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At least 37 records · Page 2Linked to original sources
USGS2024

How long have we been mistaken? Multi-tools shedding light into the systematics of the widespread deep-water genus Madrepora Linnaeus, 1758 (Scleractinia)

Deep-water coral reefs are found worldwide and harbor biodiversity levels that are comparable to their shallow-water counterparts. However, the genetic diversity and population structure of deep-water species remain poorly explored, and historical taxonomical issues still need to be resolved. Here we used microsatellite markers as well as ultraconserved elements (UCE) and exons to shed light on the population structure, genetic diversity, and phylogenetic position of the genus Madrepora , which contains M. oculata , one of the most widespread scleractinian species. Population structure of 107 samples from three Southwestern Atlantic sedimentary basins revealed the occurrence of a cryptic species, herein named M. piresae sp. nov. (authored by Kitahara, Capel and Zilberberg), which can be found in sympatry with M. oculata . Phylogeny reconstructions based on 134 UCEs and exon regions corroborated the population genetic data, with the recovery of two well-supported groups, and reinforced the polyphyly of the family Oculinidae. In order to better accommodate the genus Madrepora , while reducing taxonomical confusion associated with the name Madreporidae, we propose the monogeneric family Bathyporidae fam. nov. (authored by Kitahara, Capel, Zilberberg and Cairns). Our findings advance the knowledge on the widespread deep-water genus Madrepora , resolve a long-standing question regarding the phylogenetic position of the genus , and highlight the need of a worldwide review of the genus.

Molecular Phylogenetics and Evolution↗
USGS2024

Integrative phylogenetic, phylogeographic and morphological characterisation of the Unio crassus species complex reveals cryptic diversity with important conservation implications

The global decline of freshwater mussels and their crucial ecological services highlight the need to understand their phylogeny, phylogeography and patterns of genetic diversity to guide conservation efforts. Such knowledge is urgently needed for Unio crassus , a highly imperilled species originally widespread throughout Europe and southwest Asia. Recent studies have resurrected several species from synonymy based on mitochondrial data, revealing U. crassus to be a complex of cryptic species. To address long-standing taxonomic uncertainties hindering effective conservation, we integrate morphometric, phylogenetic, and phylogeographic analyses to examine species diversity within the U. crassus complex across its entire range. Phylogenetic analyses were performed using cytochrome c oxidase subunit I (815 specimens from 182 populations) and, for selected specimens, whole mitogenome sequences and Anchored Hybrid Enrichment (AHE) data on ∼600 nuclear loci. Mito-nuclear discordance was detected, consistent with mitochondrial DNA gene flow between some species during the Pliocene and Pleistocene. Fossil-calibrated phylogenies based on AHE data support a Mediterranean origin for the U. crassus complex in the Early Miocene. The results of our integrative approach support 12 species in the group: the previously recognised Unio bruguierianus , Unio carneus, Unio crassus , Unio damascensis , Unio ionicus , Unio sesirmensis , and Unio tumidiformis , and the reinstatement of five nominal taxa: Unio desectus stat. rev. , Unio gontierii stat. rev. , Unio mardinensis stat. rev. , Unio nanus stat. rev. , and Unio vicarius stat. rev. Morphometric analyses of shell contours reveal important morphospace overlaps among these species, highlighting cryptic, but geographically structured, diversity. The distribution, taxonomy, phylogeography, and conservation of each species are succinctly described.

