Abstract Extreme mating behaviours provide valuable opportunities to understand how sexual selection and sexual conflict shape reproductive strategies. The beetle Zygogramma bicolorata, a biocontrol agent for the invasive weed Parthenium hysterophorus, exhibits an extremely high mating rate, with each mating typically lasting several hours. We investigated mating behaviour in this beetle to assess whether long mating and high mating rate impose fitness costs on females in a manner predicted by sexual conflict theory. To this end, we tested whether natural variation in mating duration in a single uninterrupted mating determines female lifetime reproductive output. Further, in a set of controlled experiments, we manipulated the length and number of matings and assessed their impact on female fitness components. Natural variation in the duration of a single mating did not significantly affect female fitness. The results from the controlled experiment, however, suggest that repeated long matings are detrimental to both female survival and progeny output. These results, alongside previous findings that long matings serve as male mate-guarding behaviour which benefits males in this species, indicate sexual conflict over mating length and number. We discuss the significance of sexual conflict, including its potential role in reducing the efficacy of this species as a biocontrol agent.
Abstract Among the Aotearoa New Zealand radiation of 14 flightless Celatoblatta cockroaches, some species are confined to forest habitat and some to alpine habitat. We examine the phylogenetic relationships of the New Zealand cockroaches, including endemic and invasive taxa in subfamily Polyzosteriinae, using DNA sequences from the entire mitochondrial genome, and nuclear ribosomal DNA and histones. The New Zealand Celatoblatta radiation is monophyletic within our sampling and sister to representatives of genera endemic to New Caledonia. Our phylogenetic analyses suggest that habitat use is not constrained within a monophyletic group in this genus. We estimated that the most recent common ancestor of the New Zealand Celatoblatta was alive during the early or mid-Miocene. If the radiation of New Zealand Celatoblatta had begun before the development of alpine landscape in New Zealand (∼8–5 Mya), then it is more likely that adaptations to alpine environments have evolved multiple times rather than being the ancestral state of this lineage. We describe two additional New Zealand cockroach species: Celatoblatta johnsi sp. nov. from North Island forests and Celatoblatta pata sp. nov. from southern South Island snow tussock habitat.
Abstract Female colour polymorphism is a widespread trait in Ischnura and has been linked to mating strategies, sexual conflict, and evolutionary diversification. In the Colombian Andes, Ischnura cyane and Ischnura capreolus occur in sympatry, and localities contain admixed/intermediate individuals. Here, we characterize female colour polymorphism, ontogenetic colour change, and pruinescence in I. cyane and individuals of admixed/intermediate morphology, within a comparative framework including I. capreolus. We evaluate mating-associated patterns using colour traits, operational sex ratio, and mating frequency observations, and we evaluate reproductive morphology. Our results show that both taxa are dimorphic, with androchrome and gynochrome females. In I. cyane, mating-associated traits were consistent with polyandry, whereas admixed/intermediate individuals exhibited patterns associated with monandry. Females of I. cyane and admixed/intermediate individuals cannot be distinguished based on colour traits or ontogenetic colour change, but they differ from I. capreolus. In contrast, males of the three populations are differentiated by caudal appendage morphology. No relationship was detected between male cercus size and female mesostigmal plate size among mating pairs. The coexistence of overlapping colour traits, asymmetric sexual differentiation, and contrasting mating-associated patterns supports the interpretation of an admixed system involving I. cyane and I. capreolus. Female colour polymorphism nevertheless remains conserved across contrasting mating-associated patterns in Andean Ischnura.
