ABSTRACT Aim Estimate the Darwinian shortfall (i.e., the lack of knowledge about phylogenetic relationships) of bees worldwide, as well as identify their drivers. Location Global. Taxon Bees (Hymenoptera, Anthophila). Methods We built phylogenies for over 12,000 bee species, combining the most comprehensive phylogeny and an algorithm with random solutions to insert missing lineages. The Darwinian shortfall was quantified as the Phylogenetic Diversity (PD) deficit, the ratio of inserted branch lengths at the assemblage level. We identified potential ecological and socioeconomic drivers of the Darwinian shortfall using Simultaneous Autoregressive (SAR) models. Results The highest shortfalls were identified in the Southern Hemisphere. Mean species range size and species richness were the strongest drivers, as smaller ranges and higher richness were associated with higher deficits. Per capita GDP was negatively associated with PD deficits, while population and road densities showed positive but weak effects. Sample completeness had a weaker effect, limited by missing occurrence data in many regions. Main Conclusions Our findings underscore the need for integrative efforts combining taxonomy, data digitization, adequate research investments, and targeted sampling, especially in the Global South. Overcoming the Darwinian shortfall is essential to develop robust strategies to preserve the Tree of Life, especially for one of the most important groups of pollinators while facing the ongoing biodiversity crisis.
ABSTRACT Aim To quantify temporal (Middle Holocene, historical and future) and spatial changes in habitat suitability for marine species in two South American Large Marine Ecosystems, and to evaluate the ecological consistency of long‐term Species Distribution Model projections using archaeological records as independent evidence of past species occurrences. Location Humboldt Current and Patagonian Shelf Large Marine Ecosystems (LMEs). Time Period Middle Holocene (~8200–4200 years BP), present day (1850–2014), and a projected future warming scenario (2015–2099; SSP5‐8.5). Major Taxa Studied Marine fish, penguins and pinnipeds. Methods SDMs were developed for nine marine species using present‐day occurrence records and contemporary environmental predictors. Models were projected to Middle Holocene climatic conditions and to a future high‐emissions scenario. Archaeological records of fish, penguins and pinnipeds from the Middle Holocene were compiled and used as proxies for past species occurrences to evaluate model projections through time. Results Bathymetry emerged as a key predictor of habitat suitability for most species. Projections revealed pronounced temporal and spatial shifts in suitable habitat. Most fish species showed higher suitability at higher latitudes during the Middle Holocene, followed by contractions in the historical period and future projection. Penguin species exhibited heterogeneous responses, with several showing strong declines in future suitable habitat. Pinniped species displayed mixed patterns of contraction and expansion depending on region and time period. Comparison with archaeological records indicated that seven of the nine SDMs correctly identified suitable habitats consistent with Middle Holocene occurrences. Main Conclusions Zooarchaeological data provide an independent line of evidence to assess the temporal robustness of marine SDMs. Incorporating past climatic periods improves confidence in long‐term biogeographical projections and enhances understanding of species' distributional dynamics under climate change.
ABSTRACT Aim Combining camera trap data from multiple surveys has the potential to address large‐scale ecological and conservation questions. But individual surveys can differ substantially in study design and, at the large scale, these surveys typically do not constitute a spatially representative sample. Here, we use camera trap data from Snapshot USA and Snapshot Europe, two near‐continental collaborative initiatives, to explore how large‐scale sampling bias and variation in sampling design affect ecological inference. Location Continental USA and Europe. Time Period 2019–2023. Major Taxa Studied Terrestrial mammals > 300 g. Methods We analysed how environmental variables affected selection of sampled locations using logistic regression; and how they affected aspects of study design (number and spacing of sampling locations, proportion of locations along roads/trails, survey duration) using generalised linear models. We used negative binomial regression to test whether design variables affected species photographic rate, caused omitted variable bias when not included in the model, or affected species relationships with environmental variables. Results Sampled locations in both regions avoided areas high in agriculture and far from roads and preferentially sampled forest (for Europe only at higher elevations). In the USA, sampling further avoided high elevation and precipitation extremes. These same variables also predicted variation in study design, and design variables commonly affected the photographic rates of mammals. Ignoring design variation only rarely caused bias in coefficients of relationships with environmental variables (omitted variable bias), but interactions between design and environmental variables were more common. Main Conclusions For inference beyond the data at hand, researchers must consider spatial sampling bias inherent in multi‐source studies, as is regularly done in the context of citizen science. While ecological inference was often robust to ignoring design variation, researchers should consider its potential to affect, interact with or even mask environmental relationships of interest for their particular data and objectives.
