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University of Kentucky

2017

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Articles 1 - 27 of 27

Full-Text Articles in Ecology and Evolutionary Biology

Language And Socioeconomics Predict Geographic Variation In Peer Review Outcomes At An Ecology Journal, C. Sean Burns, Charles W. Fox Nov 2017

Language And Socioeconomics Predict Geographic Variation In Peer Review Outcomes At An Ecology Journal, C. Sean Burns, Charles W. Fox

Information Science Faculty Publications

Papers submitted by scientists located in western nations generally fare better in the peer review process than do papers submitted by scientists from elsewhere. This paper examines geographic variation in peer review outcomes (whether a manuscript is sent for review, review scores obtained, and final decisions by editors) for 3529 submissions over a 4.5 year period at the journal Functional Ecology. In particular, we test whether geographic variation in language and socioeconomics are adequate to explain most or are all of this variation. There was no relationship between the geographic regions of handling editors and the decisions to send …


Effect Of Population, Collection Year, After-Ripening And Incubation Condition On Seed Germination Of Stipa Bungeana, Rui Zhang, Jerry M. Baskin, Carol C. Baskin, Qing Mo, Lijun Chen, Xiaowen Hu, Yanrong Wang Oct 2017

Effect Of Population, Collection Year, After-Ripening And Incubation Condition On Seed Germination Of Stipa Bungeana, Rui Zhang, Jerry M. Baskin, Carol C. Baskin, Qing Mo, Lijun Chen, Xiaowen Hu, Yanrong Wang

Biology Faculty Publications

Knowledge of the germination behavior of different populations of a species can be useful in the selection of appropriate seed sources for restoration. The aim of this study was to test the effect of seed population, collection year, after-ripening and incubation conditions on seed dormancy and germination of Stipa bungeana, a perennial grass used for revegetation of degraded grasslands on the Loess Plateau, China. Fresh S. bungeana seeds were collected from eight locally-adapted populations in 2015 and 2016. Dormancy and germination characteristics of fresh and 6-month-old dry-stored seeds were determined by incubating them over a range of alternating temperature …


Mitochondrial Phylogenomics Of Hemiptera Reveals Adaptive Innovations Driving The Diversification Of True Bugs, Hu Li, John Moeller Leavengood Jr., Eric G. Chapman, Daniel Burkhardt, Fan Song, Pei Jiang, Jinpeng Liu, Xuguo Zhou, Wanzhi Cai Sep 2017

Mitochondrial Phylogenomics Of Hemiptera Reveals Adaptive Innovations Driving The Diversification Of True Bugs, Hu Li, John Moeller Leavengood Jr., Eric G. Chapman, Daniel Burkhardt, Fan Song, Pei Jiang, Jinpeng Liu, Xuguo Zhou, Wanzhi Cai

Entomology Faculty Publications

Hemiptera, the largest non-holometabolous order of insects, represents approximately 7% of metazoan diversity. With extraordinary life histories and highly specialized morphological adaptations, hemipterans have exploited diverse habitats and food sources through approximately 300 Myr of evolution. To elucidate the phylogeny and evolutionary history of Hemiptera, we carried out the most comprehensive mitogenomics analysis on the richest taxon sampling to date covering all the suborders and infraorders, including 34 newly sequenced and 94 published mitogenomes. With optimized branch length and sequence heterogeneity, Bayesian analyses using a site-heterogeneous mixture model resolved the higher-level hemipteran phylogeny as (Sternorrhyncha, (Auchenorrhyncha, (Coleorrhyncha, Heteroptera))). Ancestral character …


Natural Enemies Partially Compensate For Warming Induced Excess Herbivory In An Organic Growth System, Orsolya Beleznai, Jamin Dreyer, Zoltán Tóth, Ferenc Samu Aug 2017

Natural Enemies Partially Compensate For Warming Induced Excess Herbivory In An Organic Growth System, Orsolya Beleznai, Jamin Dreyer, Zoltán Tóth, Ferenc Samu

