Download or read book Population Genetics of Ranid Frogs written by Ivan Clayton Phillipsen and published by . This book was released on 2011 with total page 282 pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation focuses on the evolutionary forces of genetic drift and gene flow in frog populations. The balance of these two forces and the force of mutation largely determine the amount of neutral genetic variation within populations as well as the degree of genetic similarity among populations. The stochastic evolutionary change caused by genetic drift can be quantified through the use of the effective population size (N[subscript e]) parameter. The effective size of a population is the number of breeding individuals in a conceptual, ideal population that would evolve by genetic drift at the same rate as the real population being studied. How a population responds to mutation, selection, and gene flow depends on N[subscript e], rather than the actual census population size (N). In most natural populations, N[subscript e] is considerably smaller than N. For these reasons, N[subscript e] is a fundamental parameter in basic population genetics theory as well as in applied conservation genetics. The degree of neutral genetic similarity between populations is highly dependent upon gene flow. When gene flow between a pair of populations is low, the populations are likely to become genetically differentiated. Conversely, when gene flow between populations is high, the populations will tend to be more genetically similar. Amphibians are good model organisms for studying genetic drift and gene flow because they tend to exhibit strong population structure at small spatial scales. This is a consequence of their generally small population sizes, natal philopatry, limited dispersal capabilities, and restricted habitat requirements. They are expected to have easily-detectable signatures of spatial genetic structure and genetic drift. Amphibians can be used as models to further our understanding of evolutionary processes and that understanding can be applied to the conservation of amphibians. Equipped with knowledge of what naturally influences genetic drift and gene flow in amphibians, we can apply the principles of population genetics to mitigate the genetic consequences of amphibian declines. In Chapters 2 and 3, I used molecular genetic data from frog populations to investigate N[subscript e] and the related parameter N[subscript b] (the effective number of breeders). Chapter 2 is a study of a single population of the Oregon spotted frog (Rana pretiosa). My aim was to determine where in the life cycle of this species the greatest reduction in N[subscript b] occurs. I used genetic data from microsatellites to estimate N[subscript b] at two different life stages, eggs and metamorphs, and found that estimates of N[subscript b] were similar at both stages. This result suggests that inflated variance in family size due to egg mass mortality is not a primary cause of N[subscript e] reductions relative to N in this species. Chapter 3 is a comparison of N[subscript e] estimates within and among four species of frogs in the family Ranidae: R. pretiosa, R. luteiventris, R. cascadae, and Lithobates pipiens. I obtained N[subscript e] estimates for 90 populations across the four species, using microsatellite data and several different estimators. The first three species and the western populations of L. pipiens have very small effective sizes (

Download or read book Handbook of Genetics written by Robert King and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 664 pages. Available in PDF, EPUB and Kindle. Book excerpt: The purpose of the first four volumes of the Handbook of Genetics is to bring together collections of relatively short, authoritative essays or an notated compilations of data on topics of significance to geneticists. Many of the essays will deal with various aspects of the biology of certain species or species groups selected because they are favorite subjects for genetic investigation in nature or the laboratory. Often there will be an encyclo pedic amount of information available on such species, with new papers appearing daily. Most of these will be written for specialists in a jargon that is bewildering to a novice, and sometimes even to a veteran geneticist working with evolutionarily distant organisms. For such readers what is needed is a written introduction to the morphology, life cycle, reproductive behavior, and culture methods for the species in question. What are its particular advantages (and disadvantages) for genetic study, and what have we learned from it? Where are the classic papers, the key bibli ographies, and how does one get stocks of wild type or mutant strains? Lists giving the symbolism and descriptions for selected mutants that have been retained and are thus available for future studies are provided whenever possible. Genetic and cytological maps, mitotic karyotypes, and haploid DNA values are also included when available. Volume 4 deals with certain vertebrate species that have been studied in considerable detail from the standpoint of genetics or molecular cytogenetics. Such data are available for only a relatively few vertebrates.

