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  • Étienne Lacroix-Carignan, Julian R. Starr, Robert F. C. Naczi, Eran S. Kilpatrick, Étienne Léveillé-Bourret
    J Syst Evol. 2026, 64(3): 520-535.
    https://doi.org/10.1111/jse.70036
    A major obstacle to biodiversity conservation is that thousands, if not millions, of plant and animal species have yet to be discovered and described, even in historically well-explored regions. Carex sect. Lupulinae (Cyperaceae; “sedges”) is a small group of six showy Eastern North American species that, until recently, was thought to be well understood. However, a DNA barcoding study of North American Carex undertaken over a decade ago serendipitously revealed unsuspected molecular diversity, including one potentially undescribed cryptic species. Here, we test the hypothesis that this entity is a species on a separate evolutionary trajectory by expanding barcoding results with an integrative approach that combines a densely-sampled molecular phylogeny (five plastid and two nuclear markers, 112 sequenced specimens), morphometric analyses (93 characters, > 300 measured specimens), ecological field surveys, and common greenhouse observations. Results all support the recognition of a new, abundant species common in the southeastern United States' Coastal Plain that we name Carex gator. This study highlights how integrative taxonomy can help to describe cryptic plant species revealed by DNA barcoding. We provide illustrations, a distribution map, and an identification key, and discuss how C. gator may be a rare example of homoploid sympatric speciation in plants.
    A densely sampled phylogeny of Carex section Lupulinae (107 specimens) is presented, along with a new cryptic species from the southern United States. This species is locally abundant and genetically and morphologically distinct from other Lupulinae. An identification key is provided and phenological and ecological patterns are discussed.
  • Kaizong Wei, Chen Xie, Xianghui Zhang, Aftab Ahmad, Lei Duan, Mingji Chu, Yuanxiao Gao, Diethard Tautz, and Wenyu Zhang
    J Syst Evol. 2026, 64(3): 470-484.
    https://doi.org/10.1111/jse.70037
    While sex-biased gene expression and its evolutionary dynamics across taxa have been extensively investigated, systematic separate characterization of the evolutionary patterns in transcriptome divergence between male and female lineages remains underexplored. Here, we analyze a comprehensive RNA-seq data set from the house mouse complex, spanning multiple organs across subspecies and species, to delineate the evolutionary trajectories of gene expression in males and females in intra- and inter-species contrasts. For both sexes, we find specific gene expression divergence patterns across the surveyed organs, with a particularly high divergence rate at early evolutionary stages of separation. Comparative analysis between sexes demonstrates male reproductive organs, particularly the testis, displaying accelerated evolutionary rates of expression divergence. Strikingly, testicular long non-coding RNA genes show the most pronounced acceleration, with differences emerging already after a few thousand years of population separation. In contrast, somatic organs and female reproductive auxiliary tissues show no major sex-specific evolutionary dynamics. Genes with sex-biased expression substantially contribute to differentially expressed genes across evolutionary transitions, though without predominant directional bias toward either sex. Notably, these differentially expressed genes display significant over-representation on autosomes. A general functional divergence process is found between male and female transcriptomes across organs mainly driven by sex-specific differentially expressed genes. Collectively, our findings establish a new evolutionary framework for sex-specific expression divergence and provide novel insights into the role of reproductive constraints in shaping transcriptome evolution in mammals.
    Analysis of extensive RNA-seq data from the house mouse complex across multiple organs and subspecies reveals that male reproductive organs, especially the testis, show accelerated expression divergence, particularly of long non-coding RNAs. In contrast, somatic tissues and female reproductive organs show minimal sex-specific evolutionary dynamics.
  • Matheus de T. Moroti, Jhonny J. M. Guedes, Guilherme M. Missio, Giovana L. Diegues, Alexandra M. R. Bezerra, and Mario R. Moura
    J Syst Evol. 2026, 64(3): 536-547.
    https://doi.org/10.1111/jse.70040
    Species descriptions have become increasingly comprehensive, yet disparities persist across taxa and regions. We assess temporal trends in mammal species descriptions (1990-2025) using four proxies of comprehensiveness—counts of examined specimens and compared taxa, number of pages (only from the Methods/Results sections), and number of evidence lines (i.e., analytical tools and techniques). Using generalized linear models, we assessed how these proxies are explained by factors associated with species’ biology, geography, and taxonomic practice. Most new species originate from tropical regions, particularly among rodents and bats, reflecting the global discovery hotspots. Descriptions have grown more rigorous over time, with expanded specimen sampling, broader taxonomic comparisons, and integrative methods. However, disparities emerge along geographic and biological axes: descriptions from temperate regions incorporate more evidence lines, while small-bodied and tropical species (especially bats) remain understudied due to sampling biases and resource limitations. Body size inversely correlates with description length, as smaller species often require advanced diagnostics. Species-rich genera show greater comprehensiveness, likely due to heightened diagnostic scrutiny. Our findings highlight progress in taxonomic rigor but underscore persistent gaps tied to geography, body size, and accessibility of analytical tools. Addressing these disparities requires targeted investments in local capacity, equitable collaboration, and accessible methodologies to strengthen global taxonomic infrastructure and support conservation priorities.
    Taxonomic descriptions of mammals have become more robust from 1990 to 2025, with increased specimen sampling, broader comparisons, and more integrative methods. However, disparities remain: tropical and small-bodied species are less comprehensively described, reflecting ongoing geographic and biological biases.
  • Huanhuan Xie, Yixi Wang, Lei Zhang, Yaoqi Li, Ruijing Cheng, Xin Liang, Nawal Shrestha, Leonel Herrera-Alsina, Hong Chang, Khoon Meng Wong, Keming Yang, Xinlan Chen, Rafaela Jorge Trad, Danilo Neves, Dimitar Dimitrov, Pengshan Zhao, Xiaoting Xu, Jianquan Liu
    J Syst Evol. 2026, 64(3): 507-519.
    https://doi.org/10.1111/jse.70039
    Magnoliaceae, a typical boreotropical relict lineage, shows striking species richness in tropical regions, making it an important model for testing the time-for-speciation and diversification rate hypotheses for present-day diversity patterns. Here, we reconstructed a time-calibrated phylogeny using plastomes from 123 species, representing Liriodendron and all 15 sections of Magnolia, and investigated its colonization and diversification history. Our results reveal that Magnoliaceae likely experienced peak extinction during the mid-Eocene, accompanied by a range contraction from high latitudes to the amphi-Pacific tropics, followed by the rise of tropical clades with rapid diversification. Phylogenetic generalized least squares analysis demonstrates that diversification rate explains clade-level diversity variation more strongly than time for speciation. Tropical regions, such as South America and Southeast Asia, with high Magnoliaceae diversity consistently show elevated diversification rates and shorter time for speciation. These results indicate that higher diversification rate, rather than longer time for speciation, explains the high diversity of Magnoliaceae in tropical clades and regions. Our findings not only shed light on the evolutionary history of Magnoliaceae but also provide important insights into the broader processes that shape tropical biodiversity.
    The boreotropical relict Magnoliaceae, now rich in the tropics, experienced a major range contraction followed by the rapid radiation of tropical clades. Elevated diversification rates, rather than the time-for-speciation effect, explain extant species richness establishing that accelerated speciation drives the high tropical diversity observed in this lineage.
  • Hao Li, Qiong Zhao, Tian Wu, Xin-Yi Liao, Yu-Han Fang
    J Syst Evol. 2025, 63(6): 1293-1298.
    https://doi.org/10.1111/jse.70033
    A recent 123-genome bryophyte super-pangenome reshapes our understanding of plant systematics and gene-family innovation. This commentary examines its key findings of expanded gene-family space, new genes and horizontal transfers, refined signals of whole-genome duplications, and the lineage-balanced, genome-wide approach behind them, with implications for early terrestrial adaptation and cellular novelties.
  • Qinfeng Guo, Hong Qian, and Jian Zhang
    J Syst Evol. 2026, 64(3): 499-506.
    https://doi.org/10.1111/jse.70038
    Body size is among the key subjects in macroecology and macroevolution with important implications for conservation. Two major rules have been proposed to explain how body size changes over evolutionary time (Cope’s rule) and across temperature gradients (Bergmann’s rule). To date, however, the applicability of both rules to global terrestrial vertebrates (tetrapod) remains elusive. Here, using the newly available data, we comparatively examined the temporal variation in species body size of the world’s extant tetrapod species (tetrapoda as a whole) and of each class, amphibians (Amphibia), reptiles (Reptilia), mammals (Mammalia), and birds (Aves), through the Cenozoic Era. When all four classes were considered together, the species’ body size had increased over time and was negatively correlated with global surface temperature. However, separate analyses on each of the four classes showed that reptiles and mammals tended to support Cope’s rule while birds and amphibians did not. Also, we found no clear difference in temporal body size variation between endothermic and ectothermic species. Overall, the support for Bergmann’s rule was much stronger than that for Cope’s rule. Future research using more complete and compatible body size data from fossils is needed to better understand how species’ body size evolves over time and across space.
    Comparing the temporal variation in diversity and body size of the world's extant terrestrial vertebrate species through the Cenozoic Era showed the mean species' body size increased over time and was negatively correlated with global surface temperature, but patterns differed between classes.