ABSTRACT Aim Investigate patterns of population genetic structure in Southwestern Atlantic marine fishes and evaluate how geographic range, habitat diversity, and evolutionary history shape population connectivity. Location Southwestern Atlantic, including the Caribbean, Brazilian coast, and Patagonian region, between 0°59′ N and 40°16′ S. Period Studies published between 1980 and 2023. Main Taxa Studied With 84 species of marine, reef‐associated, and estuarine fishes either resident or transiently associated. Methods A systematic review and synthesis were conducted using a predefined Boolean search across several bibliographic databases, which initially retrieved 47 scientific papers. Based on the available literature, we categorized the species identified in these articles according to their biological, ecological, and evolutionary traits. Subsequently, a Generalized Additive Model (GAM) was employed to model species distribution and evaluate the effects of genetic breaks on fish populations. Results Most species exhibited high genetic homogeneity among populations from the Caribbean, Brazilian coast, Patagonia, and northern and northeastern Brazil, indicating extensive connectivity; however, a recurrent interruption in gene flow near 20° S, adjacent to Espírito Santo State, suggests the presence of biogeographic barriers, while differential use of reef and estuarine habitats and speciation timing were key determinants of genetic structuring; high connectivity was largely associated with pelagic egg production, the influence of major coastal currents such as the Brazil Current, benthopelagic behaviour, and rafting‐mediated larval dispersal. Main Conclusions Oceanographic processes and species‐specific biological traits jointly shape the genetic responses of marine fishes and maintain broad‐scale connectivity in the Western Atlantic, although localized disruptions in gene flow persist and require further investigation to support effective conservation and management strategies.
ABSTRACT Aim To test the hypothesis that the Japanese Archipelago has acted as a biogeographic ‘museum’ preserving ancient continental lineages, using scutigeromorph centipedes as a model and to reconstruct the region's multi‐stage biogeographic history by distinguishing between paleoendemic relicts and neoendemic radiations. Location Continental East Asia (focusing on China) and the Japanese Archipelago (including mainland and isolated islands). Methods We generated a comprehensive multi‐locus molecular dataset from extensive sampling across the region. We reconstructed a time‐calibrated phylogeny using Bayesian methods with fossil‐calibrated node dating to estimate divergence times. Phylogeographic structure, demographic history and lineage diversification patterns were analysed to infer biogeographic processes. Results The phylogeny confirmed the monophyly of the genera Thereuopoda and Thereuonema and revealed a deep, consistent phylogeographic break within two widespread species. This break separates a continental lineage (including populations from the continental East Asian and the Japanese isolated islands) from an endemic clade on the Japanese mainland. Divergence time estimates for these primary splits (~100–98 Ma) substantially predate the Miocene formation of the Japanese Archipelago (~25–15 Ma), supporting its role as a biogeographic ‘museum’ for ancient continental lineages. Notably, biogeographic model selection strongly supported a scenario of dispersal from the Japanese isolated islands to the Japanese mainland within the archipelago. Demographic expansions correlate with periods of geological stabilisation. Analyses further uncovered pronounced genetic structure indicative of unrecognised diversity. Main Conclusion Our findings provide strong support for the ‘museum’ hypothesis, demonstrating that the Japanese Archipelago harbours ancient continental lineages preserved via vicariance and long‐term refugial persistence (paleoendemism). This ancient fauna was subsequently supplemented by in situ diversification following isolation, generating neoendemic clades. The study reveals a complex, multi‐stage assembly history for the region's biota, challenging purely dispersal‐driven narratives and highlighting the critical role of ancient vicariance and landmass permanence in shaping East Asian biodiversity.