Entomology Faculty Publications

Predators can limit prey abundance and/or levels of activity. The magnitudes of these effects are contingent on predator and prey traits that may change with environmental conditions. Aberrant thermal regimes could disrupt pest suppression through asymmetric effects, e.g. heat-sensitive predator vs. heat-tolerant prey. To explore potential effects of warming on suppressing pests and controlling herbivory in a vegetable crop, we performed laboratory experiments exposing an important pest species to two spider predator species at different temperatures. Heat tolerance was characterised by the critical thermal maxima parameter (CTM50) of the cucumber beetle (Diabrotica undecimpunctata), wolf spider (Tigrosa helluo …


Life-Shortening Wolbachia Infection Reduces Population Growth Of Aedes Aegypti, Eunho Suh, David R. Mercer, Stephen L. Dobson Aug 2017

Life-Shortening Wolbachia Infection Reduces Population Growth Of Aedes Aegypti, Eunho Suh, David R. Mercer, Stephen L. Dobson

Entomology Faculty Publications

Wolbachia bacteria are being introduced into natural populations of vector mosquitoes, with the goal of reducing the transmission of human diseases such as Zika and dengue fever. The successful establishment of Wolbachia infection is largely dependent on the effects of Wolbachia infection to host fitness, but the effects of Wolbachia infection on the individual life-history traits of immature mosquitoes can vary. Here, the effects of life-shortening Wolbachia (wMelPop) on population growth of infected individuals were evaluated by measuring larval survival, developmental time and adult size of Aedes aegypti in intra- (infected or uninfected only) and inter-group (mixed with …


Effects Of Climate Warming On Net Primary Productivity In China During 1961–2010, Fengxue Gu, Yuandong Zhang, Mei Huang, Bo Tao, Rui Guo, Changrong Yan Jul 2017

Effects Of Climate Warming On Net Primary Productivity In China During 1961–2010, Fengxue Gu, Yuandong Zhang, Mei Huang, Bo Tao, Rui Guo, Changrong Yan

Plant and Soil Sciences Faculty Publications

The response of ecosystems to different magnitudes of climate warming and corresponding precipitation changes during the last few decades may provide an important reference for predicting the magnitude and trajectory of net primary productivity (NPP) in the future. In this study, a process-based ecosystem model, Carbon Exchange between Vegetation, Soil and Atmosphere (CEVSA), was used to investigate the response of NPP to warming at both national and subregional scales during 1961–2010. The results suggest that a 1.3°C increase in temperature stimulated the positive changing trend in NPP at national scale during the past 50 years. Regardless of the magnitude of …


Seedling Tolerance To Cotyledon Removal Varies With Seed Size: A Case Of Five Legume Species, Xiao Wen Hu, Rui Zhang, Yan Pei Wu, Carol C. Baskin Jun 2017

Seedling Tolerance To Cotyledon Removal Varies With Seed Size: A Case Of Five Legume Species, Xiao Wen Hu, Rui Zhang, Yan Pei Wu, Carol C. Baskin

Biology Faculty Publications

It is generally accepted that seedlings from large seeds are more tolerant to defoliation than those from small seeds due to the additional metabolic reserves present in the large seeds. However, information on the effects of amount of seed reserves (cotyledon removal) from seedlings resulting from large vs. small seeds on seedling growth and long-term survival in the field is limited. Five legume species with different sizes of seeds were sown in the field and none, one, or both cotyledons removed 7 days after seedling emergence. Seedling biomass, relative growth rate (RGR) and survival were determined at different time. Cotyledon …


Divergence In Life History Traits Between Two Populations Of A Seed-Dimorphic Halophyte In Response To Soil Salinity, Fan Yang, Jerry M. Baskin, Carol C. Baskin, Xuejun Yang, Dechang Cao, Zhenying Huang Jun 2017