  • Ruotong Yu, Dian Yu, Chaobin Li Hongyan Shan, Hongzhi Kong, Jie Cheng, Xiaofeng Yin
    J Syst Evol. 2026, 64(3): 425-436.
    https://doi.org/10.1111/jse.70035
    Maize is amongst the most agriculturally and economically important crops to human beings. It was domesticated from a wild relative called teosinte. During domestication, maize has experienced drastic morphological transformations, such that it produces fewer ears, each of which bears many more kernels covered by soft and reduced glumes. The striking differences between maize and teosinte make the origin of maize ear a fascinating question, which has been fiercely and actively debated for more than a century. Over the past few decades, the discovery of numerous key genes and genetic pathways has greatly deepened our understanding of the mechanisms underlying maize ear development and domestication. In this review, by providing an overview of the morphogenetic processes of maize and teosinte ears, and the molecular mechanisms of maize ear development, we highlight key morphodynamical distinctions between maize and teosinte ears. By recapitulating historical accounts and summarizing recent advances regarding maize domestication, we present the current understanding and propose a model for the origin of maize ear.
    This review compares maize and teosinte ears and provides a simplified model for the origin of the maize ear.
  • Yu-Xiao Zhang, Ru-Li Zhang, Xin-Yu Du, Gui-Liang Zhang, De-Zhu Li
    J Syst Evol. 2026, 64(2): 240-259.
    https://doi.org/10.1111/jse.70027
    Chimonocalamus is distinguished by pachymorph rhizome, lower culm nodes with a ring of root thorns, and semelauctant inflorescence. However, species identification in this genus can be confused due to similar morphological features and overlapped geographical distribution. To confirm the identities of Chimonocalamus species in China, plastome and nuclear ribosomal (nrDNA) of 49 accessions of 10 known species and three putative new species were newly retrieved by genome skimming. Distance-based and tree-based methods were conducted to analyze the species discrimination rate of six datasets. The Skmer method was also applied. The results indicated that Skmer analyses had the highest discriminatory power with nine species identified (69.23%). The plastome showed much higher discriminatory success rate than the combination of three standard plastid DNA barcodes, which performed worst among the six datasets. The three potentially new species of Chimonocalamus were confirmed by the plastome and nrDNA datasets, and Skmer analysis, together with morphological differences. Herein, we describe and illustrate the three species as new to science, that is, Chimonocalamus hekouensis Y. X. Zhang, Gui L. Zhang & D. Z. Li, Chimonocalamus hsuehiorum D. Z. Li & Y. X. Zhang, and Chimonocalamus shuangjiangensis D. Z. Li & Y. X. Zhang. Moreover, the Chimonocalamus fimbriatus complex was designated, calling for further investigation. Taken together, plastome and nrDNA could serve as effective super-barcodes for species discrimination of Chimonocalamus, playing important roles in recognition of cryptic new species, and Skmer analysis can be adopted in molecular identification. Our study provides an empirical case for molecular discrimination of bamboos and can be meaningful for other plant groups.
    In order to better exploit the nuclear reads from genome skimming data, an assembly-free and alignment-free analysis method, Skmer analysis, was adopted in a DNA barcoding study of the bamboo genus Chimonocalamus. It showed the highest discriminatory power compared with standard DNA barcodes and super-barcodes, with nine species (69.23%) successfully identified. Skmer analysis was recommended in DNA barcoding and taxonomic (including taxonomic revision, and cryptic and/or new species confirmation) studies of bamboos.
  • Yan‑Da Li, Zhi-Hao Qi, Di‑Ying Huang, Chen‑Yang Cai
    J Syst Evol. 2026, 64(2): 354-362.
    https://doi.org/10.1111/jse.70032
    The evolutionary arms race between insects and their predators has fueled remarkable defensive adaptations, offering insights into ecological dynamics across deep time. Fossils provide critical evidence for studying the evolution of defense strategies. Here, we describe a new lineage of Clambidae from mid-Cretaceous Kachin amber, Scutacalyptus kolibaci gen. et sp. nov. Scutacalyptus stands out within the family due to the flattened body and fully explanate body margins. The diversity of defensive morphotypes in Cretaceous Clambidae, including conglobators like Sphaerothorax, semi-flattened forms like Acalyptomerus, and shield-formers like Scutacalyptus, highlights their developmental plasticity and suggests ecological differentiation in response to varied predation pressures during the late Mesozoic. This morphological divergence reflects niche partitioning in the Cretaceous forest floor ecosystem, driven by a diverse predator array including spiders, ants, lizards, and birds. The coexistence of clambids with spines or explanate margins parallels adaptations in the modern, unrelated Cassidinae, where tortoise beetles use explanate margins and some leaf-mining beetles use spines, each tailored to counter specific predation pressures. These parallel strategies reveal how different defenses likely addressed distinct ecological challenges in the mid-Cretaceous.
    We report a new clambid beetle from mid-Cretaceous Kachin amber, Scutacalyptus kolibaci gen. et sp. nov., characterized by a flattened body and explanate margins. Alongside spiny and conglobating clambid forms, this diversity reflects niche partitioning and varied antipredator strategies in the Cretaceous forest floor. These defenses parallel those of modern Cassidinae, highlighting convergent adaptations to different predation pressures.
  • Zhihong Jin, Jie Jiang, Tinghui Li, Simin Chai, Ran Tian
    J Syst Evol. 2026, 64(2): 283-294.
    https://doi.org/10.1111/jse.70031
    Oxidative stress, triggered by hypoxia during repetitive diving, represents a notable environmental adaptation of marine mammals. Glutathione (GSH) is a widely acknowledged antioxidant that protects crucial cellular elements from damage by reactive oxygen species (ROS). Nevertheless, the role of the glutathione metabolism pathway in shaping the adaptation to oxidative stress in marine mammals is not fully elucidated. In this study, we conducted evolutionary analyses on 37 genes related to the GSH metabolism pathway in marine and terrestrial mammals. We found that in comparison with their terrestrial relatives, marine mammals showed convergently accelerated evolution on the core modules of GSH metabolism. Specifically, we identified a total of 16 genes with significant evolution signals unique to marine mammals, and several genes (e.g., accelerated evolution genes: RRM1 and SMS, positively selected genes: ANPEP and GCLC) were shared in marine mammal lineages. Eight genes were discovered to possess specific amino acid modifications that are common among all marine mammals. Functional assays of marine mammal GCLC showed a downregulation of HIF-1α and enhanced GSH levels under hypoxic conditions, suggesting heightened protection of marine mammals against oxidative stress induced by hypoxia. Our study identified key genes with significant evolutionary signals in marine mammals, providing genomic and functional support for convergent hypoxia adaptation mechanisms within this taxon.
    In this study, we conducted evolutionary analyses and functional verification on glutathione (GSH) metabolism genes across marine mammals. Marine mammals showed convergent evolution in core modules, including rapidly evolving, positively selected genes and proteins with marine mammal-specific amino acid modifications. Functional assays showed that marine mammal GCLCs downregulate HIF-1α and elevate GSH under hypoxia, suggesting heightened oxidative stress protection in marine mammals.
  • Heng Yang, Jialiang Li, Mi Yoon Chung, Myong Gi Chung, Zhitong Han, Dayu Wu, Jingge Kuang, Xinran Zhang, Xi Zhou, Linning Bai, Jianquan Liu, Jian Luo, and Kangshan Mao
    J Syst Evol. 2026, 64(1): 125-137.
    https://doi.org/10.1111/jse.70030
    Understanding the genetic diversity and genetic load of endangered species is essential for developing effective conservation strategies, particularly in ecologically sensitive regions such as the Himalayas. Cupressus austrotibetica, a rare conifer and the tallest recorded tree in Asia, reaching up to 102.3 m, faces substantial anthropogenic and environmental threats. To evaluate its genetic status, we sequenced transcriptomes of 54 individuals sampled across its restricted range and compared them with 96 individuals of C. gigantea, a closely related endangered species with broader distribution at higher elevations. Our analysis reveals that C. austrotibetica exhibits higher genetic diversity (π = 0.0091) compared to C. gigantea (π = 0.0042). Demographic analyses identified three historical bottleneck events in C. austrotibetica and two in C. gigantea, with two of these events coinciding with Quaternary climatic oscillations. Despite its relatively high genetic diversity, C. austrotibetica has a smaller effective population size based on Stairway Plot 2 (Ne ≈ 7200) than C. gigantea (Ne ≈ 17 600). Furthermore, C. austrotibetica harbors a higher proportion of severe deleterious mutations, while C. gigantea retains more moderate deleterious variants. These findings indicate that a recent anthropogenic bottleneck event has likely driven the reduced population size and increased genetic load in C. austrotibetica, emphasizing the urgent need for conservation priorities for this imperiled species.
    Comparing population evolutionary history and genetic loads revealed that Cupressus austrotibetica underwent more frequent and severe bottleneck events, maintaining a smaller effective population size. Cupressus austrotibetica carries a higher proportion of loss-of-function mutations, suggesting a heavier genetic load, which is likely linked to its limited distribution and historical population decline.