Molecular Phylogenetics and Evolution↗
USGS2025

Desert ecosystems shape diversification in glossy snakes (genus Arizona) requiring a re-alignment of evolutionary and conservation units

Subspecies are often targets for conservation, yet many lack the genetic data necessary to validate their status as distinctive evolutionary lineages. In 2016, conservationists faced this issue when designating the California glossy snake, Arizona elegans occidentalis , as a Species of Special Concern in California, a decision prompted by population declines and habitat loss but absent of genetic information about its evolutionary integrity. To address this knowledge gap, we collected genomic and mitochondrial data from a rangewide sample of the Arizona elegans complex ( n = 257) and characterized genetic structure at varying spatial scales. We confirmed an east–west phyletic division within the A. elegans complex that correlates with an ecotone between the Sonoran and Chihuahuan Deserts and pinpoint the separation to a ∼20 km area in southeastern Arizona, USA. Individuals recognized as A. e. occidentalis do not form a genetically cohesive unit within a more inclusive western clade that is sister to the endemic Arizona pacata in Baja California, México. We synonymize four subspecies circumscribed by the western clade and recognize a new species Arizona occidentalis to re-align the taxonomy with the phylogeographic structure. Most of the diversity within A. occidentalis occurs in California, with three major lineages corresponding separate desert biomes. We revise the conservation units within A. occidentalis to mirror these lineages and address concerns regarding habitat loss in transitional environments along the western edge of its range. This work underscores the importance of aligning taxonomy, evolutionary identity, and management units to design the most effective conservation strategies.

Molecular Phylogenetics and Evolution↗
USGS2003

Phylogeny of the owlet-nightjars (Aves: Aegothelidae) based on mitochondrial DNA sequence

The avian family Aegothelidae (Owlet-nightjars) comprises nine extant species and one extinct species, all of which are currently classified in a single genus, Aegotheles. Owlet-nightjars are secretive nocturnal birds of the South Pacific. They are relatively poorly studied and some species are known from only a few specimens. Furthermore, their confusing morphological variation has made it difficult to cluster existing specimens unambiguously into hierarchical taxonomic units. Here we sample all extant owlet-nightjar species and all but three currently recognized subspecies. We use DNA extracted primarily from museum specimens to obtain mitochondrial gene sequences and construct a molecular phylogeny. Our phylogeny suggests that most species are reciprocally monophyletic, however A. albertisi appears paraphyletic. Our data also suggest splitting A. bennettii into two species and splitting A. insignis and A. tatei as suggested in another recent paper. ?? 2003 Elsevier Science (USA). All rights reserved.

Molecular Phylogenetics and Evolution↗
USGS2009

Paraphyly of Cinclodes fuscus (Aves: Passeriformes: Furnariidae): Implications for taxonomy and biogeography

The Andes are a hotspot of global avian diversity, but studies on the historical diversification of Andean birds remain relatively scarce. Evolutionary studies on avian lineages with Andean–Patagonian distributions have focused on reconstructing species-level phylogenies, whereas no detailed phylogeographic studies on widespread species have been conducted. Here, we describe phylogeographic patterns in the Bar-winged Cinclodes ( Cinclodes fuscus ), a widespread and common species of ovenbird (Furnariidae) that breeds from Tierra del Fuego to the northern Andes. Traditionally, C. fuscus has been considered a single species composed of nine subspecies, but its long and narrow range suggests the possibility of considerable genetic variation among populations. Sequences of two mitochondrial genes revealed three discrete and geographically coherent groups of C. fuscus , occupying the southern, central, and northern Andes. Surprisingly, phylogenetic analyses indicated that these groups were more closely related to other species of Cinclodes than to each other. Relationships of the southern and northern C. fuscus clades to other species of Cinclodes were straightforward; in combination with available information on plumage, behavioral, and vocal variation, this suggests that each should be recognized as a distinct biological species. The central Andean group was paraphyletic with respect to C. oustaleti , and relationships among these taxa and C. olrogi were poorly resolved. We suggest that the central Andean C. fuscus should also be considered a different species, pending new information to clarify species limits in this group. These new phylogenetic data, along with recently developed methods, allowed us to review the biogeography of the genus, confirming southern South America and the central Andes as important areas for the diversification of these birds.