Divergence In Life History Traits Between Two Populations Of A Seed-Dimorphic Halophyte In Response To Soil Salinity, Fan Yang, Jerry M. Baskin, Carol C. Baskin, Xuejun Yang, Dechang Cao, Zhenying Huang

Biology Faculty Publications

Production of heteromorphic seeds is common in halophytes growing in arid environments with strong spatial and temporal heterogeneity. However, evidence for geographic variation (reflecting local adaptation) is almost nonexistent. Our primary aims were to compare the life history traits of two desert populations of this halophytic summer annual Suaeda corniculata subsp. mongolica and to investigate the phenotypic response of its plant and heteromorphic seeds to different levels of salt stress. Dimorphic seeds (F1) of the halophyte S. corniculata collected from two distant populations (F0) that differ in soil salinity were grown in a common environment under …


A Window Of Opportunity: Subdominant Predators Can Use Suboptimal Prey, Kelly A. Jackson, Joshua S. Mccord, Jennifer A. White Jun 2017

A Window Of Opportunity: Subdominant Predators Can Use Suboptimal Prey, Kelly A. Jackson, Joshua S. Mccord, Jennifer A. White

Entomology Faculty Publications

Introduced species have been linked to declines of native species through mechanisms including intraguild predation and exploitative competition. However, coexistence among species may be promoted by niche partitioning if native species can use resources that the invasive species cannot. Previous research has shown that some strains of the aphid Aphis craccivora are toxic to a competitively dominant invasive lady beetle, Harmonia axyridis. Our objective was to investigate whether these aphids might be an exploitable resource for other, subdominant, lady beetle species. We compared larval development rate, survival, and adult weight of five lady beetle species in no-choice experiments with …


Gregariousness Does Not Vary With Geography, Developmental Stage, Or Group Relatedness In Feeding Redheaded Pine Sawfly Larvae, John W. Terbot Ii, Ryan L. Gaynor, Catherine R. Linnen Apr 2017

Gregariousness Does Not Vary With Geography, Developmental Stage, Or Group Relatedness In Feeding Redheaded Pine Sawfly Larvae, John W. Terbot Ii, Ryan L. Gaynor, Catherine R. Linnen

Biology Faculty Publications

Aggregations are widespread across the animal kingdom, yet the underlying proximate and ultimate causes are still largely unknown. An ideal system to investigate this simple, social behavior is the pine sawfly genus Neodiprion, which is experimentally tractable and exhibits interspecific variation in larval gregariousness. To assess intraspecific variation in this trait, we characterized aggregative tendency within a single widespread species, the redheaded pine sawfly (N. lecontei). To do so, we developed a quantitative assay in which we measured interindividual distances over a 90-min video. This assay revealed minimal behavioral differences: (1) between early-feeding and late-feeding larval instars, …


Social Buffering In A Eusocial Invertebrate: Termite Soldiers Reduce The Lethal Impact Of Competitor Cues On Workers, Li Tian, Evan L. Preisser, Kenneth F. Haynes, Xuguo Zhou Apr 2017

Social Buffering In A Eusocial Invertebrate: Termite Soldiers Reduce The Lethal Impact Of Competitor Cues On Workers, Li Tian, Evan L. Preisser, Kenneth F. Haynes, Xuguo Zhou

Entomology Faculty Publications

While the impact of predator‐induced stress on prey has received considerable attention, there has been far less research into the effect of competitors. Cues from aggressive competitors should be particularly likely to evoke behavioral and/or physiological responses, since they may be indicative of both direct (interference) and indirect (exploitative) threats. The danger posed by such competitors, and the “fear” they evoke, should be reduced at lower competitor densities and by the presence of individual conspecifics specialized for defense. We assessed how Reticulitermes flavipes termite workers and soldiers were affected by cues from conspecific nestmates, conspecific non‐nestmates, and the heterospecific competitor …