  • Qiu-Jin Wei, Lei Cao, Xing-Cheng He, Alexei Abramov, Jin Wang, Jie Fu, Rui Li, Qi-Sen Yang, Li-Qiang Fu, Yao-Hua Huang, Cai-Quan Zhou, Zhi-Xin Wen, De-Yan Ge
    J Syst Evol. 2026, 64(2): 186-202.
    https://doi.org/10.1111/jse.70029
    Weasels represent the most widely distributed and diverse lineage within the family Mustelidae. They have experienced adaptive radiation and have long been the subject of significant taxonomic debates. This study undertakes a comprehensive study of this group, employing morphological measurements, mitochondrial genomes, nuclear genes, and single copy orthologs extracted from whole genome data. Based on the outcomes of phylogenetic tree construction using orthologous genes, it is ultimately verified that the genera Mustela and Neogale are independent genera, thereby resolving the controversy regarding the species they encompass. Through molecular systematics and morphological studies, a putative Mustela species collected from Mabian Dafengding National Nature Reserve in Sichuan is confirmed as a new species, designated Mustela mopbie sp. nov. This new species exhibits molecular phylogenetic affinity with M. altaica and M. nivalis, yet shares morphological similarities with M. kathiah, M. nivalis and M. aistoodonnivalis. Notably, it is considerably smaller than these species and possesses distinctive body coloration and tail morphology. This study provides a detailed description of this new species and demonstrates that larger datasets yield more robust phylogenetic signal. Furthermore, we observed substantial incongruence between mitochondrial and nuclear gene trees, suggesting potential genomic introgression between this new species and its closely related congeners (M. altaica and M. nivalis).
    Phylogenetic reconstruction conducted by integrating thirteen protein coding genes obtained from the complete mitochondrial genome, cytochrome b (CYTB), a concatenated dataset of nuclear genes, single copy orthologs identified through whole genome sequences, along with habitat characteristics, external morphology, and cranial morphology of Mustela mopbie sp. nov.
  • Yu Liang, Yin Zhou, Peng Nan, Yuguo Wang, Wenju Zhang, Ji Yang, Zhiping Song
    J Syst Evol. 2026, 64(2): 203-212.
    https://doi.org/10.1111/jse.70028
    Sex ratio plays a critical role in population survival. Dioecious plants may simultaneously display sexual dimorphism and deviations from the equilibrium expectation of 1:1 sex ratio in populations, that is, biased sex ratio. However, whether biased sex ratios can be attributed to sexual dimorphism has not been well investigated. Here, we conducted experiments using a three-water-depth gradient to examine sexual dimorphism performance and population sex ratios for Vallisneria natans, and investigated the variations in natural population sex ratios for it and two other congeners V. spinulosa and V. denseserrulata along water depth changes. Females of V. natans had higher reproductive investment than males, and the degree of sexual dimorphism increased with increasing water depth. At greater water depths, increased reproductive expenditure led to higher mortality in females, resulting in a male-biased sex ratio. The sex ratios of natural V. natans and V. spinulosa populations did not significantly deviate from 1:1. In contrast, populations of V. denseserrulata exhibited markedly a female-biased sex ratio, which may be attributed to female plants producing more clonal ramets. Furthermore, no evidence was found for variation in sex ratios along water depth gradients in natural populations of any of the three species. These findings highlight the plasticity both of sexual dimorphism and sex ratios in dioecious plants, indicating that sex ratios are species-specific and depend on sex-specific life-history strategy shaped by their growth environments.
    Sex ratio plays a critical role in population survival. Dioecious plants may simultaneously display sexual dimorphism and deviations from the equilibrium expectation of 1:1 sex ratio in populations, that is, biased sex ratio. However, whether biased sex ratios can be attributed to sexual dimorphism has not been well investigated. Here, we conducted experiments using a three-water-depth gradient to examine sexual dimorphism performance and population sex ratios for Vallisneria natans, and investigated the variations of natural population sex ratios for it and two congeners Vallisneria spinulosa and Vallisneria denseserrulata along water depth changes. Females of V. natans had higher reproductive investment than males, and the degree of sexual dimorphism increased with water depth. At deep water more reproductive expenditure led to higher mortality of females, resulting in male bias. The sex ratios of natural V. natans and V. spinulosa populations did not deviate from 1:1, whereas that of V. denseserrulata was markedly female-biased, likely due to female plants producing more clonal ramets. There was no evidence for variation in sex ratios of natural populations along water depth changes for any of the three species. These findings indicate the plasticity both of sexual dimorphism and sex ratios of dioecious plants, reflecting that sex ratios are species-specific and based on sex-specific life-history strategies adopted in growth environments.
  • Rui Cheng, Hong-Xiang Han, Chao-Dong Zhu
    J Syst Evol. 2026, 64(1): 19-32.
    https://doi.org/10.1111/jse.70026
    The peppered moth Biston betularia L., widely distributed across the Northern Hemisphere, represents an ideal organism for exploring phylogeographic patterns and evolutionary history. In this study, we integrated molecular, morphological, and distributional data of this species to reconstruct its phylogenetic relationships, estimate divergence times, infer the geographic origin, and trace dispersal routes. Molecular analyses identified six monophyletic lineages (HM, NC, HD, E, NA I, and NA II). With the exception of the sympatric North American lineages NA I and NA II, the remaining lineages exhibit allopatric distributions across Eurasia. Ancestral area reconstruction and approximate Bayesian computation (ABC) analyses supported a southern Xizang origin within the Himalayan Mountains, consistent with the “Xizang-origin hypothesis.” The colonization of North America occurred twice via the Bering Land Bridge during the Pleistocene glaciation. Collectively, the current genetic pattern is best explained by gradual allopatric differentiation following long-distance dispersal and subsequent isolation. Furthermore, we reconstructed the global dispersal history of B. betularia. These results indicated that in situ speciation within the Himalaya may be more common than previously recognized, challenging the notion that Himalayan fauna are predominantly considered “immigrant.” This study enhances our understanding of Himalayan zoogeography and biodiversity through the resolved evolutionary history of a widely distributed species.
    Integrating molecular, morphological, and biogeographic data resolved six distinct monophyletic lineages of peppered moth (Biston betularia) and highlighted in situ speciation in the Himalayan region, challenging the notion of Himalayan fauna as primarily “immigrant.” Genetic patterns reflected gradual allopatric differentiation driven by postdispersal isolation.
  • Huijuan Zhou, Fan Wu, Hengzhao Liu, Jiayu Ma, Huiling Yan, Renna Li, Lu Fan, Fangbing Ding, Yuwei Linghu, Bin Xie, Xiaoai Fang, Shu Yang, Ming Yue, Peng Zhao, Yaling Wang
    J Syst Evol. 2026, 64(2): 260-282.
    https://doi.org/10.1111/jse.70025
    The genus Magnolia belongs to Magnoliaceae, an early diverging lineage of the Magnoliales, and is cultivated globally for its high ornamental and commercial values. As a large genus in the family Magnoliaceae, Magnolia species are regarded as highly valuable in phylogenetic and conservation biological studies. However, the whole genome data of Magnolia is still relatively insufficient. Here, we present a high-quality, chromosome-level genome sequence of Magnolia sinostellata (1.86 Gb) with a scaffold N50 of 85.33 Mb. The 19 M. sinostellata genome chromosomes revealed 11 main duplications representing the subgenome. Comparative genomics analysis revealed that the variance in the number of abiotic stress resistance genes among Magnoliid species are related to different environmental adaptations. Most of the genes related to MAPK signaling and stress resistance pathways in the investigated M. sinostellata species are expanded, compared to the other species. Furthermore, the comparative genomics analysis of three Magnolia assemblies, M. sinostellata, Magnolia biondii, and Magnolia sieboldii revealed that large inversions were enriched in terpenoid metabolic pathways, stress resistance and flavonoid biosynthesis, and DNA replication proteins. Using transcriptome sequencing data, we analyzed the expression levels of genes related to terpenoid biosynthesis (terpene synthase) and ICE–CBF–COR gene models related to cold tolerance in various tissues and the buds under different temperature conditions. The high-quality assembly of M. sinostellata and the ICE–CBF–COR bioinformatic analysis cascade provide valuable resources for studying the phylogeny and evolution of Magnoliaceae and angiosperms, while the candidate genes will provide foundational support for molecular breeding in Magnolia species.
    A valuable genomic resource for understanding the evolution, stress resistance, and terpenoid biosynthesis in Magnolia sinostellata. The high-quality genome assembly and detailed analysis offer insights into the adaptive evolution of this endangered species and lay the foundation for future conservation and molecular breeding efforts. The findings highlight the importance of M. sinostellata as a model for studying the evolutionary dynamics and functional genomics of the Magnoliaceae family.
  • Lucía D. Moreyra, Juan Antonio Calleja, Cristina Roquet, Siri Birkeland, Carme Blanco-Gavaldà, Mercè Galbany-Casals, Abel Gizaw, Frederik Leliaert, Christian Brochmann, Alfonso Susanna
    J Syst Evol. 2026, 64(2): 401-420.
    https://doi.org/10.1111/jse.70024
    Accurate species delimitation is crucial for biodiversity research, as it significantly impacts taxonomy, ecology, and conservation. Recent advances in molecular phylogenetics and integrative taxonomy have improved classifications and resolved long-standing taxonomic uncertainties. Here, we use Hyb-Seq (489 nuclear loci) and phylogenomic approaches to investigate Afrocarduus, a genus endemic to tropical Afromontane and Afroalpine regions. Our analyses reveal 16 evolutionary lineages within this relatively young genus (crown age 2.3 Mya), with new morphological data strongly supporting the recognition of each lineage as a distinct species. We demonstrate that the stemless habit evolved independently in species from the Ethiopian Highlands and the East African Rift System (EARS). Notably, we show that the concept of the stemless Afrocarduus schimperi adopted by the Flora of Tropical East Africa, in fact, comprises seven clearly recognizable species, which we formally reinstate. Unexpectedly, the stemmed Afrocarduus nyassanus was recovered as paraphyletic with Afrocarduus ruwenzoriensis nested within it, probably due to incomplete lineage sorting or hybridization. Additionally, the stemmed Afrocarduus keniensis may represent a complex of cryptic species, and we describe a new stemmed species from southern Ethiopia, Afrocarduus kazmi sp. nov. We expand the number of accepted species in Afrocarduus from eight, as recognized in the Flora of Tropical East Africa, to 18 (including two species for which we were not able to obtain molecular data). Our study thus highlights a substantial prior underestimation of the diversity of Afrocarduus in Afromontane and Afroalpine habitats.
