Gryllidae Laicharting, 1781, the most speciose family within Grylloidea, has a rich fossil record; yet, the phylogenetic relationships among these fossil taxa remain poorly resolved. Integration of fossil and extant lineages into a systematic framework has been impeded by sexual dimorphism and the fragmentary preservation typical of compression fossils, thereby confounding homology assessment and topological stability. Here, we describe Elongatitarsus falcatus gen. & sp. nov., represented by a male and a female specimen from mid-Cretaceous Kachin amber, which serves as a morphological bridge linking Cretaceous and extant cricket diversity. To evaluate the phylogenetic signal and homoplasy of different morphological character partitions across fossil and extant Gryllidae, we conducted maximum parsimony analyses using three distinct matrices: a comprehensive morphological matrix, a wing venation-only matrix, and a matrix excluding venation-only fossils. The venation-only matrix yielded poorly resolved topologies with low nodal support; in contrast, the comprehensive morphological matrix recovered a phylogeny partially congruent with recent molecular hypotheses at the subfamilial level, and placed E. falcatus gen. & sp. nov. within Gryllinae. Our results underscore that integrative morphological data sets are essential for reliable placement of fossil taxa. This approach provides a framework for testing the reliability of isolated wings in phylogenetic inferences, offering broader implications for evaluating fragmentary fossil records in deep-time systematics.

Endosymbionts are prevalent in insects, establishing close associations with their hosts that range from mutualism to parasitism. Endosymbionts provide hosts with essential nutrients, enhance immunity, and regulate reproduction, thereby profoundly influencing host fitness and adaptive evolution. Such impacts can drive genetic divergence and even speciation over time. Consequently, endosymbionts are critical to understanding the formation of cryptic insect species, which are morphologically indistinguishable yet genetically distinct. Elucidating the mechanisms underlying cryptic speciation remains a central challenge in evolutionary biology, with endosymbionts increasingly recognized as key drivers in this process. In this review, we summarize the fundamental characteristics of insect endosymbionts and their multifaceted roles in host biology. We conceptualize endosymbionts as a critical evolutionary force, focusing on the mechanisms by which they drive cryptic speciation, including ecological adaptation divergence, genetic integration, and reproductive manipulation. By integrating current evidence and elucidating underlying mechanisms, this review presents a framework for understanding endosymbiont-mediated cryptic speciation in insects. Research in this field holds great promise for revealing fundamental evolutionary processes and informing novel strategies for biodiversity conservation and pest management.

Bulbostylis is the second-most species-rich genus in Abildgaardieae, comprising c. 221 species with a pantropical to warm-temperate distribution and a remarkable ecological and morphological diversity. Despite advances in molecular phylogenetics confirming its monophyly, relationships within Bulbostylis remain poorly resolved, and previous attempts at creating infrageneric classifications are either geographically restricted or unsupported by phylogenetic evidence. Previous molecular studies have sampled fewer than 20% of the species of the genus, limiting our understanding of its evolutionary history. Here, we investigate relationships among 149 species and 3 subspecies of Bulbostylis, representing 69% of global diversity, using a universal probe kit for targeted genomic sequencing of flowering plants (Angiosperms353 probe kit). Our sampling also includes the genus Nelmesia, which we found to fall within Bulbostylis. We propose a new infrageneric classification and suggest a set of diagnostic morphological characters. Our revised infrageneric classification for Bulbostylis includes 18 sections and 8 subsections, providing a foundation for future taxonomic and evolutionary studies of this ecologically important genus.