ABSTRACT Aim Disentangling the relative roles of environmental filtering, dispersal limitation, and biotic interactions in shaping island community assembly is a central goal in modern ecology. However, island biogeography studies have rarely quantified biotic filtering or explicitly incorporated functional traits to evaluate how abiotic environments structure communities. To address this gap, we conducted a comprehensive analysis of herpetofauna co‐occurrence patterns and biogeographical variation across islands. Location Coastal islands of southern Zhejiang, China. Methods Using herpetofauna survey data collected from 36 coastal islands between October 2021 and September 2025, we characterised island biogeographical features based on island attributes and land‐cover composition. Hierarchical modelling of species communities (HMSC) was applied to partition the effects of environmental variables, spatial structure, and species co‐occurrence on island community assembly. Species traits, phylogenetic relationships and residual covariance were jointly incorporated to infer potential interspecific interactions. Results Community assembly of island herpetofauna was predominantly driven by environmental filtering. The strength and nature of filtering differed between amphibians and reptiles. Reproductive traits, adult microhabitat preferences, and activity patterns were associated with intercept, distance to mainland, altitude and shape index. After accounting for environmental filtering, residual species associations became weaker. We detected no strong competitive exclusion or facilitative associations, contrary to the expectation of intensified competition on resource‐limited island. Main Conclusions Our findings show that biogeographic features structure insular herpetofauna communities by acting on species traits, particularly reproductive strategies. The absence of strong species interactions challenges the assumption that competition necessarily intensifies on islands. From a conservation perspective, maintaining environmental heterogeneity that supports functionally diverse life‐history strategies provides a mechanistic foundation for sustaining island herpetofauna, complementing single‐species approaches. This study advances a trait‐based understanding of island community assembly and offers empirical guidance for the conservation of island biodiversity.
ABSTRACT Aim To delineate native freshwater fish biogeographic regions in the Philippine archipelago and identify the contemporary and historical factors that structure freshwater fish diversity, endemism and species turnover. Location The Philippine archipelago. Taxon Native freshwater fishes. Methods We compiled an archipelago‐wide dataset of native freshwater fish occurrences and integrated these with environmental variables and historical biogeographic groupings, including Pleistocene Aggregate Island Complex (PAIC) configurations. Species distributions, diversity and endemism were analysed using cluster analysis of a Simpson's beta (βsim) dissimilarity matrix to delineate provinces, with provincial assignments interpreted in light of the PAIC framework and prior biogeographic evidence. Inventory completeness per province was quantified using coverage‐based rarefaction. Generalised Dissimilarity Modelling (GDM) was used to quantify the relative contributions of geographic, environmental and historical predictors to compositional turnover, with predictor importance and statistical significance assessed by matrix permutation. Indicator species analysis (IndVal) was applied to both the full dataset and the obligate primary‐freshwater (PF) subset, and dendrogram congruence between the two analyses was tested with a Mantel test and cophenetic correlation. Results Cluster analysis resolved five freshwater fish biogeographic provinces: Northern Luzon, Central/Southern Luzon, Greater Visayas, Mindanao and Palawan–Mindoro. Geographic distance was the strongest correlate of compositional turnover, while PAIC grouping and contemporary climate variables contributed comparatively little once geographic distance was accounted for. Two patterns stood out. First, the Visayan islands of Leyte and Samar clustered with the rest of the Greater Visayas rather than with Greater Mindanao, despite their conventional PAIC assignment to the latter, a pattern consistent with contemporary marine straits exerting biogeographic influence beyond what Pleistocene land‐bridge predicts. Second, Palawan–Mindoro stood out as a Sundaic outlier within the Philippine archipelago, anchored by obligate primary‐freshwater Cyprinidae of Bornean affinity. By contrast, Greater Visayas lacked any significant obligate‐freshwater indicator and was characterised instead by an estuarine–freshwater interface assemblage, supporting the interpretation of this province as a hydrologically open, marine‐influenced biogeographic system. Main Conclusions This study provides the first comprehensive biogeographic framework for Philippine freshwater fishes, clarifying how distance, palaeogeographical history and habitat context are associated with assemblage boundaries in a complex oceanic archipelago. The contrasting biogeographic character of Palawan–Mindoro and Greater Visayas illustrates how a single archipelago can host fundamentally distinct freshwater biogeographic modes shaped by geological origin and contemporary hydrological characteristics. The framework supplies a spatial template for conservation planning in Philippine inland waters and more broadly illustrates the value of integrating historical and contemporary drivers to explain freshwater biogeographic patterns in island systems.
ABSTRACT Aim East Asia spans temperate to tropical zones, with limited glacial influence and a complex geological history shaped by the Tibetan Plateau. Consequently, species here may show distinct phylogeographic patterns compared with those of Europe and North America. Using the warm‐adapted cladoceran Diaphanosoma dubium as a model, we tested whether it persisted in multiple watershed refugia, especially the Yangtze River Basin, during past climate oscillations, leading to geographically structured lineage divergence. Location East Asia, with a specific focus on watersheds across China. Taxon The cyclically parthenogenetic cladoceran Diaphanosoma dubium (‘tropical Daphnia ’). Methods We applied ecological niche modelling on a global occurrence dataset and population genetics analyses on mitochondrial and nuclear gene datasets from 60 populations. Results High‐fitness areas were identified mainly in the eastern Yellow River Basin plains during the Last Glacial Maximum (LGM). Phylogenetic analysis resolved five deep lineages coalescing in the Late Miocene. Ancestral cold‐adapted lineages dominated the Yellow River Basin in the Late Miocene, later dispersing and permeating southward into the Yangtze River Basin during pre‐Pleistocene cooling. Three deep lineages indicated a large refugium downstream of the Yellow River Basin and west of the Bohai Gulf, and two lineages indicated two cryptic southern refugia. The two most common lineages overlapped widely in China, expanding post‐LGM from the Paleo‐Bohai refugium, showing climate tracking and niche conservatism. Main Conclusion In contrast to our expectation, the Yangtze River Basin acted as a dispersal hub rather than a refugium in middle China. D. dubium exhibited a watershed‐associated latitudinal structure, distinct from Daphnia in Europe. Historical north‐to‐south colonization and strong gene flow mitigated genetic differentiation among watersheds. Life‐history traits drove D. dubium 's successful colonization of tropical China, with geographic range and mountainous landscapes further shaping its continental‐scale distribution and divergence.
ABSTRACT Aim Island archipelagos and montane regions of East and Southeast Asia represent some of the world's most biodiverse yet poorly understood biogeographic systems. Whether regional diversity accumulates primarily through in situ speciation, dispersal‐mediated range shifts, or some combination of these processes remains unclear. Using Sinomicrurus coralsnakes as a model system, we aim to understand how geographic ranges have shifted over time, whether major biogeographic events align with geological and climatic transitions across Indochina and adjacent subtropical Asia, and whether dispersal involves tracking ancestral climatic niches or evolving new niche strategies. Location Indochina and adjacent subtropical Asia (southern China, Sino‐Japan, Taiwan, Ryukyu Archipelago, Himalayan foothills). Taxon Sinomicrurus coralsnakes (Serpentes: Elapidae). Methods We use time‐calibrated phylogenies, probabilistic ancestral‐range estimations with biogeographic stochastic mapping, species distribution models, and phylogenetic and statistical analyses of multivariate climatic niches to examine historical range shifts, the timing of major biogeographic events, and patterns of niche conservatism versus niche evolution in Sinomicrurus . Results Species distribution models revealed that precipitation‐related variables largely structure Sinomicrurus distributions, with temperature and elevation contributing secondarily. Niche analyses indicated clear ecological differentiation among species, with island endemics and highland taxa occupying the most distinct climatic positions. Divergence‐time estimates place the origin of crown Sinomicrurus in the mid‐Miocene, with major clades diversifying through the Miocene–Pliocene. Phylogenetic signal in climatic niche axes was absent. Biogeographic analyses under the best‐supported DIVALIKE+J model identified founder‐event dispersal as the dominant mechanism, while vicariance was inferred at low frequency. Main Conclusions Diversification in Sinomicrurus coincides with late Miocene to early Pliocene geological and climatic transitions, with episodic founder‐event dispersal repeatedly driving range shifts from a persistent Indochinese source into climatically distinct highland and island environments. Geographic dispersal predicts niche position better than phylogenetic relatedness, consistent with niche evolution contingent on colonisation rather than phylogenetic constraint. These findings highlight that founder‐event dispersal represents an underappreciated mechanism of biodiversity generation in East and Southeast Asia, complementing the vicariance and in situ speciation more commonly invoked for this region.
