Browsing by Autor "Nora H. Oleas"

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Expelled by the Antarctic ice: Evolutionary history of the tribe Cunonieae (Cunoniaceae)
(Wiley, 2025) Francisco Fajardo‐Gutiérrez; Mariasole Calbi; Markus S. Dillenberger; J. Sebastián Tello; A C.; Nora H. Oleas; Ricardo A. Segovia; Christine E. Edwards; Yohan Pillon; James Richardson
Abstract 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.
Genotyping‐by‐sequencing informs conservation of Andean palms sources of non‐timber forest products
(Wiley, 2024) Nicolás Peñafiel; Abigail H. Chafe; Mónica Moraes R.; Nora H. Oleas; Julissa Roncal
Conservation and sustainable management of lineages providing non-timber forest products are imperative under the current global biodiversity loss. Most non-timber forest species, however, lack genomic studies that characterize their intraspecific variation and evolutionary history, which inform species' conservation practices. Contrary to many lineages in the Andean biodiversity hotspot that exhibit high diversification, the genus Parajubaea (Arecaceae) has only three species despite the genus' origin 22 million years ago. Two of the three palm species, P. torallyi and P. sunkha, are non-timber forest species endemic to the Andes of Bolivia and are listed as IUCN endangered. The third species, P. cocoides, is a vulnerable species with unknown wild populations. We investigated the evolutionary relationships of Parajubaea species and the genetic diversity and structure of wild Bolivian populations. Sequencing of five low-copy nuclear genes (3753 bp) challenged the hypothesis that P. cocoides is a cultigen that originated from the wild Bolivian species. We further obtained up to 15,134 de novo single-nucleotide polymorphism markers by genotyping-by-sequencing of 194 wild Parajubaea individuals. Our total DNA sequencing effort rejected the taxonomic separation of the two Bolivian species. As expected for narrow endemic species, we observed low genetic diversity, but no inbreeding signal. We found three genetic clusters shaped by geographic distance, which we use to propose three management units. Different percentages of missing genotypic data did not impact the genetic structure of populations. We use the management units to recommend in situ conservation by creating new protected areas, and ex situ conservation through seed collection.
Phylogeny of Weinmannia (Cunoniaceae) reveals the contribution of the southern extratropics to tropical Andean biodiversity
(Elsevier BV, 2025) Ricardo A. Segovia; Eduardo Aguirre-Mazzi; Christine E. Edwards; Alexander G. Linan; A C.; Andrea Chaspuengal; Kyle G. Dexter; Francisco Fajardo‐Gutiérrez; William Farfán-Ríos; Nora H. Oleas