Abstract Carnivores play a key role in maintaining ecosystem structure, function, and ecological processes. Understanding the coexistence mechanisms of sympatric species with similar niches is a central question in community ecology and biodiversity conservation. In this study, we applied DNA metabarcoding techniques to analyse the dietary composition and trophic niche partitioning between two sympatric canids on the Qinghai-Tibet Plateau: the red fox (Vulpes vulpes) and the Tibetan fox (V. ferrilata). Our results indicated that the winter diet of the red fox primarily consisted of Ochotonidae, Cricetidae, and Bovidae, whereas the Tibetan fox mainly consumed Ochotonidae, Spalacidae, and Cricetidae. Despite dietary niche overlap, significant differences were detected in both dietary composition and richness (P < .05). Further analysis indicated that the Tibetan fox had a significantly narrower niche breadth than the red fox (P < .05), indicating clear divergence in foraging strategies between these two congeneric canids. We demonstrated that the red fox and Tibetan fox achieve stable coexistence via divergent foraging strategies, generalist vs. specialist, respectively. These findings provide key insights into the mechanisms underpinning the coexistence of sympatric mesocarnivores, and offer critical empirical support for the conservation management of alpine carnivore communities.
Abstract Understanding how species roles in mutualistic networks relate to geographical distributions is key to predicting ecosystem stability across heterogeneous landscapes. We investigated plant–pollinator networks in the Southern Grasslands of Brazil, integrating data from the Atlantic Forest high-altitude grasslands and the Pampa. Using published studies, grey literature, and biodiversity databases, we built a regional meta-network with 8001 interactions among 422 plant and 338 bee species. Network structure was assessed using degree centrality and modularity, and we tested whether centrality relates to species geographical range size. The network showed strong modular organization, with nine well-defined modules and significantly higher modularity than null expectations. Interaction patterns were highly asymmetric, with few highly connected species and many rare interactors. Bees exhibited higher centrality than plants, particularly eusocial and generalist tribes, such as Meliponini, Apini, and Augochlorini. Despite broad variation in distribution area, geographical range size did not predict centrality for either plants or pollinators. These results indicate that species roles are driven primarily by taxonomic identity rather than spatial distribution. Conservation strategies should prioritize key functional groups, especially highly connected bees, which disproportionately sustain network structure.
Abstract Urbanization is reshaping freshwater ecosystems worldwide, altering food webs and nutrient dynamics. These ecological shifts can impose new selective pressures on consumers, driving evolutionary change in morphological traits related to resource acquisition. Gut length, which governs the balance between digestive efficiency and maintenance cost, is a likely target of such selection. To examine whether urbanization is associated with evolutionary divergence in gut morphology, we reared second-generation common-garden Trinidadian guppies, Poecilia reticulata Peters, 1859, from high- and low-urbanization sites under common garden conditions with controlled diets differing in nutrient content. Gut length was significantly shorter (10.4%) in guppies from high-urbanization origins, independent of diet treatment, indicating an evolved rather than plastic response. Our findings demonstrate that urban environments can select for reduced gut investment, highlighting a potential pathway for rapid evolutionary change in trophic traits, with broader implications for consumer-resource dynamics in human-altered ecosystems.
Abstract This study introduces a rank-dependent model of macroevolution that formalizes how biodiversity emerges from the interaction of assortative (integrative and combinatorial) and divisive (partitioning) evolutionary dynamics across hierarchical ranks. Unlike traditional approaches that impose fixed functional forms on diversification, the model generates diversity patterns from a unified dynamical system modulated by structural evolutionary potential across taxonomic levels. The results reproduce three robust diversification regimes: (i) early saturation-like dynamics at higher taxonomic levels, (ii) approximately linear transitional dynamics at intermediate levels, and (iii) sustained exponential-like diversification at lower levels. These regimes emerge from the balance between innovation-driven combinatorial exploration and density-dependent lineage splitting. The model predicts a progressive reconfiguration of macroevolutionary dynamics, with integrative novelty generation giving way to diversification through lineage partitioning. Extinction operates as a scale-dependent restructuring process that preserves higher-level organizational structure while disproportionately affecting fine-scale diversity. Overall, my results suggest that macroevolution is structured by changes in evolutionary accessibility across time and hierarchy, rather than being a uniform scaling of microevolutionary processes.
