ABSTRACT Renner recently offered a historical overview of Alexander von Humboldt and Aimé Bonpland's expeditions in the Tropical Andes and raises concerns regarding Siqueira‐Silva and colleagues, previously published in this journal. We clarify that these concerns arise from a misinterpretation of our data sources and analytical framework. Our study did not incorporate von Humboldt and Bonpland's collections, vegetation belts, or the Tableau Physique des Andes (TPA) into analyses or inferences. The initial species list was based on 21st century expeditions to Mt. Chimborazo and taxonomically standardised. All occurrence data were obtained from georeferenced GBIF records, and final analyses were conducted using 109 well‐performing species distribution models. Elevational belts were defined using the variable itself on Mt. Chimborazo, independent of historical classifications. While acknowledging importance of historical perspectives, our results rely on contemporary data and are consistent with the global literature on climate change impacts on mountain biodiversity.

ABSTRACT Aim Small pelagic species constitute a critical component of fishery resources in the northwest Pacific Ocean. Understanding the interactions among interspecific relationships, environmental niches, and resource abundance is essential for developing science‐based fisheries management. This study aims to investigate the differential habitat responses of small pelagic species in the Northwest Pacific to environmental factors, specifically evaluating the ecological interpretation of interspecific relationships through joint species distribution modelling. Location The northwest Pacific Ocean. Taxon Japanese sardine; Chub mackerel; neon flying squid. Methods This study examined three economically important small pelagic species from the northwest Pacific Ocean: Japanese sardine ( Sardinops melanostictus ), chub mackerel ( Scomber japonicus ) and neon flying squid ( Ommastrephes bartramii ). Using a joint species distribution model (JSDM) and ecological niche theory, we integrated multiple environmental variables to analyse interspecific associations and patterns of synchronous habitat variation among these species. Results The JSDM accurately predicted suitable habitats for all three species, revealing spatial synchrony in habitat suitability. Notably, a positive interspecific (0.9) association is observed between S. melanostictus and S. japonicus , while both exhibit negative associations (−0.84 and −0.95) with O. bartramii . The breadth of suitable ecological niches for key environmental factors and their corresponding response curves offers ecological insights into these interspecific interactions, confirming the dynamic variations in suitable habitat ranges for these species. Main Conclusions The interspecific relationships reflected similar species responses to environmental factors and highlighted their occupation of overlapping ecological niches. This consistency in environmental responses may drive synchronised habitat shifts, potentially affecting fluctuations in small pelagic species abundance.

ABSTRACT Aim Understanding the distribution and genetic structure of African mammals is key to reconstructing the continent's evolutionary history. While some parts of the continent (e.g., lowlands, mountain forests or savannah biomes) are now relatively well‐studied, arid regions remain underexplored despite offering unique insights into adaptation to extreme environmental conditions. This study aimed to reconstruct phylogeographic patterns and past‐to‐future distributional dynamics of two gerbil genera— Pachyuromys and Desmodilliscus . Location North Africa, including the Sahara Desert and the Sahel. Taxon Two gerbil species from two sister monotypic genera: Pachyuromys duprasi Lataste, 1880 (Northern Sahara) and Desmodilliscus braueri von Wettstein, 1916 (Sahel region). Methods Using the most comprehensive available dataset, we examined mitochondrial markers ( CYTB and COI ) and built ecological niche models across past (Last Glacial Maximum, Mid‐Holocene), present and future climate scenarios to investigate genetic structure and potential distributional shifts of both species. Results Desmodilliscus braueri exhibits a marked East–West phylogeographic structure, influenced by barriers such as the Niger River and Paleolake Chad. In contrast, Pachyuromys duprasi has genetically divergent populations in Egypt (which may be affected by a sampling gap in central‐northern Sahara), but no broader spatial structure in its regions. Niche models suggest range contractions and expansions linked to climatic oscillations for both species. The predicted distribution of Pachyuromys reflects distribution area pulses, aligning with pulses in the extent of the Sahara. Main Conclusions Our findings emphasise the evolutionary significance of arid zones and the need for further research on species' responses to desertification and climate‐driven range shifts. The contrasting patterns between the two species underscore different evolutionary trajectories in different taxa living in arid and semi‐arid environments.