Download or read book Population Genetics of the Common Frog Rana Temporaria in Relation to Climate written by Anna Patricia Muir and published by . This book was released on 2013 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Ecological Genetics of Inbreeding Outbreeding and Immunocompetence in Ranid Frogs written by and published by . This book was released on 2008 with total page 25 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Population Genetics of the Wood Frog Rana Sylvatica Across Its Geographic Range written by Tina M. Squire and published by . This book was released on 2007 with total page 140 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Population Genetics of a Sentinel Stream breeding Frog Rana Boylii written by Ryan A. Peek and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Rana boylii is an imperiled frog species native to CA and OR, and it is currently designated as a species of special concern in the state of CA. It has been petitioned as candidate for federal (USFWS) and state (CDFW) listing. As a lotic breeding amphibian, R. boylii is tied closely to local flow regimes in the watersheds it inhabits and is therefore particularly sensitive to alterations to the natural flow regime. Effective conservation management of this species should consider and prioritize maintenance of genetic diversity as part of any listing decision because it is closely related to the evolutionary capacity for adaptation to environmental change. Conservation of genetic diversity in this species will require several components, including refining potential conservation units (i.e., distinct population segments) and quantifying of genetic diversity and genetic diversity trajectories across the species range. To assess these components, fine-scale and landscape-scale analyses were conducted using genomic data from over 600 samples from 89 localities across the range of the species. Six genomically-distinct groups were identified, as well as population subdivisions at local watershed scales. One major impact on R. boylii populations has been river regulation. River regulation has been implicated as a cause of fundamental changes to downstream aquatic ecosystems. Regulation changes the natural flow regime which may restrict population connectivity and decrease genetic diversity in some species. Since population connectivity and the maintenance of genetic diversity are fundamental drivers of long-term persistence, understanding the extent that river regulation impacts these critical attributes of genetic health is an important goal. However, the extent to which R. boylii populations in regulated rivers have maintained connectivity and genetic diversity is unknown. The impacts of river regulation on R. boylii were investigated with genomic data to explore the potential for long-term persistence of R. boylii under continued regulation. R. boylii in regulated rivers showed striking patterns of isolation and trajectories of genetic diversity loss relative to unregulated rivers. For example, river regulation explained the greatest amount of variance in population genetic differentiation compared with other covariates including geographic distance. Importantly, patterns of connectivity and genetic diversity loss were observed regardless of regulation level but were most prominent in locations with the greatest regulation intensity. Using the same genomic data, fine-scale analyses of R. boylii and R. sierrae in a single region of the Sierra Nevada of California was conducted to evaluate the potential for hybridization between species. Hybridization between species may combine parental genotypes in ways that yield reproductively sterile or isolated lineages, and hybridization events may be short-lived and difficult to detect. Limited hybridization between the species was detected in the Feather basin, though it appears these are terminal events based on PCA, admixture, and tests of heterozygosity using species diagnostic SNPs. Finally, rangewide quantification and comparison of genomic variation across populations indicates the southern coast, southern Sierra Nevada, Northern Sierra Nevada, and Feather basin in California should have high prioritization in conservation efforts due to low genomic diversity and trajectories of diversity loss. More broadly, these results demonstrate both the critical need for regional conservation in a sentinel river species, and the utility and power of genetic methods for assessing and monitoring sensitive species across many scales.

Download or read book Population and Conservation Genetic Structure of the Cascades Frog Rana Cascadae Throughout the Species Range written by Kirsten J. Monsen and published by . This book was released on 2002 with total page 208 pages. Available in PDF, EPUB and Kindle. Book excerpt: A major goal of conservation biology is to elucidate the population genetic structure in threatened species and assess the relative importance of the evolutionary forces that shape that population genetic structure. I conducted three studies in the declining amphibian Rana cascadae to assess levels of population genetic differentiation and the relative importance of gene flow versus random genetic drift throughout the species' range. In the first study, 1 examined phylogeographic structure on a species-wide geographic scale with both mitochondrial and nuclear molecular markers. I found three mitochondrial groups within R. cascadae that are as divergent at the mitochondrial DNA as sister species. However, I only found two nuclear groups within R. cascadae, suggesting there are two Distinct Population Segments and three Management Units within the species' range. In the second study, I compared sequence data from mtDNA and nuclear DNA of the three R. cascadae mtl)NA groups to several closely related Pacific Northwestern ranid species. I found the surprising result that the mtDNA of R. aurora aurora is more closely related to the mtDNA of' R. cascadae than to the mtDNA of its own subspecies R. aurora drayloni. The nuclear data support the sub-specific relationship between R. aurora aurora and R. aurora draytoni. This result is most likely due to incomplete lineage sorting of ancestral mtDNA alleles. Finally, in the third study, I examined the relative importance of gene flow versus random genetic drift on a fine geographic scale using microsatellite loci. Additionally, I estimated the long-term effective population sizes and genetic neighborhood size for 11 R. cascadae populations. Rana cascadae shows extreme isolation by distance with very little gene flow occurring past a distance of 10 km. Long-term effective population sizes were unrealistically large for current effective population sizes, but the estimates oF genetic neighborhood size are consistent with those expected based on current census population size and genetic neighborhood size in other amphibians. My research suggests Rana cascadae should be managed as three separate groups corresponding to the Olympic Peninsula, the Cascades of Washington and Oregon, and Northern California. Additionally, R. cascadae exhibits extreme isolation by distance with reduced gene flow at distances greater than 10 km, suggesting metapopulation structure is weak, and populations that go extinct are unlikely to be re-colonized quickly despite the presence of nearby R. cascadae populations.

Download or read book Reproductive Patterns and Population Genetics in Pure Hybridogenetic Water Frog Populations of Rana Esculenta written by Martina Arioli and published by . This book was released on 2007 with total page 152 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Genetics of Speciation written by David L. Jameson and published by . This book was released on 1977 with total page 360 pages. Available in PDF, EPUB and Kindle. Book excerpt: The nature of populations, races, subspecies, and species. Genetic basis of isolation. Origin of isolation - theoretical. Origin of isolation - experimental. The nature of the speciation process.