Opilioacarida are among the most primitive and enigmatic lineages of mites, retaining numerous plesiomorphic characters critical to understanding the early evolution of Parasitiformes. Here, we describe a new extinct family, Plesioacaridae fam. nov., from mid-Cretaceous Kachin amber, representing the second known family within Opilioacarida. The fossil specimen, here named Plesioacarus minutus gen. et sp. nov., was investigated using high-resolution confocal laser scanning microscopy, which revealed an exceptional suite of morphological features that clearly distinguish it from the extant family Opilioacaridae. These include dendritic prodorsal setae, a strongly U-shaped prodorsal furrow, a fused sternapophysis, a pair of setae posterior to the genital plate, a three-clawed palpal apotele, and a three-segmented tarsus I. The morphology of the palp apotele and tarsus I provides new insights into the evolution of appendage segmentation and specialization in early mites. To evaluate its systematic position, we conducted the morphological phylogenetic analysis for Opilioacarida based on 36 discrete characters scored across 22 extinct and extant taxa. The analyses consistently recovered Plesioacaridae as the sister group to all other opilioacarids. This discovery expands the known diversity of Mesozoic Opilioacarida and contributes important evidence for reconstructing the ancestral morphological groundplan and early evolutionary history of Parasitiformes.

A new genus and species of Marsdenieae, Xua hongheensis, native to the Red River basin of Yunnan Province, China, is described here for the first time and compared with its close relatives. The plant is a perennial, pubescent, twining herb, and is characterized by having small (ca. 1 cm diam.) flowers and fleshy, erect staminal corona lobes with concave apices, and is endemic to the dry-hot valleys of Yimen, Xinping, and Yuanjiang Counties, between 1000 and 1200 m, in Yunnan Province, China. In this study, we used plastome data to examine the tribal position of Xua within the family, and seven plastid and nuclear loci to further clarify its phylogenetic relationship. Our family-wide phylogenetic analysis confirms that Xua is a member of Marsdenieae. Our subsequent analyses of Marsdenieae further support that Xua is a distinct genus and probably allied to Dolichopetalum, Cionura, Campestigma, Harmandiella, and Gongronema-Dischidanthus-Sarcolobus. Molecular dating analysis indicates that Xua originated at about 10 Ma and Xua and the five probable allies diverged rapidly over a period shorter than 3 million years, which might be facilitated by both the orogeny and the concurrent reinforcement of the East Asian monsoon system during the early Late Miocene. For this new genus and species, a description, illustration, assessment of the conservation status, and its placement in the Marsdenieae phylogenetic tree are provided.

Marmota represents a genus of relatively large‐bodied, fossorial rodents widely distributed across grassland and alpine meadow ecosystems in the Northern Hemisphere. This study integrates paleontological data with molecular phylogenetics from extant species to reconstruct the spatiotemporal dynamics of Marmota distribution, elucidating its origins, biogeographic dispersal patterns, phylogenetic relationships, and species divergence times. Results indicate that the genus likely originated in North America, with the earliest fossil occurrences dated to ~16.3 million years ago (Mya). The radiation of extant Marmota commenced approximately 6.09 Mya, marked by elevated speciation rates during the Late Miocene and Pliocene. Throughout the late Miocene to the early Pleistocene, the extinction rate was maintained at a relatively stable level. At around 1 Mya, both the speciation rate and the extinction rate increased synchronously, leading to a slight increase in the net diversification rate. These shifts in net diversification rate showed strong correlations with global environmental transformations, particularly the expansion of grasslands since the Late Miocene and climatic oscillations associated with the Last Glacial Maximum. Within the context of contemporary anthropogenic climate warming, Marmota species face significant survival challenges, with certain taxa potentially at risk of extinction due to maladaptation to rapidly altering environments.

Mountain regions of the Northern Hemisphere harbor exceptional biodiversity, yet the processes underlying species diversification and migration among these regions remain poorly understood. This study investigates the macroevolutionary dynamics of Androsace s.l., a genus widely distributed across temperate regions of the Northern Hemisphere, with notable diversity in the Alps and the Hengduan–Himalaya regions. Although previous phylogenetic studies have advanced understanding of the evolutionary history of Androsace, its biogeographic origins and diversification history have remained unresolved due to limited species sampling and low statistical support. Here, we revisited the inter- and infrageneric taxonomic controversies. Using chloroplast genome (cpDNA) and nuclear ribosomal ITS (nrDNA) sequences from 101 species representing four related genera and seven infrageneric sections, we reconstructed the most comprehensively sampled phylogeny of Androsace to date and established a spatiotemporal framework for its biogeographic and diversification history. Phylogenetic analyses based on cpDNA revealed four well-supported clades corresponding to distinct ecological, geographic, and morphological traits. A similar four-clade structure was recovered in the ITS phylogeny, albeit with lower statistical support. Divergence time estimation and biogeographic analyses traced the origin of Androsace s.l. to the Pan-Tibetan Highlands in the early Oligocene (~33 Ma), identifying this region as the source for other mountain systems. The genus underwent asynchronous diversification across different mountain systems and clades, driven by distinct tectonic events, environmental changes, and trait innovations. These results provide a spatiotemporal framework for understanding the evolution of alpine plants in the Northern Hemisphere.