Abstract Geographical isolation among islands, and among regions within islands, can promote adaptive radiation. However, it remains unclear how isolation at these two spatial scales (among islands and within island) contribute to overall adaptive divergence, particularly during the early stages of adaptive radiation in taxa that gradually expand their distribution across continents or continental islands. In this study, we aimed to elucidate the geographical conditions during the initial stages of adaptive radiation in the geographically polytypic, snail-feeding carabid beetle Carabus blaptoides, which is distributed across the Japanese Archipelago and has diverged into eight subspecies. We reconstructed ancestral geographical distributions, inferred ancestral character states, and conducted Ornstein–Uhlenbeck analyses. Our reconstruction revealed that body shape diverged not only between the main island and the peripheral islands, but also between the eastern and western regions of the main island. Ornstein–Uhlenbeck analysis further suggested that adaptive divergence in body shape has proceeded towards distinct optima on peripheral islands and in different regions of the main island. These findings highlight that adaptive divergence both among islands and within island have played crucial roles in the early stages of adaptive radiation in large continental island systems.
Birds exhibit diverse foraging strategies shaped jointly by the morphology and behaviour of predators and prey, as well as by habitat conditions. Some foraging tactics may result from convergent evolution when similar patterns among these factors are found across different lineages. Flush-pursue foraging, where birds use conspicuous wing and tail displays to startle hidden prey and pursue it, is known to drive plumage evolution among birds. However, the diversity and evolutionary relationship of the species using this strategy and associated traits remain poorly documented. For the first time, we compiled a global list of flush-pursuing species and conducted a family-level phylogenetic analysis. We found that flush-pursue foraging has independently evolved in four avian orders, and at least 17 families within Passeriformes, illustrating convergent adaptations to a specialized foraging niche. Flush-pursuers were more likely to be found in families with traits related to pursuit ability, such as smaller body size and longer tarsus length relative to body mass. This foraging strategy was also associated with denser habitats, likely providing various substrates and hiding spots for prey, and thus flushing prey makes foraging more efficient. Similarly, families with broader latitudinal ranges that cover more diverse habitats and prey types were also associated with a higher likelihood of flush-pursue behaviour. Family-level invertivorous diet predicted the presence of flush-pursuers, as expected from the susceptibility of arthropod sensory systems to startle displays. These findings illustrate how convergent acquisition of this unique foraging strategy of birds is shaped by the combination of morphology and ecology.
Abstract Over the last 25 years, natural history collections (NHCs) have undergone a profound transformation that extends well beyond technological modernization or improved data accessibility. Here, we examine whether and how recent conceptual frameworks and institutional developments support the interpretation of NHCs as an autonomous research field, rather than solely as repositories or auxiliary infrastructures. This conceptual review synthesizes key conceptual frameworks and institutional developments that emerged between 2000 and 2025, redefining the scientific role of collections. We examine the progression from early biodiversity informatics initiatives focused on data mobilization to integrative paradigms such as museomics, extended and holistic specimens, digital extended specimens, global museum networks, and, more recently, collectomics. These concepts mark a shift toward specimen-centred research systems in which physical vouchers are analysed as central reference points for integrating heterogeneous biodiversity data across analytical scales. By organizing these developments within a coherent conceptual and infrastructural trajectory, we assess the extent to which NHCs can be understood as being a distinct object of study with dedicated analytical frameworks and purpose-built research infrastructures. We conclude that NHCs constitute an autonomous and interdisciplinary research domain, with direct implications for biodiversity science, conservation practice, research policy, and the organization of scientific knowledge. We propose that governance frameworks will be decisive in shaping how these collections are incorporated into biodiversity science over the coming decades.