Download or read book The Tungara Frog written by Michael J. Ryan and published by University of Chicago Press. This book was released on 1985 with total page 246 pages. Available in PDF, EPUB and Kindle. Book excerpt: In a Panamanian pond, male túngara frogs (Physalaemus pustulosus) gather in choruses, giving their "advertisement" call to the females that move among them. If a female chooses to make physical contact with a male, he will clasp her and eventually fertilize her eggs. But in vying for the females, the males whose calls are most attractive may also attract the interest of another creature: the fringe-lipped bat, a frog eater. In the Túngara Frog, the most detailed and informative single study available of frogs and their reproductive behavior, Michael J. Ryan demonstrates the interplay of sexual and natural selection. Using techniques from ethology, behavioral ecology, sensory physiology, physiological ecology, and theoretical population genetics in his research, Ryan shows that large males with low-frequency calls mate most successfully. He examines in detail a number of explanations for the females' preferences, and he considers possible evolutionary forces leading to the males' success. Though certain vocalizations allow males to obtain mates and thus should be favored by sexual selection, this study highlights two important costs of such sexual displays: the frogs expand considerable energy in their mating calls, and they advertise their whereabouts to predators. Ryan considers in detail how predators, especially the frige-lipped bat (Trachops cirrhosus), affect the evolution of the túngara frog's calls.

Download or read book Phylogeography and Population Genetics of the Moor Frog Rana Arvalis Nilsson in Northern Europe written by Theresa Knopp and published by . This book was released on 2008 with total page 33 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Breeding Pond Dispersal of Interacting California Red legged Frogs Rana Draytonii and American Bullfrogs Lithobates Catesbeianus of California written by Iris Acacia Gray and published by . This book was released on 2009 with total page 334 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Bones and Cartilage written by Brian K. Hall and published by Academic Press. This book was released on 2014-12-23 with total page 911 pages. Available in PDF, EPUB and Kindle. Book excerpt: Bones and Cartilage provides the most in-depth review and synthesis assembled on the topic, across all vertebrates. It examines the function, development and evolution of bone and cartilage as tissues, organs and skeletal systems. It describes how bone and cartilage develop in embryos and are maintained in adults, how bone is repaired when we break a leg, or regenerates when a newt grows a new limb, or a lizard a new tail. The second edition of Bones and Cartilage includes the most recent knowledge of molecular, cellular, developmental and evolutionary processes, which are integrated to outline a unified discipline of developmental and evolutionary skeletal biology. Additionally, coverage includes how the molecular and cellular aspects of bones and cartilage differ in different skeletal systems and across species, along with the latest studies and hypotheses of relationships between skeletal cells and the most recent information on coupling between osteocytes and osteoclasts All chapters have been revised and updated to include the latest research. - Offers complete coverage of every aspect of bone and cartilage, with updated references and extensive illustrations - Integrates development and evolution of the skeleton, as well a synthesis of differentiation, growth and patterning - Treats all levels from molecular to clinical, embryos to evolution, and covers all vertebrates as well as invertebrate cartilages - Includes new chapters on evolutionary skeletal biology that highlight normal variation and variability, and variation outside the norm (neomorphs, atavisms) - Updates hypotheses on the origination of cartilage using new phylogenetic, cellular and genetic data - Covers stem cells in embryos and adults, including mesenchymal stem cells and their use in genetic engineering of cartilage, and the concept of the stem cell niche

Download or read book Understanding the Metapopulation Structure of Frogs in the Geocrinia Rosea Complex Through Population Genetics and Population Biology written by Don Driscoll and published by . This book was released on 1996 with total page 564 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Conservation of California Red legged Frogs written by Antonia J. D'Amore and published by . This book was released on 2007 with total page 330 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Frogs written by Henry Lambert and published by . This book was released on 2014 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this book the authors present current research in the study of frogs. Frog's neuromuscular junction (NMJ) is a classic and favourite object which have played a leading role in developing understanding of the basic mechanisms of synaptic transmission and secretion of neuromediator. The genetic diversity, neural development and ecological implications of frogs are examined throughout the book. Some of the topics the authors discuss in this compilation include poison storage and maturation in serous cutaneous glands of anurans; a mini review of the suppression of anuran metamorphosis by synthetic chemical compounds; mechanisms of suprathreshold excitation of a frog tectal neuron column by discharge of a single moving edge or darkness detector and their relation to a frog escape reactions; behavioral, ecological, and evolutionary aspects of diversity in frog colour patterns; physiological features of blood's system of frogs rana ridibuda pall; and presynaptic voltage-dependent calcium channels at the frog neurmuscular junction.

Download or read book The Distribution and Habitat Characteristics of Ranid Frogs in the Greater El Paso Area written by Margaret Smyth Jackson and published by . This book was released on 1992 with total page 128 pages. Available in PDF, EPUB and Kindle. Book excerpt: