In Memoriam: Gérard Dupré (1947–2026) — A Life Devoted to the Study of Scorpions

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  Photo Credit: Le Parisien In Memoriam: Gérard Dupré (1947–2026) — A Life Devoted to the Study of Scorpions The passing of Gérard Dupré (1947–2026) is a deeply felt loss for those of us who share an interest in the study of scorpions and other arachnids. Throughout his life, he dedicated himself to documenting and preserving arachnological knowledge, contributing valuable work on scorpion taxonomy, distribution, and bibliography. His careful attention to the literature helped bring clarity and organization to a field whose history spans centuries and many languages. Gérard was also closely associated with the journal Arachnides , which became an important outlet for sharing research, faunistic records, and historical notes within the arachnological community. Through this work, he helped ensure that observations and studies—large and small—were preserved and made accessible to others with similar scientific interests. Beyond his scholarly contributions, Gérard was a humble and gen...

The Andes as a semi-permeable geographical barrier: Genetic connectivity between structured populations in a widespread spider

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The Andes as a semi-permeable geographical barrier: Genetic connectivity between structured populations in a widespread spider


Abstract


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Geographical barriers like mountain ranges impede genetic exchange among populations, promoting diversification. The effectiveness of these barriers in limiting gene flow varies between lineages due to each species' dispersal modes and capacities. Our understanding of how the Andes orogeny contributes to species diversification comes from well-studied vertebrates and a few arthropods and plants, neglecting organisms unable to fly or walk long distances. Some arachnids, such as Gasteracantha cancriformis, have been hypothesized to disperse long distances via ballooning (i.e. using their silk to interact with the wind). Yet, we do not know how the environment and geography shape its genetic diversity. Therefore, we tested whether the Andes contributed to the diversification of G. cancriformis acting as an absolute or semi-permeable barrier to genetic connectivity between populations of this spider at opposite sides of the mountain range. We sampled thousands of loci across the distribution of the species and implemented population genetics, phylogenetic, and landscape genetic analyses. We identified two genetically distinct groups structured by the Central Andes, and a third less structured group in the Northern Andes that shares ancestry with the previous two. This structure is largely explained by the altitude along the Andes, which decreases in some regions, possibly facilitating cross-Andean dispersal and gene flow. Our findings support that altitude in the Andes plays a major role in structuring populations in South America, but the strength of this barrier can be overcome by organisms with long-distance dispersal modes together with altitudinal depressions.

Salgado-Roa, F. C., Pardo-Diaz, C., Cisneros-Heredia, D. F., Lasso, E., & Salazar, C. (2024). The Andes as a semi-permeable geographical barrier: Genetic connectivity between structured populations in a widespread spider. Molecular Ecology, 33(11), e17361. https://doi.org/10.1111/mec.17361