Ecology and Evolutionary Biology Commons^™

Explosive Diversification Following A Benthic To Pelagic Shift In Freshwater Fishes, Phillip R. Hollingsworth Jr., A M. Simons, J A. Fordyce, C D. Hulsey

Faculty Publications and Other Works -- Ecology and Evolutionary Biology

BACKGROUND:

Interspecific divergence along a benthic to pelagic habitat axis is ubiquitous in freshwater fishes inhabiting lentic environments. In this study, we examined the influence of this habitat axis on the macroevolution of a diverse, lotic radiation using mtDNA and nDNA phylogenies for eastern North America's most species-rich freshwater fish clade, the open posterior myodome (OPM) cyprinids. We used ancestral state reconstruction to identify the earliest benthic to pelagic transition in this group and generated fossil-calibrated estimates of when this shift occurred. This transition could have represented evolution into a novel adaptive zone, and therefore, we tested for a period …

Fire Promotes Pollinator Visitation: Implications For Ameliorating Declines Of Pollination Services, Michael E. Van Nuland, Elliot N. Haag, Jessica Am Bryant, Quentin D. Read, Robert N. Klein, Morgan J. Douglas, Courtney E. Gorman, Trey D. Greenwell, Mark W. Busby, Jonathan Collins, Joseph T. Leroy, George Schuchmann, Jennifer A. Schweitzer, Joseph K. Bailey

Faculty Publications and Other Works -- Ecology and Evolutionary Biology

Pollinators serve critical roles for the functioning of terrestrial ecosystems, and have an estimated annual value of over $150 billion for global agriculture. Mounting evidence from agricultural systems reveals that pollinators are declining in many regions of the world, and with a lack of information on whether pollinator communities in natural systems are following similar trends, identifying factors which support pollinator visitation and services are important for ameliorating the effects of the current global pollinator crisis. We investigated how fire affects resource structure and how that variation influences floral pollinator communities by comparing burn versus control treatments in a southeastern …

Introgressive Hybridization In A Trophically Polymorphic Cichlid, C Darrin Hulsey, Francisco J. García-De-León

Faculty Publications and Other Works -- Ecology and Evolutionary Biology

Trophically polymorphic species could represent lineages that are rapidly diverging along an ecological axis or could phenotypically mark the collapse of species through introgressive hybridization. We investigated patterns of introgression between the trophically polymorphic cichlid fish Herichthys minckleyi and its relative H. cyanoguttatus using a combination of population genetics and species tree analyses. We first examined the distribution of mitochondrial haplotypes within the alternative H. minckleyi pharyngeal jaw morphotypes that are endemic to the small desert valley of Cuatro Ciénegas. We recovered two clusters of mitochondrial haplotypes. The first contained a number of slightly differentiated cytochrome b (cytb) …

Genetic Variation In Hippocampal Microrna Expression Differences In C57bl/6 J X Dba/2 J (Bxd) Recombinant Inbred Mouse Strains, Michael J. Parsons, Christina Grimm, Jose L. Paya-Cano, Cathy Fernandes, Lin Liu, Vivek M. Philip, Elissa J. Chesler, Wilfried Neitfeld, Hans Lehrach, Leonard C. Schalkwyk

Faculty Publications and Other Works -- Ecology and Evolutionary Biology

Background

miRNAs are short single-stranded non-coding RNAs involved in post-transcriptional gene regulation that play a major role in normal biological functions and diseases. Little is currently known about how expression of miRNAs is regulated. We surveyed variation in miRNA abundance in the hippocampus of mouse inbred strains, allowing us to take a genetic approach to the study of miRNA regulation, which is novel for miRNAs. The BXD recombinant inbred panel is a very well characterized genetic reference panel which allows quantitative trait locus (QTL) analysis of miRNA abundance and detection of correlates in a large store of brain and behavioural …

Frequency-Dependent Selection By Wild Birds Promotes Polymorphism In Model Salamanders, Benjamin M. Fitzpatrick, Kim Shook, Reuben Izally

Faculty Publications and Other Works -- Ecology and Evolutionary Biology

Background

Co-occurrence of distinct colour forms is a classic paradox in evolutionary ecology because both selection and drift tend to remove variation from populations. Apostatic selection, the primary hypothesis for maintenance of colour polymorphism in cryptic animals, proposes that visual predators focus on common forms of prey, resulting in higher survival of rare forms. Empirical tests of this frequency-dependent foraging hypothesis are rare, and the link between predator behaviour and maintenance of variation in prey has been difficult to confirm. Here, we show that predatory birds can act as agents of frequency-dependent selection on terrestrial salamanders. Polymorphism for presence/absence of …

