Ultraconserved Elements Research Articles

Mystery on the Bounty: The family-level status of Pacificana cockayni Hogg, 1904 (Araneae)

The family-level placement of the species Pacificana cockayni Hogg, 1904 (Araneae, Miturgidae) has been ambiguous for over a century, with the monotypic genus initially placed in Agelenidae, later transferred to Amaurobioidinae (Anyphaenidae), and presently in Miturgidae. A recent work describing the male and molecular data consisting of a single mitochondrial gene, cytochrome c oxidase subunit I, confirmed that the species is part of the marronoid clade; however, these data did not result in conclusive family-level placement. Here, we use low-coverage whole genome sequencing (lcWGS) combined with data from the Sequence Read Archive to infer a phylogeny from ultraconserved elements (UCEs) and six legacy Sanger loci. Indications of potential family placements from prior work and the topologies from this study support a transfer of Pacificana Hogg, 1904 to Cycloctenidae Simon, 1898 (new family placement).

Phylogenetic conflict between species tree and mitochondrial gene trees in Murininae (Mammalia, Chiroptera) and validation of the genus Harpiola

AbstractThe subfamily Murininae is renowned for its inherent taxonomic challenges associated with sampling difficulties and morphological similarities. At present, three genera are acknowledged within the subfamily; however, their phylogenetic interrelations and systematic classification remain debated. In this study, the separation of Harpiola at the genus level was robustly supported by our phylogenomic analyses based on the mitochondrial genome, coding sequences (CDSs) and ultraconserved elements (UCEs) from 12 individuals covering all three genera of Murininae. Notably, a distinctive mito‐nuclear discordance emerged, with the nuclear genealogy ((Harpiocephalus, Harpiola), Murina) contrasting with the mitochondrial genealogy (Harpiocephalus, (Harpiola, Murina)). The integration of these findings with inferences of demographic history reveals that dramatic environmental changes during the Pleistocene glacial and inter‐glacial cycles have shaped the current distribution of Murininae. Moreover, the detection of extensive gene flow between ancient lineages of Harpiola and Murina suggests that an ancestral ‘ghost’ Murina lineage may have contributed its mitochondrial DNA, along with a limited portion of nuclear DNA, to Harpiola in a bygone hybridization zone. In addition to molecular analyses, we employed traditional and geometric morphometric analyses of skulls to differentiate the three genera. Harpiocephalus is readily distinguishable, but Harpiola and certain species of Murina exhibit overlapping characteristics both morphometrically and geometrically which may be the outcome of ancient introgression events. This finding highlights the importance of fine‐scale morphological distinctions within the latter genera, which may be the outcome of ancient introgression events.

Profound Non-Randomness in Dinucleotide Arrangements within Ultra-Conserved Non-Coding Elements and the Human Genome.

Profound Non-Randomness in Dinucleotide Arrangements within Ultra-Conserved Non-Coding Elements and the Human Genome.

Molecular phylogenetics of nursery web spiders (Araneae: Pisauridae)

Pisauridae Simon, 1890, or nursery web spiders, are a large family with a worldwide distribution and very diverse life history strategies. Despite being named for their nursery webs, similar structures are built by some members of Ctenidae, Trechaleidae, and Oxyopidae. Pisauridae has no known morphological synapomorphies that circumscribe all members of the family, and delineation of subfamilies has been a longstanding issue. In addition, several recent molecular phylogenetic studies have called into question the monophyly of Pisauridae. Here, we infer a phylogeny of Pisauridae with nine genetic markers (12S, 16S, 18S, 28S, actin, COI, histone H3, ITS2, and NADH) combined with ultraconserved elements (UCEs) to test the monophyly of the group and determine intrafamilial relationships. Our study includes a total of 81 terminals (59 of them pisaurids). Our maximum likelihood and gene coalescence analyses strongly suggest that as currently circumscribed, the family Pisauridae is not monophyletic. To circumscribe Pisauridae as a monophyletic group, based on our molecular results, we propose the restoration of the family Dolomedidae Simon, 1876 (rank resurrected) to include the genera DolomedesLatreille, 1804 and BradystichusSimon, 1884. In addition, based on morphological evidence, we also place in Dolomedidae the genera MegadolomedesDavies & Raven, 1980; Tasmomedes Raven, 2018; Mangromedes Raven, 2018; OrnodolomedesRaven & Hebron, 2018; and CaledomedesRaven & Hebron, 2018. We provide a phylogenetic delimitation of the three subfamilies of Pisauridae: Halinae, Thaumasiinae, and Pisaurinae. Ten pisaurid genera are deemed incertae sedis in terms of their placement. In light of our hypothesized molecular phylogeny, we discuss the morphological characters and putative synapomorphies of Pisauridae and propose diagnostic characters for its subfamilies and for the family Dolomedidae, along with taxonomic notes about genera not included in our study.