    Species delimitation is crucial for biodiversity studies. Using Hyb-Seq and phylogenomics, we reassessed Afrocarduus, endemic to Afromontane and Afroalpine regions, uncovering 16 evolutionary lineages (2.3 Mya). Morphological data support their distinctiveness, with acaulescence evolving independently twice. The traditionally broad A. schimperi includes seven species, now reinstated, and we describe A. kazmi sp. nov., expanding Afrocarduus from eight to 18 species.
  • Nicholas Bezio, Gustav Paulay, Allen Collins
    J Syst Evol. 2026, 64(2): 387-400.
    https://doi.org/10.1111/jse.70023
    We present a phylogenetic analysis of benthic ctenophores of the order Platyctenida, sampling all but one genus. Using complete mitochondrial genomes and nuclear ribosomal data and a reassessment of anatomy, our integrated analysis uncovers an unexpectedly close relationship between two unusual members of the Coeloplanidae: Coeloplana (Benthoplana) meteoris and Vallicula multiformis. These two species form a well-supported clade, deriving at or near the base of the tree of Platyctenida, distantly related to other Coeloplana, rendering Coeloplana and Coeloplanidae non-monophyletic. A unique mitochondrial gene order and a tentacle bulb with four extensions are newly identified synapomorphies of this lineage. We elevate the subgenus Benthoplana to the generic level, erect the new family Benthoplanidae for Benthoplana and Vallicula, and provide diagnoses for these taxa and their accepted species. We also show that planktonic Ctenoplana (Diploctena) neritica is the early life stage of Benthoplana meteoris, and suggest that the remaining Ctenoplanidae likely represent early life history stages of Coeloplanidae and perhaps other platyctenes. While both the nuclear ribosomal (18S and 28S) and mitochondrial protein-coding genes suggest a deep phylogenetic divergence between Benthoplanidae and Coeloplanidae, we detect conflicting phylogenetic signal between these markers, suggesting nuclear-mitochondrial discordance, leaving the placement of Tjalfiellidae and Lyroctenidae uncertain.
    The benthic ctenophore Benthoplana meteoris (adults left and bottom, planktonic juveniles to the top right), type species for the genus, which in turn is type for the newly erected family: Benthoplanidae (Ctenophora, Platyctenida).
  • Le-Le He, Bao-Zhen Hua
    J Syst Evol. 2026, 64(2): 213-228.
    https://doi.org/10.1111/jse.70019
    Many genera were erected without phylogenetic validation in Bittacidae, a cosmopolitan family in Mecoptera, leaving their generic statuses contentious. Here, we investigated the phylogenetic relationships and reconstructed the ancestral states of chromosome numbers and key morphological characters for 26 species in three genera of Bittacidae using an integrative approach combining molecular, cytogenetic, and morphological data. The phylogenetic analyses reveal that all three genera studied are paraphyletic, but cytogenetic evidence supports the generic status of Terrobittacus Tan & Hua with haploid chromosome numbers ≥20. In contrast, the genus Bittacus Latreille, 1805 exhibits an extensive chromosomal variation from n = 8 to n = 22. Ancestral state reconstruction suggests that the diagnostic character of Bicaubittacus Tan & Hua may represent an apomorphy restricted to a few species. The cytogenetic investigation indicates that n = 22 was the ancestral chromosome number in Bittacidae. Chromosome fusions were likely responsible for numerical reduction in chromosomes of Terrobittacus, whereas more complex structural and numerical variations accounted for the chromosome diversity of Bittacus and Bicaubittacus. To satisfactorily resolve the generic problem of Bittacidae, taxon sampling should be greatly expanded at the global scale, and more attention should be paid to the integrative taxonomy.
    Many genera were erected without phylogenetic validation in Bittacidae (Insecta: Mecoptera), leaving their generic statuses contentious. We investigated the phylogenetic relationships and reconstructed the ancestral states of chromosome numbers for hangingflies using an integrative approach combining molecular, cytogenetic, and morphological data. The phylogenetic analyses reveal that all three genera studied are paraphyletic. Chromosomal data likely play a critical role in the systematics of bittacids. Complex structural and numerical variations of chromosomes occurred in hangingflies during evolution.
  • Chen Feng, Xiangbo Guo, Yuhui Zhuang, Qingqing Zhang, Corentin Jouault, Edmund Aleksander Jarzembowski, Yu Liu
    J Syst Evol. 2026, 64(2): 344-353.
    https://doi.org/10.1111/jse.70018
    Pseudoscorpiones are a group of small-sized to medium-sized arachnids under the species-rich Chelicerata. They are found in many terrestrial habitats, normally cryptic, including leaf litter and soil, under tree bark or rocks. The fossil record of pseudoscorpions is mainly composed of species belonging to extinct genera in extant families, with a small number of taxa described from the famous Kachin amber, sometimes referred to as Burmese amber or Burmite (12 species in six families). Here, we describe a well preserved male specimen of pseudoscorpion from mid-Cretaceous Kachin amber, representing the first fossil record of Cheliferidae from Burmese amber. This new taxon, Echinochelifer curvatus gen. & sp. nov., is characterized by elongate tubercle-bearing pedipalps and several trichobothrial features. Based on these, we discuss the systematic placement and palaeoecological implications of the new taxon in Burmese amber.
    This study presents the first fossil record of Cheliferidae from mid-Cretaceous Kachin amber, specifically a well preserved male specimen (Echinochelifer curvatus gen. et sp. nov.) from amber mines near Noije Bum, Hukawng Valley, Kachin State, northern Myanmar (26°20′N, 96°36′E). The new taxon is distinguished by unique features such as elongate tubercle-bearing pedipalps and specific trichobothrial traits. Using advanced techniques like micro-CT scanning and wide-field fluorescence imaging, we elucidate its systematic placement and explore its ecological role within the Burmese amber biota.
  • Kawtar Lhayani, Karim Rabeh, Leila Medraoui
    J Syst Evol. 2026, 64(2): 229-239.
    https://doi.org/10.1111/jse.70021
    Identification of Fabaceae family plants traditionally relies on either morphological traits or DNA barcoding, each with limitations in accuracy and efficiency. Deep learning has emerged as a promising tool for integrating multiple data sources, but its full potential remains underexplored. This study aimed to utilize a deep learning model that integrates morphological and molecular data for species identification within the Fabaceae family, bridging the gap between the two methods of identification. The research involved four main phases: (i) data collection; (ii) data preprocessing; (iii) training and testing the model; and (iv) analysis of results. The data comprised DNA barcode sequences retrieved from the BOLD database, and images were collected from different websites. The model was trained for identification on the genera and species levels, with two different barcodes: ITS2 and matK+rbcL. Only species with four available copies of ITS2, matK, and rbcL sequences were selected to ensure consistent input across samples. The final data set included seven genera and 21 species. While the model achieved high accuracy during training, test accuracy remained low (14%–19%), indicating overfitting, likely due to the limited data set size. However, the model demonstrated the ability to evaluate barcode discrimination across genera. Specifically, it highlighted ITS2 and matK+rbcL as having varying levels of effectiveness depending on the genus. These findings introduce a new application for deep learning in plant systematics not only for species identification but also for evaluating barcodes. This approach could help reduce the reliance on trial-and-error in barcode selection and enhance the efficiency of molecular taxonomy.
    This study proposes a deep learning framework integrating morphological traits and DNA barcodes (ITS2, matK, rbcL) to identify Fabaceae species. By combining image data and molecular sequences, a CNN artificial neural network (MMNet) enables automatic species identification and barcode evaluation. The model improves identification accuracy and suggests the most informative barcode per genus. This integrative approach enhances the reliability of plant taxonomy and supports large-scale biodiversity monitoring, providing a tool that bridges traditional and molecular identification methods through automation and intelligent feature fusion.
  • Jie Huang, Shuai Li, Zhuo-Huan Zheng, Jun Liu, Yi-Jun Mo, Ting-Ting She, Li-Jia Huang, Wen-Sheng Shu, Lei Dong, Wen-Jun Li
    J Syst Evol. 2026, 64(2): 363-386.
    https://doi.org/10.1111/jse.70020
    The genus Kineococcus is primarily found in extreme environments and plant-associated habitats, suggesting its potential for stress tolerance and plant growth promotion. However, the diversity and functional potential of this genus remain largely unexplored, mainly due to the limited availability of strains and genomic resources. In this study, 33 Kineococcus strains were isolated from the Gurbantunggut Desert and Shanshan Kumtag Desert in Xinjiang, China. Based on the overall genome-relatedness indices (OGRI) and sampling origins, 12 representative Kineococcus strains were selected for polyphasic taxonomy and assessment of plant growth-promoting traits. By integrating phylogenetic, morphological, physiological, chemotaxonomic, and genomic analyses, these strains were classified into nine novel species (one with two subspecies). The representative isolates exhibited various key plant growth-promoting traits, including siderophore production, cellulose degradation, organophosphate solubilization, and indole-3-acetic acid (IAA) production. This study significantly expands the strains, species, and genome resources of the genus Kineococcus, providing valuable insight into its ecological adaptation, particularly in saline–alkali tolerance, and growth-promoting potential for sustainable agriculture.