Molecular Phylogenetics and Evolution↗
USGS2019

Relative abundance and molecular evolution of Lake Sinai Virus (Sinaivirus) clades

Lake Sinai Viruses (Sinaivirus) are commonly detected in honey bees ( Apis mellifera ) but no disease phenotypes or fitness consequences have yet been demonstrated. This viral group is genetically diverse, lacks obvious geographic structure, and multiple lineages can co-infect individual bees. While phylogenetic analyses have been performed, the molecular evolution of LSV has not been studied extensively. Here, I use LSV isolates from GenBank as well as contigs assembled from honey bee Sequence Read Archive (SRA) accessions to better understand the evolutionary history of these viruses. For each ORF, substitution rate variation, codon usage, and tests of positive selection were evaluated. Outlier regions of high or low diversity were sought with sliding window analysis and the role of recombination in creating LSV diversity was explored. Phylogenetic analysis consistently identified two large clusters of sequences that correspond to the current LSV1 and LSV2 nomenclature, however lineages sister to LSV1 were the most frequently detected in honey bee SRA accessions. Different expression levels among ORFs suggested the occurrence of subgenomic transcripts. ORF1 and RNA-dependent RNA polymerase had higher evolutionary rates than the capsid and ORF4. A hypervariable region of the ORF1 protein-coding sequence was identified that had reduced selective constraint, but a site-based model of positive selection was not significantly more likely than a neutral model for any ORF. The only significant recombination signals detected between LSV1 and LSV2 initiated within this hypervariable region, but assumptions of the test (single-frame coding and independence of substitution rate by site) were violated. LSV codon usage differed strikingly from that of honey bees and other common honey-bee viruses, suggesting LSV is not strongly co-evolved with that host. LSV codon usage was significantly correlated with that of Varroa destructor , however, despite the relatively weak codon bias exhibited by the latter. While codon usage between the LSV1 and LSV2 clusters was similar for three ORFs, ORF4 codon usage was uncorrelated between these clades, implying rapid divergence of codon use for this ORF only. Phylogenetic placement and relative abundance of LSV isolates reconstructed from SRA accessions suggest that detection biases may be over-representing LSV1 and LSV2 in public databases relative to their sister lineages.

PeerJ↗
USGS2023

Coevolution with host fishes shapes parasitic life histories in a group of freshwater mussels (Unionidae: Quadrulini)

Ecological interactions among species often lead to parasitic lineages coevolving with host resources, which is often suggested as the primary driver of parasite diversification. Freshwater mussels are bivalves that possess a parasitic life cycle requiring larval encystment on freshwater vertebrates to complete metamorphosis. The North American freshwater mussel tribe Quadrulini has a suite of life history adaptations including highly specialized patterns of host use, infection strategies, and variable larval morphologies. However, the evolution of life histories has yet to be explored using phylogenetic comparative methods. In this study, we use a holistic approach incorporating biogeographical, ecological, molecular, and morphological datasets to reconstruct the evolution of Quadrulini. Comparative phylogenetic analyses suggested the diversification of Quadrulini has been driven, at least in part, by codiversification with their primary host fishes in Ictaluridae. Major diversification events in both ictalurids and quadrulines were estimated to have occurred in the Mississippi River basin throughout the Miocene. Life history characteristics associated with parasitism were supported to have coevolved with host repertories, supporting the hypothesis that ecological interactions with host fishes have shaped the evolution of highly specialized traits in this group. Our findings demonstrate the importance of ecological interactions with host resources in shaping the evolutionary history of freshwater mussels.

Bulletin of the Society of Systematic Biologists↗
USGS2023

Data mining reveals tissue-specific expression and host lineage-associated forms of Apis mellifera filamentous virus

Apis mellifera filamentous virus (AmFV) is a large double-stranded DNA virus of uncertain phylogenetic position that infects honey bees ( Apis mellifera ). Little is known about AmFV evolution or molecular aspects of infection. Accurate annotation of open-reading frames (ORFs) is challenged by weak homology to other known viruses. This study was undertaken to evaluate ORFs (including coding-frame conservation, codon bias, and purifying selection), quantify genetic variation within AmFV, identify host characteristics that covary with infection rate, and examine viral expression patterns in different tissues.