ABSTRACT Aim Several mechanisms contribute to the plant biodiversity of the Neotropics, with the highlands of South America serving as important hotspots of diversity. In particular, the Brazilian highlands exhibit high biodiversity due to complex diversification dynamics and a mixture of contributions from different biomes. In this study, we reconstruct the timing and potential triggers of diversification of Agalinis , hemiparasitic plants that inhabit open grassland habitats, to investigate their biogeographic history and migration patterns across the Americas. Location North, Central and South America. Taxon Agalinis . Methods We reconstructed dated phylogenies of Agalinis using a secondary calibration approach, sampling 73% of the known species, including multiple species from the Andes and Brazilian highlands. We inferred ancestral distributions to understand migration patterns between North and South America and within South America. Additionally, we investigated shifts in diversification rates within the genus and reconstructed ancestral pollination syndrome and life‐history strategy states. All analyses were performed across a distribution of trees to account for phylogenetic uncertainty. Results Agalinis likely originated in south‐eastern North America during the early Miocene and rapidly diversified, followed by movement into South America in the Late Miocene or Early Pliocene. We propose two possible routes for Agalinis movement into South America: either through the Andes or via the South American lowland grasslands (e.g., Chaco, Pampas, Cerrado, Caatinga, Llanos), using grassland corridors for dispersal within the continent. After its arrival in South American highlands, the clade underwent rapid diversification. State reconstructions indicated that the genus had a bee‐pollinated ancestor and that hummingbird pollination evolved only once, with many transitions back to bee pollination. In contrast, the perennial life strategy evolved multiple times within the genus, including at least once in the ancestor of all South American species and twice in the North American species. Main Conclusions Agalinis likely originated in North America and later migrated to South America, followed by rapid diversification (i.e., ‘dispersification’). Thus, Agalinis is a clade that refutes the tropical conservatism hypothesis and the out‐of‐the‐tropics model. Moreover, the dispersal to the Brazilian highlands was from nearby species pools and not from other highland habitats such as the Andes, followed by several in situ speciation events. These high diversification rates were partly associated with Quaternary climatic oscillations, and perennial and hummingbird‐pollinated species exhibited higher turnover rates.

ABSTRACT Aim The isolated nature of islands makes them particularly vulnerable to climate change. The freshwater fishes of the Greater Antilles remain understudied and are further threatened by habitat fragmentation and the introduction of exotic invasive species. A practical solution to protect this diversity is to develop a spatially explicit framework to inform conservation actions. We test whether biogeographically significant subregions can be identified within the Greater Antilles. Location The Greater Antilles, Caribbean Basin. Taxa Freshwater Fishes (Atheriniformes, Cichliformes, Cyprinodontiformes, Lepisosteiformes, and Ophidiiformes). Methods We compiled a dataset of 1704 occurrence records across the Greater Antilles based on museum vouchers and the authors' fieldwork. River basins were used as analytical units for hierarchical agglomerative clustering both among and within islands. We also combined genetic data to examine phylogeographic patterns and uncover potential substructure within islands. Results Ninety‐two per cent of the freshwater fish fauna of the Greater Antilles is endemic. Although diversity is unevenly distributed among and within islands, patterns of species richness and weighted endemism partially align across islands. The region is not a single biogeographic unit but consists of multiple subregions of biogeographic significance, where river basins from the same island are more similar to each other than to basins from other islands, with Hispaniola as the only exception. Main Conclusions The Greater Antilles comprise a mosaic of biogeographically meaningful subregions, each harbouring unique, highly vulnerable, and often range‐restricted species assemblages. The patterns recovered reflect a complex interplay among the region's geological history, multiple colonization events, and diversification processes. Our proposed areas of endemism represent testable hypotheses for investigating the evolutionary history of freshwater taxa in the region. These areas also provide natural management units that can serve as geographical targets for conservation prioritisation and policymaking for freshwater ecosystems across the Greater Antilles.