ABSTRACT Aim Understanding whether invasive species retain or shift their ecological niches has relied on scalar overlap metrics that quantify the magnitude of niche change but not its structure. Here, we test whether biological invasions involve a reorganisation of the environmental axes along which native and invasive ranges are differentiated, and whether the dominant axis of this reorganisation is associated with invasion pathway type. Location Global (North America, Europe, Africa, Asia, Australasia). Taxon Freshwater crayfish (Decapoda: Astacidea): Procambarus clarkii , Faxonius limosus , F. virilis , F. rusticus , Pacifastacus leniusculus . Methods We analysed native and invasive occurrences for five crayfish invaders representing intercontinental and within‐continent pathways, using ~400 hydrologically resolved environmental variables (long‐term averages, 1980–2021) from the Global Crayfish Database of Geospatial Traits. Decision tree and random forest classifiers quantified environmental differentiation between ranges, and feature contributions were aggregated by domain (climate, topography, soil, land cover). Robustness was assessed using spatially blocked cross‐validation, grouped‐permutation importance (which is reduces sensitivity to within‐domain collinearity), exact permutation tests, sample‐size sensitivity analysis and comparison with classical niche overlap metrics. Results Native and invasive occurrences were consistently distinguishable (random forest accuracy 98.2%–100.0%). Intercontinental invaders were differentiated predominantly along climatic axes (57%–76% of model importance), with topography contributing negligibly, whereas within‐continent invaders retained climate as the dominant axis (~42%) but showed a substantial secondary topographic contribution (~33%), including river network position. This contrast was stable across cross‐validation folds (SD < 1.3%), and the observed pathway grouping was the most extreme of the 10 possible species partitions (exact one‐sided p = 0.10, the minimum attainable at this sample size). Classical overlap metrics (Schoener's D = 0.30–0.62) did not capture this distinction. Main Conclusions Biological invasions involve not only changes in niche position but a reorganisation of the environmental axes that distinguish species' distributions. The dominant axis of reorganisation differs with invasion pathway, reflecting whether species encounter novel climatic regimes or shift within existing climatic space along topographic and network‐position gradients. This axis‐specific approach complements scalar overlap metrics and provides a basis for more mechanistic interpretations of invasion processes.
ABSTRACT Aim Human impacts are increasingly recognized as drivers of biogeographic patterns, yet it remains unclear whether they match or potentially surpass climate in shaping species distributions. Here we aim to investigate the relative importance of anthropogenic versus climatic factors in determining mammalian distributions. Location North America. Taxon Mammal. Methods We modelled the relationship between the contemporary (1990–2020) distributions of 219 mammal species and 12 representative anthropogenic and climatic factors, and quantified variable importance with ecological niche models and explainable artificial intelligence (i.e., SHapley Additive exPlanations or SHAP) at range‐wide and local scales. We also constructed the response curve of human impact index (HII) for each species, and investigated the association between the response curves and species' biological traits. Results We found that anthropogenic factors were ranked as top contributors for more than half of the species examined, and HII showed permutation importance comparable to, and in many cases greater than, individual or principal components of bioclimatic variables. The SHAP maps showed that the dominating effects of HII were widespread across the continent, and the effects of other factors often showed spatial clusters at different subsections of species' ranges. Species' response to human impacts displayed diverse patterns, and the positive responses were associated with traits of reduced conflicts with humans, faster reproduction, and greater mobility. Main Conclusions These results suggest that contemporary mammal distributions are co‐determined by anthropogenic and climatic factors, with anthropogenic effects varying across space and among species. The extent of human impacts is comparable to and, in some cases, exceeds that of climate in shaping contemporary mammalian biogeography patterns. This highlights the need to broadly consider anthropogenic factors alongside climate when studying biogeography and biodiversity patterns in the Anthropocene.
ABSTRACT Aim Dramatic Quaternary climate fluctuations impacted the evolutionary history and contemporary biogeography of many residents of the Great Basin Desert of western North America. This study investigates the historical biogeographic processes that shaped the contemporary distribution of genetic variation in a polytypic group of specialized butterflies that are residents of unique dune and playa habitats. Many of the subspecies are considered to be threatened and this study uses high‐resolution SNP data to understand their history and quantify patterns of differentiation to inform conservation. Location Great Basin, western North America. Taxon The pallid dotted blue butterfly complex ( Euphilotes pallescens , Lycaenidae). Methods We constructed reduced‐representation genomic libraries to generate population genomics data that were used in clustering, ordination, and phylogenetic analyses. Pairwise differentiation between localities was quantified and the relationship between genomic differentiation and geography was analysed using a linear model. In addition, an estimated effective migration surface illustrated geographic patterns of genomic variation. Results Euphilotes pallescens populations were clearly differentiated from congeneric species and several subspecies, especially in the northwestern portion of the sampled range, were identifiable from genomic variation. When geographic distance was controlled, genetic differentiation was greatest between populations of Eu. pallescens compared to congeners, and within Eu. pallescens , northwestern populations were more differentiated than southern populations. The estimated effective migration surface also showed greater areas of reduced gene flow in the northwestern region. Main Conclusions Euphilotes pallescens comprises isolated populations on dune habitats in the Great Basin. Populations in the northwestern region are especially isolated and their patterns of genetic variation are consistent with the history of climate change and ancient pluvial lakes that occupied much of this region at intervals during the Quaternary. These butterflies are members of unique, localized communities whose persistence requires protections from anthropogenic threats, especially habitat loss including from recreation and off‐road vehicles in sensitive habitats.
