A5076927265- Ecology and Vegetation Dynamics Studies
- Plant Taxonomy and Phylogenetics
- Plant and animal studies
- Botany, Ecology, and Taxonomy Studies
- Genetic diversity and population structure
- Species Distribution and Climate Change
- Plant Diversity and Evolution
- Evolution and Genetic Dynamics
- Chromosomal and Genetic Variations
- Plant Pathogens and Fungal Diseases
- Horticultural and Viticultural Research
- Rangeland and Wildlife Management
- Plant Reproductive Biology
- Plant Toxicity and Pharmacological Properties
- Botanical Research and Chemistry
- Genetically Modified Organisms Research
- Environmental Conservation and Management
- Lichen and fungal ecology
- Plant and fungal interactions
- Plant Ecology and Taxonomy Studies
- Botanical Research and Applications
- Yeasts and Rust Fungi Studies
- Plant Stress Responses and Tolerance
- Botany and Plant Ecology Studies
- Mycorrhizal Fungi and Plant Interactions
University of British Columbia
2010-2025
Université de Montréal
2008
Indiana University Bloomington
1995-1997
University of Connecticut
1994-1995
Burton Hospitals NHS Foundation Trust
1957
The Edgbaston Hospital
1954-1956
Faculty of 1000 (United Kingdom)
1956
City, University of London
1956
Norwood Hospital
1954
Abstract Genetic analyses of reproductive barriers represent one the few methods by which theories speciation can be tested. However, genetic study is often restricted to model organisms that have short generation times and are easily propagated in laboratory. Replicate hybrid zones with a diversity recombinant genotypes varying age offer increased resolution for mapping experiments expand pool amenable study. Using 88 markers distributed across 17 chromosomes, we analyze introgression...
Apomixis, the asexual production of seed, is a trait estimated to occur in fewer than 1% flowering plant species, with an uneven distribution among lineages. In past decade, targeted research efforts have aimed at clarifying genetic basis apomixis, goal engineering or breeding apomictic crops. Recent work suggests simple for but it also indicates that natural populations apomicts are much more complex often assumed. For example, nature, nearly all go through megagametophyte stage...
Abstract The univariate and multivariate study of variation for phenotypic plasticity is central to providing a clear understanding hypotheses about the genetic control evolution reaction norms in natural populations. Arabidopsis thaliana an ideal organism Genotype × Environment interactions (i.e., plasticity), because ease with which it can be grown large numbers due amount information already available on its genetics, physiology developmental biology. In this paper, we report plasticity,...
The meaningful incorporation of independent scientific advice into effective public policy is a hurdle for any conservation legislation. Canada's Species at Risk Act (SARA; 2002) was designed to separate the science-based determination species' risk status from decision award it legal protection. However, thereafter, input science has not been clearly identifiable. Audits SARA have identified clear deficiencies in protection and recovery luted species; example, 176 species legally protected...
Premise of the study: Constructing complete, accurate plant DNA barcode reference libraries can be logistically challenging for large‐scale floras. Here we demonstrate promise and challenges using herbarium collections building a library vascular flora Canada. Methods: Our study examined 20,816 specimens representing 5076 5190 species in Canada (98%). For 98% specimens, at least one regions was recovered from plastid loci rbcL matK nuclear ITS2 region. We used beta regression to quantify...
• Sodium, potassium, calcium, and magnesium ion uptake physiology tolerance to sodium were characterized in two edaphic races (A C) of closely related species the Lasthenia californica complex. Uptake rates race A plants 20-fold higher for Na + , 2-fold Ca 2+ Mg than those C plants. Race translocated c. 50% absorbed shoot compared with < 30% C. For corresponding values > 95% ≤ 50%, respectively. Germination, root growth survivorship estimates indicated greater by . Significant genotype...
Genetic variation, plasticity and genotype x environment interaction have been studied in four populations of Arabidopsis thaliana exposed to a set treatments including one 'optimal' three 'stressful' conditions. We found strong phenotypic for all nine traits measured, highly significant genetic variation among except two those directly related reproductive fitness the phenological, vegetative, early size fitness-related character. Flowering time life span formed distinct covariance clearly...
