Ecology and Evolutionary Biology Commons^™

Competition And Herbivory Influence The Survival, Growth, And Physiology Of Native Tree Seedlings In The Kentucky Inner Bluegrass Savanna-Woodland, James D. Shaffer

Theses and Dissertations--Biology

Terrestrial plant communities are shaped by competition for resources, herbivory, and abiotic processes. Savanna systems represent a dynamic coexistence of contrasting life forms (grasses and trees) shaped by competition and disturbance. The Kentucky Inner Bluegrass Savanna-Woodland (KIBSW) is described as an open woodland of shade intolerant species; however, climatic, and edaphic conditions can support closed-canopy forest. After European pioneer settlement (c1750-1800), over 99% of “savanna-woodlands” have been lost. KIBSW remnants are experiencing a recruitment failure, leading to a dominance shift in tree communities. I researched how tree-grass competition and mammalian herbivory influence KIBSW regeneration and maintenance. The KIBSW does not …

Variation In Behavioral Strategies For Coping With Environmental Uncertainty, Allison Mclaughlin

Theses and Dissertations--Biology

My dissertation investigates how animals behaviorally respond to environmental change, especially when there is limited information about that change. Uncertainty about the environment comes in various forms, including food resources which vary unpredictably and novel cues which present an unknown level of potential risk or benefit. Various behavioral strategies help animals cope with such uncertainty. Tactics to manage unpredictable variation in food include gathering information to reduce uncertainty (sampling) and strategically adjusting preference or aversion to variation in resources (variance-sensitivity). To manage the uncertainty of a novel cue, animals may generalize their previous experience with similar cues, or they may …

Linking Previous Experiences To Behavior And Health In The Honey Bee (Apis Mellifera), Rebecca R. Westwick

Theses and Dissertations--Entomology

An organism’s ability to respond to changing conditions can be vital to its success. Indeed, plasticity is a common feature of living organisms. Much of the research in this area, though, has focused on effects caused by environmental conditions. What has received relatively less attention is how social experiences and broader features of an organism’s social environment can lead to long-lasting changes in health and behavior. This knowledge gap exists despite the well-documented existence of health and behavioral effects after social interactions in certain taxa such as humans.

Social insects such as honey bees provide an excellent opportunity to better …

Parental Effects On Offspring Reaction Norms: Consequences For Complex Phenotypes In Variable Environments, Alexandra G. Cones

Theses and Dissertations--Biology

Organismal traits all exhibit some degree of environmental sensitivity, and both the strength and direction of these phenotypically plastic responses to the environment can evolve in adaptive ways. For example, parents can use information about their own environment to precondition the traits of their offspring so that they thrive in their future environment. This transgenerational plasticity can also alter the plasticity of offspring, but explicit investigations of this specific phenomenon are rare. I begin with a review of the literature and provide a quantitative genetic framework to investigate this phenomenon, which I then explore empirically using avian embryos. The metabolic …

Multilevel Phenotypic Integration Of Metabolism And Behavior In House Sparrows And Mice, Tim Salzman

Theses and Dissertations--Biology

Patterns of multilevel variation in behavior, both within and among individuals, raise challenging questions about underlying mechanisms and the selective pressures acting on them. One intriguing hypothesis is that physiology shows parallel multilevel variation, and so might represent a latent trait that integrates multilevel behavioral responses. For example, foraging acquires the fuel needed to maintain metabolism, and in turn, an individual’s metabolism affects expression of foraging, and other, behaviors. Metabolism and behavior thus might coevolve to become integrated traits. Despite the appeal of this hypothesis, numerous investigations into the link between metabolism and behavior have yielded largely equivocal results.

To …

Against The Odds: Hybrid Zones Between Mangrove Killifish Species With Different Mating Systems, Waldir M. Berbel-Filho, Andrey Tatarenkov, George Pacheco, Helder M. V. Espírito-Santo, Mateus G. Lira, Carlos Garcia De Leaniz, John C. Avise, Sergio M. Q. Lima, Carlos M. Rodriguez Lopez, Sofia Consuegra

Horticulture Faculty Publications

Different mating systems are expected to affect the extent and direction of hybridization. Due to the different levels of sexual conflict, the weak inbreeder/strong outbreeder (WISO) hypothesis predicts that gametes from self-incompatible (SI) species should outcompete gametes from self-compatible (SC) ones. However, other factors such as timing of selfing and unilateral incompatibilities may also play a role on the direction of hybridization. In addition, differential mating opportunities provided by different mating systems are also expected to affect the direction of introgression in hybrid zones involving outcrossers and selfers. Here, we explored these hypotheses with a unique case of recent hybridization …