ABSTRACT Aim Spatial genetic patterns of populations are a reflection of the combined influence of historical and contemporary climatic and landscape dynamics. This study investigates the influence of these extrinsic factors on the genetic structuring of a climbing palm in the Andaman and Nicobar (A&N) archipelago. Although the archipelago has experienced dramatic geomorphological transformations and climatic fluctuations during and since the Last Glacial Maximum (LGM), phylogeographic studies examining species responses to these changes remain limited. Location Andaman and Nicobar Islands, Bay of Bengal, India. Taxon Korthalsia laciniosa , climbing palm. Methods Genetic diversity of 13 populations sampled across the archipelago's major geographic barriers was assessed using 17 nuclear and 9 chloroplast microsatellites. The influence of LGM‐associated climatic and geomorphological changes was tested using alternative demographic scenarios based on the island's biogeographic affinities and Ecological Niche Modelling (ENM). A landscape genetic framework was used to assess the contemporary environmental factors that drive genetic divergence. Results Genetic data reveal a deep divergence between the Andaman and Nicobar Island groups, consistent with their broader biogeographic affinities. Within the Andaman Islands, ENM and demographic models indicate the presence of a potential southern refugium during LGM, and afterwards demographic expansion. In the contemporary landscape, genetic differentiation is primarily driven by a tangled effect of isolation by distance and resistance. Main Conclusions The genetic architecture of K. laciniosa in the A&N archipelago reflects a hierarchical interplay of biogeographical barriers and geographical and climate dynamics during the LGM. The potential habitat reduction during the LGM, followed by post‐LGM expansion, has restructured the phylogeographical patterns. The identification of a potential southern refugium, along with the genetic distinctness of Nicobar and Little Andaman populations, highlights the need for conservation efforts to prioritize the delineation and preservation of evolutionarily significant units in this underexplored tropical archipelago.
ABSTRACT Aim This study sought to evaluate how historical drainage connectivity and contemporary basin isolation have shaped population genetic structure and diversity in an imperilled species of freshwater mussel, Pleurobema riddellii. Location Covers the range of P. riddellii , spanning seven river basins of the Gulf Coastal Plains of the southern USA, including the San Jacinto, Neches, Sabine, Calcasieu, Red, Ouachita and Pearl river systems. Methods A genome‐wide single nucleotide polymorphism (SNP) dataset was generated using a restriction‐site associated DNA sequencing approach. After filtering and assembly, a dataset consisting of 12,062 SNP loci from 351 individuals was retained. Population genetic structure was evaluated using principal components analysis and a Bayesian clustering model, ENTROPY. Genetic differentiation among river basins was quantified using Nei's G ST and patterns of genetic diversity were assessed using observed heterozygosity and Watterson's θ . Results Population genetic analyses revealed structuring that corresponded closely with river basin boundaries. Centrally distributed populations from the Neches, Sabine and Calcasieu basins formed a genetically cohesive group characterised by low genetic differentiation and elevated genetic diversity. Marginal populations from the San Jacinto, Red, Ouachita and Pearl basins exhibited higher levels of genetic differentiation and reduced genetic diversity. Main Conclusions Here, we demonstrate a central‐marginal pattern in genomic structure and diversity across the range of P. riddellii . These results suggest that historical hydrological connectivity, coupled with prolonged isolation and reduced effective population sizes at range margins, likely played a role in shaping standing genomic variation in this system. More broadly, the genomic structure observed in P. riddellii is consistent with other unionid mussels in the region, highlighting the contributions of historical hydrological configurations in structuring freshwater biodiversity.
ABSTRACT Aim To assess the relationship between measures of species' range size and range structure, and to analyse how these measures differ in their relationships to species' intrinsic characteristics and external geographic drivers. Location Europe. Taxon 813 vascular plant taxa endemic to Europe. Methods We analysed the relationship between two measures of range size (extent of occurrence and area of occupancy) and two of range structure (range cover and expected patch size) using complete occurrence data from the Atlas Florae Europaeae. We used phylogenetically corrected linear mixed models to compare the effect of species' climatic niche breadth and continental land morphology (range‐wide elevation heterogeneity, proximity to continental coasts and geographic position of species' ranges) on species' range size and range structure. Results The strength and sign of the correlation between different geographic range size and range structure measures varied substantially. In addition, narrow niche breadth and continental land morphology constrained different range size and range structure measures unequally, with the effect sizes varying across individual measures. Main Conclusions Geographic range structure metrics are complementary to measures of geographic range size in explaining occurrence patterns, contributing distinct insight to our knowledge of ecological processes. Comparative analysis of patterns of range size and structure can complement our mechanistic understanding of species' distributions.