    Thirty-three new Kineococcus strains were isolated from a desert habitat. By integrating phylogenetic, morphological, physiological, chemotaxonomic, and genomic analyses, these strains were classified into nine novel species (one with two subspecies). The representative isolates exhibited various key plant growth-promoting traits. This study expands the resources of the genus Kineococcus and enhances our understanding of its potential applications in sustainable agriculture.
  • Ming-Fai Liu, Jérôme Munzinger, Piya Chalermglin, Junhao Chen, Bine Xue, Richard M. K. Saunders
    J Syst Evol. 2026, 64(2): 313-329.
    https://doi.org/10.1111/jse.70017
    Meiogyne is a genus of shrubs, trees and treelets occurring in India, tropical Southeast Asia, and Australasia–Pacific, an unusually wide distribution across Australasia and the Western Pacific compared to other genera of Annonaceae. Previous chloroplast phylogenies of the genus offered poor resolution and support. Here, a molecular phylogeny was reconstructed based on 27 described Meiogyne species (ca. 70% sampling) using seven chloroplast and 11 nuclear markers. The combined data set generated a well-resolved and well-supported phylogeny. Estimation of divergence time utilized two fossil calibrations and an uncorrelated log-normal relaxed clock model. Trait-dependent and trait-independent biogeographical models in BioGeoBEARS were compared using corrected Akaike information criterion weight and the likelihood ratio test. The results suggest that narrow monocarp width is correlated with increased macroevolutionary dispersal. Under the best-fitting trait-dependent DEC + j + t12 + t21 + m2 model, a single colonization event from Sunda to Sahul during the middle Miocene and two dispersal events from New Guinea and Australia into the Pacific during the late Miocene to early Pliocene were detected. BayesTraits analysis strongly supports a correlation between narrow monocarp width and bright fruit colors. Bird dispersal and the associated traits (narrow monocarp width) may have driven macroevolutionary dispersal for Meiogyne in Australasia–Pacific.
    Molecular phylogeny based on 11 nDNA and seven cpDNA markers and ancestral range reconstruction sugges that the genus Meiogyne dispersed from tropical Southeast Asia to Sahul and the Western Pacific. Trait-dependent biogeographical models and correlated evolution analysis reveal that the bird dispersal trait narrow fruitlet width may have aided the colonization of Meiogyne in the Australasia–Pacific region.
  • Ziqiang Xu, ChungKun Shih, Chenxin Zhou, Wei Yuan, Yu Liu, Dong Ren, Ying Wang
    J Syst Evol. 2026, 64(2): 330-343.
    https://doi.org/10.1111/jse.70016
    A new species, Sinocurvicubitus haotianus Xu, Shih, Ren & Wang, sp. nov. (Curvicubitidae), is described from the Upper Permian Leping Formation in Jiangxi Province, South China. This constitutes the second definitive occurrence of Curvicubitidae in the Late Permian. Through comparative wing morphology and cladistic analyses, we resolved phylogenetic relationships within the superfamily as ((Ignotalidae + Pereboriidae*) + Curvicubitidae) and validated the exclusion of Scytophara extensa from Pereboriidae. Additionally, we estimated divergence times across Pereborioidea lineages, reconstructed ancestral distribution ranges, and elucidated the origin centers and dispersal routes for Curvicubitidae. Wing eyespots and bands suggested predator mimicry, a novel defense strategy in Permian insects.
    This study revised the generic diagnosis based on Sinocurvicubitus haotianus Xu, Shih, Ren & Wang, sp. nov., a new species from Jiangxi Province, and interpreted the color bands and eyespot on the forewing as defensive mimicry in early insects. By constructing a phylogenetic tree using phenotypic wing data, we clarified the relationships within the superfamily and reconstructed both divergence times and ancestral distribution ranges for key nodes.
  • Shabir A. Rather, Sajjad Asaf, Amish Kumar, Hongmei Liu, Harald Schneider
    J Syst Evol. 2025, 63(6): 1536-1559.
    https://doi.org/10.1111/jse.70015
    The generic delimitation of the Caesalpinia group continues to be under contention, similar to several other lineages of the hyper diverse legume family. Despite its known ecological and economic importance and role as a model to explore correlations between ecological diversification and genomic traits, both intergeneric and infrageneric relationships remain unresolved, despite recent phylogenetic analyses. While phylogenomic approaches have elucidated complex relationships within the angiosperm tree of life, the phylogenetic backbone of the Caesalpinia group remains poorly defined owing to limited genomic data. To address this gap, this study combined de novo assembled and characterized plastomes from 19 samples across nine genera, along with 27 previously published plastomes, to achieve a comprehensive dataset of 46 plastomes representing 16 of the 26 genera. The phylogenomic analysis generated a robust phylogenetic hypothesis, distinguishing two main clades, of which one occurs exclusively in the Neotropics in contrast to the other Pantropical clade, in addition to resolving several previously ambiguous relationships. Notable changes in the plastome gene content were observed, including six gene losses (psbL, rpl22, rps2, rpl32, ycf1, ycf2) and six gene duplications (ndhB, rpl23, rps7, rps12, ycf1, ycf2). Other changes included shifts in inverted repeat (IR) boundaries and genome rearrangements, indicating lineage-specific plastome evolution. Hypervariable regions were identified as potential mini-barcodes, with cpSSRs providing valuable resources for species delimitation and population genetics studies. Codon usage revealed a strong AT bias, while relaxed purifying selection in genes such as accD, clpP, and rps16. These findings offer novel insights into Caesalpinia group evolution, emphasizing the utility of plastome data for resolving complex evolutionary questions and establishing a genomic toolkit for future research in systematics, conservation, and evolutionary biology of legumes.
    Studying plastome evolution within the Caesalpinia group revealed key genomic features and their variations across species. It visualized the chloroplast genome structure, illustrating gene duplications, losses, and rearrangements, providing insights that deepened our understanding of the Caesalpinia group's diversity and have significant implications for systematics, conservation, and population genetics.
  • Xin Yao, Zhi-Rong Zhang, Jun-Bo Yang, Richard T. Corlett, De-Zhu Li, Wen-Bin Yu
    J Syst Evol. 2025, 63(6): 1519-1535.
    https://doi.org/10.1111/jse.70014
    Investigating the evolutionary history and species diversification patterns in hyperdiverse lineages is essential for understanding how species diversity accumulates and how floras assemble historically across diverse regions. A large angiosperm family, Apocynaceae, exhibited remarkable diversity in functional traits including growth form, fruit types, and pollen aggregation, which may have a substantial impact on species diversification rates. However, the lack of a robust and well dated phylogeny has hindered our understanding of Apocynaceae diversification. To address this gap, we reconstructed a robust phylogeny covering 22 of 25 tribes using plastome sequences, then employed this framework to estimate divergence times, analyze diversification patterns, and investigate associations between species diversification and functional traits. The plastome phylogenies received strong nodal support across most branches. Among higher taxonomic groupings, three subfamilies (Asclepiadoideae, Secamonoideae, and Periplocoideae) were monophyletic. At the tribal levels, 19 tribes were strongly supported as monophyletic except Melodineae, Willughbeieae, and Vinceae. Additionally, five genera (Vincetoxicum, Cynanchum, Hoya, Marsdenia, and Aganosma) were identified as nonmonophyletic. Our analyses revealed that Apocynaceae originated in the paleotropics during the middle Late Cretaceous. Integrating binary state speciation and extinction (BiSSE), hidden state speciation and extinction (HiSSE), and fast, intuitive state-dependent speciation-extinction (FiSSE) analyses, we found that species with pollinia had a higher speciation rate than those without. Dry-fruited species had a higher speciation rate than those with fleshy fruits. Furthermore, Bayesian analysis of macro-evolutionary mixtures (BAMM) detected a diversification rate increase coinciding with the evolution of pollinia with clip-type attachment mechanisms in the subfamily Asclepiadoideae. Herbs had the highest speciation rate, followed by climbers and self-supporting species. Our findings contribute to understanding the historical assembly of floras in tropical and subtropical Asia.
    Our results showed the Apocynaceae originated in the middle Late Cretaceous in the paleotropics. We found that changes in speciation rate are associated with changes in growth form, fruit type, and pollen aggregation. We further detected a diversification rate shift to increase at the node in which pollinia with clip-type attachment started to evolve in BAMM.
  • Xiao-Xu Pang, Da-Yong Zhang
    J Syst Evol. 2025, 63(6): 1560-1576.
    https://doi.org/10.1111/jse.70013
    Population genetic clustering methods are widely used to detect hybridization events between closely related populations within species, as well as between deeply diverged lineages across phylogenetic time scales. Their strengths and limitations in the latter cases, however, remain poorly explored. This study presents a systematic evaluation of the performance of the most popular population clustering method, STRUCTURE, under a variety of cross-species hybridization scenarios, including hybrid speciation, as well as introgression involving ghost (i.e., extinct or unsampled) lineages or otherwise. Our simulations demonstrate that STRUCTURE performs well in identifying hybrids and their parental donors when admixture happens very recently between sampled extant lineages, but generally fails to detect signals of admixture when hybridization occurs in deep time or when gene flow stems from ghost lineages. We find that symmetrical parental contribution in cases of hybrid speciation will often be revealed as extremely asymmetrical in STRUCTURE, especially when the admixture event occurred a long time ago. Our results suggest that population genetic clustering methods may be inefficient for detecting ancient or ghost admixtures, which may partly explain why ghost introgression has escaped the attention of evolutionary biologists until recently.