Abstract Lasthenia californica sensu Ornduff consists of two races that differ in their flavonoid pigments and edaphic tolerances. Recent phylogenetic studies have revealed members L . belong to species. The relationship the these new species each other is focus this study. Characterization profiles placement 33 populations demonstrates taxa are not concordant, suggesting one or both evolved parallel clades. We hypothesize an edaphically linked ecological role for differences first existence races.
Abstract Geographic patterns of parthenogenesis and the number transitions from sexual diploidy to asexual (apomictic) autopolyploidy were examined for 40 populations Easter daisy, Townsendia hookeri . Analyses pollen diameter stainability characterized 15 diploid 25 apomictic polyploid throughout plant's western North American range. Sexual diploids restricted two Wisconsin refugia: Colorado/Wyoming, south ice sheets, northern Yukon/Beringia. Chloroplast DNA sequencing uncovered 17...
Two edaphic races of Lasthenia californica sensu Ornduff (races A and C) grow in parapatry on a serpentine outcrop at Jasper Ridge Biological Preserve, California. The occupy distinct habitats that have different water‐holding capacities. We predict the two will show differentiation reproductive strategies related to their response water stress. In order test this hypothesis, we performed greenhouse experiment characterize reaction norms exposed gradient availability. measured five variables...
We used randomizations to analyse patterns of co-occurrence sexual and apomictic (asexual) members the North American Crepis agamic complex (Asteraceae). expect strong asymmetry in reproductive interactions : apomicts produce clonal seeds with no need for pollination are not subject interference from co-occurring relatives. However, because they still some viable pollen, can reduce success nearby relatives, potentially leading eventual local exclusion sexuals. Consistent this, reveal that...
British Columbia has the greatest biological diversity of any province or territory in Canada. Yet increasing numbers species are threatened with extinction. The current patchwork provincial laws and regulations not effectively prevented declines. Recently, Provincial Government committed to enacting an endangered law. Drawing upon our scientific legal expertise, we offer recommendations for key features legislation that build strengths avoid weaknesses observed elsewhere. We recommend...
The Lactuceae is perhaps the most easily recognizable tribe in Asteraceae, distinguished by presence of milky latex and ligulate florets inflorescence. Three existing taxonomic treatments establish subtribal classifications but fail to resolve relationships among major lineages. Our study chloroplast DNA restriction site variation sampled 60 taxa. We detected 1268 mutations, 612 which are phylogenetically informative. Despite large amount detected, little resolution lineages was obtained...
Abstract Forecasting how climate change will impact biological systems represents a grand challenge for biologists. However, biology lacks an effective framework anticipating and resolving uncertainty. Here, we introduce the concept of wildcards: or bioclimatic processes with high degree uncertainty large on our ability to address biotic consequences change. Wildcards may occur at multiple points in progression research—from understanding, predicting, forecasting responses. Our understanding...
Since the implementation of Canadian Species at Risk Act (SARA) in 2003, deficiencies SARA and its application have become clear. Legislative policy inconsistencies among responsible federal agencies use a subjective approach for prioritizing species protection lead to taxonomic biases protection. Variations legislation provinces/territories reluctance government take actions make SARA’s often inefficient on nonfederally managed lands. Ambiguous key terms (e.g., critical habitat) disregard...
Biologists and philosophers of science have been unable to fully resolve the decades-long controversy as what kind unit living biodiversity should receive valued label “species”: reproductive communities (among sexual organisms), genealogical groups, or clusters organisms that share traits. Among these choices, which represent a spectrum from process history observable outcome (respectively), latter (more operationalist) concepts are not viable. Species must embody imply cohesive integrating...
Numerous studies have found a positive association between dioecy and polyploidy; however, this presents theoretical conflict: While polyploids are predicted to benefit from self-reproduction for successful establishment, dioecious species cannot self-reproduce. We propose framework resolve apparent conflict. hypothesize that the inability of self-reproduce hinders their establishment as polyploids. therefore expect genera with many fewer polyploids, leading negative polyploidy across genera.
After a transition from sexuality to asexuality, the evolutionary dynamics in apomictic lineages will largely depend on frequency of recombination. We evaluated presence and extent asexuality recombination within populations Easter daisy, Townsendia hookeri, Yukon Territory, Canada. Amplified fragment‐length polymorphism (AFLP) fingerprints were used genotype 78 individuals four populations. Multilocus AFLP genotypes each population subjected tests for deviations free among loci, long‐term...