ABSTRACT Aim We evaluated how native vegetation cover influences the diversity of arachnid assemblages across multiple spatial scales in major Brazilian ecosystems. Location Brazil (Amazon and Atlantic rainforests, Cerrado savanna and Caatinga dry forest). Taxon Arachnida (Opiliones, Pseudoscorpiones and Scorpiones). Methods We sampled arachnids at 120 sites using active search and litter sifting. Native vegetation cover was quantified at three spatial scales (100, 200 and 300 m buffers) using GIS data. Assemblage structure was assessed using abundance, species richness, and Hill numbers ( q = 0, 1 and 2). Generalized linear mixed models were used to evaluate responses across taxonomic groups and ecosystems. Results We recorded 3986 individuals from 179 species. Diversity responses to native vegetation cover were taxon‐, ecosystem‐ and scale‐dependent. Positive effects of vegetation cover were stronger and more consistent in rainforest than in savanna and dry forest ecosystems. In rainforests, most responses occurred at smaller spatial scales (100–200 m), whereas no significant effects were detected in the savanna. Opiliones richness showed limited variation with vegetation cover but differed in dominance structure among ecosystems. Scorpion assemblages were characterized by low richness and high dominance, while pseudoscorpions exhibited low evenness in more species‐rich sites, particularly in the Amazon. Main Conclusions Native vegetation cover plays an important role in structuring arachnid diversity in Brazil, but its effects vary across taxa, ecosystems and spatial scales. These findings highlight the need for taxon‐ and scale‐specific conservation strategies and reinforce the importance of multi‐scale approaches to biodiversity conservation in Neotropical landscapes under increasing anthropogenic pressure.
ABSTRACT Huntley and Wilkinson ( Journal of Biogeography , 53, 2025) analysed climatic niche conservation in the invasive eastern grey squirrel ( Sciurus carolinensis ) and concluded that a niche shift occurred between North America and Europe. Nevertheless, their study suffers from two major flaws: ignoring prior literature and misinterpreting ecological niche theory. Previous research (Qiao et al. Scientific Reports , 7, 2017) demonstrated that reported niche shifts in this species were methodological artefacts, emphasizing the need for rigorous quantitative approaches and consideration of accessible environments. Huntley and Wilkinson relied on qualitative visual assessments, neglecting established methods for niche comparison. Furthermore, their framework confuses realized and fundamental niches, the latter being key to detecting evolutionary changes. Differences in realized niches may still be informative but often reflect environmental availability or biotic interactions, not physiological adaptation. True niche shifts in mammals require rapid evolutionary changes, which are unlikely during invasions. Thus, claims of niche shifts in S. carolinensis remain unsupported and should be interpreted cautiously for this and other mammal invaders.
ABSTRACT Aim The evolution of the East Asian Summer Monsoon (EASM) is critical for understanding Asian biodiversity and ecosystem stability. While models and geological records suggest the EASM reached the Qaidam Basin during the Miocene, macrofossil evidence remains scarce. We aimed to test the hypothesis of a northwestward monsoon expansion using newly discovered Populus fossils as bioclimatic indicators. Location Wulan Basin, northeastern Tibetan Plateau, Qinghai Province, China. Taxon Angiosperms (Salicaceae: Populus L.). Methods We conducted morphological analyses on leaf fossils and identified their Nearest Living Relative (NLR). By establishing correlations between the leaf traits of the NLR and modern climatic factors, we reconstructed the paleoclimate of the Wulan Basin. Furthermore, we employed Species Distribution Modelling (MaxEnt) to simulate the potential range of this lineage under Early Miocene conditions to explore monsoon‐driven habitat shifts. Results The late Early Miocene fossils from the Wulan Basin are morphologically most similar to the extant Populus davidiana , a species characteristic of temperate, semi‐humid environments. The presence of this lineage indicates that the Wulan Basin—currently an arid region—experienced significantly higher precipitation and a temperate semi‐humid climate during the Early Miocene. MaxEnt modelling reveals that the suitable bioclimatic envelope for this Populus group extended much further northwest than its modern range, providing a potential biological signal of enhanced moisture transport into the interior of East Asia. Main Conclusions The occurrence of Populus fossils in the Wulan Basin provides a preliminary biological indicator for the northwestward expansion of the EASM into the northeastern Tibetan Plateau during the late Early Miocene, although corroboration from additional proxy records and localities is still needed. This climatic shift, likely driven by the phased uplift of the Tibetan Plateau, transformed the regional hydrological cycle and facilitated the migration of mesic woody taxa into Asia's interior. Our findings highlight the profound impact of tectonic‐monsoon interactions on historical plant distributions.
