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.

Comparative Population Genomic Diversity and Differentiation in Trapdoor Spiders and Relatives (Araneae, Mygalomorphae).

Although patterns of population genomic variation are well-studied in animals, there remains room for studies that focus on non-model taxa with unique biologies. Here we characterise and attempt to explain such patterns in mygalomorph spiders, which are generally sedentary, often occur as spatially clustered demes and show remarkable longevity. Genome-wide single nucleotide polymorphism (SNP) data were collected for 500 individuals across a phylogenetically representative sample of taxa.

Broken Ring Speciation in California Mygalomorph Spiders (Nemesiidae, ).

AbstractIdealized ring species, with approximately continuous gene flow around a geographic barrier but singular reproductive isolation at a ring terminus, are rare in nature. A broken ring species model preserves the geographic setting and fundamental features of an idealized model but accommodates varying degrees of gene flow restriction over complex landscapes through evolutionary time. Here we examine broken ring species dynamics in spiders, which, like the classic ring species salamanders, are distributed around the Central Valley of California.

Phylogeny and biogeography of harmochirine jumping spiders (Araneae: Salticidae).

We use ultraconserved elements (UCE) and Sanger data to study the phylogeny, age, and biogeographical history of harmochirine jumping spiders, a group that includes the species-rich genus Habronattus, whose remarkable courtship has made it the focus of studies of behaviour, sexual selection, and diversification. We recovered 1947 UCE loci from 43 harmochirine taxa and 4 outgroups, yielding a core dataset of 193 UCEs with at least 50 % occupancy. Concatenated likelihood and ASTRAL analyses confirmed the separation of harmochirines into two major clades, here designated the infratribes Harmochirita and Pellenita.

Species delimitation, biogeography, and natural history of dwarf funnel web spiders (Mygalomorphae, Hexurellidae, ) from the United States / Mexico borderlands.

The rarely encountered spider genus Gertsch & Platnick, 1979 includes some of the smallest mygalomorph spiders in the world, with four poorly known taxa from central and southeastern montane Arizona, southern California, and northern Baja California Norte. At time of description the genus was known from fewer than 20 individuals, with sparse natural history information suggesting a vagrant, web-building, litter-dwelling natural history. Here the first published taxonomic and natural history information for this taxon is provided in more than 50 years, working from extensive new geographic sampling, consideration of male and female morphology, and sequence capture-based nuclear phylogenomics and mitogenomics.

New species in old mountains: integrative taxonomy reveals ten new species and extensive short-range endemism in spiders (Araneae, Nesticidae) from the southern Appalachian Mountains.

This revision is based on sampling efforts over the past three decades in the southern Appalachian Mountains which have provided (Araneae, Nesticidae) collections of approximately 2100 adult specimens from more than 475 unique collecting events. Using a "morphology first" framework we examined recently collected specimens plus museum material to formulate morphology-based species hypotheses for putative new taxa (discovery phase). Using sequence capture of nuclear ultraconserved elements (UCEs) we analyzed 801 nuclear loci to validate new (and prior) morphology-based species hypotheses (validation phase) and reconstructed a robust backbone phylogeny including all described and new species.

Phylogenomics of paleoendemic lampshade spiders (Araneae, Hypochilidae, ), with the description of a new species from montane California.

is a relictual lineage of Nearctic spiders distributed disjunctly across the United States in three montane regions (California, southern Rocky Mountains, southern Appalachia). Phylogenetic resolution of species relationships in has been challenging, and conserved morphology coupled with extreme genetic divergence has led to uncertain species limits in some complexes. Here, interspecies relationships have been reconstructed and cryptic speciation more critically evaluated using a combination of ultraconserved elements, mitochondrial CO1 by-catch, and morphology.

Using natural history to guide supervised machine learning for cryptic species delimitation with genetic data.

The diversity of biological and ecological characteristics of organisms, and the underlying genetic patterns and processes of speciation, makes the development of universally applicable genetic species delimitation methods challenging. Many approaches, like those incorporating the multispecies coalescent, sometimes delimit populations and overestimate species numbers. This issue is exacerbated in taxa with inherently high population structure due to low dispersal ability, and in cryptic species resulting from nonecological speciation.

Combining genomic, phenotypic and Sanger sequencing data to elucidate the phylogeny of the two-clawed spiders (Dionycha).

