Phylogeography of the Brownback Salamander reveals patterns of local endemism in Southern Appalachian springs

Systematics and biogeography of Appalachian Anillini, and a taxonomic review of the species of South Carolina (Coleoptera, Carabidae, Trechinae, Anillini)

In the eastern United States, 74 species of Anillini in two genera have been described, with most belonging to Anillinus Casey. Until now, no systematic framework has existed for this large genus, hampering integrative studies. Using DNA sequences from 101 Nearctic species, we present a well-resolved molecular phylogeny supporting a sound systematic framework. Sixteen species groups of Appalachian Anillinus are diagnosed, in part using newly recognized variation in the number of modified male protarsi and the state of the spermathecal duct. We present the first descriptions of Nearctic anilline larvae, which possess none of the synapomorphies of previously described anilline larvae. Within Anillinus, two major clades are mostly consistent with setation of the right paramere: a "hairy clade" with more than four setae, and a "quadrisetose clade." Throughout the phylogeny, microhabitat use varies within each clade, and several endogean lineages are phylogenetically isolated. Our work increases the South Carolina fauna by nearly five-fold. Nine new species are described, Serranillusmonadnock sp. nov., Anillinuscastaneus sp. nov., Anillinuschoestoea sp. nov., Anillinusdentatus sp. nov., Anillinusjancae sp. nov., Anillinusmica sp. nov., Anillinusmicamicus sp. nov., Anillinusseneca sp. nov., and Anillinussimplex sp. nov. Several species are newly reported from South Carolina, bringing the total to 20 described species representing seven species groups. Two endemic groups inhabit deep clay soils in the Piedmont and possess unique male sexual characters. The Anillini are a unique component of Nearctic biodiversity, with great potential as a model system for studies of biogeography, secondary male sexual modification, and endogean adaptations.

River Drainage Reorganization and Reticulate Evolution in the Two-Lined Salamander (Eurycea bislineata) Species Complex

The origin and eventual loss of biogeographic barriers can create alternating periods of allopatry and secondary contact, facilitating gene flow among distinct metapopulations and generating reticulate evolutionary histories that are not adequately described by a bifurcating evolutionary tree. One such example may exist in the two-lined salamander (Eurycea bislineata) species complex, where discordance among morphological and molecular datasets has created a "vexing taxonomic challenge." Previous phylogeographic analyses of mitochondrial DNA (mtDNA) suggested that the reorganization of Miocene paleodrainages drove vicariance and dispersal, but the inherent limitations of a single-locus dataset precluded the evaluation of subsequent gene flow. Here, we generate triple-enzyme restriction site-associated DNA sequencing (3RAD) data for > 100 individuals representing all major mtDNA lineages and use a suite of complementary methods to demonstrate that discordance among earlier datasets is best explained by a reticulate evolutionary history influenced by river drainage reorganization. Systematics of such groups should acknowledge these complex histories and relationships that are not strictly hierarchical. [Amphibian; hybridization; introgression; Plethodontidae; stream capture.].

Phylogeographic History of Endangered Hokuriku Salamander, Hynobius takedai (Amphibia: Caudata)

Knowledge of the phylogeographic history of organisms is valuable for understanding their evolutionary processes. To the best of our knowledge, the phylogeographic structure of Hokuriku salamander, Hynobius takedai, an endangered species, remains unclear. This study aimed to elucidate the phylogeographic history of H. takedai, which is expected to be strongly influenced by paleogeographic events. Phylogenetic analysis based on partial sequences of the mitochondrial DNA cytochrome b gene confirmed the genetic independence of H. takedai, and the divergence time with closely related species was estimated to be from the Late Pliocene to the Early Pleistocene. In the phylogenetic tree, two clades were identified within H. takedai, and their haplotypes were found in samples collected from the west and east of the distribution range. These intraspecific divergences were strongly influenced by geohistorical subdivisions of the current major distribution areas in the Middle Pleistocene. One clade was further subdivided and its formation may have been influenced by sea level changes in the Late Pleistocene.

Genetic structure of the endangered Greater Short-horned Lizard (Phrynosoma hernandesi) in Canada: evidence from mitochondrial and nuclear genes

The northern edge of the range of the Greater Short-horned Lizard (Phrynosoma hernandesi Girard, 1858) occurs in western Canada, where the species has “endangered” status and exhibits a patchy distribution. Phylogenetic inference and genetic analyses were employed to investigate the genetic structure of P. hernandesi throughout its Canadian range. One nuclear and two mitochondrial DNA genes were sequenced from 94 lizard tail tips. Overall, sequences from lizards from both Alberta and Saskatchewan displayed very little variability, and the consistent clustering of all the P. hernandesi mitochondrial and nuclear DNA sequences from Canada in both phylogenetic and population genetic analyses is consistent with the lizards from all sampled localities having originated from a single glacial refugium, and with being, until recently (or currently) interconnected genetically. The genetic data obtained so far furnish no information useful for interpreting the species’ present-day patchy distribution patterns or for formulating conservation strategies.

Evolution of paedomorphosis in plethodontid salamanders: ecological correlates and re-evolution of metamorphosis

Life-history modes can profoundly impact the biology of a species, and a classic example is the dichotomy between metamorphic (biphasic) and paedomorphic (permanently aquatic) life-history strategies in salamanders. However, despite centuries of research on this system, several basic questions about the evolution of paedomorphosis in salamanders have not been addressed. Here, we use a nearly comprehensive, time-calibrated phylogeny of spelerpine plethodontids to reconstruct the evolution of paedomorphosis and to test if paedomorphosis is (1) reversible; (2) associated with living in caves; (3) associated with relatively dry climatic conditions on the surface; and (4) correlated with limited range size and geographic dispersal. We find that paedomorphosis arose multiple times in spelerpines. We also find evidence for re-evolution of metamorphosis after several million years of paedomorphosis in a lineage of Eurycea from the Edwards Plateau region of Texas. We also show for the first time using phylogenetic comparative methods that paedomorphosis is highly correlated with cave-dwelling, arid surface environments, and small geographic range sizes, providing insights into both the causes and consequences of this major life history transition.