ABSTRACT Aim The Andes are a global biodiversity hotspot, and the formation of this mountain range is linked to the rapid diversification of many lineages across the Tree of Life. The high species richness of the Andes might also act as a reservoir for lineages to disperse across the South American continent. Recent syntheses of Andean geological history and the accumulation of phylogenetic studies of different Andean clades present an opportunity for a synthesis of the historical biogeography of the Andean biota. Location The Andes. Taxon All taxonomic groups. Methods We conducted a meta‐analysis of phylogenetic studies, scoring disjunction events within and out of the Andes inferred from biogeographic reconstructions. Results We show that, across time and clades, dispersals among regions in the Andes are approximately as common as dispersals out of the Andes. The greatest number of extra‐Andean disjunctions originated from the northern Andes, even though the northern section of this mountain range is the most recently uplifted. There has been continued bi‐directional movement within the Andes over the last 50 million years. Dispersals northward occur at a slightly, but significantly, greater rate than dispersals southward. Andean plant crown clades tended to be older than animal crown clades, which almost exclusively originate in the last 30 million years. Main Conclusions Our findings reveal that the Andes have equally acted as a reservoir and a corridor of biodiversity across clades with widely divergent dispersal strategies.

ABSTRACT Aim African freshwater fishes serve as important biogeographical indicators of geomorphological and hydrological history across the continent. However, research focusing on the phylogeny, biogeography and diversification of African fishes, particularly in central Africa, is relatively scarce. Here, we evaluate three geological hypotheses regarding the formation of the contemporary Congo basin: (1) the dominance of the Ogooué and Kouilou rivers along the western continental margin during the Cretaceous, (2) an eastward‐flowing Congo‐Zambezian system forming the Rufiji Delta during the Paleogene and (3) river basin capture resulting in the formation of the Lower Congo River during the Pliocene. To do this, we reconstructed the phylogeny of featherfin tetras of the genus Bryconaethiops using their mitochondrial genomes, estimated diversification chronology, and detected biogeographic transitions in Central Africa. Location Afrotropical rivers of Nilo‐Sudan, Lower Guinea, Congo and Malagarasi‐Tanganyika. Time Period Oligocene, Neogene and Quaternary. Taxon Bryconaethiops (Teleostei: Characiformes: Alestidae). Methods Analysis of a molecular matrix of complete mitochondrial genomes comprising 13 protein‐coding genes totaling 14,869 bp for 36 Bryconaethiops and related alestid taxa. Phylogenetic analyses included maximum likelihood, Bayesian fossil calibration, and parametric biogeographic reconstructions. Support for generic monophyly was evaluated using internal and external anatomy with microcomputed tomography (μCT) and conventional morphometric/meristic analyses. Data from museum specimens provided updated distributional ranges for each Bryconaethiops species. Results Time‐calibrated phylogenetic and biogeographic analyses suggest initial diversification of Bryconaethiops occurred in Lower Guinea during the Oligocene ( ca. 25 Ma), followed by transitions to the Nilo‐Sudan and Middle Congo regions during the Early Miocene ( ca. 19–17 Ma). Three distinct Pleistocene dispersal events to the Lower Congo ( ca. 0.7–0.05 Ma) and three to the Upper Congo and Malagarasi of Tanganyika ( ca. 1.5–0.1 Ma) were detected. Morphological analysis reveals four generic synapomorphies associated with modification of the upper and lower jaws, dentition and elongation of dorsal‐fin lepidotrichia, in addition to evidence for revalidation of B. mocquardianus (Thominot, 1886) from Atlantic coastal rivers of the eastern Gulf of Guinea. Main Conclusions Genetic and biogeographical analysis of Bryconaethiops supports the hypothesis that an expansive, centrally situated lowland proto‐Congo was captured by the modern Lower Congo during the Plio‐Pleistocene. Sympatric occurrences of sister taxa point to a complex scenario of allopatric speciation followed by secondary contact and/or resource partitioning across the Congo basin.

ABSTRACT Aim To quantify the connectivity and degree of population differentiation of a planktonic model species along an extreme environmental gradient in order to understand source–sink dynamics and processes leading to local adaptation. Location Baltic Sea/North Sea. Taxon Scyphozoan Jellyfish Aurelia aurita . Methods Levels of genetic connectivity and population differentiation were analyzed by integrating molecular data with 40 years of Lagrangian stepping‐stone drift‐route simulations. Drifters represented different A. aurita life‐stages that were traced over 40 consecutive life‐cycles from four empirically confirmed start locations. Suitable habitat for polyp recruitment was parameterized from high‐resolution bottom topography maps to allow for stepping‐stone range expansion across the Baltic Sea, with additional physiological experiments. Results Molecular and drift analyses revealed a large degree of isolation, identifying two major clusters in the Baltic Sea: (1) the low saline central‐eastern and (2) the intermediate saline south‐western regions, respectively. Additionally, molecular analyses confirmed the southern North Sea as an independent cluster with limited connectivity to the Baltic Sea. The Skagerrak/central North Sea was further confirmed as a transition zone between both regions. Lagrangian simulations suggested only one seeding event from this transition zone (Skagerrak) into the Baltic Sea over the 40‐year study period. Furthermore, a 2.5‐fold lower genetic diversity in the low saline Baltic relative to the high saline North Sea indicated limited current gene flow. A significant correlation was found between haplotype frequency and salinity in Baltic Sea samples, together with successful settlement of northern Baltic individuals at low salinities. Main Conclusions Limited connectivity leads to population differentiation of A. aurita in the Baltic Sea. Furthermore, active recruitment at low salinities suggests local adaptation within the low saline Baltic Sea. Local adaptation is likely widespread among Baltic species of marine origin, raising concerns for biodiversity conservation and ecosystem management of the Baltic Sea under continued freshening due to climate change.

ABSTRACT Aim Multi‐faceted and multi‐scale biodiversity assessments and disentangling the factors driving the biodiversity patterns are fundamental for effective protection of biodiversity and prediction of future community changes. Despite its importance, groundwater is still a data‐deficient and under‐studied ecosystem. Here, to fill the knowledge gap, we quantify multiple facets of beta diversity (βD) and identify their drivers on a regional level in a groundwater biodiversity hotspot. Location Western Balkans, Europe. Taxon Subterranean amphipods of the family Niphargidae. Methods We compiled three datasets: distribution, phylogeny, and functional traits of Niphargidae and assessed taxonomic (TβD), phylogenetic (PβD) and functional beta diversity (FβD) at different spatial scales. We evaluated the spatial variability between these different facets and identified the drivers of βD patterns using generalised dissimilarity models (GDMs). Lastly, we constructed null models to test whether geographic distance nonrandomly explains βD in observed groundwater communities. Results We found a high βD with a dominant replacement component in all three facets, but their spatial patterns were incongruent. GDMs revealed that geographic distance between communities was by far the most significant predictor of βD in all three facets. Additionally, karst share and maximum temperature were important predictors of TβD and PβD. Both the results of GDMs and null models showed that the decay in community similarity mostly happens at relatively local scales (< 100 km distance) in all three facets. Main Conclusions Our results show that βD patterns in groundwater are primarily influenced by geographic distance between communities and are possibly an outcome of dispersal constraints, while the role of ecological factors remains elusive. As there is a high replacement at even relatively local scales (up to 100 km), a strategy for effective groundwater biodiversity protection in the region would require multiple smaller protected areas rather than a few large ones.