The importance of morphology in the phylogenomic era has recently gained attention, but relatively few studies have combined both types of information when inferring phylogenetic relationships. Sanger sequencing legacy data can also be important for understanding evolutionary relationships. The possibility of combining genomic, morphological and Sanger data in one analysis seems compelling, permitting a more complete sampling and yielding a comprehensive view of the evolution of a group.

Sitticine jumping spiders: phylogeny, classification, and chromosomes (Araneae, Salticidae, Sitticini).

The systematics of sitticine jumping spiders is reviewed, with a focus on the Palearctic and Nearctic regions, in order to revise their generic classification, clarify the species of one region (Canada), and study their chromosomes. A genome-wide molecular phylogeny of 23 sitticine species, using more than 700 loci from the arachnid Ultra-Conserved Element (UCE) probeset, confirms the Neotropical origins of sitticines, whose basal divergence separates the Aillutticina (a group of five Neotropical genera) from the subtribe Sitticina (five genera of Eurasia and the Americas). The phylogeny shows that most Eurasian sitticines form a relatively recent and rapid radiation, which we unite into the genus Simon, 1868, consisting of the subgenera Simon, 1901 (seven described species), (41 described species), and Prószyński, 2017 (one species).

Phylogenetic Systematics and Evolution of the Spider Infraorder Mygalomorphae Using Genomic Scale Data.

The infraorder Mygalomorphae is one of the three main lineages of spiders comprising over 3000 nominal species. This ancient group has a worldwide distribution that includes among its ranks large and charismatic taxa such as tarantulas, trapdoor spiders, and highly venomous funnel-web spiders. Based on past molecular studies using Sanger-sequencing approaches, numerous mygalomorph families (e.

Evolutionary divergences mirror Pleistocene paleodrainages in a rapidly-evolving complex of oasis-dwelling jumping spiders (Salticidae, Habronattus tarsalis).

We aimed to understand the diversification history of jumping spiders in the Habronattus tarsalis species complex, with particular emphasis on how history in this system might illuminate biogeographic patterns and processes in deserts of the western United States. Desert populations of H. tarsalis are now confined to highly discontinuous oasis-like habitats, but these habitats would have been periodically more connected during multiple pluvial periods of the Pleistocene.

A demonstration of unsupervised machine learning in species delimitation.

One major challenge to delimiting species with genetic data is successfully differentiating population structure from species-level divergence, an issue exacerbated in taxa inhabiting naturally fragmented habitats. Many fields of science are now using machine learning, and in evolutionary biology supervised machine learning has recently been used to infer species boundaries. These supervised methods require training data with associated labels.

Phylogenomic analysis and revised classification of atypoid mygalomorph spiders (Araneae, Mygalomorphae), with notes on arachnid ultraconserved element loci.

The atypoid mygalomorphs include spiders from three described families that build a diverse array of entrance web constructs, including funnel-and-sheet webs, purse webs, trapdoors, turrets and silken collars. Molecular phylogenetic analyses have generally supported the monophyly of Atypoidea, but prior studies have not sampled all relevant taxa. Here we generated a dataset of ultraconserved element loci for all described atypoid genera, including taxa ( and key to understanding familial monophyly, divergence times, and patterns of entrance web evolution.

Sequence capture phylogenomics of eyeless spiders from Texas caves, with emphasis on US federally-endangered species from Bexar County (Araneae, Hahniidae).

Morphological, mitochondrial, and nuclear phylogenomic data were combined to address phylogenetic and species delimitation questions in cave-limited spiders from central Texas. Special effort was focused on specimens and cave locations in the San Antonio region (Bexar County), home to four eyeless species listed as US Federally Endangered. Sequence capture experiments resulted in the recovery of ~200-400 homologous ultra-conserved element (UCE) nuclear loci across taxa, and nearly complete COI mitochondrial DNA sequences from the same set of individuals.

A stable phylogenomic classification of Travunioidea (Arachnida, Opiliones, Laniatores) based on sequence capture of ultraconserved elements.

Molecular phylogenetics has transitioned into the phylogenomic era, with data derived from next-generation sequencing technologies allowing unprecedented phylogenetic resolution in all animal groups, including understudied invertebrate taxa. Within the most diverse harvestmen suborder, Laniatores, most relationships at all taxonomic levels have yet to be explored from a phylogenomics perspective. Travunioidea is an early-diverging lineage of laniatorean harvestmen with a Laurasian distribution, with species distributed in eastern Asia, eastern and western North America, and south-central Europe.

Phylogenomic reclassification of the world's most venomous spiders (Mygalomorphae, Atracinae), with implications for venom evolution.