Recruitment Of Reviewers Is Becoming Harder At Some Journals: A Test Of The Influence Of Reviewer Fatigue At Six Journals In Ecology And Evolution, Charles W. Fox, Arianne Y. K. Albert, Timothy H. Vines Mar 2017

Recruitment Of Reviewers Is Becoming Harder At Some Journals: A Test Of The Influence Of Reviewer Fatigue At Six Journals In Ecology And Evolution, Charles W. Fox, Arianne Y. K. Albert, Timothy H. Vines

Entomology Faculty Publications

Background: It is commonly reported by editors that it has become harder to recruit reviewers for peer review and that this is because individuals are being asked to review too often and are experiencing reviewer fatigue. However, evidence supporting these arguments is largely anecdotal.

Main body: We examine responses of individuals to review invitations for six journals in ecology and evolution. The proportion of invitations that lead to a submitted review has been decreasing steadily over 13 years (2003–2015) for four of the six journals examined, with a cumulative effect that has been quite substantial (average decline from 56% of …


Effect Of Seed Position On Parental Plant On Proportion Of Seeds Produced With Nondeep And Intermediate Physiological Dormancy, Juan J. Lu, Dun Y. Tan, Carol C. Baskin, Jerry M. Baskin Feb 2017

Effect Of Seed Position On Parental Plant On Proportion Of Seeds Produced With Nondeep And Intermediate Physiological Dormancy, Juan J. Lu, Dun Y. Tan, Carol C. Baskin, Jerry M. Baskin

Biology Faculty Publications

The position in which seeds develop on the parental plant can have an effect on dormancy-break and germination. We tested the hypothesis that the proportion of seeds with intermediate physiological dormancy (PD) produced in the proximal position on a raceme of Isatis violascens plants is higher than that produced in the distal position, and further that this difference is related to temperature during seed development. Plants were watered at 3-day intervals, and silicles and seeds from the proximal (early) and distal (late) positions of racemes on the same plants were collected separately and tested for germination. After 0 and 6 …


Oviposition Traits Generate Extrinsic Postzygotic Isolation Between Two Pine Sawfly Species, Emily E. Bendall, Kim L. Vertacnik, Catherine R. Linnen Jan 2017

Oviposition Traits Generate Extrinsic Postzygotic Isolation Between Two Pine Sawfly Species, Emily E. Bendall, Kim L. Vertacnik, Catherine R. Linnen

Biology Faculty Publications

Background: Although empirical data indicate that ecological speciation is prevalent in nature, the relative importance of different forms of reproductive isolation and the traits generating reproductive isolation remain unclear. To address these questions, we examined a pair of ecologically divergent pine-sawfly species: while Neodiprion pinetum specializes on a thin-needled pine (Pinus strobus), N. lecontei utilizes thicker-needled pines. We hypothesized that extrinsic postzygotic isolation is generated by oviposition traits. To test this hypothesis, we assayed ovipositor morphology, oviposition behavior, and host-dependent oviposition success in both species and in F1 and backcross females.

Results: Compared to N. lecontei, N. …


Effect Of Seed Morph And Light Level On Growth And Reproduction Of The Amphicarpic Plant Amphicarpaea Edgeworthii (Fabaceae), Keliang Zhang, Jerry M. Baskin, Carol C. Baskin, Xuejun Yang, Zhenying Huang Jan 2017

Effect Of Seed Morph And Light Level On Growth And Reproduction Of The Amphicarpic Plant Amphicarpaea Edgeworthii (Fabaceae), Keliang Zhang, Jerry M. Baskin, Carol C. Baskin, Xuejun Yang, Zhenying Huang

Biology Faculty Publications

Amphicarpic plants produce aerial and subterranean fruits on an individual plant, and these heteromorphic diaspores give rise to plants that differ in growth and ecology. Amphicarpaea edgeworthii is a summer annual amphicarpic species that grows over a range of light levels. We aimed to compare the response to shading intensity of plants of A. edgeworthii grown throughout their life cycle from aerial seeds (ASP) and from subterranean seeds (SSP). We hypothesized that vegetative and reproductive growth of plants from ASP and SSP respond differently to light. Plants were grown from ASP and SSP under 0, 46, 71 and 90% shading …


