Biology subjects

Arellano, G.

Publications and source records attributed to Arellano, G..

5 recordsLinked to original sources

bioRxiv2025

Aridity Drives Climatic Specialization and Phylogenetic Clustering in Terrestrial Vertebrates

Arid environments constitute one of the main terrestrial biomes on Earth and are predicted to expand under ongoing climate change. Studying the effect of arid conditions on biodiversity patterns and ecological dynamics is therefore critical to understand the evolutionary fate of desert-adapted faunas. Here we provide a global assessment of how aridity influences climatic niche breadth and phylogenetic structure across terrestrial vertebrates. Using distributional data for over 34,000 species of amphibians, squamates, birds, and mammals, combined with environmental data and nearly complete phylogenies of these clades, we quantified species positions along aridity gradients and their climatic niche breadth, and evaluated phylogenetic clustering at multiple spatial scales. Across all groups, species occupying more arid environments exhibited significantly narrower climatic niches than those from non-arid habitats, supporting the hypothesis that ecological filtering in deserts promotes climatic specialization. Further, analyses of system-wide community phylogenetic structure revealed significant phylogenetic clustering in most arid systems for all clades except birds, underscoring that deserts broadly act as ecological filters at large scale, but this effect is subjected to clade-specific traits. However, finer-scale analyses showed significant phylogenetic overdispersion in several cases, suggesting that competition and micro-niche dynamics might be stronger determinants of phylogenetic structure at the local-to-regional level. Together, our results demonstrate that drylands act as ecological filters shaping both functional and evolutionary dimensions of biodiversity, with implications for predicting biotic responses to desertification and climate change.

evolutionary biology↗

bioRxiv2025

Dosing and Serostatus Shape the Efficacy of Adenovirus, mRNA, and Protein Vaccines

Despite the widespread use of adenovirus, mRNA, and protein-based vaccines during the COVID-19 pandemic, their relative immunological profiles and protective efficacies remain incompletely defined. Here, we compared antigen kinetics, innate and adaptive immune responses, and protective efficacy following Ad5, mRNA, and protein vaccination in mice. Ad5 induced the most sustained antigen expression, but mRNA induced the most potent interferon responses, associated with robust antigen presentation and costimulation. Unlike Ad5 vaccines, which were hindered by pre-existing vector immunity, mRNA vaccines retained efficacy after repeated use. As a single-dose regimen, Ad5 vaccines elicited superior immune responses. However, as a prime-boost regimen, and particularly in Ad5 seropositive mice, mRNA vaccines outperformed the other vaccine platforms. These findings highlight strengths of each vaccine platform and underscore the importance of host serostatus in determining optimal vaccine performance.

immunology↗

bioRxiv2023

Woody plant taxonomic, functional, and phylogenetic diversity decrease along elevational gradients in Andean tropical montane forests: environmental filtering and arrival of temperate taxa

AimMountains are paramount for exploring biodiversity patterns and their causes due to the rich mosaic of topographies and climates encompassed over short geographical distances. Biodiversity changes along elevational gradients have traditionally been explored in terms of taxonomic diversity, but other aspects must be considered. For first time, we simultaneously assessed elevational trends in the taxonomic, functional, and phylogenetic diversity of woody plants in Andean tropical montane forests (TMFs) and explored their underlying ecological and evolutionary causing processes. LocationTropical Andes Time period2011/2012 and 2017/2019 Tropical Andes Major TaxaWoody plants MethodsWe investigated taxonomic, functional, and phylogenetic diversity along four transects (traversing ca. 2,200 m altitudinal gradients) encompassing 114 0.1 ha plots across a broad latitudinal range (ca. 10{degrees}). We used Hill numbers to quantify differences in the abundance-based diversity of 37,869 woody plant individuals with DBH [≥] 2.5 cm. ResultsTaxonomic, functional, and phylogenetic diversity decreased as elevation increased. The decrease was less pronounced for Hill numbers of higher orders. The only exception was a slight increase in phylogenetic diversity when more weight was given to dominant species. These results were consistent between transects. Main conclusionsThe decrease in taxonomic and functional diversity with elevation might be due to an environmental filtering process where the increasingly harsher conditions towards highlands exclude species and functional strategies. Besides, the differences in the steepness of the decrease between Hill orders suggest that rare species contribute disproportionately to functional diversity. The shifting elevational trend in the phylogenetic diversity between Hill orders indicates a greater than previously considered influence in central tropical Andean highlands of species originated in lowlands with strong niche conservatism relative to distantly related temperate lineages. This could be explained by a decreasing presence and abundance of extratropical taxa towards the central Andes relative to northern or southern Andes. BIOSKETCHGuillermo Banares-de-Dios is a plant ecologist with interests in community assembly, biodiversity patterns, and global change. He completed his PhD in 2020 and belongs to "Grupo de Ecologia Tropical", an international network of researchers from different institutions with broad interests in tropical biology (http://www.grupoecologiatropical.com/?lang=en). Currently he works as Project Manager implementing the European Pollinator Monitoring Scheme in Spain.

