ratio test. The results suggest that narrow monocarp width is correlated with increased macroevolutionary dispersal. Under the best-fitting trait-dependent DEC +  j +  t₁₂ +  t₂₁ +  m₂ model, a single colonization event from Sunda to Sahul during the middle Miocene and two dispersal events from New Guinea and Australia into the Pacific during the late Miocene to early Pliocene were detected. BayesTraits analysis strongly supports a correlation between narrow monocarp width and bright fruit colors. Bird dispersal and the associated traits (narrow monocarp width) may have driven macroevolutionary dispersal for Meiogyne in Australasia–Pacific.

Keywords

Annonaceae / Australasia / biogeography / bird / endozoochory / fruit color / fruit morphology / Meiogyne / Pacific / seed dispersal

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2025 Institute of Botany, Chinese Academy of Sciences.