Biogeography can illuminate spatial patterns of intraspecific morphological variation along environmental gradients. We evaluated whether body size in the common vampire bat (Desmodus rotundus) varies with climate and elevation across Colombia using 1076 museum and field specimens (1921-2023). Field specimens originated from diverse environmental conditions, including sites with mean annual temperatures ranging from 8.94 to 28.94 °C, annual precipitations from 515 to 7132 mm, and elevations from 4.6 to 3476 m a.s.l. Forearm length, a proxy for body size, was analysed with regression models, including Colombian department as a random effect. Linear models showed that forearm length decreased with mean annual temperature (females: R 2 = .023, β = -.143, P = .006; males: R 2 = .044, β = -.173, P = 1.03 × 10-5) and increased with elevation (females: R 2 = .038, β = .001, P = 3.66 × 10-4; males: R 2 = .039, β = .001, P = 3.35 × 10-5), with an overall decrease of .19 mm per 1°C across all individuals. In contrast, linear mixed-effects models found no significant effects of temperature, elevation, precipitation, or latitude. These contrasting results suggest data limitations and that patterns detected by simpler models disappear when accounting for the spatial structure of the sampling. We argue that temperature is not a robust predictor of body size in D. rotundus. Our findings advance the biogeography of D. rotundus and provide a foundation for the uncertainty of climate change effects on bat morphology.
Tubular shells have evolved repeatedly across Mollusca, constraining both shell form and internal organization of the soft body. This convergent morphology is often linked to sessile or endolithic life, but the minute gastropod Caecum laqueatum C. B. Adams, 1852 remains mobile in interstitial habitats. Using high-resolution synchrotron microtomography, we reconstructed the soft anatomy of this species, resolving delicate systems, such as the nervous system and glandular oviduct. We identify several structures previously unreported in the family Caecidae, including a mantle (hypobranchial) gland, nephridial gland, and paired oesophageal glands, and we confirm a reduced monopectinate ctenidium. These results align C. laqueatum with other Truncatelloidea and provide a new anatomical reference point for the clade. More broadly, we show how tubular shell morphology interacts with small body size to shape internal anatomy, highlighting consistent patterns of elongation, organ reduction, and glandular rearrangement. Molluscan taxa with tubular shells, living and extinct, show recurrent solutions to mechanical and spatial constraints. In Caecum, the tubular form might itself be an adaptation that facilitates functional organization at small body size, enabling retention of a long gut and complex reproductive system. Once obscure and poorly studied, Caecum now provides a key anatomical reference point for recognizing convergence and recurring evolutionary patterns across Mollusca.
Natural history collections provide crucial research infrastructure, valued for the physical voucher, biomaterial, and associated data, yet few growing research collections exist in Africa, especially in West Africa. ‘Private’ collections are present in West African universities or scientific institutions that are held as research materials but uncatalogued and without standard management plans. Without formalization, these collections remain inaccessible to the research community. The expertise required to grow, manage, and develop these collections for research and other biodiversity-related work is largely lacking because of limited investment, isolation of scientists, and insufficient capacity development. We report a consortium of mammal collections in the West Africa Mammal Partnership, a growing network of biodiversity practitioners. By forming a consortium, each collection is better positioned to grow through collective fundraising, training, and deployment of standard collection management practices. We present information on mammal collections based in four countries (Burkina Faso, Cameroon, Cote d’Ivoire, and Nigeria), including taxonomic coverage, number of specimens, duration, geographical focus, and contributions. Collections in the consortium are focused primarily on bats and have contributed to new species descriptions and >30 new country records, with two maintaining tissue samples (muscle, liver, fur, skin biopsies, and faecal material). We anticipate that with increased attention and integration of collecting goals during ecological surveys, species monitoring, and disease surveillance efforts, each collection will work towards formalization, improving access to specimens and data, while raising the capacity of in-country scientists for biodiversity science that informs decision-making and, ultimately, species conservation.
The South American Transition Zone (SATZ) encompasses the Andean highlands from western Venezuela to northern Chile, the desert areas of coastal Peru and northern Chile, and the Monte and Comechingones mountain ranges from central western Argentina. Its biota extends from sea level to similar to 4800 m a.s.l. A general theory to explain the biotic assembly of the SATZ is proposed, including the existence of an original Neotropical horobiota; the successive dispersal of the Subantarctic, Patagonian, Central Chilean, and Nearctic cenocrons to it; and the existence of a Recent horobiota. The main events that affected the biotic assembly of the SATZ include: the original isolation of the South American craton and the Patagonian terrane during the Cretaceous-Palaeogene; the uplift of the Andes, which began in the Early Jurassic and occurred gradually from the Late Cretaceous onwards, allowing the passive uplift and vertical colonization of Neotropical taxa and the geodispersal of the Subantarctic, Patagonian, and Central Chilean cenocrons; the development of the Isthmus of Panama, which allowed the geodispersal of the Nearctic cenocron; and the Holocene and Quaternary climatic changes that influenced vegetational changes and provided vicariance events within the different provinces of the SATZ.