Ultraconserved element (UCE) phylogenomics illuminates the evolutionary history and biogeography of Dorymyrmex pyramid ants

AbstractLatitudinal diversity gradients are one of the most widely discussed patterns in global biogeography, generally in the context of high diversity in tropical regions. In contrast, ‘amphitropical’ or ‘inverse’ distributions, once thought to be unusual, are increasingly recognized as common among many hymenopteran insects. One such group is the ant genus Dorymyrmex, which specializes in arid habitats throughout the Americas. To evaluate when and how Dorymyrmex acquired its present‐day distribution, I sequenced partial genomes of 167 Dorymyrmex representing 69 species by targeting ultraconserved elements (UCEs). A matrix of 870 genetic loci was used to infer maximum likelihood and Bayesian phylogenies, estimate divergence dates and reconstruct hypothesized ancestral areas. These new analyses reveal that Dorymyrmex comprises four species groups, the D. flavescens, tener, wolffhuegeli, and pyramicus groups. The D. pyramicus group likely dispersed from South America to North America only once, via Central America. Like many Hymenoptera, this dispersal occurred before the traditional closure date of the Isthmus of Panama, corroborating and extending the results of previous studies. Finally, I discuss life history strategies of Dorymyrmex that may have contributed to the geographic and genetic radiation of the D. pyramicus group, detail significant insights into Dorymyrmex morphology and classical taxonomy with new comparative illustrations, and provide recommendations for future work.

A hairy giant among dwarves: Trichopelma grande, a distinct new species of tarantula from Cuba (Araneae: Theraphosidae)

ABSTRACT Large size, tropical climate, topographic complexity, and millions of years of isolation have turned the Greater Antillean islands into natural laboratories of evolution. Several groups have experienced explosive diversification across these islands, leading to highly diverse and endemic biotas and species experiencing unique adaptations. Here we describe a new tarantula species from the Viñales area, a biodiversity hotspot in western Cuba. Despite being a middle-sized species with large projected setae on the legs, reminiscent of those in arboreal tarantulas, phylogenomic analysis, diagnostic morphological features, and trap-door retreat building behaviour identifies it as the largest known representative of Trichopelma, and the only one with such hirsute legs. We provide mitochondrial barcoding data and a database of ultraconserved elements loci of the holotype of this species, which will help to include it in future phylogenetic studies of Theraphosidae. Given its limited distribution range, and its apparent absence in natural history collections despite its distinct appearance, this species might be scarce, positioning it as a potential conservation concern. http://www.zoobank.org/urn:lsid:zoobank.org:pub:2F9ED7A1-1345-4295-A876-6B617ABF7C75

A phylogenomic tree of wood-warblers (Aves: Parulidae): Dealing with good, bad, and ugly samples

The New World warblers (Parulidae) are a model group for ecological and evolutionary analyses. However, current phylogenetic relationships across this family are based upon few loci. Here we use ultraconserved elements (UCEs) to estimate a rigorous species-level phylogeny for the family. As is true for many groups, high-quality tissues were unavailable for some taxa. Thus, we explored methods for incorporating sequences derived from historical (toe pad) samples to expand the phylogenetic datasets. We recovered an average of 4,186 UCE loci and mitochondrial bycatch data (supplemented with published mitochondrial data) from 96% of all currently recognized species. We found that the UCE phylogeny built with alignments with less than 70% of gaps and ambiguities recovered the most robust phylogenetic relationships for this family, representing 101 species. Using this phylogeny as a topological backbone and adding ten fair quality “bad” samples effectively generated an overall well supported phylogeny, representing 108 species (∼90% of all species). Based on this tree, we then added in seven poor quality “ugly” samples and six of those were placed within their expected genera. We also explored the phylogenetic positions of the likely extinct Leucopeza semperi and the endangered Catharopeza bishopi where limited data was obtained. Overall, taxonomic placements in our UCE trees largely correspond to previously published studies with the recovery of all currently recognized genera as monophyletic except for Basileuterus which was rendered paraphyletic by B. lachrymosus. Our study provides insights in understanding the phylogenetic relationships of a model Passeriformes family and outlines effective practices for managing sparse genomic data sourced from historical museum specimens. Variable topological arrangements across datasets and analyses reflect the evolutionary complexity of this group and provide future topics for in-depth studies.

