Browsing Biology Faculty Research, Publications and Presentations by Title
Now showing items 113-132 of 185
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Natural Selection, Variation, Adaptation, and Evolution: a Primer of Interrelated Concepts
Natural selection is an elegantly simple concept but one that can manifest in complex ways. I review how the basic model of single-trait viability selection has been extended to more complex forms of selection on multiple ... -
Non-linear genetic isolation by distance: implications for dispersal estimation in anadromous and marine fish populations
Indirect genetic approaches such as those based on the association between genetic and geographic distance (isolation by distance, IBD) may provide one of the best means of estimating dispersal in marine systems. We ... -
Non-Occurrence of Free-Living Paramoeba-Invadens in Water and Sediments of Halifax Harbour Nova Scotia Canada
Seawater and sediment samples from various sites in or near Halifax Harbour were cultured for Paramoeba as were tissues of the natural sea urchin host Stronglyocentrotus droebachiensis sampled from Halifax Harbour. An ... -
Nonbreeding-Season Drivers of Population Dynamics in Seasonal Migrants: Conservation Parallels Across Taxa
For seasonal migrants, logistical constraints have often limited conservation efforts to improving survival and reproduction during the breeding season only. Yet, mounting empirical evidence suggests that events occurring ... -
Nucleotide sequence of 5S rDNA and localization of the ribosomal RNA genes to metaphase chromosomes of the Tilapiine cichlid fish, Oreochromis niloticus
In this study, we report the cloning and nucleotide sequence of PCR-generated 5S rDNA from the Tilapiine cichlid fish, Oreochromis niloticus. Two types of 5S rDNA were detected that differed by insertions and/or deletions ... -
Nucleotide sequence, genomic organization and evolution of a major repetitive DNA family in tilapia (Oreochromis mossambicus/hornorum )
A highly repetitive DNA sequence from tilapia (Oreochromis mossambicus/hornorum ) has been cloned and sequenced. It is a tandemly arrayed sequence of 237 bp and constitutes 7% of the fish genome. The copy number of the ... -
Observer Effects and Avian-Call-Count Survey Quality: Rare-Species Biases and Overconfidence
Wildlife monitoring surveys are prone to nondetection errors and false positives. To determine factors that affect the incidence of these errors, we built an Internet-based survey that simulated avian point counts, and ... -
Otolith elemental composition and adult tagging reveal spawning site fidelity and estuarine dependency in rainbow smelt
Observations of homing and straying in marine organisms based on traditional Eulerian approaches may fail to resolve dispersal kernels or be unable to differentiate homing from invariant local residency, The roles of ... -
Overestimating Fish Counts by Non-Instantaneous Visual Censuses: Consequences for Population and Community Descriptions
Background: Increasingly, underwater visual censuses (UVC) are used to assess fish populations. Several studies have demonstrated the effectiveness of protected areas for increasing fish abundance or provided insight into ... -
Oxygen transport in egg masses of the amphibians Rana sylvatica and Ambystoma maculatum: Convection, diffusion and oxygen production by algae
Many amphibians lay their eggs in gelatinous masses up to 10-20 cm in diameter, posing problems for diffusive oxygen delivery. Oxygen may also be provided by water convection between eggs or by oxygen production by endogenous ... -
Pacific Salmon in Hot Water: Applying Aerobic Scope Models and Biotelemetry to Predict the Success of Spawning Migrations
Concern over global climate change is widespread, but quantifying relationships between temperature change and animal fitness has been a challenge for scientists. Our approach to this challenge was to study migratory ... -
Patch Dynamics of a Phytophagous Mite Population Effect of Number of Subpopulations
I conducted a field test of the hypothesis that the dynamics of a predator-prey interaction should be affected by the number of interacting subpopulations within an assemblage. I used a "successful" biological control ... -
Phylogenomic analysis of natural selection pressure in Streptococcus genomes
Background: In comparative analyses of bacterial pathogens, it has been common practice to discriminate between two types of genes: (i) those shared by pathogens and their non-pathogenic relatives (core genes), and (ii) ... -
Physical and biological factors influencing mussel (Mytilus trossulus, M. edulis) settlement on a wave-exposed rocky shore
Settlement rates of mussels Mytilus trossulus and M. edulis on artificial collectors (aquarium filter wool) and natural substrata were measured in tidepools and on emergent rock in recently ice-scoured and non-scoured ... -
Polar Bear Diets and Arctic Marine Food Webs: Insights from Fatty Acid Analysis
We used quantitative fatty acid signature analysis (QFASA) to examine the diets of 1738 individual polar bears (Ursus maritimus) sampled across the Canadian Arctic over a 30-year span. Polar bear foraging varied over ... -
Pollen limitation of plant reproduction: Ecological and evolutionary causes and consequences
Determining whether seed production is pollen limited has been an area of intensive empirical study over the last two decades. Yet current evidence does not allow satisfactory assessment of the causes or consequences of ... -
Population Structure as Revealed by mtDNA and Microsatellites in Northern Fur Seals, Callorhinus ursinus, throughout Their Range
Background: The northern fur seal (Callorhinus ursinus; NFS) is a widely distributed pinniped that has been shown to exhibit a high degree of philopatry to islands, breeding areas on an island, and even to specific ... -
Population-specific gene expression responses to hybridization between farm and wild Atlantic salmon
Because of intrinsic differences in their genetic architectures, wild populations invaded by domesticated individuals could experience population-specific consequences following introgression by genetic material of ... -
Positive Darwinian Selection in the Piston That Powers Proton Pumps in Complex I of the Mitochondria of Pacific Salmon
The mechanism of oxidative phosphorylation is well understood, but evolution of the proteins involved is not. We combined phylogenetic, genomic, and structural biology analyses to examine the evolution of twelve mitochondrial ... -
Potential for anthropogenic disturbances to influence evolutionary change in the life history of a threatened salmonid
Although evolutionary change within most species is thought to occur slowly, recent studies have identified cases where evolutionary change has apparently occurred over a few generations. Anthropogenically altered ...
