https://rdi.uncoma.edu.ar/handle/uncomaid/15888 2026-06-18T08:06:58Z 2026-06-18T08:06:58Z https://rdi.uncoma.edu.ar/handle/uncomaid/19469 2026-06-17T19:16:41Z

Exploring mitochondrial diversity in the species-rich genus Liolaemus: the interplay between isolation by distance and environmental thermal variability Intraspecific genetic variation enhances a species´ capacity to endure diverse environments. Such variation can drive genetic divergence among populations, often manifesting as isolation by distance (IBD). Here, we investigated how ecological, environmental, life-history, body size, and phylogenetic factors shape IBD and nucleotide diversity (π) using two mitochondrial genes in Liolaemus lizards. From GenBank database, we examined two genes: Cytochrome b (Cytb; 88 species) and 12S ribosomal RNA (12S rRNA; 37 species), integrating them with geographic information of each species. We then estimated Mantel’s correlation coefficient (r), isolation-by-distance slope (βIBD), and π for each genetic marker, then evaluated the relationship between βIBD and π. IBD was present in 55.40% of species for Cytb and 42.42% for 12S rRNA. Species from higher altitudes were associated with steeper βIBD in Cytb, whereas larger species showed a weaker βIBD-Cytb effect. Bayesian generalized linear mixed models indicated that IBD positively explained π for both genes. In Cytb, π declined with increasing variability in environmental temperature and larger body size, whereas π in 12S rRNA was negatively associated with annual mean temperature. Our results suggest that, although IBD and environmental temperature may generate shared patterns influencing mitochondrial genetic diversity in Liolaemus lizards, the two mitochondrial markers also exhibit distinct trends in how they shape genetic structure and diversity. This study represents an initial step toward understanding how mitochondrial genetic diversity may be maintained and structured within this species-rich genus.

https://rdi.uncoma.edu.ar/handle/uncomaid/18934 2025-08-20T17:30:06Z

First Record of Flower Bud Galls in Senega (Fabales: Polygalaceae): The Case of S. salasiana and Their Effect on Plant Reproduction. We report the first case of flower bud galls in a species of the mainly American genus Senega (Polygalaceae), specifically in the South Andean Patagonian plant species S. salasiana. The galls were found to be induced by gall midges (Diptera, Cecidomyiidae) and mites (Acari). We also assessed their impact on plant reproduction by measuring the relationship between inflorescence density (number of inflorescences/plant cover) and gall abundance in two populations next to San Carlos de Bariloche, Patagonia, Argentina. Plant reproduction was negatively related to the number of galled inflorescences, suggesting that high levels of gall abundance strongly reduced plant reproductive success. Our study illustrates a novel case of flower galls in the genus Senega and highlights the negative impact of this type of herbivory on plant fitness.

https://rdi.uncoma.edu.ar/handle/uncomaid/18835 2025-07-22T17:53:04Z

Everything everywhere all at once? Disentangling the long-lasting riddle of phylogenetic relationships and cryptic hybridization in the amphitropical genus Larrea The genus Larrea has an amphitropical distribution in North and South American deserts, and its phylogeny remains unresolved. This genus is conspicuous and specious within the Monte Desert, the largest, although understudied, southern South American dryland. Larrea presents an interesting case for phylogenetic studies due to its paternally inherited chloroplasts, its species hybridize in nature, and although nominal species are morphologically distinct, hybrids might be cryptic. We analysed ITS2 nuclear (nDNA) and rbcL chloroplast (cpDNA) sequences of the bifoliolate section, Bifolium, including L. tridentata (Lt) from North America, and its South American congeners: L. cuneifolia (Lc) and L. divaricata (Ld), and sequences of the multifoliolate Larrea section: L. ameghinoi (La), L. nitida (Ln), and a morphological hybrid swarm. We aligned and analysed sequences from 111 individuals collected at 31 populations sampled along the range of each species. The nDNA revealed 56 haplotypes, and median-joining and maximum likelihood reconstructions provided clear separation among species and suggested hybridization between Lc-Ld. The nuclear phylogeny showed that the section Larrea diverged earlier than Bifolium, within which Lc diverged first, meanwhile, consistent with previous studies, Lt forms a monophyletic group sister to Ld. Comparatively, cpDNA was less variable, with only six haplotypes shared between Ln-Lc and Ln-La, and rarely between Ld-Lc. Our results emphasize the significance of separately considering nuclear and plastid evolutionary signals when reconstructing unresolved relationships. While nuclear markers clarified phylogenetic relationships and cryptic hybridization among Larrea species, the chloroplast revealed the retention of widespread ancient polymorphisms, which were conserved in populations of distinct species. Each marker provided insights into particular evolutionary patterns, highlighting that genetic variation may be more influenced by hybridization and mode of chloroplast inheritance than previously recognized.

https://rdi.uncoma.edu.ar/handle/uncomaid/18725 2025-06-10T13:22:24Z

El futuro de la etnobiología argentina en riesgo En este texto discutimos el futuro de la etnobiología argentina en base a una encuesta on line y aun workshop realizado junto a jóvenes que practican la disciplina. Luego de una caracterización de lastemáticas, los sitios de desarrollo, así como las motivaciones y dificultades referidas por los participantes,encontramos que los jóvenes están preocupados por su futuro profesional en el contexto actual dedesfinanciamiento y desprestigio de la actividad científica en que se encuentra Argentina. Discutimosla necesidad de articular en red y de mejorar la representatividad de la etnobiología en el grado y elpostgrado de las universidades argentinas.