Oleas Gallo, Nora Helena

Preferred name

Main Affiliation

Centro de Investigación de la Biodiversidad y Cambio Climático

Quito

noraoleas@uti.edu.ec

ORCID

0000-0002-1948-4119

Scopus Author ID

12645534600

Now showing 1 - 10 of 37

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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
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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Molecular Systematics of Threatened Seed Plant Species Endemic in the Caribbean Islands
(2013)
Oleas Gallo, Nora Helena
;
Jestrow B.
;
Calonje M.
;
Peguero B.
;
Jiménez F.
A review of available Caribbean Island red-lists species (CR and EN categories based on the IUCN guidelines from 2001, and E category established according to the IUCN guidelines from 1980) is presented. A database of over 1,300 endemic species that are either Critically Endangered or Endangered sensu IUCN was created. There are molecular systematic studies available for 112 of them. Six of these species (in six genera) are the only members of early divergent lineages that are sister to groups composed of a large number of clades. Seven of the species (in seven genera) belong to clades that have a small number of taxa but are sister to species/genus-rich clades. Ten of the species (in six genera) are sister to taxa restricted to South America or nested in clades endemic to this region. Fifty-seven of the species (in 35 genera) are sister to Caribbean Island endemic species. Erigeron belliastroides, an Endangered (EN) Cuban endemic, is sister to the Galapagos genus Darwiniothamnus. The phylogenetic placement of four of the threatened species resulted in changes in their taxonomic placement; they belong to polyphyletic or paraphyletic genera. © 2013 The New York Botanical Garden.
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Water quality assessment of the cutuchi river basin (Ecuador): A review of technical documents
(2021)
Zapata D.
;
Oleas Gallo, Nora Helena
;
Páez-Vacas, Mónica
;
Tobes, Ibon
The Cutuchi River Basin extends over the inter-Andean valley south of the Cotopaxi Volcano, in Ecuador. It flows through two provinces, Cotopaxi and Tungurahua, and its waters are extensively used to irrigate crops that provide food to the main cities in the country. Unfortunately, the basin receives untreated domestic and industrial discharges. The need for an environmental quality assessment of the river has been acknowledged over the years. The aim of this study is to gather information about water quality of the Cutuchi River through a historical bibliographic review. A total of 57 works published between 2007 and 2018 were found, including books, articles, thesis and project reports. Only 18 documents provided biological, physical, or chemical data linked to water quality. The data obtained through the literature review were compared with maximum thresholds from national and international regulations. Unfortunately, revised studies were scattered on time and randomly along the basin and did not provide robust information to evaluate the state of the water-system. Some contamination was detected significantly exceeding safety thresholds. More exhaustive studies along the basin are needed as a baseline to help the decision makers to design management plans and mitigate human impacts. © 2020 Institute of Physics Publishing. All rights reserved.
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In vitro and in silico analysis of galanthine from Zephyranthes carinata as an inhibitor of acetylcholinesterase
(2022)
Sierra, K.
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de Andrade, J.P.
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R. Tallini, L.
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Osorio, E.H.
;
Yañéz, O.
Zephyranthes carinata Herb., a specie of the Amaryllidoideae subfamily, has been reported to have inhibitory activity against acetylcholinesterase. However, scientific evidence related to their bioactive alkaloids has been lacking. Thus, this study describes the isolation of the alkaloids of this plant, and their inhibition of the enzymes acetylcholinesterase (eeAChE) and butyrylcholinesterase (eqBuChE), being galanthine the main component. Additionally, haemanthamine, hamayne, lycoramine, lycorine, tazettine, trisphaeridine and vittatine/crinine were also isolated. The results showed that galanthine has significant activity at low micromolar concentrations for eeAChE (IC50 = 1.96 μg/mL). The in-silico study allowed to establish at a molecular level the high affinity and the way galanthine interacts with the active site of the TcAChE enzyme, information that corroborates the result of the experimental IC50. However, according to molecular dynamics (MD) analysis, it is also suggested that galanthine presents a different inhibition mode that the one observed for galanthamine, by presenting interaction with peripheral anionic binding site of the enzyme, which prevents the entrance and exit of molecules from the active site. Thus, in vitro screening assays plus rapid computer development play an essential role in the search for new cholinesterase inhibitors by identifying unknown bio-interactions between bioactive compounds and biological targets. © 2022 The Authors
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Recent diversification in the high Andes: Unveiling the evolutionary history of the Ecuadorian hillstar, Oreotrochilus chimborazo (Apodiformes: Trochilidae)
(2021)
Bonaccorso E.
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Rodríguez-Saltos C.A.
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Freile J.F.
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Peñafiel N.
;
Rosado-Llerena L.
Studying the genetic signatures of evolutionary diversification in young lineages is among the most promising approaches for unveiling the processes behind speciation. Here, we focus on Oreotrochilus chimborazo, a high Andean species of hummingbird that might have experienced rapid diversification in the recent past. To understand the evolution of this species, we generated a dataset of ten microsatellite markers and complementary data on morphometrics, plumage variation and ecological niches. We applied a series of population and coalescent-based analyses to understand the population structure and differentiation within the species, in addition to the signatures of current and historical gene flow, the location of potential contact zones and the relationships among lineages. We found that O. chimborazo comprises three genetic groups: one corresponding to subspecies O. c. chimborazo, from Chimborazo volcano and surroundings, and two corresponding to the northern and southern ranges of subspecies O. c. jamesonii, found from the extreme south of Colombia to southern Ecuador. We inferred modest levels of both contemporary and historical gene flow and proposed the location of a contact zone between lineages. Also, our coalescent-based analyses supported a rapid split among these three lineages during the mid-to-late Holocene. We discuss our results in the light of past and present potential distributions of the species, in addition to evolutionary trends seen in other Andean hummingbirds. © 2021 The Linnean Society of London, Biological Journal of the Linnean Society.
