Author: H. Diane TuckerPublisher:
ISBN:
Category :
Languages : en
Pages : 236
Book Description
Effects of Environmental Change on the Intestinal Bacteria of the Western Fence Lizard, Sceloporus Occidentalis
Author: H. Diane TuckerMultiple Environmental Stressors Elicit Complex Interactive Effects in the Western Fence Lizard (Sceloporus Occidentalis)
Author: Craig A. McFarlandPublisher:
ISBN:
Category : Endangered species
Languages : en
Pages : 19
Book Description
The Evolutionary Ecology of Morphological Variation Within Populations of the Western Fence Lizard (Sceloporus Occidentalis)
Author: Kenneth John HalamaPublisher:
ISBN:
Category : Lizards
Languages : en
Pages : 438
Book Description
The Effects of Irrigation on the Dietary Ecology of the Western Fence Lizard (Sceloporus Occidentalis)
Author: Par SinghaseniPublisher:
ISBN:
Category : Sceloporus occidentalis
Languages : en
Pages : 62
Book Description
Diversification and Local Adaptation in Western Fence Lizards, Sceloporus Occidentalis
Author: Nassima Mahdjouba BouzidPublisher:
ISBN:
Category :
Languages : en
Pages : 171
Book Description
I am fascinated by intraspecific variation-by both its sources and its potential implications for how organisms interact with their environments. The importance of intraspecific variation for predicting species responses to climate change has recently become a research priority. Differences in the sources of intraspecific variation0́3genetic divergence, phenotypic plasticity, and drift0́3can have profoundly different outcomes for species responses. Variation in traits produced by heritable differences in genes will be sensitive to future selection, while variation produced by phenotypic plasticity may be buffered. Time and again, mechanistic studies of species responses have highlighted the importance of considering trait variation to predict idiosyncratic responses, and the sources of trait variation must also be considered. I studied intraspecific variation in Western Fence Lizards (Sceloporus occidentalis) at three spatial scales and three levels of organization. In Chapter 1 I investigated species-wide phylogeographic patterns and demographic scenarios throughout western North America. In Chapter 2 I characterized clinal variation in genotypes and phenotypes and gene flow along an elevation gradient in Yosemite National Park. In Chapter 3 I disentangled the genetic and plastic constituents of divergent phenotypes in a lab rearing experiment. My dissertation research provides an integrative framework for studying local adaptation in a polymorphic and well-established vertebrate system. Chapter 1 is the culmination of over two decades of research on phylogeographic structure within S. occidentalis. We sampled 108 individuals from 83 localities throughout the range in western North America. We used 4,555 SNPs from ddRADseq to characterize population structure and estimate demographic history. We found five genetically distinct populations including: one in the southwest, south of the Transverse Ranges; two west of the Sierra Nevada-Cascades cordillera, separated from north-to-south just north of San Francisco Bay; and two east of the Sierra Nevada-Cascades cordillera, separated from east-to-west in the Great Basin desert. The branching pattern of populations suggests that populations south of the Transverse Ranges and west of the Sierra Nevada-Cascades cordillera are divergent from populations east of the Sierra Nevada-Cascades cordillera. The predominant mechanism of population divergence is allopatric divergence and contemporary secondary contact, which supports Quaternary glacial cycles as drivers of intraspecific genetic divergence. Chapter 2 builds on foundational work by Leaché et al. (2010) to characterize genetic and phenotypic clines along an elevation gradient in Yosemite National Park. At high elevations lizards are larger and more melanistic, while at low elevations lizards are smaller and lighter-colored. We sampled 78 individuals from a 21 km stretch of the Grand Canyon of the Tuolumne River in northern Yosemite. The elevation gradient spanned 1321 m from N Hetch Hetchy Reservoir (37.9168 N, 119.6595 W, 1167 m) in the west to E Glen Aulin (37.9076 N, 119.4196 W, 2488 m) in the east. We used 721 SNPs from ddRADseq to characterize genetic clines and estimate demographic history of populations along the elevation gradient. We found evidence for additional population structure and genetic divergence between phenotypically divergent individuals; one genetically distinct population corresponds to low elevation individuals and another corresponds to high elevation individuals. Analyses of SNPs, maximum size (snout-vent length, SVL), and coloration (ventral patch area) confirm that genes and phenotypes vary clinally, and not discretely, along the elevation gradient. Genetically distinct populations diverged in allopatry, but contemporary gene flow between populations is asymmetric. Genes flow uphill, with five times as many migrants entering the high elevation population