Belowground Interactions Shift The Relative Importance Of Direct And Indirect Genetic Effects, M A. Genung, J K. Bailey, J A. Schweitzer

Faculty Publications and Other Works -- Ecology and Evolutionary Biology

Intraspecific genetic variation can affect decomposition, nutrient cycling, and interactions between plants and their associated belowground communities. However, the effects of genetic variation on ecosystems can also be indirect, meaning that genes in a focal plant may affect ecosystems by altering the phenotype of interacting (i.e., neighboring) individuals. We manipulated genotype identity, species identity, and the possibility of belowground interactions between neighboring Solidago plants. We hypothesized that, because our plants were nitrogen (N) limited, the most important interactions between focal and neighbor plants would occur belowground. More specifically, we hypothesized that the genotypic identity of a plant's neighbor would have …

Alternative Forms For Genomic Clines, Benjamin M. Fitzpatrick

Faculty Publications and Other Works -- Ecology and Evolutionary Biology

Understanding factors regulating hybrid fitness and gene exchange is a major research challenge for evolutionary biology. Genomic cline analysis has been used to evaluate alternative patterns of introgression, but only two models have been used widely and the approach has generally lacked a hypothesis testing framework for distinguishing effects of selection and drift. I propose two alternative cline models, implement multivariate outlier detection to identify markers associated with hybrid fitness, and simulate hybrid zone dynamics to evaluate the signatures of different modes of selection. Analysis of simulated data shows that previous approaches are prone to false positives (multinomial regression) or …

Long-Term Insect Herbivory Slows Soil Development In An Arid Ecosystem, Aimee T. Classen, Samantha K. Chapman, Thomas G. Whitham, Stephen C. Hart, George W. Koch

Faculty Publications and Other Works -- Ecology and Evolutionary Biology

Although herbivores are well known to alter litter inputs and soil nutrient fluxes, their long-term influences on soil development are largely unknown because of the difficulty of detecting and attributing changes in carbon and nutrient pools against large background levels. The early phase of primary succession reduces this signal-to-noise problem, particularly in arid systems where individual plants can form islands of fertility. We used natural variation in tree-resistance to herbivory, and a 15 year herbivore-removal experiment in an Arizona piñon-juniper woodland that was established on cinder soils following a volcanic eruption, to quantify how herbivory shapes the development of soil …

Biogeography Of The Ecosystems Of The Healthy Human Body, Yanjiao Zhou, Hongyu Gao, Kathie A. Mihindukulasuriya, Patricio S. La Rosa, Kristine M. Wylie, Tatiana Vishnivetskaya, Mircea Podar, Barb Warner, Phillip I. Tarr, David E. Nelson, J. D. Fortenberry, Martin Holland, Sarah E. Burr, William D. Shannon, Erica Sodergren, George M. Weinstock

Faculty Publications and Other Works -- Ecology and Evolutionary Biology

Background

Characterizing the biogeography of the microbiome of healthy humans is essential for understanding microbial associated diseases. Previous studies mainly focused on a single body habitat from a limited set of subjects. Here, we analyzed one of the largest microbiome datasets to date and generated a biogeographical map that annotates the biodiversity, spatial relationships, and temporal stability of 22 habitats from 279 healthy humans.

Results

We identified 929 genera from more than 24 million 16S rRNA gene sequences of 22 habitats, and we provide a baseline of inter-subject variation for healthy adults. The oral habitat has the most stable microbiota …

The Afterlife Of Interspecific Indirect Genetic Effects: Genotype Interactions Alter Litter Quality With Consequences For Decomposition And Nutrient Dynamics, Mark A. Genung, Joseph K. Bailey, Jennifer A. Schweitzer

Faculty Publications and Other Works -- Ecology and Evolutionary Biology

Aboveground-belowground linkages are recognized as divers of community dynamics and ecosystem processes, but the impacts of plant-neighbor interactions on these linkages are virtually unknown. Plant-neighbor interactions are a type of interspecific indirect genetic effect (IIGE) if the focal plant’s phenotype is altered by the expression of genes in a neighboring heterospecific plant, and IIGEs could persist after plant senescence to affect ecosystem processes. This perspective can provide insight into how plant-neighbor interactions affect evolution, as IIGEs are capable of altering species interactions and community composition over time. Utilizing genotypes of Solidago altissima and Solidago gigantea, we experimentally tested whether …