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Population Dynamics of the Endangered Plant, Phaedranassa tunguraguae, from the Tropical Andean Hotspot
(2012)
Oleas Gallo, Nora Helena
;
Meerow A.W.
;
Francisco-Ortega J.
The Tropical Andes is a diversity hotspot for plants, but there is a scant knowledge about patterns of genetic variation within its constituent species. Phaedranassa tunguraguae is an IUCN endangered plant species endemic to a single valley in the Ecuadorian Andes. We estimate the levels of genetic differentiation across the geographic distribution of P. tunguraguae using 12 microsatellite loci. We discuss factors that might influence the genetic structure of this species. Genetic distance was used to evaluate relationship among populations and geographic patterns. Bayesian methods were used to investigate population structure, migration, evidence of recent bottlenecks, and time of divergence. The 7 populations form 2 genetic clusters. These clusters show highly significant differentiation between them, along with isolation by distance. Allele richness decreases from the most diverse westernmost population to the least diverse easternmost population. The species overall shows an excess of homozygotes, with highest levels of inbreeding in the easternmost population. We found evidence of recent bottleneck events. Migration rates were in general low but were higher between populations within each of the clusters. Time of divergence between populations was related to historical volcanic activity in the area. Based on our results, we propose 2 management units for P. tunguraguae. © The American Genetic Association. 2012. All rights reserved.
Scopus© Citations 10 34
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First records of the genus Pyrolirion Herb. (Liliopsida, Asparagales, Amaryllidaceae) in Ecuador
(2025)
Oleas Gallo, Nora Helena
;
Lou Jost
;
Ricardo Zambrano C.
;
Cristian Guzmán Torres
;
Jorge Heredia
We report for the first time in Ecuador the small plant genus <jats:italic>Pyrolirion</jats:italic> Herb. (Amaryllidaceae). We identify several Ecuadorian populations of <jats:italic>Pyrolirion tubiflorum</jats:italic> (L&rsquo;H&eacute;r.) M. Roem. located in four provinces along the Ecuadorian Andes. This species has been previously recorded in Peru, Bolivia, and Chile. An updated description of <jats:italic>P. tubiflorum</jats:italic> is provided, along with detailed photographs of some of the Ecuadorian examples of the species.
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Using species distribution models as a tool to discover new populations of Phaedranassa brevifolia Meerow, 1987 (Liliopsida: Amaryllidaceae) in Northern Ecuador
(2014)
Oleas Gallo, Nora Helena
;
Meerow A.W.
;
Feeley K.J.
;
Gebelein J.
;
Francisco-Ortega J.
Phaedranassa brevifolia Meerow (1987) is an endangered plant species endemic to Ecuador. Until recently, this species was only known by the type location and four other adjacent subpopulations in a restricted area of less than four km2. We combined geo-referenced occurrences of this species and bioclimatic variables to generate a prospective species distribution model. Using the resulting map as a guide for field work, we found three new populations of P. brevifolia, increasing its geographic distribution to 16 km2. © 2014 Check List and Authors.
Scopus© Citations 4 24
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A Comprehensive Database of Expert‐Curated Occurrences for the Genus
<i>Carex</i>
L. (Cyperaceae)
(2025)
María Sanz‐Arnal
;
Pablo García‐Moro
;
Carmen Benítez‐Benítez
;
Marina Coca‐de‐la‐Iglesia
;
Angélica Gallego‐Narbón
Motivation: Geographic occurrences are essential for biodiversity studies, but publicly available repositories like GBIF often contain errors and biases, especially for taxonomically complex groups like Carex L. (Cyperaceae). This work provides an expert-curated global dataset of occurrences compiled from different sources to enhance data accuracy and usability. The final dataset includes 384,067 occurrences of 1790 Carex species. Main Types of Variables Contained: The dataset includes species occurrence records with geographic coordinates, taxonomic identifications, and curation flags (e.g., introduced, erroneous records). Spatial Location and Grain: The dataset covers a global scale, using the WGS84 projection. Spatial resolution is standardised to a minimum of three decimal degrees (~1 km, if possible). Time Period and Grain: Online records span from 1950 to 2020, but some manually georeferenced records are earlier (1850). There is also fieldwork data after 2020, specifically up to 2023. Major Taxa and Level of Measurement: Cyperaceae: Carex. Most records have species-level identification, and some of them are identified at subspecies or variety levels. Software Format: Data are supplied as comma-separated values files with UTF-8 encoding.
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Conservation profile of endemic species of Berberis from Ecuador (Berberidaceae, Ranunculales)
(2025)
Carmen Ulloa Ulloa
;
Sánchez Lara, Enmily
;
Oleas Gallo, Nora Helena
Background The plant family Berberidaceae is represented in Ecuador by a single genus, Berberis. It comprises 15 species, seven endemic to the high Andean forests and páramos above 2,400 meters of altitude. These ecosystems, globally recognized for their exceptional biodiversity, are increasingly threatened by fragmentation and degradation, placing endemic species at serious risk of extinction. The conservation status of Berberis species in Ecuador was last assessed more than 20 years ago, underscoring the urgent need for a comprehensive and updated evaluation. New information This study presents IUCN Red List assessments for all endemic species of the genus Berberis in Ecuador. Incorporating the latest taxonomic revision, we evaluate Berberis engleriana and B. rigida for the first time. Among the five species previously assessed, three have retained their original conservation status, while two are now classified under a higher threat category. Conservation measures are proposed to mitigate extinction risk and support the preservation of these species.
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Oleas Gallo, Nora Helena

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