Co-flowering species in sympatry sharing a common pollinator can mitigate potential reproductive interference through a combination of ethological and mechanical barriers. However, empirical studies integrating both sex-specific foraging behavior and mechanical trait divergence within a specialized pollination system have been rarely conducted. To bridge this gap, the floral rewards, floral visitors, foraging behavior, visitation frequency, pollen-transfer efficiency, and reproductive isolation were compared between two sympatric Lysimachia species: oil-flowered L. congestiflora and nectar-bearing L. stenosepala, which share the oil-collecting bee Macropis omeiensis. Furthermore, we examined the mechanics of spatial partitioning by detecting the precise sites of pollen placement and stigma contact on the bee body for both species. In L. congestiflora, female M. omeiensis bees collected floral oil and pollen, and their pollen-transfer efficiency (pollen deposition/pollen removal) was higher than that of other bees (Halictus sp. and Lasioglossum occidens). While in L. stenosepala, both female and male M. omeiensis foraged only for nectar, acting as efficient pollinators. Pollen placement sites on the female oil bee were ventral in L. congestiflora and on the head in L. stenosepala. Male M. omeiensis bees visited the nectar-bearing flower, but not the oil flower. Female bees visited both oil-offering and nectar-bearing species; yet, differential pollen placement further reduced interspecific pollen transfer. These results suggest that mechanical isolation via spatial pollen placement on shared female bees is a key mechanism for reducing interspecific pollen transfer, while the specialized behavior of male bees provides a complementary barrier. This combination of floral reward divergence and sex-specific foraging behavior facilitates the coexistence of sympatric congeners.

Bioluminescence in lampyroid clades represented one of the most distinctive behavioral traits among insects. Although the oldest-known bioluminescent lampyroid clade has recently been reported from the Cretaceous, the diversity and phylogenetic evolutionary history of early bioluminescent lampyroid clades remained unclear. Here, we documented the diversity of early bioluminescent lampyroid clades based on exceptionally well-preserved fossil specimens and further investigated their phylogenetic evolution. Our findings in this study: (i) support multiple independent origins of bioluminescence within the lampyroid clade; (ii) present early ecological diversification in the extinct family Cretophengodidae; (iii) advance our understanding of biological adaptations in the Cretaceous lampyroid clade; and (iv) offer key insights into the evolutionary pathways underlying the origin and diversification of bioluminescence in insects.

Derris trifoliata Lour. is a common mangrove-associated legume important for coastal ecosystem stability and serves as a natural source of rotenoids. However, the lack of high-quality reference genomes has hindered the investigation of its evolutionary history and key functional traits. Here, we present a high-quality, chromosome-level genome assembly for D. trifoliata, representing the first reported genome resource for rotenoid-producing legumes. The assembled genome spans 811 Mb across 11 chromosomes, with a BUSCO completeness of 98.3% and all telomeres and centromeres identified. Evolutionary analysis revealed two rounds of whole-genome duplication event shared with Papilionoideae. The more recent event, along with lineage-specific tandem and proximal duplications, drove the expansion of genes involved in stress responses and secondary metabolism, facilitating adaptation to extreme intertidal environments. Metabolomic profiling identified four major rotenoids predominantly accumulated in roots, which likely provide effective chemical defense against the belowground stress in mangrove habitats. By integrating transcriptomic and metabolomic data, we reconstructed the rotenone biosynthesis pathway and identified candidate enzymes and transcription factors. Notably, the potential tandem expansion and functional evolution of the key biosynthesis genes 2ODDs offer clues to the evolution of specialized biosynthesis pathways. This high-quality genome, combined with multi-omics analyses, provides insight into the environmental adaptation and specialized metabolism of D. trifoliata, establishing a valuable foundation for broader evolutionary research and future biotechnological applications of rotenoid-producing legumes.