ecology↗

bioRxiv2023

Elevational Range Sizes of Woody plants Increase with Climate Variability in the Tropical Andes

AimThe climate variability hypothesis proposes that species subjected to wide variation in climatic conditions will evolve wider niches, resulting in larger distributions. We test this hypothesis in tropical plants across a broad elevational gradient; specifically, we use a species-level approach to evaluate whether elevational range sizes are explained by the levels of thermal variability experienced by species. LocationCentral Andes Time periodPresent day Major taxa studiedWoody plants MethodsCombining data from 479 forest plots, we determined the elevational distributions of nearly 2300 species along an elevational gradient ([~]209 - 3800 m). For each species, we calculated the maximum annual variation in temperature experienced across its elevational distribution. We used phylogenetic generalized least square models to evaluate the effect of thermal variability on range size. Our models included additional covariates that might affect range size: body size, local abundance, mean temperature and total precipitation. We also considered interactions between thermal variability and mean temperature or precipitation. To account for geometric constraints, we repeated our analyses with a standardized measure of range size, calculated by comparing observed range sizes with values obtained from a null model. ResultsOur results supported the main prediction of the climate variability hypothesis. Thermal variability had a strong positive effect on the range size, with species exposed to higher thermal variability having broader elevational distributions. Body size and local abundance also had positive, yet weak effects, on elevational range size. Furthermore, there was a strong positive interaction between thermal variability and mean annual temperature. Main conclusionsThermal variability had an overriding importance in driving elevational range sizes of woody plants in the Central Andes. Moreover, the relationship between thermal variability and range size might be even stronger in warmer regions, underlining the potential vulnerability of tropical montane floras to the effects of global warming.

ecology↗

bioRxiv2020

The evolutionary assembly of forest communities along environmental gradients: recent diversification or sorting of pre-adapted clades?

O_LIBiogeographic events occurring in the deep past can contribute to the structure of modern ecological communities. However, little is known about how the emergence of environmental gradients shape the evolution of species that underlie community assembly. In this study, we address how the creation of novel environments lead to community assembly via two non-mutually exclusive processes: 1) the immigration and ecological sorting of pre-adapted clades (ISPC), and 2) recent adaptive diversification (RAD). We study these processes in the context of the elevational gradient created by the uplift of the Central Andes. C_LIO_LIWe develop a novel approach and method based on the decomposition of species turnover into within- and among-clade components, where clades correspond to lineages that originated before mountain uplift. Effects of ISPC and RAD can be inferred from how components of turnover change with elevation. We test our approach using data from over 500 Andean forest plots. C_LIO_LIWe found that species turnover between communities at different elevations is dominated by the replacement of clades that originated before the uplift of the Central Andes. C_LIO_LIOur results suggest that immigration and sorting of clades pre-adapted to montane habitats is the primary mechanism shaping communities across elevations. C_LI

ecology↗