PeerJ↗
USGS1999

Data set incongruence and correlated character evolution: An example of functional convergence in the hind-limbs of stifftail diving ducks

The unwitting inclusion of convergent characters in phylogenetic estimates poses a serious problem for efforts to recover phylogeny. Convergence is not inscrutable, however, particularly when one group of characters tracks phylogeny and another set tracks adaptive history. In such cases, convergent characters may be correlated with one or a few functional anatomical units and readily identifiable by using comparative methods. Stifftail ducks (Oxyurinae) offer one such opportunity to study correlated character evolution and function in the context of phylogenetic reconstruction. Morphological analyses place stifftail ducks as part of a large clade of diving ducks that includes the sea ducks (Mergini), Hymenolaimus, Merganetta , and Tachyeres , and possibly the pochards (Aythyini). Molecular analyses, on the other hand, place stifftails far from other diving ducks and suggest, moreover, that stifftails are polyphyletic. Mitochondrial cytochrome b gene sequences of eight stifftail species traditionally supposed to form a clade were compared with each other and with sequences from 50 other anseriform and galliform species. Stifftail ducks are not the sister group of sea ducks but lie outside the typical ducks (Anatinae). Of the four traditional stifftail genera, monophyly of Oxyura and its sister group relationship with Nomonyx are strongly supported. Heteronetta probably is the sister group of that clade, but support is weak. Biziura is not a true stifftail. Within Oxyura , Old World species ( O. australis, O. leucocephala, O. maccoa ) appear to form a clade, with New World species ( O. jamaicensis, O. vittata ) branching basally. Incongruence between molecules and morphology is interpreted to be the result of adaptive specialization and functional convergence in the hind limbs of Biziura and true stifftails. When morphological characters are divided into classes, only hind-limb characters are significantly in conflict with the molecular tree. Likewise, null models of synonymous and nonsynonymous substitution based on patterns of codon-degeneracy and chemical dissimilarity indicate that the nucleotide and amino acid changes postulated by the molecular tree are more plausible than those postulated by the morphological tree. These findings teach general lessons about the utility of highly adaptive characters (in particular those related to foraging ecology) and underscore the problems that convergence can pose for attempts to recover phylogeny. They also demonstrate how the concept of natural data partitions and simple models of evolution (e.g., parsimony, likelihood, neutrality) can be used to test the accuracy of independent phylogenetic estimates and provide arguments in favor of one tree topology over another.

Systematic Biology↗
USGS2004

Chromosome numbers and karyotype evolution in holoparasitic Orobanche (Orobanchaceae) and related genera

Chromosome numbers and karyotypes of species of Orobanche , Cistanche , and Diphelypaea (Orobanchaceae) were investigated, and 108 chromosome counts of 53 taxa, 19 counted for the first time, are presented with a thorough compilation of previously published data. Additionally, karyotypes of representatives of these genera, including Orobanche sects. Orobanche and Trionychon , are reported. Cistanche ( x = 20) has large meta- to submetacentric chromosomes, while those of Diphelypaea ( x = 19) are medium-sized submeta- to acrocentrics. Within three analyzed sections of Orobanche , sects. Myzorrhiza ( x = 24) and Trionychon ( x = 12) possess medium-sized submeta- to acrocentrics, while sect. Orobanche ( x = 19) has small, mostly meta- to submetacentric, chromosomes. Polyploidy is unevenly distributed in Orobanche and restricted to a few lineages, e.g., O . sect. Myzorrhiza or Orobanche gracilis and its relatives (sect. Orobanche ). The distribution of basic chromosome numbers supports the groups found by molecular phylogenetic analyses: Cistanche has x = 20, the Orobanche -group ( Orobanche sect. Orobanche , Diphelypaea ) has x = 19, and the Phelipanche -group ( Orobanche sects. Gymnocaulis , Myzorrhiza , Trionychon ) has x = 12, 24. A model of chromosome number evolution in Orobanche and related genera is presented: from two ancestral base numbers, x h = 5 and x h = 6, independent polyploidizations led to x = 20 ( Cistanche ) and (after dysploidization) x = 19 ( Orobanche -group) and to x = 12 and x = 24 ( Phelipanche -group), respectively.