Zoogeographical divisions are shaped by species distribution patterns and ecological factors, in which regions delineate areas of faunal similarity and boundaries mark transitions in species composition. However, the zoogeographical division of China has not been assessed using shared‐species similarity among multiple basic geographic units, and the effects of given ecological factors on zoogeographical regions and their boundaries in China remain unclear. Herein, using the multivariate similarity clustering analysis method, we delineated the zoogeographical areas of China based on the distribution data of terrestrial vertebrate species. Then, we assessed the effects of ecological factors on zoogeographical subrealms, regions, and their boundaries by adopting generalized linear models and hierarchical generalized linear models. The results showed that the zoogeo-graphical patterns of China comprised two realms, three subrealms, and eight regions. Contemporary climate, past climate change, vegetation, and terrain influenced the formation of subrealms, while contemporary climate, past climate change, vegetation, terrain, and tectonic movements influenced the formation of regions. Moreover, contemporary climate, past climate change, and tectonic movements shaped intersubrealm boundaries, while contemporary temperature seasonality governed interregion boundaries. Our findings provide a comprehensive quantitative analysis of zoogeographical patterns in China, offer a useful analytical framework for research on biogeographical divisions, and provide insights into the ecological drivers of biogeographical divisions across different spatial scales and biotic groups.

We used double-digest restriction site-associated DNA sequencing (ddRADseq) to investigate the evolutionary relationships of Myosurus in California. Our phylogenetic analysis reveals a deep divergence between two major subclades, “Longipes” and “Brevipes,” so named because members of the former have scapes generally surpassing the leaves, while those of the latter have shorter scapes (or the flowers and fruiting spikes are ± sessile). Bayesian species delimitation under the multispecies coalescent consistently found 10 species in our sample. European M. minimus (represented by one sample) is placed in the “Longipes” subclade, but evidently not closely related to the Californian taxa. Also in the “Longipes” subclade, M. filiformis (based on M. minimus var. filiformis) is resolved as sister to a newly discovered lineage, M. “collinus.” Within the “Brevipes” subclade, M. apus (based on M. minimus var. apus) is evidently a rare species restricted to coastal Southern California and northwestern Baja California. Plants previously assigned to M. apus from the Central Valley and Carrizo Plain are resolved in two other newly discovered lineages: M. “vallicola” and M. “digitiformis.” Classification of the plants from Riverside County remains uncertain due to a gap in sampling. Myosurus clavicaulis, first described from southeastern Oregon, is resolved as a distinct species ranging from Northern California and more widely in the Pacific Northwest (east of the Cascade Range). A strong signal of genetic admixture was found in many of our samples, consistent with a model of predominant self-pollination and occasional hybridization as drivers of adaptive divergence.

Phoebe zhennan, an endemic species of Lauraceae in China, is an ecologically and economically important timber tree that has undergone severe population decline and is considered endangered. Despite its importance and threatened status, the absence of haplotype‐resolved genomic resources has hindered detailed genetic and evolutionary studies. Here, we report the first haplotype‐resolved chromosome‐level genome of P. zhennan using ONT ultra‐long reads and Hi‐C technology. The assemblies for Haplotype A (HapA, 956.20 Mb) and Haplotype B (HapB, 910.89 Mb) were each anchored to 12 chromosomes, with scaffold N50 values of 86.27 Mb and 77.12 Mb, respectively. A total of 33 757 and 33 651 protein‐coding genes were identified for HapA and HapB, respectively, of which 95% were functionally annotated. Comparative analyses revealed extensive structural heterozygosity, including 112 inversions, 2371 translocations, 6 059 780 single‐nucleotide polymorphisms (SNPs), 345 228 insertions, and 348 584 deletions. This haplotype‐resolved assembly further elucidates the characteristics of chromosomal structural variation and provides an important genetic resource for future studies on the evolution, conservation, and functional biology of P. zhennan.

