Download or read book Phylogeography and Genetic Diversity of the Seal Salamander Desmognathus Monticola written by Erin D. Casey and published by . This book was released on 2002 with total page 90 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Ecological Interactions and Phylogenetics of Desmognathine Salamanders Caudata Plethodontidae Across the Eastern Continental Divide written by Leslie Jane Rissler and published by . This book was released on 2000 with total page 354 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Study of the Reproductive Biology of the Seal Salamander Desmognathus Monticola in Bedford County Virginia written by Margaret L. Duncan and published by . This book was released on 1970 with total page 84 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Genetic Diversity and Phylogeography of Landlocked Seals written by Jukka Palo and published by . This book was released on 2003 with total page 63 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Feeding Coactions of the Seal Salamander Desmognathus Monticola Dunn written by Lois Ann Donavan and published by . This book was released on 1972 with total page 148 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Phylogenetic History Morphological Parallelism and Speciation in a Complex of Appalachian Salamanders genus Desmognathus written by Nathan D. Jackson and published by . This book was released on 2005 with total page 128 pages. Available in PDF, EPUB and Kindle. Book excerpt: Understanding the mechanisms that generate shared morphologies across closely related taxa is important when identifying distinct evolutionary lineages using morphological characters. Desmognathus salamanders are an ideal group for testing hypotheses concerning the correlation between morphological similarity and genetic exchange within and among nominal species due to a pattern of high discordance between the two. Phylogeographic hypotheses are tested for populations of the D. quadramaculatus species complex throughout southern Appalachia by combining phylogenetic and population genetic methods with geographical information. Phylogenetic and phylogeographic inferences are then assessed in conjunction with morphological characteristics that have traditionally diagnosed taxonomic entities to understand the genetic basis of shared morphology in this complex, and to assess species boundaries. A history of fragmentation followed by range expansion is suggested as a recurrent pattern that has shaped the current population structure within this complex. The current taxonomy is found to unite populations that share similar morphologies due to parallel evolution rather than ancestry. We suggest revisions in taxonomy that will better reflect the evolutionary history of these lineages. Appreciation of the hidden genetic variation and homoplasious morphological variation often present in and among salamander species can foster the implementation of more appropriate methods for detecting and recognizing the complex history of these organisms.

Download or read book The Evolution of Courtship Behavior in Plethodontid Salamanders written by Michelle Lee Mabry and published by . This book was released on 2004 with total page 250 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Official Meeting Program written by Ecological Society of America. Meeting and published by . This book was released on 2002 with total page 820 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Ecological Society of America Annual Meeting Abstracts written by Ecological Society of America. Meeting and published by . This book was released on 2002 with total page 900 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Towards Rectifying Limitations on Species Delineation in Dusky Salamanders Desmognathus Plethodontidae written by David A. Beamer and published by . This book was released on 2020 with total page 61 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Abstract: Dusky salamanders (Desmognathus) constitute a large, species-rich group within the family Plethodontidae, and though their systematic relationships have been addressed extensively, most studies have centered on particular species complexes and therefore offer only piecemeal phylogenetic perspective on the genus. Recent work has revealed Desmognathus to be far more clade rich--35 reciprocally monophyletic clades versus 22 recognized species--than previously imagined, results that, in turn, provide impetus for additional survey effort within clades and across geographic areas thus far sparsely sampled. We conceived and implemented a sampling regime combining level IV ecoregions and independent river drainages to yield a geographic grid for comprehensive recovery of all genealogically exclusive clades. We sampled over 550 populations throughout the distribution of Desmognathus in the eastern United States of America and generated mitochondrial DNA sequence data (mtDNA; 1,991 bp) for 536 specimens. A Bayesian phylogenetic reconstruction of the resulting haplotypes revealed forty-five reciprocally monophyletic clades, eleven of which have never been included in a comprehensive phylogenetic reconstruction, and an additional three not represented in any molecular systematic survey. Although general limitations associated with mtDNA data preclude new species delineation, we profile each of the 45 clades and assign names to 10 new clades (following a protocol for previous clade nomenclature). We also redefine several species complexes and erect new informal species complexes. Our dataset, which contains topotypic samples for nearly every currently recognized species and most synonymies, will offer a robust framework for future efforts to delimit species within Desmognathus. Keywords: Amphibia, Caudata, Desmognathus, mtDNA phylogeny, level IV ecoregion X independent drainage sampling, new clades"--Page 3.