Unveiling hidden diversity: Phylogenomics of neotomine rodents and taxonomic implications for the genus Peromyscus

Neotomine rodents (Cricetidae, Neotominae) represent one of the most commonly encountered and diverse group of rodents in North America, yet phylogenetic relationships within this group remain uncertain. This subfamily is known for its rapid evolution, adding more complexity to our efforts to unravel their evolutionary history. The main debate revolves around the recognition of the genus Peromyscus as monophyletic or paraphyletic due to its relationship with other genera such as Habromys, Megadontomys, Podomys, Neotomodon, and Osgoodomys. Here, we aim to resolve phylogenetic relationships within Neotominae, to further explore their evolutionary history and taxonomic boundaries. We used target capture and high-throughput sequencing of complete mitogenomes and thousands of genome-wide ultraconserved elements loci (UCEs). Our comprehensive analyses encompassed 53 species of Neotominae spanning 12 previously described genera, along with one yet-undescribed genus. We also investigated 12 out of the 13 species groups within Peromyscus. Our analyses, including Maximum Likelihood and Bayesian Inference with both mitogemomes and UCEs, as well as the coalescent species-tree-based approach with UCEs, consistently recovered concordant and well-resolved phylogenies with high levels of nodal support. We identified seven main clades within Neotominae that could potentially be recognized at the generic level, mostly to categorize the genus Peromyscus as a monophyletic group, including one species group within “Peromyscus”. Furthermore, our divergence dating estimates place the crown age of Neotominae to be around the late Miocene at ca. 7.9 – 10.7 mya. While generic level diversification continued through the Pliocene, species level diversification predominantly occurred during the late Pliocene, extending through the Pleistocene and Holocene. These epochs have been recognized as periods with significant changes in flora and fauna, driving ecological transformations on a global scale. We hypothesized that climatic and vegetation shifts during the Neogene and Quaternary, coupled with geological events, topographical features, and the presence of biogeographical corridors played a pivotal role in the speciation and diversification of Neotominae. Recognizing the importance of generating genomic-scale data coupled with a broad taxonomic sampling, our study, for the first time, offers resolution of the relationships among the main lineages of Neotominae. We expect that the phylogeny presented here will serve as a foundational resource for future systematic and evolutionary studies. This includes facilitating a proper comprehensive taxonomic revision of the group and the formal description and naming of new genera.

Clarifying the phylogenetic placement of Eupoinae Maddison, 2015 (Araneae, Salticidae) with ultra-conserved element data.

The subfamily Eupoinae Maddison, 2015 is an enigmatic group of minute leaf-litter-dwelling jumping spiders from Southeast Asia. Although previous molecular phylogenetic studies have suggested that it is one of the basal (non-salticine) lineages within jumping spiders, its exact placement remains unclear. In this study, ultra-conserved element data were collected from major salticid lineages to investigate the phylogenetic relationships of all salticid subfamilies, with a special focus on the placement of Eupoinae. The results provide a well-supported phylogeny for jumping spider subfamilies, and suggest a sister relationship of Eupoinae with Spartaeinae Wanless, 1984, a basal lineage of jumping spiders with relatively high species diversity and morphological and behavioural diversity. With the placement of Eupoinae, we have resolved the relationships of all salticid subfamilies, supplying a robust framework for evolutionary studies of jumping spiders.