from low elevation than the converse. Chapter 3 delves into the underlying sources of trait divergence between low and high elevation individuals from the Grand Canyon of the Tuolumne River elevation gradient. While low and high elevation lizards mature at the same age, high elevation lizards are larger and more melanistic than low elevation lizards. We disentangled the genetic and environmental constituents of phenotypic variation by rearing hatchling lizards under controlled lab conditions. We collected five gravid females from low elevation (N Hetch Hetchy Reservoir [37.96 N, -119.78 W, ca. 1200 m]) and eight gravid females from high elevation (Glen Aulin [37.91 N, -119.42 W, ca. 2400 m]), who produced 36 and 51 hatchling lizards, respectively. We evenly distributed hatchlings from both populations among two treatments that varied in potential activity time: short activity period (6 hrs) and long activity period (12 hrs). We varied activity time by limiting access to heat-lamp-produced thermal gradients, which are necessary for thermoregulation. We found evidence that differences in size are genetically-based; high elevation hatchlings were larger than low elevation hatchlings, regardless of treatment. We found evidence that differences in color are at least partially produced by phenotypic plasticity; high elevation hatchlings were capable of plastically lightening to a color that was lighter than low elevation hatchlings. We found evidence that differences in behavior are genetically-based; high elevation hatchlings spent more time engaged in active behaviors. Overall, our findings are suggestive of local adaptation of high elevation hatchlings to restricted activity periods at high elevation.
Functional Consequences of Acute Temperature Stress in the Western Fence Lizard, Sceloporus Occidentalis
Author: David Michael McMillanPublisher:
ISBN:
Category : Heat shock proteins
Languages : en
Pages : 105
Book Description
Morphological Effects of Injected Progesterone on Western Fence Lizards, Sceloporus Occidentalis
Author: Marco Brandon CampbellPublisher:
ISBN:
Category :
Languages : en
Pages : 66
Book Description
Masters Abstracts
Author: Publisher:
ISBN:
Category : Dissertations, Academic
Languages : en
Pages : 538
Book Description
Infectious Disease Ecology
Author: Richard S. OstfeldPublisher: Princeton University Press
ISBN: 140083788X
Category : Science
Languages : en
Pages : 521
Book Description
News headlines are forever reporting diseases that take huge tolls on humans, wildlife, domestic animals, and both cultivated and native plants worldwide. These diseases can also completely transform the ecosystems that feed us and provide us with other critical benefits, from flood control to water purification. And yet diseases sometimes serve to maintain the structure and function of the ecosystems on which humans depend. Gathering thirteen essays by forty leading experts who convened at the Cary Conference at the Institute of Ecosystem Studies in 2005, this book develops an integrated framework for understanding where these diseases come from, what ecological factors influence their impacts, and how they in turn influence ecosystem dynamics. It marks the first comprehensive and in-depth exploration of the rich and complex linkages between ecology and disease, and provides conceptual underpinnings to understand and ameliorate epidemics. It also sheds light on the roles that diseases play in ecosystems, bringing vital new insights to landscape management issues in particular. While the ecological context is a key piece of the puzzle, effective control and understanding of diseases requires the interaction of professionals in medicine, epidemiology, veterinary medicine, forestry, agriculture, and ecology. The essential resource on the subject, Infectious Disease Ecology seeks to bridge these fields with an ecological approach that focuses on systems thinking and complex interactions.
High Mountain Conservation in a Changing World
Author: Jordi CatalanPublisher: Springer
ISBN: 3319559826
Category : Nature
Languages : en
Pages : 413
Book Description
This book provides case studies and general views of the main processes involved in the ecosystem shifts occurring in the high mountains and analyses the implications for nature conservation. Case studies from the Pyrenees are preponderant, with a comprehensive set of mountain ranges surrounded by highly populated lowland areas also being considered. The introductory and closing chapters will summarise the main challenges that nature conservation may face in mountain areas under the environmental shifting conditions. Further chapters put forward approaches from environmental geography, functional ecology, biogeography, and paleoenvironmental reconstructions. Organisms from microbes to large carnivores, and ecosystems from lakes to forest will be considered. This interdisciplinary book will appeal to researchers in mountain ecosystems, students and nature professionals. This book is open access under a CC BY license.