American Journal of Botany↗
USGS2006

Phylogeny and evolutionary history of old world suboscine birds (aves: Eurylaimides)

Molecular and morphological data were used to derive a phylogenetic hypothesis for the Eurylaimides, an Old World bird group now known to be distributed pantropically, and to investigate the evolution and biogeography of the group. Phylogenetic results indicated that the Eurylaimides consist of two monophyletic groups, the pittas (Pittidae) and the broadbills (Eurylaimidae sensu lato), and that the broadbills consist of two highly divergent clades, one containing the sister genera Smithornis and Calyptomena , the other containing Pseudocalyptomena graueri , Sapayoa aenigma , the asity genera Philepitta and Neodrepanis , and five Asian genera. Our results indicate that over a ~10 million year time span in the early Tertiary, the Eurylaimides came to inhabit widely disjunct tropical regions and evolved disparate morphology, diet, and breeding behavior. Biogeographically, although a southern origin for the lineage is likely, time estimates for major lineage splitting do not correspond to Gondwanan vicariance events, and the biogeographic history of the crown clade is better explained by Laurasian climatic and geological processes. In particular, the timing and phylogenetic pattern suggest a likely Laurasian origin for the sole New World representative of the group, Sapayoa aenigma .

American Museum Novitates↗
USGS2000

Microsatellites: Evolutionary and methodological background and empirical applications at individual, population, and phylogenetic levels

The recent proliferation and greater accessibility of molecular genetic markers has led to a growing appreciation of the ecological and evolutionary inferences that can be drawn from molecular characterizations of individuals and populations (Burke et al. 1992, Avise 1994). Different techniques have the ability to target DNA sequences which have different patterns of inheritance, different modes and rates of evolution and, concomitantly, different levels of variation. In the quest for 'the right marker for the right job', microsatellites have been widely embraced as the marker of choice for many empirical genetic studies. The proliferation of microsatellite loci for various species and the voluminous literature compiled in very few years associated with their evolution and use in various research applications, exemplifies their growing importance as a research tool in the biological sciences. The ability to define allelic states based on variation at the nucleotide level has afforded unparalleled opportunities to document the actual mutational process and rates of evolution at individual microsatellite loci. The scrutiny to which these loci have been subjected has resulted in data that raise issues pertaining to assumptions formerly stated, but largely untestable for other marker classes. Indeed this is an active arena for theoretical and empirical work. Given the extensive and ever-increasing literature on various statistical methodologies and cautionary notes regarding the uses of microsatellites, some consideration should be given to the unique characteristics of these loci when determining how and under what conditions they can be employed.

Book chapter↗
USGS2016

Fluid spatial dynamics of West Nile virus in the USA: Rapid spread in a permissive host environment

The introduction of West Nile virus (WNV) into North America in 1999 is a classical example of viral emergence in a new environment, with its subsequent dispersion across the continent having a major impact on local bird populations. Despite the importance of this epizootic, the pattern, dynamics and determinants of WNV spread in its natural hosts remain uncertain. In particular, it is unclear whether the virus encountered major barriers to transmission, or spread in an unconstrained manner, and if specific viral lineages were favored over others indicative of intrinsic differences in fitness. To address these key questions in WNV evolution and ecology we sequenced the complete genomes of approximately 300 avian isolates sampled across the USA between 2001-2012. Phylogenetic analysis revealed a relatively ‘star-like' tree structure, indicative of explosive viral spread in US, although with some replacement of viral genotypes through time. These data are striking in that viral sequences exhibit relatively limited clustering according to geographic region, particularly for those viruses sampled from birds, and no strong phylogenetic association with well sampled avian species. The genome sequence data analysed here also contain relatively little evidence for adaptive evolution, particularly on structural proteins, suggesting that most viral lineages are of similar fitness, and that WNV is well adapted to the ecology of mosquito vectors and diverse avian hosts in the USA. In sum, the molecular evolution of WNV in North America depicts a largely unfettered expansion within a permissive host and geographic population with little evidence of major adaptive barriers.

