A5027782495- Plant and animal studies
- Ecology and Vegetation Dynamics Studies
- Genetic diversity and population structure
- Evolution and Genetic Dynamics
- Genetic Mapping and Diversity in Plants and Animals
- Genomics and Phylogenetic Studies
- Chromosomal and Genetic Variations
- Weed Control and Herbicide Applications
- Plant Parasitism and Resistance
- Plant Reproductive Biology
- Plant Diversity and Evolution
- Gene Regulatory Network Analysis
- Rangeland and Wildlife Management
- Animal Behavior and Reproduction
- Species Distribution and Climate Change
- Forest Insect Ecology and Management
- Plant Molecular Biology Research
- Coastal wetland ecosystem dynamics
- Microbial Community Ecology and Physiology
- Plant-Microbe Interactions and Immunity
- Animal Ecology and Behavior Studies
- Environmental DNA in Biodiversity Studies
- Genetic and phenotypic traits in livestock
- Bioinformatics and Genomic Networks
- Classical Philosophy and Thought
University of Georgia
2005-2021
University of Chicago
1997-2003
John Brown University
2002
Duke University
1990-1998
Harvard University
1990
Although biologists have long assumed that plant resistance characters evolved under selection exerted by such natural enemies as herbivores and pathogens, experimental evidence for this assumption is sparse. We present exert on particular characters. Specifically, we demonstrate elimination of from an field population Arabidopsis thaliana alters the pattern genetic variation in two been shown to reduce herbivore damage field: total glucosinolate concentration trichome density. The change...
Plants can employ two general strategies to defend themselves against herbivory: they either reduce the amount of damage experience (resistance), or tolerate herbivore damage. Theoretical considerations suggest that, in many cases, tolerance and resistance are redundant strategies, may therefore be mutually exclusive adaptations. In this investigation natural populations annual plant Arabidopsis thaliana we examine whether pattern selection acting on favors evolution one defense strategy,...
The annual plant Arabidopsis thaliana is widely used as a model system in molecular genetics, but little known about populations the field. In this experimental field study of natural Arabidopsis, I tested assumption that resistance has fitness costs. Models evolution assume cost, which envisioned reduction absence enemies, such insect herbivores and pathogens. presumed basis cost diversion limiting resources away from present future growth reproduction. Recent failures to detect allocation...
Measuring natural selection has been a fundamental goal of evolutionary biology for more than century, and techniques developed in the last 20 yr have provided relatively simple means biologists to do so. Many these techniques, however, share common limitation: when applied phenotypic data, environmentally induced covariances between traits fitness can lead biased estimates misleading predictions about change. Utilizing breeding values instead data with methods eliminate bias, although this...
Abstract Pathogen resistance is an ecologically important phenotype increasingly well understood at the molecular genetic level. In this article, we examine levels of avrRpt2-dependent and Rps2 locus DNA sequence variability in a worldwide sample 27 accessions Arabidopsis thaliana. The rooted parsimony tree sequences drawn from diverse set ecotypes includes deep bifurcation separating major susceptibility clades alleles. We find evidence for selection maintaining these alleles identify...
We investigated how the pattern of leaf damage influences reproduction, growth, and allocation in wild radish, Raphanus sativus (Brassicaceae). removed an equivalent area from plants with four leaves five treatments ranging concentrated to dispersed damage: one entire mature removed, on new 50% two 25% all removed. Plants a control group were undamaged. Reproduction, not affected by age damaged leaf. However, significantly our three measures plant fitness: number flowers produced,...
Molecular ecologists seek to genotype hundreds thousands of loci from individuals at minimal cost per sample. Current methods, such as restriction-site-associated DNA sequencing (RADseq) and sequence capture, are constrained by costs associated with inefficient use data sample preparation. Here, we introduce RADcap, an approach that combines the major benefits RADseq (low specific start positions) those capture (repeatable loci) significantly increase efficiency reduce relative current...
Molecular ecologists frequently use genome reduction strategies that rely upon restriction enzyme digestion of genomic DNA to sample consistent portions the from many individuals (e.g., RADseq, GBS). However, researchers often find existing methods expensive initiate and/or difficult implement consistently, especially because it is multiplex sufficient numbers samples fill entire sequencing lanes. Here, we introduce a low-cost and highly robust approach for construction dual-digest RADseq...
Next-generation sequencing (NGS) of amplicons is used in a wide variety contexts. In many cases, NGS amplicon remains overly expensive and inflexible, with library preparation strategies relying upon the fusion locus-specific primers to full-length adapter sequences single identifying sequence or ligating adapters onto PCR products. Adapterama I, we presented universal stubs produce thousands unique index combinations modifiable system for incorporating them into Illumina libraries. Here,...
Abstract The extent to which epistasis contributes adaptation, population differentiation, and speciation is a long-standing important problem in evolutionary genetics. Using recombinant inbred (RI) lines of Arabidopsis thaliana grown under natural field conditions, we have examined the genetic architecture fitness-correlated traits with respect epistasis; identified both single-locus additive two-locus epistatic QTL for variation fruit number, germination, seed length width. For found seven...
Glyphosate, the active ingredient in herbicide RoundUp, has increased dramatically use over past decade and constitutes a potent anthropogenic source of selection. In southeastern United States, weedy morning glories have begun to develop tolerance glyphosate, representing unique opportunity examine evolutionary genetics novel trait. We found genetic variation for tolerance, indicating potential population respond selection by glyphosate. However, following significant constraint exists:...
Abstract In salt marsh habitats, noted for their extreme environments, a widely held assumption is that few large clones dominate plant populations. Using number of polymorphic genetic markers, we were able to test this two plants known span salinity gradients. For both species, clonal diversity was surprisingly high across populations: Simpson's indices 0.96 and 0.99. Although high, there no pattern association between specific or alleles with microhabitat. Our findings suggest sexual...
Evolutionary biologists explain the maintenance of intermediate levels defense in plant populations as being due to trade-offs, or negative genetic covariances among ecologically important traits. Attempts at detecting trade-offs constraints on evolution have not always been successful, leading some conclude that such rarely current population. Using agricultural pest Ipomoea purpurea, we measured correlations between traits involved glyphosate, active ingredient Roundup, a widely used...
Abstract We investigated neutral genetic variation within and among 53 wild‐collected populations of the weedy annual plant, Arabidopsis thaliana , in North America, using amplified fragment length polymorphism (AFLP) markers. A. is thought to have been introduced America from Eurasia by humans; such an introduction might be expected leave a clear geographical signal data. To detect patterns, we sampled at several hierarchical levels. collected individuals two areas Southeast one Midwest, as...
Abstract. 1. To examine ecological and evolutionary aspects of caterpillar foraging behaviour, this study focused on observation the individual behaviour two lepidopteran species, Pieris rapae L. Euphydryas phaeton (Drury), their respective host plants. 2. Periodic observations over course a day showed that larvae move considerable distances, forage upper surfaces leaves, often immediately leave areas from which they have fed, leaving pattern dispersed herbivory. 3. Differences in were not...