Phylogenomic insights and geographic distribution of the New World genus Amphibolips Reinhard (Hymenoptera: Cynipidae, Cynipini) using ultraconserved elements

AbstractIn recent years, new wasp species and genera of Cynipidae have been described, and their species delimitation and evolutionary relationships have been supported using molecular markers. However, few studies have included comprehensive and extensive sampling of specimens across the complete distribution of a single genus. In this study, we analysed the phylogenetic relationships of the genus Amphibolips throughout its range using ultraconserved elements (UCEs). We collected 520 adult wasps from 401 sites in various geographic locations, predominantly in Mexico, and used 78 wasps for UCE analysis. Our results demonstrate that Amphibolips forms a monophyletic clade. Amphibolips can be further subdivided into four genetically well‐differentiated clades. Each clade had morphological traits that could be collectively characterised. Species delimitation using molecular sequencing highlights the taxonomic complexity involved in separating and assigning species using exclusively morphological criteria. This approach offers an opportunity to refine current morphological taxonomic criteria or propose new criteria to establish more accurate classifications. The rich diversity of host species and geographic regions in Mexico represents a biodiversity hotspot for Amphibolips. The number of undescribed species remains high. This study facilitates the determination of appropriate boundaries for putative new Amphibolips species.

Evolutionary History and Ecology of Andrena (Foveoandrena) androfovea: A New Nearctic Mining Bee (Hymenoptera, Andrenidae) Species and Subgenus.

With about 1700 described species, the mining bee genus Andrena is a rapidly diversifying lineage and one of the most species-rich groups of bees. Recent phylogenomic advances have greatly improved our understanding of the phylogeny of the genus, yet many species still await description, subgeneric assignments that are in line with their evolutionary history, as well as study of their morphology and behavior. Here we provide a comprehensive account of a newly discovered species, Andrena androfovea n. sp. We sequence the genome of the new species and include it in the presently most comprehensive phylogenomic analysis of Andrena using ultraconserved element (UCE) sequence data, comprising 264 samples and 249 species. Given the recovered phylogenetic position of the new species, we establish a new subgenus, Foveoandrena, provide a detailed morphological description, and discuss the antiquity and historical biogeography of the lineage in light of molecular divergence time estimates. Lastly, we study and document the foraging behavior of the new species with photos and video footage, and discuss the species' unusual host plant associations with Chamaesaracha and Quincula, both Solanaceae. Being likely oligolectic on these plants, we present the first documented case of an Andrena species being narrowly associated with members of this plant family. By integrating multiple lines of documentation, our study provides a particularly detailed account of species discovery and description.

Phylogenomic and anatomical evidence for the Late Cretaceous diversification of African characiform fishes, including a new family, under the influence of the Trans-Saharan Seaway

Abstract Geological evidence supports the occurrence of an epicontinental Trans-Saharan Seaway bisecting the African continent during the Late Cretaceous to early Paleogene. The seaway formed a wide saltwater channel connecting the Neotethys with the South Atlantic, yet no previous study has investigated its impact on freshwater fish diversification. Phylogenomic data and time-calibrated trees indicate a Late Cretaceous signature for the appearance of three modern lineages of characiform fishes. Phylogenetic analyses using ultraconserved elements of 83 characiforms reveals that Alestidae, Hepsetus, and Lepidarchidae fam. nov. originated during the Santonian-Campanian of the Late Cretaceous (84–77.5 million years ago; Ma). Lepidarchidae consists of two monotypic taxa not previously recognized as sister species: the Niger tetra Arnoldichthys endemic to the lower Niger and Ogun rivers of Nigeria, and the dwarf jellybean tetra Lepidarchus from coastal rivers of Ghana, Côte d'Ivoire, Liberia, Sierra Leone, and Guinea. Microcomputed tomography scans (µCT) of 117 characiforms provide three novel morphological characters supporting Hepsetus and Lepidarchidae, four characters for monophyly of Lepidarchidae and five for a restricted Alestidae. The Santonian-Campanian divergence indicates allopatric speciation processes influenced by the Trans-Saharan Seaway, partitioning the African ichthyofauna in a west-east orientation. The timing for African characiform cladogenesis aligns with the Cenomanian fossil record and is circa 16–23 Ma younger than the earliest characiform-like fossils from Late Cretaceous outcrops of Morocco and Sudan. This study highlights the magnitude of Cretaceous transgression events shaping the freshwater biota and gaps in our understanding of the evolutionary history and paleobiogeography of ray-finned fishes across the African continent.