Journal of Virology↗
USGS1995

Molecular epizootiology and evolution of the glycoprotein and non-virion protein genes of infectious hematopoietic necrosis virus, a fish rhabdovirus

Infectious hematopoietic necrosis virus (IHNV) causes a highly lethal, economically important disease of salmon and trout. The virus is enzootic throughout western North America, and has been spread to Asia and Europe. The nucleotide sequences of the glycoprotein (G) and non-virion (NV) genes of 12 diverse IHNV isolates were determined in order to examine the molecular epizootiology of IHN, the primary structure and conservation of NV, and the evolution of the virus. The G and NV genes and their encoded proteins were highly conserved, with a maximum pairwise nucleotide divergence of 3.6 and 4.4.%, and amino acid divergence of 3.7 and 6.2%, respectively. Conservation of NV protein sequence (111 amino acids in length) confirms that the protein is functional and plays an important role in virus replication. The phylogenetic relationship of viruses was found to correlate with the geographic origin of virus isolates rather than with host species or time of isolation. These data are consistent with stable maintenance of virus in enzootic foci. Two main IHNV genetic lineages were identified; one in the Columbia River Basin (Oregon, Washington and Idaho), the other in the Sacramento River Basin (California). The first major IHNV outbreak in chinook salmon in 1973 in the Columbia River was genetically linked to importation of virus-infected fish eggs from the Sacramento River where outbreaks in chinook salmon are common. However, the introduced virus apparently did not persist, subsequent virus outbreaks in Columbia River chinook salmon being associated with Columbia River genetic lineages. In general, virus monoclonal antibody reactivity profiles and phylogenetic relationships correlated well.

Virus Research↗
USGS2020

Systematics, evolution, and genetics of bears

Molecular genetics are key to understanding current and historical relationships between isolated populations, including species’ colonizations during glacial–interglacial cycles, to determine viability of local populations, needs for habitat corridors, and other aspects of population management, especially where bears are harvested for sport, etc. As natural habitats shrink, some bear species will inevitably require high levels of management, perhaps combining captive and wild populations following the IUCN’s One Plan Approach. In this chapter we review the systematics of the Ursidae and its relationships with other Carnivora, the molecular phylogenetic of extant ursid species, the phylogeography of and morphological variation within each species, and the use of molecular genetics to monitor bear populations for management and conservation.

Book chapter↗
USGS2003

Phylogeny and biogeography of Pacific Rubus subgenus Idaeobatus (Rosaceae) species: Investigating the origin of the endemic Hawaiian raspberry R. macraei

The endemic Hawaiian raspberries Rubus hawaiensis and R. macraei (both subgenus Idaeobatus ) had been thought to be closely related species until recent molecular studies demonstrated otherwise. These studies suggest that they are the products of separate colonizations to the Hawaiian Islands. Affinities of R. hawaiensis to R. spectabilis of western North America were clearly confirmed. However, no clear relation to R. macraei has been published. This study was initiated to examine species of subg. Idaeobatus from the surrounding Pacific region as well as species from other subgenera to better evaluate biogeographic and phylogenetic affinities of R. macraei by means of chromosome analysis and molecular data using the chloroplast gene ndbF . Results show that R. macraei clusters in a clade with species of blackberries, subg. Rubus , and of these it is most closely linked to R. ursinus . Chromosomally, R. macraei is 2 n = 6 x = 42, a number that would be a new report for subg. Idaeobatus . However, polyploidy is common in subg. Rubus . Analyses indicate that R. macraei and R. hawaiensis are derived from separate colonizations from North America and that similarities between them are due to convergent evolution in the Hawaiian environment.