    Simulations provide a systematic evaluation of STRUCTURE in cross-species hybridization scenarios, showing that STRUCTURE performs well in identifying hybrids and their parental donors only when admixture happens very recently, but generally fails to detect hybridization when admixture occurs in deep time or when gene flow stems from ghost lineages.
  • Qun Liu, Nan Lin, Dai-Gui Zhang, Xian-Han Huang, Yan-Bo Li, Ying-Ying Zheng, Umida Tojiboeva, Jian-Wen Zhang, Tao Deng
    J Syst Evol. 2026, 64(1): 95-105.
    https://doi.org/10.1111/jse.70012
    Carpesium (Asteraceae) represents the largest Asian genus within the subtribe Inulinae of the tribe Inuleae, exhibiting maximum species diversity in China. This study presents the first comprehensive phylogenetic analysis of Carpesium, utilizing nuclear ribosomal internal transcribed spacer (ITS), specific chloroplast DNA sequences (rps16-trnQ, rpl32-trnL, and ndhF-rpl32), whole chloroplast genomes and chloroplast coding sequence (CDS). The results demonstrate that Carpesium, excluding C. abrotanoides, constitutes a monophyletic group. The Carpesium s.str. clade contains two well-supported lineages with distinct morphological characteristics. Based on morphological analyses, molecular phylogenetic evidence, and karyotypic studies, this research establishes Cladocarpesium gen. nov. to accommodate C. abrotanoides. The comprehensive sampling approach has facilitated a thorough phylogenetic reconstruction of the Inula complex, establishing a robust systematic framework that clarifies previously uncertain relationships among constituent species. This multilocus methodology provides essential insights for reassessing infrageneric classifications within this taxonomically complex group.
    Cladocarpesium T. Deng & Qun Liu, gen. nov. (separated from Carpesium) is established with Cladocarpesium abrotanoides (L.) T. Deng & Qun Liu designated as the type species. The new genus is morphologically distinguished from Carpesium s.str. by its sympodial growth form (typically producing three branches), sessile capitula, and three-seriate phyllaries.
  • Gildas Gâteblé, Ryusuke Ikeda, Giliane Karnadi-Abdelkader, Jacqueline Ounémoa, Yoshihisa Suyama, Yuji Isagi
    J Syst Evol. 2025, 63(6): 1299-1311.
    https://doi.org/10.1111/jse.70011
    While conducting a population genetic study aiming at refining previous conclusions about cladogenesis in the Oxera genus (Lamiaceae) in New Caledonia, we uncovered an unexpected result for the well-known Oxera palmatinervia Dubard species. To better understand the preliminary molecular results that revealed two distinct sister species, we performed extensive field studies in order to sample, measure, hand-pollinate, and observe the flower and fruit visitors on different populations of O. palmatinervia and other species of the “robusta” clade. We found flower morphology differences to be congruent with the molecular results, so that we propose to describe a new species as O. sympatrica Gâteblé & Karnadi sp. nov. The differences in flower morphology between the two species, which can grow in true sympatry and flower at the same time of the year, are striking so that flower visitors and pollination syndromes were investigated as far as possible. We find that two species of honeyeaters Glycifohia undulata and Philemon diemenensis are likely the preferred pollinators, respectively, of O. palmatinervia and O. sympatrica sp. nov. because of their respective sizes, bill and tongue lengths, and behavior. Even though, to date, it cannot be proven that initial speciation of both Oxera occurred in sympatry, today's sympatry is observed along with a remarkable supposed coevolution pollination syndrome. The new species is fully described, mapped, evaluated against Red List criteria, and illustrated. Pollination syndromes are discussed and illustrated.
    Investigating the morphology and ecology of two sympatric species of the Oxera (Lamiaceae) genus in New Caledonia and their respective putative pollinators showed that two species of honeyeaters are likely the preferred pollinators because of their respective sizes, bill and tongue lengths, and behavior.
  • Paranchai Malailkanok, Friðgeir Grímsson, Reinhard Zetter, Paul J. Grote, Thomas Denk, Wongkot Phuphumirat
    J Syst Evol. 2025, 63(6): 1458-1480.
    https://doi.org/10.1111/jse.70010
    Fossil Ericales pollen from late Oligocene to Early Miocene sediments of the Ban Pa Kha Subbasin, Li Basin, northern Thailand, were examined using the single-grain method. A total of 24 different ericalean pollen types belonging to Ebenaceae (Diospyros), Ericaceae (Cassiope, Vaccinium, and Rhododendron), Pentaphylacaceae (Adinandra), Sapotaceae, Styracaceae (Rehderodendron and Styrax), and Symplocaceae (Symplocos) were identified. All the fossil pollen, except that of Sapotaceae, represent families/genera that are described for the first time from the Cenozoic of Thailand. By considering present terrestrial biome occupancy, Köppen–Geiger climate profiles, and vertical distributions of potential modern analogs of the parent plants producing the fossil pollen, the phytosociological and paleoecological preferences of the fossil taxa were assessed. Our results demonstrate that modern analogs of most of the ericalean taxa have wide ecological and climatic amplitudes with a broad zone of convergence in warm and cold temperate humid or seasonally dry climates. Exceptions are Sapotaceae, which rarely occur outside lowland tropical forests, and Cassiope, which at present occurs at high elevations and, besides Rehderodendron, is one of two modern analogs absent from the modern flora of Thailand. Along with a review of phytosociological studies in montane forests of northern Thailand and neighboring regions, this suggests that the assemblage of dispersed ericalean pollen of the Ban Pa Kha Subbasin likely derives from more than one vegetation type and possibly from different vertical zones.
    Ericalean pollen was recovered from the Ban Pa Kha Subbasin, Li Basin, northern Thailand. Based on the ecological preferences of their modern analogs, the assemblage of dispersed ericalean pollen likely derives from more than one vegetation type and possibly from different vertical zones of mountainous areas.
  • Xin-Yu Lin, Yan Liu, Jing-Fei Zhang, Jia-Xiu Zhong, Shu-Han Duan, Xiang-Ping Li, Hao-Ran Su, Qing-Xin Yang, Xiao-Jun Liu, Qiu-Xia Sun, Chao Liu, Meng-Ge Wang, Guang-Lin He, Yong-Xin Ma
    J Syst Evol. 2025, 63(6): 1370-1389.
    https://doi.org/10.1111/jse.70009
    The genetic structure and population history of ethno-linguistically diverse populations from the Yunnan–Guizhou Plateau remain underrepresented in human genomic research. We analyzed genome-wide data from 239 individuals in Guizhou, combined with modern and ancient datasets, to investigate their fine-scale genetic structure, demographic events, and functional consequences of adaptive genomic signatures. Our findings revealed three genetically distinct groups corresponding to linguistic categories, shaped by differential gene flow from ancient millet farmers and southern Chinese populations. We identified population-specific adaptive candidate genomic regions associated with immune, metabolic, and hematological functions. Additionally, we detected clinically relevant variants with implications for disease risk prediction and precision medicine. These findings underscore the importance of genetic diversity in understanding human adaptation and health disparities, offering a framework for equitable genomic research in underrepresented populations.
    Exploring the genomic diversity of underrepresented Guizhou multi-ethnic populations by analysis of the fine-scale genetic structure and admixture patterns, revealed substructures tied to linguistic categories, adaptive signatures linked to key functions, and clinical-related variants, highlighting the critical role of population-specific genomic diversity in refining precision medicine for tailored therapeutic interventions.
  • Ke-Yi Wang, Peng Zhou, Yan-Fang Cui, Yi-Zhen Liu, Wen-Gen Zhang, Bo Pan, Yu-Song Huang, Zhi-You Guo, Zhen-Yu Li, Wei-Tao Jin, Qiang Zhang, Chun-Ce Guo, Xiao-Guo Xiang
    J Syst Evol. 2025, 63(6): 1358-1369.
    https://doi.org/10.1111/jse.70007
    Karst areas are well known for their extreme biodiversity and the investigation of plant adaptation in these unique environments is a research hotspot. Previous studies have primarily focused on the genomic adaptation of karst endemic species, but the specific adaptation of facultative species remains unclear. Hemiboea subcapitata, a traditional medicinal plant growing in both karst and non-karst areas serves as a valuable model for understanding these genomic mechanisms. Here, the H. subcapitata genome was sequenced using the PacBio and Illumina platforms and de novo assembled with a contig N50 value of 21.11 Mb. The assembled genomic size was 763.59 Mb. The Benchmarking Universal Single-Copy Orthologs (BUSCO) quality value was 98.10%, and 92.87% of sequences were anchored to 16 chromosomes. Comparative genome analyses identified three whole-genome duplication (WGD) events: the γ-WGT event (115–130 Ma) shared by all eudicots, WGD2 shared within Lamiales except Oleaceae (67.57 Ma) and the recently independent WGD1 unique to H. subcapitata (16.92 Ma). These three WGD events probably facilitate the expansion of stress-responsive gene families, which in turn influence functional pathway regulation. In particular, genomic and transcriptome analyses identified 25 key genes in the flavonoid pathway and candidate MYB transcription factors related to environmental adaptation. Compared with the karst endemic Primulina tabacum, H. subcapitata showed the upregulation of 25 key flavonoid pathway genes (96% in roots, 92% in leaves, 88% in flowers). This mechanism of expanding ecological niches through metabolic pathway regulation is a unique adaptive strategy of H. subcapitata. This study provides valuable data for further resource utilization and conservation of Hemiboea.