Apomixis is an asexual mode of reproduction through seeds and nearly all gametophytic apomictic species are polyploid. Psidium cattleyanum, a polyploid species with several described ploidy levels, exhibits apomixis and requires effective pollination for fruiting (pseudogamy). The aim of this study was to determine the frequency of apomixis and sexuality in heptaploid and octoploid accessions of P. cattleyanum, and to analyse maternal and paternal contributions to endosperm formation. Flow cytometry was used on mature seeds obtained from hand-pollinated crosses between two octoploid and two heptaploid accessions to determine the ploidy levels of embryo and endosperm. Among the 492 seeds analysed, embryo: endosperm ploidy ratios ranged from the expected 2:5 (64.2%, pseudogamous apomixis) and 2:3 (4.7%, sexuality) to unexpected values including 1:3 (0.4%), 2:6 (2.4%), 2:7 (0.2%), 3:5 (8.8%), 2:3:5 (18.5%), and 2:4:6 (0.8%), associated with polyhaploid parthenogenesis, pseudogamous apomixis involving reduced and unreduced gametophytes, and female gametophytes with two or three polar nuclei. Embryos with both higher and lower ploidy than the maternal plant were detected, and the implications of these findings for wild populations are discussed.
Inselbergs are ancient rock outcrops that have undergone minimal weathering and harbour vegetation distinct from the surrounding matrix owing to harsh edaphic and microclimatic conditions, such as intense solar radiation and rapid water loss. In Atlantic Forest lowland inselbergs, the Bromeliaceae are the richest family and exhibit several water-use-related traits along a coastal-inland climatic gradient, making bromeliads a suitable model for understanding community structure in contrasting conditions. We investigated the functional composition of bromeliad communities to assess whether water-use traits influence species distribution between coastal and inland regions, which differ in precipitation and seasonality. Focusing on monocotyledonous mats (a microhabitat where plants grow directly on bare rock or shallow soils), we analysed functional groups, leaf traits, and CSR (C, competitor; S: stress tolerant; R, ruderal) ecological strategies of bromeliad mats across both regions. All functional groups are mat forming. The C3 tank and C3 non-tank species occur in coastal and inland inselbergs, whereas Crassulacean acid metabolism (CAM) tank and CAM non-tank species are restricted to inland inselbergs and CAM atmospheric species to coastal ones. Trait patterns suggest environmental filtering associated with water availability, with coastal species exhibiting more acquisitive strategies and inland species showing more conservative traits. The high endemism among bromeliads in inselbergs highlights the importance of understanding community structure for conservation.
A combination of wing shape, size, and flight strategy has enabled flying organisms to move within and among habitats, climate conditions, and elevations. We evaluated the elevation effect on wing morphology and two flight performance descriptors in 31 dung beetle species (12 genera) on a mountain in the Mexican Transition Zone (MTZ). We quantified the variation in wing morphology (shape and size) and analysed their relationship with aspect ratio and wing loading. Both wing shape and wing size covary with elevation at different taxonomic levels (genus, species). Highly significant associations were also recovered between wing shape and flight biomechanical descriptors. The lowest diversity and variation of wing shapes and biomechanics were found at high elevations. Two extreme morphologies are presented along the gradient: broad and slightly swept-back wings in the large-sized Neotropical genera Deltochilum, Phanaeus, and Eurysternus (tapered wings) and larger and more elliptical wings in the Nearctic genus Onthophagus. Colonization of the high mountains in the MTZ by Onthophagus may be favoured by its elliptic wings and high aspect ratio, which are suited to these environments. This study contributes to our understanding of the variation in insect wing morphology on a mountain colonized by species with different biogeographic affinities.
Unravelling the origin and mechanisms of interspecific hybridization and clarifying its evolutionary and ecological consequences constitutes a central theme in evolutionary biology. This study elucidates the origin and mechanisms underlying the persistence of individuals carrying introgressed alleles resulting from historical hybridization between two closely related salmonid species, Salvelinus curilus and S. leucomaenis, in a region where the donor species is now absent. We employed two complementary approaches. First, we conducted a comprehensive comparative phylogeographical analysis across the full geographical ranges of both species to characterize spatial patterns of historical hybridization and infer the origin of introgressed individuals. Second, we developed and applied evolutionary models based on the Wright-Fisher model to evaluate whether the persistence of these individuals is explained by the combined effects of genetic drift and natural selection. Introgressed individuals carried a single mitochondrial DNA haplotype substantially divergent from the recipient species (S. curilus) and matching a haplotype of the donor species (S. leucomaenis) that occurs in areas geographically distant from the current distribution of introgressed individuals. Simulation-based analyses indicated that the observed frequencies of introgressed individuals can be explained largely by genetic drift. Although a model incorporating both genetic drift and selection provided a modestly better fit to the data, support for selection was suggestive rather than conclusive. Even under a weak selective disadvantage, the stochastic effects of genetic drift may allow these individuals to persist over multiple generations, particularly in small populations.
The distribution of dichogamy in Acanthaceae is unknown, yet studies in the genus Justicia from Africa described the occurrence of protandry with staminal movement. A review of the genus suggests African species show protandry with staminal movement but New World species do not. In this study, we test this hypothesis. We also propose that hummingbird pollination led to the loss of this form of dichogamy. We inferred a time-calibrated molecular phylogeny of Acanthaceae and scored species within tribe Justicieae for protandry with staminal movement and pollination syndrome. We used ancestral state reconstruction to determine how many times staminal movement evolved in Justicieae, and tested for correlated evolution between changes in staminal movement and changes in pollination syndrome and geography. We scored a total of 333 species in tribe Justicieae, of which 58 showed protandry with staminal movement and 275 did not. Mapping staminal movement onto the phylogeny revealed multiple origins of this type of protandry, and significantly a loss in the common ancestor of New World 'justicioids' with a single regain in the Neotropics. Protandry with staminal movement is common in Old World Justicieae but confirmed to be almost absent in the New World. As Neotropical Justicia are nested in an Old World clade, it is clear they lost protandry with staminal movement and regained it once in the New World. Insect foraging behaviour probably drove the evolution of protandry with staminal movement and hummingbird foraging behaviour probably drove the loss of protandry with staminal movement in this clade.This summary, translated into Spanish, is available in the Supporting Information section (Appendix S1).
With 58 species, the pantropical papilionoid legume genus Macropsychanthus (Leguminosae: Diocleae) has long posed taxonomic challenges. In this study, we reconstructed its evolutionary history and revised its infrageneric classification using a comprehensive phylogenetic framework based on our newly produced plastome and nuclear DNA data from 59 taxa, including 51 species of Macropsychanthus. Our analyses confirm the monophyly of the genus and its division into the subgenera Macropsychanthus and Platylobium, each characterized by both molecular and morphological traits. Within subg. Macropsychanthus, we identify six well-supported clades, here proposed as sections, each supported by synapomorphies and biogeographic patterns. Divergence dating places the origin of the genus in the Amazon during the Miocene (similar to 12 Mya), followed by rapid diversification and subsequent long-distance dispersals into South-east Asia and Africa, representing rare cases of amphi-Pacific rainforest disjunctions. Overall, this study resolves long-standing taxonomic uncertainties, establishes a stable infrageneric classification, and provides novel insights into the timing, geography, and drivers of diversification in Macropsychanthus. The genus emerges as a valuable model for investigating biome shifts, long-distance dispersal, and morphological convergence in tropical lianas.
