A5021929368- Plant and animal studies
- Ecology and Vegetation Dynamics Studies
- Plant Parasitism and Resistance
- Botany, Ecology, and Taxonomy Studies
- Plant Reproductive Biology
- Botany and Plant Ecology Studies
- Genetic diversity and population structure
- Rangeland and Wildlife Management
- Plant Water Relations and Carbon Dynamics
- Insect-Plant Interactions and Control
- Forest ecology and management
- Plant Pathogens and Fungal Diseases
- Hymenoptera taxonomy and phylogeny
- Mycorrhizal Fungi and Plant Interactions
- Insect and Arachnid Ecology and Behavior
- Lichen and fungal ecology
- Plant Diversity and Evolution
- Plant-Derived Bioactive Compounds
- Yeasts and Rust Fungi Studies
- Fungal Biology and Applications
- Chemical synthesis and alkaloids
- Forest Insect Ecology and Management
- Plant Pathogens and Resistance
- Soil and Environmental Studies
- Turfgrass Adaptation and Management
Morehouse College
2025
California State University, Chico
2009-2023
Missouri Botanical Garden
2007
North Carolina Agricultural and Technical State University
2005
Richard Bland College
2001-2004
Illinois Archaeological Survey
2004
University of Virginia
2003
Organization For Tropical Studies
2001
Florida International University
2001
University of Georgia
1999
The contribution of a pollinator toward plant fitness (i.e., its “effectiveness”) can determine importance for the plant's evolutionary ecology. We compared pollinators in population Asclepias incarnata (Apocynaceae) several components effectiveness over two flowering seasons to evaluate their reproduction. Insects order Hymenoptera predominate A. pollination, but there appears be no specialization pollination within this order. Pollinators varied significantly nearly every component that we...
Most models of mating system evolution predict mixed to be unstable, although it is commonly reported from nature. Ecological interactions with mutualistic pollinators can help account for this discrepancy, but antagonists such as herbivores are also likely play a role. In addition, inbreeding alter ecological and directly affect selfing rates, which may contribute maintaining variation. We explored herbivore effects on pollinator behavior rates in Mimulus guttatus . First, individual...
The remarkable diversity of mating patterns and sexual systems in flowering plants has fascinated evolutionary biologists for more than a century. Enduring questions about this topic include why polymorphisms have evolved independently over 100 plant families, proportions self- cross-fertilization often vary dramatically within among populations. Important new insights concerning the dynamics built upon strong foundation theoretical models innovative field laboratory experiments. However, as...
Self-fertilizing taxa are often found at the range margins of their progenitors, where sub-optimal habitats may select for alternative physiological strategies. The extent to which self-fertilization is favoured directly vs. arising indirectly through correlations with other adaptive life history traits unclear. Trait responses selection depend on genetic variation and covariation, as well phenotypic altered environmental conditions. We tested predictions hypothesis that in Mimulus arises...
In Drosophila melanogaster genetic screens are often used to identify genes associated with different biological processes. Here, we have utilized the Flp/FRT system generate mitotic clones within developing eye. These were screened for mutations that disrupt cell division, organ patterning, and growth. One such mutation from this screen, mutant M.3.2, resulted in an expansion of cuticle area normally covered by ommatidium as well overall smaller eye size. Genetic molecular mapping revealed...
Inbreeding, which is common in plants, may increase the vulnerability of populations to natural enemies. Similarly, enemies expression inbreeding depression their hosts, resulting altered selection on host mating-system evolution. To examine effects tolerance herbivory, we transplanted experimentally self- and cross-fertilized plants into four field Mimulus guttatus applied single Philaenus spumarius (spittlebug) nymphs half. At end growing season, scored for five fitness components...
Abstract Barriers to reproduction are often how progress in speciation is measured. Nonetheless, an unresolved question concerns the extent which reproductive barriers diminish gene flow between incipient species. The Sierra Nevada foothill endemic Mimulus glaucescens and widespread M. guttatus considered distinct species based on striking differences vegetative morphology, but have not been previously identified, nor has characterized. Here, we examined 15 potential within a Northern...
Abstract Three major hypotheses have been advanced for the adaptive nature of plant galls: nutrition, enemy‐avoidance, and microenvironment. Of these, microenvironment hypothesis has frequently invoked, but rarely tested directly. We this in a population Andricus quercuscalifornicus (Bassett) (Hymenoptera: Cynipidae) wasps inducing galls on Quercus lobata Née (Fagaceae) trees Northern California, USA. Relative humidity temperature data gathered from both immature mature field indicated that...