Biogeography confounds the signal of cospeciation in Batesian mimicry

Since the inception of the field of evolution, mimicry has yielded insights into foundational evolutionary processes, including adaptive peak shifts, speciation, and the emergence and maintenance of phenotypic polymorphisms.1,2,3 In recent years, the coevolutionary processes generating mimicry have gained increasing attention from researchers. Despite significant advances in understanding Batesian and Müllerian mimicry in Lepidopteran systems, few other mimetic systems have received similar detailed research. Here, we present a Batesian mimicry complex involving flightless, armored Pachyrhynchus weevils and their winged Doliops longhorn beetle mimics and examine their coevolutionary patterns within the Philippine archipelagos. Pachyrhynchus weevils are primarily found in the Philippines, where distinct species radiations have occurred on different islands, each with unique color patterns serving as a warning to predators. This defensive trait and mimicry between unrelated species were first described by Wallace in 1889. Notably, the distantly related longhorn beetle Doliops, despite being soft-bodied and ostensibly palatable, mimics the heavily armored, flightless Pachyrhynchus. To address mimicry in this system, we reconstructed the phylogeny of Doliops using a probe set consisting of 38,000 ultraconserved elements. Our study examines the following questions central to understanding the Pachyrhynchus-Doliops mimicry system: (1) to what extent are coevolutionary interactions conserved (i.e., lineage-constrained) and (2) are the codiversification patterns primarily driven by biotic or abiotic factors?4,5,6 To assess color mimicry and cospeciation, we examined the evolution of nanostructure-based warning colors and the effect of island biogeography on cospeciation. Our findings demonstrate the beetle's ability to repeatedly evolve multiple solutions to similar evolutionary challenges, evolving similar color patterns using different types of photonic crystals with varying degrees of order. We revealed that the observed pattern of cospeciation is driven mainly by abiotic factors from their biogeographic history. Unlike the patterns of coevolution seen between angiosperms and insect lineages,7 most ecological interactions do not persist longer than a few million years, leading to patterns of modularity rather than ecological nestedness.4,6,7.

Detectability of Varied Hybridization Scenarios Using Genome-Scale Hybrid Detection Methods

Hybridization events complicate the accurate reconstruction of phylogenies, as they lead to patterns of genetic heritability that are unexpected under traditional, bifurcating models of species trees. This phenomenon has led to the development of methods to infer these varied hybridization events, both methods that reconstruct networks directly, as well as summary methods that predict individual hybridization events from a subset of taxa. However, a lack of empirical comparisons between methods – especially those pertaining to large networks with varied hybridization scenarios – hinders their practical use. Here, we provide a comprehensive review of popular summary methods: TICR, MSCquartets, HyDe, Patterson’s D-Statistic (ABBA-BABA), D3, and Dp. TICR and MSCquartets are based on quartet concordance factors gathered from gene tree topologies and HyDe, Patterson’s D-Statistic, D3, and Dp use site pattern frequencies to identify hybridization events between sets of three taxa. We then use simulated data to address questions of method accuracy and ideal use scenarios by testing methods against complex networks which depict gene flow events that differ in depth (timing), quantity (single vs. multiple, overlapping hybridizations), and rate of gene flow (γ). We find that deeper or multiple hybridization events may introduce noise and weaken the signal of hybridization, leading to higher relative false negative rates across all methods. Despite some forms of hybridization eluding quartet-based detection methods, MSCquartets displays high precision in most scenarios. While HyDe results in high false negative rates when tested on hybridizations involving extinct or unsampled ghost lineages, HyDe is the only method able to identify the direction of hybridization, distinguishing the source parental lineages from recipient hybrid lineages. Lastly, we test the methods on a dataset of ultraconserved elements from the bee subfamily Nomiinae, finding possible hybridization events between clades which correspond to regions of poor support in the species tree estimated in a previous study.