Download or read book Phylogeographic and Phylogenetic Exploration of Plethodon Plethodontidae Caudata Salamanders in the Pacific Northwest written by and published by . This book was released on 2009 with total page 99 pages. Available in PDF, EPUB and Kindle. Book excerpt: Genetic studies of amphibians often reveal substantial population structure due to either historical demographics from changing climate and geographic features over varying timeframes. Eight species of terrestrial salamanders (Family: Plethodontidae, Genus: Plethodon) reside in forests of the Pacific Northwest (PNW). Plethodon vehiculum is the most widespread and abundant terrestrial salamander in the PNW yet evolutionary studies are lacking. Using mitochondrial DNA (mtDNA) sequence data (D-loop and cytb) questions regarding the phylogeography of P. vehiculum and phylogenetics of western Plethodons are explored. Two major clades were defined in P. vehiculum, a southern clade in the Klamath-Siskiyou region and a northern clade ranging from northern Oregon to British Columbia using parsimony and maximum likelihood trees and a haplotype network. High divergence levels between the north and south clades are observed warranting further investigation into the southern clade's unique evolutionary trajectory. The northern populations were not highly differentiated with high levels of haplotype sharing, not common in other terrestrial salamander species. A large recent range expansion or high habitat connectivity for these salamanders is suggested. The Columbia River did not act as barrier to dispersal in this species, however, Vancouver Island and the population of Washington's Olympic Peninsula revealed unique haplotypes only to those areas, due to the presence of geographic barriers to dispersal and/or multiple glacial refugia. The D-loop and cytb provided evidence for recent range expansion in the northern clade. This was the first study to incorporate all western Plethodon salamanders in a phylogenetic study. Parsimony and maximum likelihood methods offered strong support for recognized relationships among western Plethodons, however relationships between the major groups remain unhighly supported. Lack of genetic diversity in the mtDNA cytb gene in P. vehiculum is highly inconsistent with other Plethodon salamanders and highlights the importance of understanding mtDNA evolution in ectotherms. Divergence measures were used to estimate divergence times among species, dating all speciation before the Pleistocene glaciations. The southern OR clade of P. vehiculum was dated to have been separated from the northern clade at the start of the Pleistocene. The deep phylogeographic break here justifies the possibility of reclassification of the southern clade.

Download or read book Phylogeography and Range Limit Evolution in the Cumberland Plateau Salamander Plethodon Kentucki written by Emily F. Watts and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Gene flow and geography are critically influential factors in shaping the genetic history of a species. Gene flow can have beneficial effects on a population that may allow for new adaptations to occur, such as increasing genetic variation. However, gene flow may also result in negative consequences for populations if their fitness is decreased through the introduction of non-optimized traits or through selection resulting in a reduction of locally adapted individuals. Asymmetrical gene flow can even prevent local adaptation in edge populations when gene flow from central populations adapted to central conditions swamps locally adapted populations. This phenomenon can prevent a species from expanding its range, as it is unable to adapt to local conditions at the range edges. Thus, patterns of gene flow can determine the extent to which gene flow slows or promotes adaptation. Gene flow can also create problems for the inference of species relationships, because it is a source of gene tree-species tree discordance. While speciation is commonly modeled as a finite event, divergence is a process. Even after divergence, hybridization is common, and neglecting to account for it can lead to incorrect species tree inference. Nonetheless, the development of species tree inference methods that account for gene flow remains in its infancy. Even with the addition of more loci from genomic-scale data, gene flow misleads phylogenetic reconstruction. Thus, it is vital to account for gene flow with phylogenetic networks when inferring species relationships. This dissertation examines the role of gene flow in constraining adaptation in the Cumberland Plateau Salamander, Plethodon kentucki, a cryptic species with respect to the sympatric Northern Slimy Salamander, Plethodon glutinosus. After its description in 1983 by Highton and MacGregor using allozyme data, its taxonomic status was unclear, as the authors reported extreme levels of genetic differentiation for a single species with a narrow distribution, and follow-up studies found patterns of genetic variation that were discordant with the allozyme data. In chapter 1, I describe genetic variation within P. kentucki and conclude it is best recognized as a single species with substantial genetic structure within its limited distribution. In chapter 2, I describe the heterogeneity of the landscape within the range of P. kentucki. I also quantify the genetic connectivity across the range of P. kentucki and describe how the two interact to maintain the range of P. kentucki. I also test a novel theory about how different types of range edges impact adaptation at the periphery of a species’ range. This dissertation also examines the role of gene flow in confounding phylogenetic inference using two prominent phylogenetic network methods. In chapter 3, I use computer modeling to examine how these two methods perform under varying degrees of gene flow and population history, as well as how they perform under two different datasets. This dissertation explores the role of gene flow, or lack thereof, in maintaining species boundaries, inhibiting range expansion, and confounding the inference of species relationships.

Download or read book Aggressive Behavior and Chemical Communication in the Seal Salamander D e s m o g n a t h u s M o n t i c o l a written by Linda June Nelson and published by . This book was released on 1979 with total page 82 pages. Available in PDF, EPUB and Kindle. Book excerpt: The aggressive behavior of salamanders is relatively little known, most observations being associated with courtship behavior. Specific sequences of aggressive behavior and the role of chemical communication in territory maintenance are known for only a few species. The purpose of this study is to determine the sequence of aggressive behavior in Desmognathus monticola and to determine the win ratio of residents versus non-residents, with possible implications regarding territorial behavior in this species. Chemical communication in the form of "tapping" behavior was also studied to determine its role in territory maintenance.