Establishment Of American Chestnuts On Surface Mined Lands In Appalachian Coalfields Region, Michael E. French Jan 2017

Establishment Of American Chestnuts On Surface Mined Lands In Appalachian Coalfields Region, Michael E. French

Theses and Dissertations--Forestry and Natural Resources

American chestnut (Castanea dentata (Marsh.) Borkh.) was an dominant hardwood throughout eastern North America until the introduction of an exotic fungus (Cryphonectria parasitica (Murr.) Barr) in the early 20th century devastated American chestnut populations. Chestnuts that have been bred for blight resistance have recently become available for testing. Due to the overlap of American chestnut’s natural range and the Appalachian coalfields region, the potential establishment of founder populations of blight-resistant chestnuts on reclaimed coal surface mines has recently gained attention. This work examined chestnut establishment on a surface mine in eastern Kentucky to assess factors controlling early …


Fluvial-Lacustrine Processes Shaping The Landforms Of The Distal Paraguay Fluvial Megafan, Edward Limin Lo Jan 2017

Fluvial-Lacustrine Processes Shaping The Landforms Of The Distal Paraguay Fluvial Megafan, Edward Limin Lo

Theses and Dissertations--Earth and Environmental Sciences

Tropical wetlands such as the Pantanal help regulate global biogeochemical cycles, but climate change is modifying these environments. Controls on environmental changes can potentially be assessed from ancient, well-dated lacustrine sedimentary records. An integrated field and laboratory approach was undertaken to study the limnogeology of Lake Uberaba in the northern Pantanal, and test whether the lake has preserved a reliable record of environmental change in its strata. This study was designed to understand how the basin accumulates sediment and to assess its sensitivity to hydroclimatic variability. The data showed that modern Lake Uberaba is a highly dynamic, freshwater fluvial-lacustrine basin. …


Sexual Dimorphism In The Moss Bryum Argenteum And Its Implications For Sex Ratio Bias, Jonathan David Moore Iii Jan 2017

Sexual Dimorphism In The Moss Bryum Argenteum And Its Implications For Sex Ratio Bias, Jonathan David Moore Iii

Theses and Dissertations--Biology

In dioecious plants, selection due to sex function differences has produced sex-specific life histories, morphologies, and physiologies. In many dioecious seed plants, dimorphisms and population sex ratios have been plausibly linked, but similar links are not yet apparent in dioecious bryophytes. Population sex ratio bias is often expected to favor the sex with lower investment in sexual reproduction, especially in resource-poor environments. Unlike in seed plants, bryophyte males may have higher average reproductive investment than females, which typically have low offspring production rates due to sperm limitation. However, traits aside from reproductive investment such as shoot and leaf arrangement may …


Mitochondrial And Nuclear Patterns Of Conflict And Concordance At The Gene, Genome, And Behavioral Scales In Desmognathus Salamanders, Justin D. Kratovil Jan 2017

Mitochondrial And Nuclear Patterns Of Conflict And Concordance At The Gene, Genome, And Behavioral Scales In Desmognathus Salamanders, Justin D. Kratovil

Theses and Dissertations--Biology

Advancements in molecular sequencing have revealed unexpected cryptic genetic diversity and contrasting evolutionary histories within genes and between genomes of many organisms; often in disagreement with recognized taxonomy. Incongruent patterns between the mitochondrial and nuclear evolutionary history can have several plausible explanations, but widespread systematic conflict inevitably challenges our conceptions of species boundaries when there is discordance between coevolving and coinherited genomes. It is unknown to what degree mitonuclear conflict drives the process of divergence, or how ubiquitous these patterns are across the tree of life. To understand the evolutionary relevance of intergenomic discordance we must identify the conflicting patterns …