    Analysis of a chromosome-level genome for Hemiboea subcapitata identified three whole-genome duplication events and 25 flavonoid pathway genes cooperating with MYB transcription factors, which might promote unique facultative adaptation to karst and non-karst environments by H. subcapitata.
  • Jia-Rui Yu, Si-Ao Li, Dong-Xue Zhao, Francis M. Martin, Hai-Sheng Yuan
    J Syst Evol. 2025, 63(6): 1344-1357.
    https://doi.org/10.1111/jse.70006
    Ectomycorrhizal (ECM) fungi form symbiotic relationships with woody plants, completing their life cyclesthrough mutualistic associations. The evolution of this symbiosis involves genomic adaptations including gene gain andloss. However, how these genomic characteristics reflect speciation and adaptation throughout the evolutionaryhistory of ECM fungi remains unclear. In the present study, we explored speciation and host adaptation in Tricholoma species, an ecologically relevant clade of ECM basidiomycetes. We compared the genomes of three species, Tricholoma matsutakeT. populinum, and T. bakamatsutake, which despite their close phylogenetic relationships, have different tree hosts. A phylogenetic tree constructed using single‐copy orthologous genes estimated the divergence time of T. populinum to be approximately 28.48 Mya, coinciding with the diversification of subg. Eupopulus in East Asia. The split between T. matsutake and T. bakamatsutake was estimated at around 8.08 Mya, corresponding to the diversification period of evergreen broadleaved forests in East Asia. In this study, we identified 19, 13, and 13 positively selected genes in the genomes of T. bakamatsutake, T. matsutake, and T. populinum, respectively. Additionally, 2983, 2783, and 1548 genes have undergone rapid evolution in their genomes. Gene ontology enrichment analysis revealed the functions of these rapidly evolving genes, including those associated with cell cycle, cytoplasmic components, and GTPase mediation. Gene flow analysis indicated unidirectional migration from the ancestor of Tpopulinum to Tmatsutake and Tbakamatsutake, whereas bidirectional gene flow was observed in the ancestors of T. matsutake and T. bakamatsutake. This study suggested that host‐induced immigrant unviability in symbiotic fungi is the primary causeof prezygotic isolation. The combination of ecology‐based genomic evidence and gene flow analysis offers new insightinto the speciation and evolutionary mechanisms of symbiotic fungi.
    Comparative genomics of three Tricholoma species with differing host spectra identified genes and gene families related to adaptive evolution and statistical analysis revealed the role of repetitive sequences in adaptive evolution, allowing an exploration of how hosts promote speciation.
  • Francisco Fajardo‐Gutiérrez, Mariasole Calbi, Markus S. Dillenberger, Sebastian Tello, AlfredoFuentes, Nora H. Oleas, Ricardo A. Segovia, Christine E. Edwards, Yohan Pillon, James E.Richardson, Thomas Borsch
    J Syst Evol. 2025, 63(6): 1441-1457.
    https://doi.org/10.1111/jse.70004
    The tribe Cunonieae comprises five genera and 214 species of shrubs and trees currently distributed in the Southern Hemisphere and the tropics, exhibiting an amphi‐Pacific disjunct distribution shared with Araucariaceae, Myrtaceae, Nothofagaceae, Podocarpaceae, and Proteaceae, among others. To address the central question of how historical geological forces have shaped the distribution of plant diversity in the southern hemisphere, we aimed to provide evidence from the biogeographical history of Cunonieae. We generated themost densely sampled phylogenetic trees of Cunonieae available to date, with 121 samples and 81 species, basedon 404 new sequences of plastid and nuclear DNA regions with high hierarchical phylogenetic signal (matK, trnL‐F, rpl16, and internal transcribed spacer (ITS)). We included 184 samples of Rosids to estimate divergence times using fossil calibration points. For biogeographic inference, we employed a time‐stratified model including fossils as tips. Cunonia and Pterophylla were paraphyletic in the ITS tree, and Cunonia was paraphyletic in the plastid tree. Pancheria, Vesselowskya, and Weinmannia were monophyletic, the latter with conflicting nuclear and plastid phylogenies. The crown group Cunonieae was dated at ~56 Ma, and its ancestral areas were Antarctica and Patagonia. Antarctica acted as a bridge between Australia and South America before the consolidation of the Antarctic Ice Sheet and the extinction of the lineage in Antarctica from the Oligocene to the Miocene. Following that, Cunonieae spread to lower latitudes via Zealandia/Oceania and Patagonia/South America. Geological changes during the Pliocene facilitated a further burst in diversification along the Andes, in Madagascar, and in New Caledonia, where at least three colonization events occurred.
    Fossil calibration reveals recent radiations and biogeographical history of the Cunonieae tribe. The most densely sampled phylogeny indicated Antarctica and Patagonia as areas of origin, confirming the reestablishment of Pterophylla and revealing the northward movement of Weinmannia into the tropical Andes. Conflicting plastid and nuclear phylogenies suggest past chloroplast capture.
  • Jairo Arroyave, Adán Fernando Mar-Silva, Bruno F. Melo, Sonia Gabriela Hernández-Ávila, Jesús M. López-Vila, Gabriel S. C. Silva, Píndaro Díaz-Jáimes
    J Syst Evol. 2025, 63(6): 1501-1518.
    https://doi.org/10.1111/jse.70003
    Neotropical catfishes of the genus Rhamdia are divided into cis- and trans-Andean/Middle American reciprocally monophyletic components, the latter notable for its considerable cave-dwelling diversity. Despite previous research, uncertainties regarding the systematics and historical biogeography of the Middle American clade remain. To test previous phylogenetic hypotheses and improve our understanding of the evolutionary history of this group of Middle American freshwater fishes, we generated and analyzed comparative mitogenome-wide data from most valid species and known cave-dwelling forms. Our results corroborate this clade as divided into two reciprocally monophyletic groups (split dated at ~9 Ma): a clade representing the species Rhamdia guatemalensis (crown group dated at ~2.8 Ma) and a clade consisting of the remaining Middle American species (i.e., the Rhamdia laticauda species group; crown group dated at ~4 Ma). Our results also confirm the notion that R. laticauda is deeply paraphyletic and that phylogenetically scattered geographic lineages of this taxon could represent different species. Our divergence time estimates, coupled with present-day distribution patterns, support the biogeographic scenario in which northward dispersal and colonization of Central America and southern North America by Rhamdia was catalyzed by the emergence of the Panamanian Isthmus land bridge and stream captures across Lower Central America. Cave colonization in Middle American Rhamdia is widespread, convergent, relatively recent (dating from the Pleistocene), and most likely opportunistic, with established cave-dwelling populations possibly representing “evolutionary dead ends.”
    Investigating the systematics and biogeography of Neotropical catfishes of the genus Rhamdia refined phylogenetic hypotheses, including deep paraphyly of Rhamdia laticauda, supported northward dispersal catalyzed by emergence of the Panamanian Isthmus and imply that cave colonization is widespread, convergent, and recent, with established cave-dwelling populations possibly representing “evolutionary dead ends”.
  • Michael Heads
    J Syst Evol. 2025, 63(6): 1415-1440.
    https://doi.org/10.1111/jse.70002
    The 26 genera of aurantioids and the 28 species of one genus, Citrus, are mapped. The distributions are explained, not by using fossil-calibrated clade ages and ancestral-area algorithms, but by focusing on the geometry of the clade distributions and the tectonic history at the break zones (nodes). Allopatry is attributed to vicariance, while overlap is attributed to normal dispersal. Subfamily Aurantioideae is allopatric with its sister groups in Eurasia and the Americas. In contrast, the seven main clades within Aurantioideae show a high level of overlap. But within each of these seven main clades, there is again a high level of allopatry. The pattern is explained by vicariance events at the first and third levels. The overlap at the second level can be accounted for if vicariance (now obscured) generated the clades and subsequent dispersal caused secondary overlap of the clades. This latter phase of mobilism can be explained by the migration of coastlines and maritime flora far inland during marine transgressions, especially in the mid-Cretaceous. Many aurantioids inhabit mangrove-associated vegetation, beach thicket, limestone substrate, and areas with high levels of disturbance. Within Citrus, the five main clades overlap in South-Central China (Nanling Mountains) and are allopatric elsewhere. The overlap zone has been interpreted as a center of origin, but it is explained here as a break zone, the site of vicariance in a widespread ancestor, where localized, secondary overlap has developed later. The zone coincides with a belt of mid-Cretaceous deformation manifested in voluminous magmatism, subsidence, rifting, back-arc extension, and the opening of the East China Sea.
    Distribution of the Rutaceae subfamily Aurantioideae can be explained through vicariance and secondary range expansion. Citrus originated in situ by vicariance with its allopatric sisters, and the origin of Citrus in southern China is likely to represent a break zone in a widespread ancestor.
  • Su-Xin Yin, Chong Dong, Biao Pan, Zhuo Feng, Jian-Guo Hui, Fabiany Herrera, Patrick S. Herendeen, Peter R. Crane, and Gong-Le Shi
    J Syst Evol. 2025, 63(6): 1401-1414.
    https://doi.org/10.1111/jse.70000
    Pinaceae are one of the most economically and ecologically important tree families and play a key role in boreal, temperate, and montane forests of the Northern Hemisphere. The family have a rich fossil record with the earliest occurrence of the Pinaceae crown group probably from the Late Jurassic, and diverse seed cones, woods, leaves, and pollen grains from the Early Cretaceous of the Northern Hemisphere. However, the origin and early evolutionary history of Pinaceae is not well understood, in part because of uncertainty about the phylogenetic position of early fossils. In this article we describe a new woody stem of Pinaceae based on well-preserved material from the Early Cretaceous Huolinhe Formation in Jarud Banner, eastern Inner Mongolia, Northeast China. Piceoxylon jarudense sp. nov. has distinct growth rings with secondary xylem composed of tracheids, ray tracheids, ray parenchyma cells, axial parenchyma cells, and axial and radial resin canals. Pitting on radial walls of tracheids is abietinean; cross-field pitting is piceoid and taxodioid with two to six pits arranged in one to two rows per cross-field. Axial and radial resin canals are lined by thick-walled epithelial cells. Piceoxylon has been considered to include species with wood anatomy comparable to extant Larix, Pseudotsuga, Picea, and Cathaya. Comparisons of wood anatomy and constrained phylogenetic analyses of P. jarudense, one of the earliest records of Piceoxylon, both suggest that P. jarudense is most likely allied with Larix and Pseudotsuga within the pinoid clade suggesting divergence of the Larix–Pseudotsuga clade before ~125.6 Ma.
    Comparisons of wood anatomy and constrained phylogenetic analyses of a woody stem of Piceoxylon jarudense sp. nov. (Pinaceae) from the Early Cretaceous of Northeast China suggest that it is allied with Larix and Pseudotsuga within the pinoid clade and that the Larix-Pseudotsuga clade diverged before ~125.6 Ma.
  • Xinkun Kang, Zhixin Wen, Jin Wang, Liang Lu, Alexei Abramov, Wenjuan Shan, Deyan Ge
    J Syst Evol. 2025, 63(6): 1390-1400.
    https://doi.org/10.1111/jse.13200
    The rodent family Platacanthomyidae encompasses both the Malabar spiny tree mouse (genus Platacanthomys) and the soft-furred tree mice (genus Typhlomys). This family represents a typical relict group of ancient origin, and its evolutionary history and dynamics warrant further investigation. A critical scientific question concerns whether the evolutionary trajectory of this ancient taxon has been shaped by environmental perturbations, such as the periodic climatic oscillations of the Quaternary glacial periods. This study aims to elucidate the evolutionary trajectory of the Platacanthomyidae by examining fossil records alongside extant species. Molecular dating revealed that the most speciose genus Typhlomys within this family began diverging approximately 21.15 Ma. The speciation rate and net diversification rate of the Platacanthomyidae was notably high around 20 Ma, but it has shown a continuous decline since then, while the extinction rate of this taxa has remained stable. The current dataset indicates that the evolutionary trajectory of this family appears to have remained unaffected by late Cenozoic climatic fluctuations and subsequent anthropogenic influences associated with societal development. The ancestral distribution reconstruction has not yielded conclusive evidence regarding the origin of this family, thereby positioning it among the most enigmatic taxa within Rodentia. Moreover, the evolutionary mechanisms underlying the divergence of these ancestral species and their subsequent ecological adaptations to paleoenvironmental changes require future studies.
    Elucidating the evolutionary trajectory of the Platacanthomyidae based on fossil occurrences and genomic data of extant species suggested that the evolutionary trajectory of this family has remained unaffected by major climatic oscillation and lead to a hypothesis of its origin in Central Asia.
  • Long-Fei Fu, Chi Xiong, Jian He, Feng Chen, Zi-Bing Xin, Fang Wen, Xin-Yun Lv, Yi-Gang Wei, Alexandre K. Monro
    J Syst Evol. 2025, 63(6): 1327-1343.
    https://doi.org/10.1111/jse.13199
    Apomixis can confer fertility upon spontaneous hybrids and allopolyploids, both of which have played a pivotal role in the evolutionary trajectory and diversification of flowering plants. We hypothesized that an unusual morphotype of Elatostema represents a viable hybrid species between E. scabrum and E. hirticaule, as opposed to a sterile F1 hybrid. To test this, we employed phylogenomic, flow cytometry (FC), cytological, and morphological analyses. A two-step phylogenomic approach was used. Genome skimming was performed on one E. longpingii population, three populations of each parent (E. scabrum, E. hirticaule), and ten Elatostema and one Pilea species. Population genetic analyses were then conducted using RAD sequencing data from the type population of hybrid and parent species. Phylogenomic analyses using genome skimming and RAD sequencing data consistently supported a hybrid origin, placing E. longpingii close to or nested within E. scabrum and distant from E. hirticaule. Chromosome counts revealed pentaploid, triploid, and tetraploid ploidy levels in E. longpingii, E. scabrum, and E. hirticaule, respectively. FC suggested apomixis in E. longpingii and E. scabrum, while E. hirticaule exhibited sexual reproduction. Morphological studies indicated that E. longpingii shares traits from both parents. Our findings demonstrate a novel reproductively viable hybrid species in Elatostema, likely originated through a natural hybridization event involving heteroploidy, coupled with the inheritance of an apomictic reproductive pathway from its maternal parent. These results provide compelling evidence that hybridization and apomixis have played pivotal roles in driving reticulate evolution and promoting diversification within the Elatostema.
    Elatostema longpingii, hypothesized to be a heteroploid hybrid between E. scabrum and E. hirticaule, was investigated using phylogenomic, flow cytometric, cytological, and morphological analyses. Results confirmed its hybrid origin, with E. longpingii inheriting apomixis from its maternal parent, E. scabrum. This provides a case how hybridization and apomixis contribute to diversification in Elatostema.
  • Ying Wang, Xiuxiu Zhu, Kaibin Wang, Jiayue Zhou, Zechen Tang, Siying Fu, Chenguang Zheng, Wenjun Bu
    J Syst Evol. 2025, 63(6): 1312-1326.
    https://doi.org/10.1111/jse.13197
    East Asia has been hypothesized to be separated into distinct northern and southern regions by a climatic barrier, which is an east–west-oriented arid zone at approximately 40° N in eastern China. However, the impacts of climate change and local environmental selection on widespread species in this area are still poorly understood. In this study, we generated extensive genomic data for the crop pest Aelia fieberi (Hemiptera: Pentatomidae), which was sampled across its entire distribution in China, and we used these data in combination with niche analyses to investigate its phylogeographic pattern and examine the impact of climate change on its population structure and demographic history. We found that A. fieberi comprised two genetic lineages (southern and northern) that diverged during the middle Pleistocene, leading to a distinct “south–north” genetic pattern; this divergence was probably triggered by Pleistocene climate change in the arid belt. The two lineages of A. fieberi both experienced population expansion after the Last Interglacial (LIG) until the Last Glacial Maximum (LGM) and experienced secondary contact in the late Pleistocene. Local environmental adaptation may play an important role in maintaining and/or reinforcing the south–north divergence. Our study provides a detailed example of how climatic barriers and local environmental selection collaborate to facilitate adaptation to heterogeneous landscapes in East Asia from a phylogeographic perspective.
    Integrating mitochondrial fragments, nuclear SNPs, whole genome data sets, and geographic distribution elucidated the phylogeographical pattern of Aelia fieberi. Population structure analyses revealed that A. fieberi comprises distinct southern and northern genetic lineages, possibly related to middle Pleistocene climate change in the arid belt and maintained by local environmental adaptation.
  • Jianyu Chen, Yunshan Yang, Bo Liu, Weihang Wang, Daochuan Zhang, Ming Bai, Xinjiang Li
    J Syst Evol. 2025, 63(6): 1481-1500.
    https://doi.org/10.1111/jse.13196
    Grylloblattids are an ancient insect lineage crucial for understanding insect evolution and phylogeny. Systematic and in-depth studies of this taxon are still needed. This investigation advances grylloblattid systematics through three principal contributions: taxonomic revision of extant Grylloblattidae with redesigned diagnostic keys; description of a new species Grylloblattella aletaiensis sp. nov.; and geometric morphometrics analyses to quantify interspecific differentiation in the first tergum morphology across all genera of extant Grylloblattidae. We further sequenced and assembled the first complete mitochondrial genome (16 625 bp) from an Asian-lineage grylloblattid, revealing conserved gene arrangement and structural conservation shared with polyneopteran lineages. Phylogenetic delineation of basal lineages within Grylloblattidae was conducted using concatenated mitochondrial and nuclear loci, coupled with divergence time estimation analyses to reconstruct historical biogeographic dynamics. This multidisciplinary operational framework synthesizes molecular phylogenetics and temporal biogeography, establishing a robust empirical foundation for interdisciplinary research in paleoentomology, evolutionary developmental biology, and evidence-based conservation prioritization for relict insect lineages. The evolutionary history of grylloblattids is closely coupled with global geo-climate changes since the Mesozoic Era, serving as a model system for investigating the macroevolution of insects.
    Review of the extant Grylloblattidae species and description of a new species, Grylloblattella aletaiensis sp. nov., with the biology of Grylloblattella, along with geometric morphometrics and phylogenetic analysis clarified the genetic relationships among the genera of extant Grylloblattidae.