Is The Life History Flexibility Of Cold Desert Annuals Broad Enough To Cope With Predicted Climate Change? The Case Of Erodium Oxyrhinchum In Central Asia, Huiliang Liu, Yanfeng Chen, Lingwei Zhang, Jerry M. Baskin, Carol C. Baskin, Lan Zhang, Yan Liu, Daoyuan Zhang, Yuanming Zhang

Biology Faculty Publications

Interannual seasonal variability in precipitation may strongly affect the life history and growth of desert annual plants. We compared the effects of dry and wet springs and dry and wet autumns on growth and F2 seed dormancy of plants from spring (SG)- and autumn (AG)-germinated seeds of the cold desert annual Erodium oxyrhinchum. Vegetative and reproductive growth and F2 seed dormancy and germination were monitored from September 2016 to November 2020 in the sandy Gurbantunggut Desert in NW China in Central Asia. Dry autumns decreased the density of AG plants, and dry springs decreased the density of SG plants …

Residual Spatial Autocorrelation In Macroecological And Biogeographical Modeling: A Review, Guetchine Gaspard

Theses and Dissertations--Geography

Macroecological and biogeographical modelers have predicted the distribution of species across space relying on the relationship between biotic processes and environmental variables. Such a method employs data associated, for instance, with species abundance or presence/absence, climate, geomorphology, and soils. Statistical analyses found in previous studies have highlighted the importance of accounting for the effects of spatial autocorrelation (SAC), which indicates a level of dependence between pairs of nearby observations. A consensus has existed that residual spatial autocorrelation (rSAC) can substantially impact modeling processes and inferences. However, more emphasis should be put on identifying the sources of rSAC and the degree …

The Social Behavior Of Pine Sawflies In The Genus Neodiprion, John W. Terbot Ii

Theses and Dissertations--Biology

Group living is found across the animal kingdom ranging from temporary mating aggregations to complex, eusocial lifestyles. A particularly common form of group living found among insects are larval or nymphal herds. This lifestyle consists of immature insects living together and results in several proposed costs and benefits. Benefits of this lifestyle include improved ability to regulate a group’s microenvironment, more efficient use of their host, and the ability to engage in collective predator defenses. Offsetting these benefits are costs resulting from living in close proximity to conspecifics which include increased competition, greater visibility to predators, and heightened disease risks. …

Effects Of Shelterwood And Patch Cut Harvests On A Post White-Nose Syndrome Bat Community In The Cumberland Plateau In Eastern Kentucky, Phillip Lee Arant

Theses and Dissertations--Forestry and Natural Resources

The impact of shelterwood and patch cuts harvests on bat communities was tested at three sites in Eastern Kentucky. Shelterwood harvests had 50% of the basal area and understory removed to create a uniform spacing of residual trees. Patch cuts had 1-hectare circular openings created to remove 50% of the basal area creating an aggregated spacing of residual trees. Acoustic detectors were deployed to assess activity levels pre-harvest. Sites were then sampled from 1 – 2 years post-harvest to determine differences. Pre-harvest data revealed little acoustic activity for the Myotis spp. at two sites. The remaining site had high activity …

Diet Of A Recently Reintroduced River Otter (Lontra Canadensis) Population In Taos County, New Mexico, Gabriela Alexandra Wolf-Gonzalez

Theses and Dissertations--Forestry and Natural Resources

North American river otters (Lontra canadensis), native to every U.S. state and Canada, experienced extensive population decreases and range reduction until the mid-20th century as a result of overexploitation and habitat loss during European colonization. The last known river otter in New Mexico was killed on the Gila River in 1953, although unverified reports continued thru 2008. After a nearly 60-year absence from New Mexico, 33 adult river otters were reintroduced to the Rio Pueblo de Taos in the northern part of the state between 2008-2010; however, they were not subsequently monitored or studied. I characterized diet of …

Genetic Analysis Of The Endangered Gray Bat Species (Myotis Grisescens), Emma Fitzgerald

Lewis Honors College Capstone Collection

This study attempts to analyze the genetics using specific haplotype sequences of the endangered gray bat to determine genetic events that have happened in the past as well as determining how the species population has changed over time. We were able to conduct a Tajima’s D test to investigate whether a potential bottleneck has occurred. A linear regression of the genetic vs. geographical distance was produced to investigate the patterns of haplotype distribution. The species past distribution was compared to the current distribution using known collected specimens. A map of future predictions was constructed using present and future climate layers …

From Genes To Species: Ecological Speciation With Gene Flow In Neodiprion Pinetum And N. Lecontei, Emily E. Bendall