Phylogenomic insights into the worldwide evolutionary relationships of the stingless bees (Apidae, Meliponini)

Stingless bees (tribe Meliponini) are remarkable for their characteristically large social colonies, their capacity to produce honey and other useful products, and their morphological and behavioral diversity. They have a disjunct pan-tropical distribution, primarily occurring in warm and humid environments in the Neotropical, Afrotropical, and Indo-Australasian regions. Even though phylogenetic hypotheses have been proposed for Meliponini based on morphology and molecular data, many questions are still unsolved regarding the evolutionary relationships and systematics of the tribe. In this contribution, we present a large phylogenomic dataset comprising over 2500 ultra-conserved element (UCE) loci sequenced for 153 species of Meliponini, representing all known genera of stingless bees. The genera Camargoia, Paratrigonoides, Plectoplebeia, Cleptotrigona, Ebaiotrigona, Papuatrigona, Pariotrigona, Platytrigona, and Sahulotrigona were included in molecular phylogenetic analyses for the first time. Concatenated and species-tree analyses were performed using different partitioning strategies and summary methods. We performed gene-genealogy interrogation (GGI) on several recalcitrant nodes to resolve discordances among recovered tree topologies. Results were mostly consistent among analyses, recovering three main lineages of Meliponini congruent with the biogeographic domains to which they are associated. Within major clades, discordances were found in relation to previous works. The genus Frieseomelitta was recovered as paraphyletic in relation to Trichotrigona, and the genus Lepidotrigona was revealed to be composed of two independent lineages. Even though concatenated and weighted ASTRAL analyses were mostly effective in recovering the relationships favored by GGI, they retrieved different results in relation to the phylogenetic placements of Oxytrigona and Cephalotrigona. The most favored hypothesis in GGI analyses was not found in any other analyses, being more congruent with morphological evidence and highlighting the relevance of exploring the support given to alternative hypotheses through topological tests. Recent advances in our capacity to generate molecular sequences from old specimens using modern sequencing methods allowed for unparalleled sampling across genera, yielding a backbone for the phylogenetic relationships of stingless bees, which will further investigations into their systematics and evolution.

Revisiting evolutionary relationships of Antrodiaetus (Araneae, Mygalomorphae, Antrodiaetidae) using phylogenomics; implications for species diversity and biogeography of a persistent Holarctic lineage

Antrodiaetus is a lineage of mygalomorph spider (Mygalomorphae: Antrodiaetidae) that has persisted since the late Cretaceous and has a disjunct Holarctic distribution and strong morphological conservatism. These folding-door spiders possess a life history (i.e., limited dispersal, conserved environmental niche) that closely ties their evolution to geology. This study produces a robust, well-supported phylogenomic inference of all currently recognized Antrodiaetus species using UCEs (Ultraconserved Elements), corroborates previous biogeographical hypotheses, and proposes new hypotheses about diversification patterns. We also confirm that previously suspected cryptic diversity within A. pacificus is underestimated, as this nominal species comprises multiple divergent and cryptic lineages. Our phylogeny now serves as a foundation for understanding Antrodiaetus species relationships, biogeography, and speciation.

Tenkana, a new genus of jumping spiders (Salticidae, Plexippina) from South Asia, with the new Indian species Tenkanajayamangali.

We describe a new plexippine genus, Tenkana gen. nov., supported by phylogenomic data from ultraconserved elements (UCEs), Sanger sequences of four genes, and morphological evidence. The type species, Tenkanamanu (Caleb, Christudhas, Laltanpuii & Chitra, 2014), comb. nov. is transferred from Colopsus, as is Tenkanaarkavathi (Caleb, 2022), comb. nov. The phylogenomic data places Tenkana among the plexippines near Hyllus C.L. Koch, 1846 and Telamonia Thorell, 1887, while the constrained four-gene phylogeny indicates that Tenkana is distinct from Colopsus. Additionally, we describe a new species, Tenkanajayamangali sp. nov.