The extent of asexual reproduction and the spatial distribution clones can influence ecological evolutionary processes in populations. Sawgrass, Cladium jamaicense, which is dominant ecosystem component Florida Everglades, reproduce sexually asexually. We examined patterns genotypic diversity evaluated importance clonal Everglades populations C. using allozymes as genetic markers. sampled plants a replicated grid along 11‐m transects 18 sawgrass distributed throughout Everglades. Genotypic...
Background and Aims Mating systems of plants are diverse evolutionarily labile. Abiotic environmental factors, such as seasonal drought, may impose selection on physiological traits that could lead to transitions in mating system if genetically correlated with influence system. Within Clarkia, self-fertilizing taxa have higher photosynthetic rates, earlier flowering phenology, faster individual floral development more compressed periods than their outcrossing sister taxa, potentially...
In habitats where resource availability declines during the growing season, selection may favor early-flowering individuals. Under such ephemerally favorable conditions, late-blooming species (and individuals) be particularly vulnerable to limitation of seed production. California, a region prone seasonal drought, members annual genus Clarkia are among last flower in spring. We compared pollen (PL) set and outcrossing rates between early- late-flowering individuals two mixed-mating taxa...
Genetic diversity studies of wetland plants are scarce, but estimates genetic useful for learning about plant biology or developing appropriate management strategies. We used allozymes to examine patterns in Cladium jamaicense, the dominant species Florida Everglades. sampled 18 populations (a total 818 plants) a replicated grid pattern. Because C. jamaicense can reproduce asexually, we compared calculated using all ramets those only genets within populations. Fewer than half 13 loci studied...
Plant-pollinator interactions constitute one of the most widely recognized mutualisms, yet investigations focus on single species or specialized pollinators. We used multiple measures to evaluate efficiency and effectiveness a diverse assemblage pollinators three co-flowering species: Asclepias syriaca L., A. incarnata verticillata L. Hymenopterans exceeded other insects in their prevalence as major pollinators, but did not vary significantly among plant number flowers visited visit duration...
PREMISE OF THE STUDY: Local ecological conditions influence the impact of species interactions on evolution and community structure. We investigated whether pollinator‐mediated between coflowering plants vary with plant density, neighbor identity, flowering season. METHODS: conducted a field experiment in which time floral neighborhood were manipulated factorial design. Early‐ late‐flowering Clarkia unguiculata placed into arrays C. biloba neighbors, noncongeneric additional conspecific...
Oak leaf morphology is highly variable. Leaf shape in oaks has been shown to covary with climate, and dissection negatively correlated hydraulic resistance. Such patterns may reflect local adaptation of genotypes or plastic responses environments. We tested two hypotheses regarding variation Quercus lobata Née, a widely distributed oak tree endemic California, using subsamples trees from large provenance trial involving source populations throughout the species range. First, we hypothesis...
In multivariate regression, interest lies on how the response vector depends a set of covariates. A regression model is proposed where covariates explain variation in only direction first principal component axis. This not parsimonious, but it provides an easy interpretation allometric growth studies log-transformed data corresponds to constants growth. The naturally generalizes two–group extension situation groups differ according bootstrap test for and study plant Florida Everglades used...
WYATr, R. (Institute of Ecology, University Georgia, Athens, GA 30602), C. T IVEY AND S. LiPOW (Department Botany, 30602). The breeding system desert milkweed, Asclepias subulata. Bull. Torrey Bot. Club 123: 180-183. 1996.-Like most other species Asclepias, A. subulata is largely genetically self-incompatible; 99 cross-pollinations, 15 were successful, versus only 1 self-pollinations. number apparently viable seeds per cross-pollinated fruit was unexpectedly variable and low, averaging 98.5,...
Deciduous trees leaf out in the spring beginning with bud burst. Proximally, timing of that process is triggered by temperature, but natural selection on burst may have acted local populations through additional factors, such as frost damage, insect herbivores and fungal pathogens. Valley Oak, Quercus lobata Née, a deciduous California endemic tree species shapes ecosystems where it found. We examined phenology collected from 674 maternal families across range, grown two replicate common...