Evolution Of Equine Arteritis Virus During Persistent Infection In The Reproductive Tract Of The Stallion And The Male Donkey, Bora Nam Jan 2017

Evolution Of Equine Arteritis Virus During Persistent Infection In The Reproductive Tract Of The Stallion And The Male Donkey, Bora Nam

Theses and Dissertations--Veterinary Science

Equine arteritis virus (EAV) establishes persistent infection in the stallion reproductive tract, and the carrier stallion continues to shed virus in semen for weeks to years or lifelong. The objective of this study was to elucidate the intra-host evolution of EAV during persistent infection in stallions. Seven EAV seronegative stallions were experimentally infected with EAV KY84 strain and followed for 726 days post-infection, and sequential clinical samples including semen were collected for virus isolation and next-generation sequencing (NGS). In addition, archived sequential semen samples from two stallions that were naturally infected with EAV KY84 for a long-period (up to 10 …


Invasion Dynamics Of The Exotic Liana Euonymus Fortunei (Turcz.) Hand.-Mazz. (Wintercreeper), Todd J. Rounsaville Jan 2017

Invasion Dynamics Of The Exotic Liana Euonymus Fortunei (Turcz.) Hand.-Mazz. (Wintercreeper), Todd J. Rounsaville

Theses and Dissertations--Biology

Elevated atmospheric CO2 has been implicated as a driver of increased liana abundance worldwide. Known as disturbance creators and beneficiaries, lianas possess the potential to significantly influence forest ecosystems. I investigated the early-invasion dynamics of Euonymus fortunei (wintercreeper), an evergreen liana that is invading forests in eastern North America, disrupting native plant communities and ecosystem functions.

Wintercreeper is widely cultivated as an ornamental groundcover, frequently invading natural areas via asexual stem growth. Invasion of remote natural areas is dependent upon seed transport and may occur less frequently. I examined the mechanisms of seed dormancy by conducting a ‘move-along’ experiment …


Vegetation Response To Repeated Prescribed Burning And Varied Wildfire Severity In Upland Forests On The Cumberland Plateau, Kentucky, Zachary W. Poynter Jan 2017

Vegetation Response To Repeated Prescribed Burning And Varied Wildfire Severity In Upland Forests On The Cumberland Plateau, Kentucky, Zachary W. Poynter

Theses and Dissertations--Forestry and Natural Resources

As a result of decades of fire suppression, oaks (Quercus L.) and other disturbance-dependent tree species are experiencing widespread regeneration failure. Today, fire takes the form of relatively low to moderate intensity prescribed fire, used to restore fire adapted ecosystems, and wildfires which often vary in severity. I investigated long-term changes to forest structure and composition in response to repeated prescribed burning followed by an extended period of no fire. Burning reduced total basal area, midstory stem density and sapling stem density. However, the fire-free interval significantly increased sapling layer stem densities of oaks and competitor species. This research …


Altitude- And Sex-Specific Variation In Roosting Ecology And Thermoregulation Of Myotis Lucifugus In Yellowstone National Park, Alexandra C. Slusher Jan 2017

Altitude- And Sex-Specific Variation In Roosting Ecology And Thermoregulation Of Myotis Lucifugus In Yellowstone National Park, Alexandra C. Slusher

Theses and Dissertations--Forestry and Natural Resources

Fifty-nine female and six male little brown myotis (Myotis lucifugus) were radio-tagged during the summers of 2012, 2013, 2014, and 2015 in Yellowstone National Park. The grand models for daily maximum skin temperature (F98,154 = 1.55, P = 0.007), daily minimum skin temperature (F98,154 = 1.33, P = 0.05), and daily variation in skin temperature (F98,154 = 1.56, P = 0.006) were significant across roost type and reproductive condition class for adult females. Roosts were classified into Types A (warmest roosts), B (roosts with largest daily temperature variance), and C (stable and cool roosts) depending …