ABSTRACT Aim To characterise the evolution of climatic niches during the diversification of the Phyllotis darwini species group, in order to assess the extent to which divergences involved in radiation were associated with patterns of conservatism or divergence of climatic niches, and whether the differentiation found among climatic niches correlated with species' phylogenetic relationships. Location South‐central Andes, surrounding lowlands and Patagonia, South America. Methods Species' climatic niches were characterised by sampling contemporaneous precipitation and temperature conditions across occurrence locations and entire distributional ranges. Climatic niches were analysed and modelled using multivariate analyses (PCA, PERMANOVA), a maximum entropy‐based algorithm and novel methods developed to explore levels of differentiation (niche overlap test) and divergence (niche divergence test) between realised and fundamental niches. Comparative phylogenetic methods were applied using a time‐calibrated phylogeny and integrating climate niche data to estimate ancestral environmental niches within geographic and environmental spaces. Results Comparisons revealed low levels of climatic niche overlap, both among species' realised niches and among their fundamental niches, suggesting high levels of niche differentiation during the diversification of Phyllotis species. Quantifications of niche overlap further showed that observed differences among species lay primarily in the multidimensional nature of climatic niches, as unidimensional quantifications exhibited higher levels of overlap. Evolved differences among species' climatic niches were better fitted to a Brownian motion model of evolution, but lacked phylogenetic signal and showed no significant association with species' phylogenetic distances. Main Conclusions Low levels of differentiation between ancestral climatic niches suggest that the early radiation of species in the Phyllotis darwini species group was promoted by geographic isolation, whereas the more recent diversification of extant species was accompanied by climatic niche differentiation, possibly involving local adaptation to regional ecoclimatic changes associated with Quaternary glacial cycles. The spatial separation of sister species, the complete divergence of their climatic niches and the lack of phylogenetic signal in niche differences suggest a scenario of diversification in which divergences were prompted by spatial isolation, but also by the divergent selection exerted by regional climatic differences.
ABSTRACT Aim Some habitats serve particularly important functions for wildlife. Identifying and appropriately managing these ‘essential habitats’ is critical, especially for wildlife that have faced severe population declines like sharks. Nursery habitats aid in the survival and development of juvenile sharks, which until recently were not formally identified or managed throughout most regions. Managing shark nurseries was in part challenging because there was no standardized quantitative method to delineate these essential habitats prior to the seminal paper written by Michelle Heupel and colleagues in 2007. Management in some regions now includes the protection of shark nurseries; however, changes in nursery dynamics in response to environmental change and human impacts are unclear. Here, we used long‐term monitoring data to identify bull shark ( Carcharhinus leucas ) and blacktip shark ( C. limbatus ) nurseries and assess how they have changed over time. Location Alabama coast and Texas coast, USA. Time Period 1982–2023. Taxa Bull shark, blacktip shark. Methods Shark catch records (catch per unit effort) from long‐term gillnet monitoring were assessed with general linear models and generalized linear models to determine (1) if shark nurseries exist in the Northern Gulf of Mexico, and (2) if and how they have changed over the study period using the shark nursery criteria established in 2007. Results Northern Gulf of Mexico nurseries first (re)emerged in the early 2000s on the Texas coast for bull sharks, followed by a relatively rapid expansion along the Texas and Alabama coast. Fewer nurseries were identified for blacktip sharks, which (re)emerged more recently starting in the 2010s. Main Conclusions Improved management has led to the re‐establishment of shark nurseries. We expect that changes in these essential habitats will continue as environmental conditions and human impacts shape coastal ecosystems and the dynamics of nurseries within their waters. The delineation, management and reassessment of nurseries will therefore be imperative moving forward as shark populations continue to recover from historic and persistent overfishing and habitat degradation. Predicting where nurseries will (re)emerge in response to improved management and habitat suitability will also be essential to achieve conservation goals.