Molecular phylogenetic relationships among lineages in the genus Carabus (Coleoptera: Carabidae) and radiation of the subgenus Apotomopterus

Abstract The genus Carabus (Coleoptera: Carabidae: Carabinae) is a group of predacious ground beetles found throughout Holarctic temperate zones. The diversification of this group is attributed not only to allopatric speciation but also to diversification in life-history traits and morphological traits that are involved in ecological adaptation and reproductive isolation. Precise phylogenetic reconstruction of Carabus is important to understanding the factors associated with species’ divergence in relation to such character divergence. Here, we analyse the phylogeny of Carabus among higher taxonomic groups and among species of the subgenus Apotomopterus, a hyper-diverse group endemic to East Asia. We used genome-wide sequence data from ultraconserved elements for phylogenetic reconstruction via maximum-likelihood and species-tree reconstruction methods. With regard to the relationships among higher taxonomic groups, the obtained phylogenetic trees resolved two structures with previously unresolved divergence. The subgenus Apotomopterus contained three lineages, i.e. the Vitalisi, Prodigus, and Sauteri groups. It showed diversification of the spinula, a sclerotized male genital structure, and variation in the female elytral notch (preapical emargination). These morphological traits may be involved in copulatory behaviour and potentially affect reproductive isolation, and their character state divergence may have facilitated species divergence of Apotomopterus.

“Picking up signals” in male genital morphospace and integrating phylogenomics to delimit Neotropical Nylanderia Emery species (Hymenoptera: Formicidae)

Abstract Genital morphology, a cornerstone in taxonomy that predates Linnaeus’s Systema Naturae, is vital for species delimitation. However, the widely accepted paradigm that genitalia are taxonomically informative lacks robust testing between closely related species, and supporting evidence is often limited to taxonomic literature in which genitalia are assumed a priori to be species-specific. The cosmopolitan ant genus Nylanderia Emery includes 123 described species, with most in the Neotropics still undescribed. Workers are often morphologically cryptic, and males are rare in collections but required for morphological delimitation. Using Ultraconserved Elements (UCEs) from 236 samples, including 53 Neotropical Nylanderia species, we reconstructed a phylogenetic framework to compare the genitalia (gonopods) of males collected alongside workers. We used geometric morphometrics on images of slide-mounted genitalia from 16 species and nano-CT scans of Nylanderia fulva (Mayr) and Nylanderia pubens (Forel) genital capsules and interpreted results considering phylogeny under maximum likelihood and the multispecies coalescent. We found strong morphological and molecular support for 2 distantly related American clades, identifiable by gonopod shape, with significant differences observed among most species. Three previously reported COI clades of N. fulva were not supported as monophyletic, nor were their gonopods significantly different. However, N. pubens was supported as distinct by all phylogenetic and 3DGM results. Our findings emphasize the importance of male genitalia for delimiting species boundaries and revising Neotropical Nylanderia. Given their importance, particularly in morphologically cryptic taxa, we recommend a greater focus on linking male and worker phenotypes, which can be facilitated through comprehensive nest series collection.

Robust phylogenomics settles controversies of classification and reveals evolution of male embolic complex of the Laufeia clade (Araneae, Salticidae, Euophryini).

The Laufeia clade is a peculiar lineage of euophryine jumping spiders showing rapid divergence of male genital structures, especially the embolic complex that directly interacts with female genitalia during sperm transfer. With the rapid growth of species discovery and the perplexing morphology of male genitalia in the Laufeia clade, the controversy in its classification has become a crucial problem. In this study, we applied a phylogenomic approach using ultra-conserved elements data to infer the phylogeny of the Laufeia clade with extensive taxon sampling. A comparative morphological study was performed to evaluate diagnostic characters and understand the evolution of the male embolic complex within the Laufeia clade. The evolution of microhabitats (foliage, tree trunk, rock and surface litter) was also investigated to uncover the potential link between the microhabitat shifts and male embolic complex divergence. The results provide a strongly supported phylogenetic framework and updated generic concepts for the Laufeia clade. The synapomorphies for the updated genera within the Laufeia clade were identified through character mapping on the phylogeny. Ancestral state reconstruction analyses revealed that the Type I embolic complex (characterized by a disc-like embolic disc with a lamina as its outer edge) was ancestral and gradually evolved into the Type II (without lamina of embolic disc, base of embolic complex often modified into a functional "conductor") and Type III (lacking lamina of embolic disc and base of embolic complex) embolic complex, and that some embolic shapes evolved multiple times independently in different lineages of the Laufeia clade. The shift from foliage-dwelling to tree trunk-dwelling in the common ancestor of the Laufeia clade may have facilitated the divergent evolution of male embolic complex in the Laufeia clade. This study provides a solid foundation for future studies of systematics and evolution of this group.