Download or read book The Historical and Ecological Biogeography of the Eastern Red Backed Salamander Plethodon Cinereus written by Brian P. Waldron and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Patterns in the distributions of species result from numerous ecological and evolutionary processes, including competitive interactions, evolved physiological tolerances, and the historical environmental fluctuations that have caused ranges to shift, expand, or contract over long time periods. For some groups of species, these processes have resulted in an elaborate diversification of traits. For other groups, however, such as woodland salamanders (genus Plethodon), closely related species may be phenotypically similar or even identical. It is less clear what drives the formation of such species, whether and how they maintain their identities and interact after initial divergence, and how such similar species might have evolved ecologically in subtle ways to differentially utilize the landscape. The Eastern Red-backed Salamander (Plethodon cinereus) is a small, fully terrestrial woodland salamander notable for its wide distribution and high phylogeographic diversity in the eastern United States and southeastern Canada. Most of its current distribution, however, was covered by ice sheets at the end of the Pleistocene, suggesting recent and rapid post-glacial expansion. It is not yet clear how P. cinereus colonized these landscapes, and what ecological characteristics made P. cinereus so successful in its range expansion compared to other species. Some studies comparing narrowly-distributed montane Plethodon to their lowland counterparts have suggested a combination of physiological specialization and competitive superiority of montane species relative to generalist lowland species such as P. cinereus, but it is unknown if this asymmetry applies to sets of lowland species outside of montane systems. In this dissertation, I explore the biogeography of woodland salamanders, with special attention to P. cinereus, at ecological and evolutionary time scales to uncover the processes that shape genetic diversity and species distributions. Chapters 1 and 2 concern the historical biogeography and evolution of P. cinereus, while Chapters 3 and 4 compare the habitat use of P. cinereus to two of its more broadly distributed relatives, the Northern Ravine Salamander (P. electromorphus) and the Southern Ravine Salamander (P. richmondi), to test if they have diverged ecologically, including multiple ecological scales. In Chapter 1, I used next-generation DNA sequencing to explore the phylogeographic structure and demographic history of P. cinereus, using the species as a model for the formation of incipient lineages of Plethodon. I identified several groups that diverged within the Pleistocene, yet I also found numerous and sometimes extensive regions of admixture between groups, suggesting a model of range fragmentation and fusion during incipient species formation. In Chapter 2, I focus on the most recent post-glacial expansion of P. cinereus, using DNA sequencing from range-wide samples to uncover the origins and routes of colonization. Results generally supported a southeastern coastal origin that expanded northward, westward into the Great Lakes region, and then a novel colonization route southward back into unglaciated areas. In Chapter 3, I used ecological niche modeling to test if niche differentiation between P. cinereus, P. electromorphus, and P. richmondi explains their broad distributional patterns. All species had estimated niches that were more different than expected by chance, and historical habitat suitability has fluctuated dramatically in the Holocene epoch, although I did not find strong evidence that climatic or topographic variables differentiated occurrences of P. cinereus and P. electromorphus within their overlapping distribution. Finally, in Chapter 4, I explore microhabitat differentiation between P. cinereus and P. electromorphus where they occur and interact at fine spatial scales. Plethodon cinereus greatly outnumbered P. electromorphus, and P. electromorphus used cooler, wetter microhabitats that were also occupied by P. cinereus, with no evidence for a negative correlation in their occupancies or abundances. Taken together, my work suggests that current distributions, including patterns within and between species, are shaped by historical range expansion and contractions, as well as subtle differences in habitat use at multiple spatial scales.

Download or read book Scientific and Standard English Names of Amphibians and Reptiles of North America North of Mexico written by Society for the Study of Amphibians and Reptiles. Committee on Standard English and Scientific Names and published by . This book was released on 2001 with total page 104 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Biodiversity Biogeography and Nature Conservation in Wallacea and New Guinea written by Dmitry Telnov and published by The Entomological Society of Latvia. This book was released on 2011-08-01 with total page 451 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Evolutionary Patterns and Processes written by D. R. Lees and published by Academic Press. This book was released on 1993 with total page 346 pages. Available in PDF, EPUB and Kindle. Book excerpt: Evolution is the central theme of all biology. Researcarcch in the many branches of evolutionary study continues to flourish. This book, based on a symposium of the Linnean Society, discusses the diversity in currentevolutionary research. It approaches the subject ambitiously and from several angles, bringing ttogether eminent authors from a variety of disciplines paleontologists traditionally with a macroevolutionary bias, neontologists concentrating on microevolutionary processes, and those studying the very essence ofsses and those studying the very essence of evolution the process of speciation in living organisms. Evolutionary Patterns and Processes will appeal to a broad spectrum of professional biologistsworking in such fields as paleontology, population biology, and evolutionary genetics. Biologists will enjoy chapters by Stephen J. Gould, discovering in the much earlier work of Hugo de Vries parallels with his ideas on punctuational evolution; Guy Bush,considering why there are so many small animals; Peter Sheldon, examining detailed fossil trilobite sequences for evidence of microevolutionary processes and considering models of speciation; as well as others dealing with cytological, ecological, and behavioral processes leading to the evolution of new species. None