Hawai'i↗
USGS2003

Molecular epidemiology of infectious hematopoietic necrosis virus reveals complex virus traffic and evolution within southern Idaho aquaculture

Infectious hematopoietic necrosis virus (IHNV) is a rhabdovirus which infects salmon and trout and may cause disease with up to 90% mortality. In the Hagerman Valley of Idaho, IHNV is endemic or epidemic among numerous fish farms and resource mitigation hatcheries. A previous study characterizing the genetic diversity among 84 IHNV isolates at 4 virus-endemic rainbow trout farms indicated that multiple lineages of relatively high diversity co-circulated at these facilities (Troyer et al. 2000 J Gen Virol. 81:2823-2832). We tested the hypothesis that high IHNV genetic diversity and co-circulating lineages are present in aquaculture facilities throughout this region. In this study, 73 virus isolates from 14 rainbow trout farms and 3 state hatcheries in the Hagerman Valley, isolated between 1978 and 1999, were genetically characterized by sequence analysis of a 303 nucleotide region of the glycoprotein gene. Phylogenetic and epidemiological analyses showed that multiple IHNV lineages co-circulate in a complex pattern throughout private trout farms and state hatcheries in the valley. IHNV maintained within the valley appears to have evolved significantly over the 22 yr study period.

Diseases of Aquatic Organisms↗
USGS2025

Phylogenomics of endangered troglobiotic rove beetles (Coleoptera: Staphylinidae: Pselaphinae) from central Texas karst regions

The karst habitats of central Texas, USA, are home to an array of endemic subterranean-obligate (troglobiotic) invertebrates. This includes several species of rove beetles (Coleoptera: Staphylinidae: Pselaphinae). Here we developed a molecular dataset using sequence capture of Ultra-Conserved Elements (UCEs) from the Coleoptera-UCE-1.1 K v1 baits kit. These data were used to assess species relationships and patterns of diversification in this group, specifically among species within the genera Batrisodes Reitter 1882 and Texamaurops Barr and Steeves 1963 ; with a specific focus on the relationships of the federally listed as endangered B. texanus Chandler 1992 and B.cryptotexanus Chandler and Reddell 2001 . Our final datasets consisted of 69 individuals (two genera, Batrisodes [five species] and Texamaurops [one species], from 34 localities), and a molecular dataset of 658,560 aligned base pairs across 672 UCE loci. Concatenated and species-tree phylogenetic analyses resolved all troglobiotic taxa as a monophyletic group. Within the Travis and Williamson County troglobionts, we recovered four well-supported clades that generally follow hypothesized geologic barriers to dispersal formalized as karst fauna regions (KFRs). A northward pattern of diversification was observed among these groups: (A) Texamaurops reddelli Barr and Steeves 1963 (Jollyville Plateau KFR); (B) Batrisodes reyesi Chandler 1997 (West Cedar Park and Post Oak Ridge KFRs); (C) B. reyesi (McNeil-Round Rock KFR); (D) B. cryptotexanus + B. texanus (Georgetown and North Williamson KFRs). The morphologically defined Batrisodes texanus and B. cryptotexanus were not reciprocally monophyletic, nor clustered into two unique groups in clustering analyses of single nucleotide polymorphisms (SNPs). Rather, we found support for five major subclades and five to seven genetic clusters. These results suggest that diversification and subsequent isolation of clades may have occurred with the progressive availability of karst habitats over time in the North Williamson and Georgetown KFRs resulting from the interactions of faulting, geologic structure, and drainage basin evolution. Comparison with recent U.S. Fish and Wildlife Service cave habitat resiliency assessments indicated that four genetic clusters occur within at least partially resilient habitat, whereas three are confined to caves with low or impaired resiliency. Integrating genetic results presented here along with results of other molecular studies of co-occurring troglobiotic invertebrates supports considering additional geological substructure within the North Williamson KFR in conservation efforts for these rare and unique lineages and systems.

Texas↗