Here we show that the most venomous spiders in the world are phylogenetically misplaced. Australian atracine spiders (family Hexathelidae), including the notorious Sydney funnel-web spider Atrax robustus, produce venom peptides that can kill people. Intriguingly, eastern Australian mouse spiders (family Actinopodidae) are also medically dangerous, possessing venom peptides strikingly similar to Atrax hexatoxins.

Population genomics and geographical parthenogenesis in Japanese harvestmen (Opiliones, Sclerosomatidae, ).

Naturally occurring population variation in reproductive mode presents an opportunity for researchers to test hypotheses regarding the evolution of sex. Asexual reproduction frequently assumes a geographical pattern, in which parthenogenesis-dominated populations are more broadly dispersed than their sexual conspecifics. We evaluate the geographical distribution of genomic signatures associated with parthenogenesis using nuclear and mitochondrial DNA sequence data from two Japanese harvestman sister taxa, and .

The spider tree of life: phylogeny of Araneae based on target-gene analyses from an extensive taxon sampling.

We present a phylogenetic analysis of spiders using a dataset of 932 spider species, representing 115 families (only the family Synaphridae is unrepresented), 700 known genera, and additional representatives of 26 unidentified or undescribed genera. Eleven genera of the orders Amblypygi, Palpigradi, Schizomida and Uropygi are included as outgroups. The dataset includes six markers from the mitochondrial (12S, 16S, COI) and nuclear (histone H3, 18S, 28S) genomes, and was analysed by multiple methods, including constrained analyses using a highly supported backbone tree from transcriptomic data.

Cryptic elevational zonation in trapdoor spiders (Araneae, Antrodiaetidae, Aliatypus janus complex) from the California southern Sierra Nevada.

The relative roles of ecological niche conservatism versus niche divergence in promoting montane speciation remains an important topic in biogeography. Here, our aim was to test whether lineage diversification in a species complex of trapdoor spiders corresponds with riverine barriers or with an ecological gradient associated with elevational tiering. Aliatypus janus was sampled from throughout its range, with emphasis on populations in the southern Sierra Nevada Mountains of California.

Comparative transcriptomics of Entelegyne spiders (Araneae, Entelegynae), with emphasis on molecular evolution of orphan genes.

Next-generation sequencing technology is rapidly transforming the landscape of evolutionary biology, and has become a cost-effective and efficient means of collecting exome information for non-model organisms. Due to their taxonomic diversity, production of interesting venom and silk proteins, and the relative scarcity of existing genomic resources, spiders in particular are excellent targets for next-generation sequencing (NGS) methods. In this study, the transcriptomes of six entelegyne spider species from three genera (Cicurina travisae, C.

High phylogenetic utility of an ultraconserved element probe set designed for Arachnida.

Arachnida is an ancient, diverse and ecologically important animal group that contains a number of species of interest for medical, agricultural and engineering applications. Despite their importance, many aspects of the arachnid tree of life remain unresolved, hindering comparative approaches to arachnid biology. Biologists have made considerable efforts to resolve the arachnid phylogeny; yet, limited and challenging morphological characters, as well as a dearth of genetic resources, have hindered progress.

Population genomic evidence for multiple Pliocene refugia in a montane-restricted harvestman (Arachnida, Opiliones, Sclerobunus robustus) from the southwestern United States.

The integration of ecological niche modelling into phylogeographic analyses has allowed for the identification and testing of potential refugia under a hypothesis-based framework, where the expected patterns of higher genetic diversity in refugial populations and evidence of range expansion of nonrefugial populations are corroborated with empirical data. In this study, we focus on a montane-restricted cryophilic harvestman, Sclerobunus robustus, distributed throughout the heterogeneous Southern Rocky Mountains and Intermontane Plateau of southwestern North America. We identified hypothetical refugia using ecological niche models (ENMs) across three time periods, corroborated these refugia with population genetic methods using double-digest RAD-seq data and conducted population-level phylogenetic and divergence dating analyses.

Comparative performance of double-digest RAD sequencing across divergent arachnid lineages.

Next-generation sequencing technologies now allow researchers of non-model systems to perform genome-based studies without the requirement of a (often unavailable) closely related genomic reference. We evaluated the role of restriction endonuclease (RE) selection in double-digest restriction-site-associated DNA sequencing (ddRADseq) by generating reduced representation genome-wide data using four different RE combinations. Our expectation was that RE selections targeting longer, more complex restriction sites would recover fewer loci than RE with shorter, less complex sites.