Theses and Dissertations--Biology

My dissertation focuses on how differences accumulate across the genome during ecological speciation with geneflow. To do this I used two species of Neodiprionpine sawflies, which are plant-feeding hymenopterans with high host specificity. I used experimental crosses to measure both intrinsic and extrinsic postzygotic isolation and to understand the contribution of specific traits to reproductive isolation. Despite substantial genetic divergence and haploid males in which all recessive incompatibilities should be expressed, I found surprisingly little evidence of intrinsic postzygotic isolation. Recombination in hybrid males may reconstitute viable genotypes and counteract the effects of haploidy in males. Nevertheless, hybrids have …

From Organisms To Ecosystems: Impacts Of Limb Loss And Regeneration On Crayfish Behavior, Luc Arnaud Dunoyer

Theses and Dissertations--Biology

The ability of some organisms to regenerate tissues and organs has fascinated naturalists since antiquity, dating back to the earliest accounts of scientific inquiry with Aristotle in Ancient Greece. Then, Darwin’s theory invigorated some scientists’ dream of stimulating (or reactivating) regenerative capacities in human beings by showing that we are related to highly regenerative organisms. More recently, a renewed interest in discovering the molecular and genetic basis for organ and tissue regeneration has led biologists to focus more specifically on a restrictive set of model organisms.

Although the process of limb regeneration is different between invertebrate and vertebrate organisms, it …

Amplicon Sequencing Of 42 Nuclear Loci Supports Directional Gene Flow Between South Pacific Populations Of A Hydrothermal Vent Limpet, Sophie Plouviez, Abigail Leavitt Labella, David W. Weisrock, F. A. Bastiaan Von Meijenfeldt, Bernard Ball, Joseph E. Neigel, Cindy L. Van Dover

Biology Faculty Publications

In the past few decades, population genetics and phylogeographic studies have improved our knowledge of connectivity and population demography in marine environments. Studies of deep‐sea hydrothermal vent populations have identified barriers to gene flow, hybrid zones, and demographic events, such as historical population expansions and contractions. These deep‐sea studies, however, used few loci, which limit the amount of information they provided for coalescent analysis and thus our ability to confidently test complex population dynamics scenarios.

In this study, we investigated population structure, demographic history, and gene flow directionality among four Western Pacific hydrothermal vent populations of the vent limpet Lepetodrilus …

Effects Of Increased Precipitation On The Life History Of Spring- And Autumn-Germinated Plants Of The Cold Desert Annual Erodium Oxyrhynchum (Geraniaceae), Yanfeng Chen, Xiang Shi, Lingwei Zhang, Jerry M. Baskin, Carol C. Baskin, Huiliang Liu, Daoyuan Zhang

Biology Faculty Publications

Future increased precipitation in cold desert ecosystems may impact annual/ephemeral plant species that germinate in both spring and autumn. Our primary aim was to compare the life history characteristics of plants from spring-germinating (SG) and autumn-germinating (AG) seeds of Erodium oxyrhynchum. Plants in field plots with simulated increases in precipitation of 0, 30 and 50 % in spring and summer were monitored to determine seedling survival, phenology, plant size, seed production and biomass accumulation and allocation. Germination characteristics were determined in the laboratory for seeds produced by plants in all increased precipitation treatments. Increased precipitation in spring significantly improved survival …

Seed Germination Responses To Seasonal Temperature And Drought Stress Are Species‐Specific But Not Related To Seed Size In A Desert Steppe: Implications For Effect Of Climate Change On Community Structure, Fengyan Yi, Zhaoren Wang, Carol C. Baskin, Jerry M. Baskin, Ruhan Ye, Hailian Sun, Yuanyuan Zhang, Xuehua Ye, Guofang Liu, Xuejun Yang, Zhenying Huang

Biology Faculty Publications

Investigating how seed germination of multiple species in an ecosystem responds to environmental conditions is crucial for understanding the mechanisms for community structure and biodiversity maintenance. However, knowledge of seed germination response of species to environmental conditions is still scarce at the community level. We hypothesized that responses of seed germination to environmental conditions differ among species at the community level, and that germination response is not correlated with seed size. To test this hypothesis, we determined the response of seed germination of 20 common species in the Siziwang Desert Steppe, China, to seasonal temperature regimes (representing April, May, June, …

Ecology, Monogamy, And The Evolution Of Animal Families, Jacqueline Rae Dillard

Theses and Dissertations--Biology

Family-living has been recognized as a necessary prerequisite for the evolution of advanced cooperative societies, yet the evolutionary and ecological processes that drive the coupling of different forms of cooperation in family-based societies are still poorly understood. In my dissertation, I investigate the correlated evolution of parental care, monogamy, and cooperative breeding in a variety of family-based taxa. I explore the mating and social behavior of family-living beetles with incipient cooperation to better understand the factors driving these social traits. Specifically, I evaluate different causes of extra-pair mating in socially monogamous beetles, the potential benefits that young adult offspring may …

The Ecology And Behavior Of Spring Migrating Indiana Bats (Myotis Sodalis), Piper Lee Roby

Theses and Dissertations--Animal and Food Sciences

Migration of animals has been studied for decades and has included everything from large terrestrial and pelagic mammals traveling thousands of kilometers to many types of birds flying through several countries to insects going through multiple life cycles in a single migration. The migration of bats has been studied in broad terms to gather coarse information such as distance traveled, connecting summer and winter habitat, and a general understanding of timing. However, only recently have researchers begun to understand the specifics of bat migration including physiology and fine resolution behavior.