Many bird species with broad geographic distributions show complex patterns of lineage divergence shaped by historical isolation, migration, and gene flow. The American robin, Turdus migratorius, is found throughout North America and includes seven described subspecies that differ in plumage and migratory behavior; yet, their evolutionary relationships remain uncertain. Here, we used genome‐wide SNP data, population structure analyses, phylogenomic inference, divergence time estimation, and D‐statistics to reconstruct relationships within the T. migratorius complex and evaluate patterns of lineage divergence and introgression. Our analyses consistently recovered four principal genomic lineages that do not correspond to currently recognized subspecies: (1) T. m. confinis from Baja California Sur, (2) a Mexican lineage, (3) western North America, and (4) boreal eastern North America. Time‐calibrated analyses indicate a deep late‐Miocene divergence (~8 Ma) separating T. m. confinis from all other lineages, followed by Pleistocene diversification among the remaining groups. Genome‐wide differentiation and long‐term isolation support the recognition of T. m. confinis as an independently evolving lineage consistent with species‐level status. In contrast, Turdus rufitorques, which is traditionally considered the sister species of T. migratorius, was nested within the Mexican lineage. Significant D‐statistics revealed excess allele sharing between the Mexican lineage and T. rufitorques, supporting a history of introgression. This study refines species limits within the American robin complex and highlights the importance of genome‐wide data for resolving evolutionary independence in widespread migratory birds.

DNA methylation is an essential epigenetic mark that is involved in a range of biological activities in all domains of life. Molecular mechanisms underlying how the DNA methyltransferases (DNMTs) catalyze cytosine methylation have been well documented in model species. However, it still remains underinvestigated as to how the functional divergence of different DNMT duplicates has evolved among closely related species. Here, our study addressed evolutionary dynamic, transcriptional regulation and enzyme activities of all three DNMTs (DNMT1, DNMT2, and DNMT3) in extant Poaceae species. Our results show that, although all Poaceae species are derived from the most recent common ancestor, biased genetic fractionation acting on different DNMT duplicates has resulted in high copy number variations among extant species. In addition, expression-level subfunctionalization (i.e., differential expression genes) is a common mechanism that regulates the transcriptional pattern of different DNMT duplicates in extant Poaceae species. Neo-functionalization and positive selection further promote functional divergence (i.e., different catalytic efficiency) among different DNMT duplicates. In particular, estimates of enzyme activities demonstrate that highly expressed gene copies of the DNMT1 (i.e., MET1a and MET1b) tend to show high catalytic efficiency. Furthermore, functional analyses of seven DNMT mutants also reveal that loss of function of three DNMT genes (OsCMT3a, OsCMT2, and OsDRM2) exerts complementary impacts on the transcriptional landscape. Our study provides evidence that, while DNA methylation of all three cytosine contexts (CG, CHG, and CHH) is catalyzed by the three DNMTs, different mechanisms have together promoted high evolutionary dynamic and functional divergence in extant Poaceae species.

The tribe Trichosporeae is the most species-rich, systemically complex, and morphologically diverse tribe in the Old World Gesneriaceae. It has long been a focal point and a challenge in the phylogeny of Trichosporeae, with frequent unclear relationships and delimitations among a lot of genera. Here, we conducted a molecular phylogenetic analysis by employing nine DNA fragments with a high sampling coverage for key clades in the tribe Trichosporeae. Meanwhile, we carried out a comprehensive morphological and anatomical investigation on vegetative and floral organs in related genera and species, and try to uncover morphological synapomorphies associated with molecular clades. Our results demonstrated a well-supported phylogeny of major clades in the tribe, strongly corroborated by morphological data. We find that some genera, such as Raphiocarpus, Briggsia, and Boeica, are not monophyletic. Based on molecular phylogenetic and morphological analyses, we established five new genera and revived a genus in the tribe Trichosporeae, including Neoraphiocarpus, Anisophyllaea, Hispidopalata, Pseudobriggsia, and Kaiyua with revival of Boeicopsis. We further redefined the genera Raphiocarpus and Briggsiopsis. Our results would deepen our understanding about the phylogeny of the Old World Gesneriaceae.