Oleas Gallo, Nora Helena
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Oleas Gallo, Nora Helena
Main Affiliation
Quito
Email
noraoleas@uti.edu.ec
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Scopus Author ID
12645534600

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Expelled by the Antarctic ice: Evolutionary history of the tribe Cunonieae (Cunoniaceae)

2025 , Francisco Fajardo‐Gutiérrez , Mariasole Calbi , Markus S. Dillenberger , Sebastian Tello , Alfredo Fuentes , Oleas Gallo, Nora Helena , Ricardo A. Segovia , Christine E. Edwards , Yohan Pillon , James E. Richardson , Thomas Borsch

The tribe Cunonieae comprises five genera and 214 species of shrubs and trees currently distributed in the Southern Hemisphere and the tropics, exhibiting an amphi-Pacific disjunct distribution shared with Araucariaceae, Myrtaceae, Nothofagaceae, Podocarpaceae, and Proteaceae, among others. To address the central question of how historical geological forces have shaped the distribution of plant diversity in the southern hemisphere, we aimed to provide evidence from the biogeographical history of Cunonieae. We generated the most densely sampled phylogenetic trees of Cunonieae available to date, with 121 samples and 81 species, based on 404 new sequences of plastid and nuclear DNA regions with high hierarchical phylogenetic signal (matK, trnL-F, rpl16, and internal transcribed spacer (ITS)). We included 184 samples of Rosids to estimate divergence times using fossil calibration points. For biogeographic inference, we employed a time-stratified model including fossils as tips. Cunonia and Pterophylla were paraphyletic in the ITS tree, and Cunonia was paraphyletic in the plastid tree. Pancheria, Vesselowskya, and Weinmannia were monophyletic, the latter with conflicting nuclear and plastid phylogenies. The crown group Cunonieae was dated at ~56 Ma, and its ancestral areas were Antarctica and Patagonia. Antarctica acted as a bridge between Australia and South America before the consolidation of the Antarctic Ice Sheet and the extinction of the lineage in Antarctica from the Oligocene to the Miocene. Following that, Cunonieae spread to lower latitudes via Zealandia/Oceania and Patagonia/South America. Geological changes during the Pliocene facilitated a further burst in diversification along the Andes, in Madagascar, and in New Caledonia, where at least three colonization events occurred

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Phylogeny of Weinmannia (Cunoniaceae) reveals the contribution of the southern extratropics to tropical Andean biodiversity

2025 , Ricardo A. Segovia , Eduardo Aguirre-Mazzi , Christine E. Edwards , Alexander G. Linan , Alfredo Fuentes , Andrea Chaspuengal , Kyle G. Dexter , Francisco Fajardo-Gutiérrez , William Farfan-Rios , Oleas Gallo, Nora Helena , Juan C. Penagos Zuluaga , J. Sebastián Tello

The Andes are a relatively young mountain range with impressive biodiversity, but the biogeographic processes underlying its hyperdiversity are still being unraveled. Novel mid- to high-elevation climates may have served as a biological corridor for the immigration of temperate-adapted lineages to more equatorial latitudes, contributing unknown levels of diversity to this region. We tested the hypothesis that Weinmannia is a lineage of extratropical origin that recently reached and then diversified extensively in the tropical Andes. Using a 2bRAD seq approach to generate a time-calibrated phylogeny for the genus, we found that extratropical species were placed as sister to the rest of Weinmannia and that younger clades were distributed towards more equatorial latitudes. Although Weinmannia exhibited low niche conservatism in elevation and latitude, trait reconstructions of climatic variables showed that the common ancestor of Weinmannia occupied cool climates, with high conservatism of thermal and water availability niche across the phylogeny. Thus, Andean uplift likely created habitats with suitable environmental conditions, providing a dispersal route for extant Weinmannia to colonize the tropical Andes from the southern extratropics. These southern lineages likely converged with those originating in other tropical and extratropical centers of diversification, providing multiple origins for the hyperdiversity in the modern montane forests of the tropical Andes.

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