Genetic Perspectives On Biodiversity In Rocky Mountain Alpine Streams, Scott Hotaling Jan 2017

Genetic Perspectives On Biodiversity In Rocky Mountain Alpine Streams, Scott Hotaling

Theses and Dissertations--Biology

In alpine regions worldwide, climate change is dramatically altering ecosystems, affecting biodiversity across habitats and taxonomic scales. For streams, the associated recession of mountain glaciers and snowfields, paired with altered precipitation regimes, are driving shifts in hydrology, species distributions, and basal resources – often threatening the very existence of some habitats and biota. Globally, alpine streams harbor particularly substantial species and genetic diversity due to significant habitat insularity and environmental heterogeneity: however, anthropogenic warming threatens to homogenize habitats through the reduction of the cryosphere, thereby reducing biodiversity from micro- to macroscopic organisms and genes to communities. Still, alpine stream biodiversity, …


Examining The Role Of Host Use On Divergence In The Redheaded Pine Sawfly, Neodiprion Lecontei, Across Multiple Spatial Scales, Robin Kimberly Bagley Jan 2017

Examining The Role Of Host Use On Divergence In The Redheaded Pine Sawfly, Neodiprion Lecontei, Across Multiple Spatial Scales, Robin Kimberly Bagley

Theses and Dissertations--Biology

Phytophagous insects make up over one quarter of described species on Earth, and this incredible diversity seems directly linked to feeding on plants. Comparative studies of sister groups have shown shifts to herbivory are consistently associated with increased species diversity in insects, but the reasons for this diversification remain unclear. While other explanations, such as decreased extinction rates or influences on population structure, exist, one prominent hypothesis suggests shifts and subsequent adaptation to novel host plants can lead to the evolution of reproductive barriers.

Given their extreme specialization on host plants in the genus Pinus and intimate, life-long association with …


Using Genomics To Understand Population Demographics In The Context Of Amphibian Conservation, Schyler O. Nunziata Jan 2017

Using Genomics To Understand Population Demographics In The Context Of Amphibian Conservation, Schyler O. Nunziata

Theses and Dissertations--Biology

Understanding the demography of species over recent history (e.g., < 100 years) is critical in studies of ecology and evolution, but records of population history are rarely available. Large single nucleotide polymorphism datasets generated with restriction-site associated DNA sequencing (RADseq), in combination with demographic inference methods, are improving our ability to gain insights into the population history of both model and non-model species. However, to assess the performance of genetic methods it is important to compare their estimates of population history to known demography, in both simulation and empirical settings. Here, I used a simulation approach to examine the potential for RADseq datasets to accurately estimate effective population size (Ne) in Wright-Fisher populations over the course of stable and declining population trends, and distinguish stable from steadily declining populations over a contemporary time scale (20 generations). Overall, my results reveal that demographic inference using genome-wide data can be successfully applied to estimate Ne, and the detection of population-size declines. Next, I assess these methods in an empirical study from a wetland with 37 years of amphibian mark-recapture data to study the utility of genetically-based demographic inference on salamander species with documented population declines (Ambystoma talpoideum) and …


Genomic Perspectives On Amphibian Evolution Across Multiple Phylogenetic Scales, Paul Michael Hime Jan 2017

Genomic Perspectives On Amphibian Evolution Across Multiple Phylogenetic Scales, Paul Michael Hime

Theses and Dissertations--Biology

Genomes provide windows into the evolutionary histories of species. The recent accessibility of genome-scale data in non-model organisms and the proliferation of powerful statistical models are now providing unprecedented opportunities to uncover evolutionary relationships and to test hypotheses about the processes that generate and maintain biodiversity. This dissertation work reveals shallow-scale species boundaries and population genetic structure in two imperiled groups of salamanders and demonstrates that the number and information content of genomic regions used in species delimitation exert strong effects on the resulting inferences. Genome scans are employed to test hypotheses about the mechanisms of genetic sex determination in …