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1. Ongoing hybridization obscures phylogenetic relationships in the Drosophila subquinaria species complex

   https://doi.org/10.1111/jeb.13512  

   Ginsberg, Paul S.; Humphreys, Devon P.; Dyer, Kelly A. (August 2019, Journal of Evolutionary Biology)

   Abstract Inferring evolutionary relationships among recently diverged lineages is necessary to understand how isolating barriers produce independent lineages. Here, we investigate the phylogenetic relationships between three incompletely isolated and closely related mushroom‐feedingDrosophilaspecies. These species form theDrosophila subquinariaspecies complex and consist of one Eurasian species (D. transversa) and two widespread North American species (D. subquinariaandD. recens) that are sympatric in central Canada. Although patterns of pre‐ and post‐mating isolation among these species are well characterized, previous work on their phylogenetic relationships is limited and conflicting. In this study, we generated a multi‐locus data set of 29 loci from across the genome sequenced in a population sample from each species, and then, we inferred species relationships and patterns of introgression. We find strong statistical support thatD. subquinariais paraphyletic, showing that samples from the geographic region sympatric withD. recensare most closely related toD. recens, whereas samples from the geographic region allopatric withD. recensare most closely related toD. transversa. We present several lines of evidence that both incomplete lineage sorting and gene flow are causing phylogenetic discordance. We suggest that ongoing gene flow primarily fromD. recensintoD. subquinariain the sympatric part of their ranges causes phylogenetic uncertainty in the evolutionary history of these species. Our results highlight how population genetic data can be used to disentangle the sources of phylogenetic discordance among closely related species. 

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2. Soil origin corresponds with variation in growth of an invasive Centaurea , but not of non‐invasive congeners

   https://doi.org/10.1002/ecy.3141  

   Montesinos, Daniel; Callaway, Ragan M. (August 2020, Ecology)

   Abstract Why only a small proportion of exotic species become invasive is an unresolved question. Escape from the negative effects of soil biota in the native range can be important for the success of many invasives, but comparative effects of soil biota on less successful exotic species are poorly understood. Studies of other mechanisms suggest that such comparisons might be fruitful. Seeds of three closely relatedCentaureaspecies with overlapping distributions in both their native range of Spain and their nonnative range of California were grown to maturity in pots to obtain an F1 generation of full sibling seeds with reduced maternal effects. Full sibling F1 seeds from both ranges were subsequently grown in pots with inoculations of soil from either the native or nonnative ranges in a fully orthogonal factorial design. We then compared plant biomass among species, regions, and soil sources. Our results indicate that escape from soil pathogens may unleash the highly invasiveCentaurea solstitialis, which was suppressed by native Spanish soils but not by soils from California. In contrast, the two non‐invasiveCentaureaspecies grew the same on all soils. These results add unprecedented phylogenetically controlled insight into why some species invade and others do not. 

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3. Hidden diversity in eastern North America: The genus Ligidium (Oniscidea, Ligiidae) in the southern Appalachian Mountains

   https://doi.org/10.1111/zsc.12661  

   Recuero, Ernesto; Caterino, Michael S (May 2024, Zoologica Scripta)

   Abstract The terrestrial isopod genusLigidiumincludes 58 species from Europe, Asia, and North America. In Eastern North America four species are recognized:L. floridanumandL. mucronatum, known just from their type localities in Florida and Louisiana respectively,L. blueridgensis, endemic to the southern Appalachians, andL. elrodii, widespread from Georgia to Ontario. The genus shows a marked morphological conservatism, and species are differentiated mostly by small morphological differences; it is not always easy to determine if such variability represents inter‐ or intraspecific variation. Here, we explore the diversity ofLigidiumfrom the southern Appalachian Mountains, exploring the congruence of morphologically defined groups with multilocus phylogenetic reconstructions and molecular species delimitation methods. We have studied a total of 130 specimens from 37 localities, mostly from the southern Appalachians, and analysed mtDNA (Cox1) and nuclear (28S, NaK) sequences. Morphologically, we recognized eight morphotypes, most of them assignable to current concepts ofL.elrodiiandL.blueridgensis. Phylogenetic analyses supported the evolutionary independence of all morphotypes, and suggest the existence of 8–9 species, including limited cryptic diversity. Single‐locus delimitation analyses based on mtDNA data suggest the existence of a much higher number of species than the multilocus analyses. The estimated age of the ancestors of sampled lineages indicates a long presence of the genus in eastern North America and old speciation events through the Miocene. Our results indicate a higher diversity than previously thought among theLigidiumpopulations present in the southern Appalachian Mountains, with several species to be described. 

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4. Checklist of the genus Dendrophorbium (Senecioneae: Compositae) in Peru including a new combination and a new species

   https://doi.org/10.1111/njb.04385  

   Montesinos‐Tubée, Daniel B (November 2024, Nordic Journal of Botany)

   The genusDendrophorbiumoccurs in South America with one species known from the Caribbean. Despite recent advances in taxonomy and phylogeny, there is a still lack of molecular studies on the delimitation and identification of the genus.Dendrophorbiumis known to occupy a wide range of ecosystems mostly restricted to subtropical montane forests and montane scrub vegetation of the central Andes. In this study, a review of the species occurring in Peru is presented, in addition to material examined at different herbaria. The new combinationD. ligulatumwhich is separated fromD. yalusay, and the new species,D. arachnoideumis described from the department of Huánuco in central Peru. The species are assessed using the standards of the IUCN and additional notes are given. 

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5. Larval stages of the Antarctic dragonfish Akarotaxis nudiceps (Waite, 1916), with comments on the larvae of the morphologically similar species Prionodraco evansii Regan 1914 (Notothenioidei: Bathydraconidae)

   https://doi.org/10.1111/jfb.15267  

   Corso, Andrew D; McDowell, Jan R; Biesack, Ellen E; Muffelman, Sarah C; Hilton, Eric J (February 2023, Journal of Fish Biology)

   Abstract The notothenioid family Bathydraconidae is a poorly understood family of fishes endemic to the Southern Ocean. There is especially little information onAkarotaxis nudiceps, one of the deepest‐dwelling and least fecund bathydraconid species. Using genetic and morphological data, we document and describe the larval stages of this unique species, offer a novel characteristic to distinguish it from the morphologically similar bathydraconidPrionodraco evansiiand use the sampling locations to infer a possible spawning area ofA. nudicepsalong the western Antarctic Peninsula. These results provide important baseline information for locating, identifying and studying the biology ofA. nudiceps, an important component of the Southern Ocean ecosystem. 

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