Using nine years of spring migration data collected on VHF …

Intraspecific Variation In Dehydration Tolerance: Insights From The Tropical Plant Marchantia Inflexa, Rose A. Marks

Theses and Dissertations--Biology

Plants are threatened by global change, increasing variability in weather patterns, and associated abiotic stress. Consequently, there is an urgent need to enhance our ability to predict plant community dynamics, shifts in species distributions, and physiological responses to environmental challenges. By building a fundamental understanding of plant stress tolerance, it may be possibly to protect the ecological services, economic industries, and communities that depend on plants. Dehydration tolerance (DhT) is an important mechanism of water stress tolerance with promising translational applications. Here, I take advantage natural variation in DhT to gain a deeper insight into this complex trait. In addition, …

Quantifying White-Tailed Deer Density And Its Impacts On Agricultural Systems, Jonathan A. Matthews

Theses and Dissertations--Forestry and Natural Resources

White-tailed deer (Odocoileus virginianus) commonly consume row crops, with yield losses often attributed to their browsing. Deer density and field morphology may predict yield losses within local areas. We sought to 1) determine the effects of deer browsing on corn and soybean yields and investigate if deer density or field morphology correlated to yield loss in western Kentucky, and 2) compare pellet-based distance sampling to game camera surveys to determine if a distance sampling technique could accurately estimate deer density during the growing season. Overall, deer reduced corn and soybean yields on one-half of surveyed properties. Deer density …

Miniscule Differences Between Sex Chromosomes In The Giant Genome Of A Salamander, Melissa C. Keinath, Nataliya Y. Timoshevskaya, Vladimir A. Timoshevskiy, S. Randal Voss, Jeramiah J. Smith

Biology Faculty Publications

In the Mexican axolotl (Ambystoma mexicanum), sex is determined by a single Mendelian factor, yet its sex chromosomes do not exhibit morphological differentiation typical of many vertebrate taxa that possess a single sex-determining locus. As sex chromosomes are theorized to differentiate rapidly, species with undifferentiated sex chromosomes provide the opportunity to reconstruct early events in sex chromosome evolution. Whole genome sequencing of 48 salamanders, targeted chromosome sequencing and in situ hybridization were used to identify the homomorphic sex chromosome that carries an A. mexicanum sex-determining factor and sequences that are present only on the W chromosome. Altogether, …

Meta-Analysis Challenges A Textbook Example Of Status Signalling And Demonstrates Publication Bias, Alfredo Sánchez-Tójar, Shinichi Nakagawa, Moisès Sánchez-Fortún, Dominic A. Martin, Sukanya Ramani, Antje Girndt, Veronika Bókony, Bart Kempenaers, András Liker, David F. Westneat, Terry Burke, Julia Schroeder

Biology Faculty Publications

The status signalling hypothesis aims to explain within-species variation in ornamentation by suggesting that some ornaments signal dominance status. Here, we use multilevel meta-analytic models to challenge the textbook example of this hypothesis, the black bib of male house sparrows (Passer domesticus). We conducted a systematic review, and obtained primary data from published and unpublished studies to test whether dominance rank is positively associated with bib size across studies. Contrary to previous studies, the overall effect size (i.e. meta-analytic mean) was small and uncertain. Furthermore, we found several biases in the literature that further question the support available …

The Evolutionary History Of Nebraska Deer Mice: Local Adaptation In The Face Of Strong Gene Flow, Susanne P Pfeifer, Stefan Laurent, Vitor C. Sousa, Catherine R. Linnen, Matthieu Foll, Laurent Excoffier, Hopi E. Hoekstra, Jeffrey D. Jensen

Biology Faculty Publications

The interplay of gene flow, genetic drift, and local selective pressure is a dynamic process that has been well studied from a theoretical perspective over the last century. Wright and Haldane laid the foundation for expectations under an island-continent model, demonstrating that an island-specific beneficial allele may be maintained locally if the selection coefficient is larger than the rate of migration of the ancestral allele from the continent. Subsequent extensions of this model have provided considerably more insight. Yet, connecting theoretical results with empirical data has proven challenging, owing to a lack of information on the relationship between genotype, phenotype, …

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 …

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

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 …

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, …

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

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. …