Open Access. Powered by Scholars. Published by Universities.®
- Discipline
- Keyword
-
- Predation (3)
- Adaptation (1)
- Age-specific mortality hypothesis (1)
- Brachyrhaphis rhabdophora (1)
- COR theory (1)
-
- Costa Rica (1)
- Economics (1)
- Elasticity analysis (1)
- Endangered species (1)
- Foreign direct investment (1)
- Freshwater fish (1)
- Geometric morphometrics (1)
- Globalization (1)
- Immunocompetence (1)
- Leatherside chub (1)
- Life history (1)
- Live-bearer (1)
- Morphology (1)
- Mortality rates (1)
- Natural selection (1)
- PHA (1)
- Poeciliidae (1)
- Population growth rate (1)
- Population matrix modeling (1)
- Postconflict (1)
- Posttraumatic stress (1)
- Poverty (1)
- Prey (1)
- Reproduction (1)
- Resource allocation (1)
Articles 1 - 7 of 7
Full-Text Articles in Entire DC Network
Predators As Agents Of Selection And Diversification, Jerald B. Johnson, Mark C. Belk
Predators As Agents Of Selection And Diversification, Jerald B. Johnson, Mark C. Belk
Faculty Publications
Predation is ubiquitous in nature and can be an important component of both ecological and evolutionary interactions. One of the most striking features of predators is how often they cause evolutionary diversification in natural systems. Here, we review several ways that this can occur, exploring empirical evidence and suggesting promising areas for future work. We also introduce several papers recently accepted in Diversity that demonstrate just how important and varied predation can be as an agent of natural selection. We conclude that there is still much to be done in this field, especially in areas where multiple predator species prey …
Toward Understanding Posttraumatic Stress And Depression Among Trauma-Affected Widows In Sri Lanka, Jessica E. Lambert, Alyssa Banford Witting, Spencer James, Lakmal Ponnamperuma, Thulitha Wickrama
Toward Understanding Posttraumatic Stress And Depression Among Trauma-Affected Widows In Sri Lanka, Jessica E. Lambert, Alyssa Banford Witting, Spencer James, Lakmal Ponnamperuma, Thulitha Wickrama
Faculty Publications
Objective: In this study, we applied conservation of resources theory (Hobfoll, 1989) to explain high rates of depression and posttraumatic stress symptoms (PTSS) among war- and disaster-affected Tamil widows in the Eastern Province of Sri Lanka. We hypothesized exposure to potentially traumatic events and severity of current contextual problems would influence PTSS and depressive symptoms directly and indirectly through loss of psychological (view of self), environmental (sense of community), and energy (physical health) resources. Method: Trained research assistants interviewed a convenience sample (N = 381) of women, using established measures of the constructs of interest. Data were analyzed using …
North Versus South: The Effects Of Foreign Direct Investment And Historical Legacies On Poverty Reduction In Post-Đổi Mới Vietnam, Scott R. Sanders
North Versus South: The Effects Of Foreign Direct Investment And Historical Legacies On Poverty Reduction In Post-Đổi Mới Vietnam, Scott R. Sanders
Faculty Publications
This research examines the factors that account for variance in provincial poverty reduction rates between 2002 and 2008 in Vietnam. In particular, this paper uses spatial regression modeling to show that foreign direct investment (FDI) and the capitalist legacies of southern Vietnam significantly affected provincial poverty reduction during this time period. These findings suggest that although Vietnam as a whole has benefited from post-Đổi Mới economic reform and FDI, the historical capitalist legacies of the former Republic of Vietnam played a strong role in aiding provinces in the south in attracting FDI and subsequently reducing provincial poverty.
Morphological Convergence During Pregnancy Among Predator And Nonpredator Populations Of The Livebearing Fish Brachyrhaphis Rhabdophora (Teleostei: Poeciliidae), Jeff S. Wesner, Eric J. Billman, Adam Meier, Mark C. Belk
Morphological Convergence During Pregnancy Among Predator And Nonpredator Populations Of The Livebearing Fish Brachyrhaphis Rhabdophora (Teleostei: Poeciliidae), Jeff S. Wesner, Eric J. Billman, Adam Meier, Mark C. Belk
Faculty Publications
Predation can drive morphological divergence in prey populations, although examples of divergent selection are typically limited to nonreproductive individuals. In livebearing females, shape often changes drastically during pregnancy, reducing speed and mobility and enhancing susceptibility to predation. In the present study, we document morphological divergence among populations of nonreproductive female livebearing fish (Brachyrhaphis rhabdophora) in predator and nonpredator environments. We then test the hypothesis that shape differences among nonreproductive females are maintained among reproductive females between predator and nonpredator environments. Nonreproductive females in predator environments had larger caudal regions and more fusiform bodies than females in nonpredator environments; …
Differential Mortality Drives Life-History Evolution And Population Dynamics In The Fish Brachyrhaphis Rhabdophora, Jerald B. Johnson, J. Jaime Zuniga-Vega
Differential Mortality Drives Life-History Evolution And Population Dynamics In The Fish Brachyrhaphis Rhabdophora, Jerald B. Johnson, J. Jaime Zuniga-Vega
Faculty Publications
Life-history theory predicts that populations experiencing different levels of extrinsic mortality will evolve divergent reproductive strategies. Previous work in the live bearing fish Brachyrhaphis rhabdophora shows that individuals from populations that occur with piscivorous fish mature earlier and at smaller sizes and have more and smaller offspring than fish from populations without predators. However, until now, there have been no data to demonstrate that differences in mortality rates actually exist between predator and predator free sites. Here we present the results of a serial mark-recapture field study designed to estimate mortality rates in natural populations of B. rhabodophora from Costa …
Differential Resource Allocation In Deer Mice Exposed To Sin Nombre Virus, Eric Wilson, Erin M. Lehmer, Christine A. Clay, Stephen St. Jeor, Denise M. Dearing
Differential Resource Allocation In Deer Mice Exposed To Sin Nombre Virus, Eric Wilson, Erin M. Lehmer, Christine A. Clay, Stephen St. Jeor, Denise M. Dearing
Faculty Publications
The resource allocation hypothesis predicts that reproductive activity suppresses immunocompetence; however, this has never been tested in an endemic disease system with free-ranging mammals. We tested the resource allocation hypothesis in wild deer mice (Peromyscus maniculatus) with natural exposure to Sin Nombre Virus (SNV). Immunocompetence was estimated from the extent of swelling elicited after deer mice were injected with phytohemagglutinin (PHA); swelling is positively correlated with immunocompetence. After livetrapping deer mice, we determined their reproductive state and SNV infection status. Males were more likely to be seropositive for SNV than females (37% vs. 25%) and exhibited 10% less swelling after …
Biological Status Of Leatherside Chub: A Framework For Conservation Of Western Freshwater Fishes, Mark C. Belk, Jerald B. Johnson
Biological Status Of Leatherside Chub: A Framework For Conservation Of Western Freshwater Fishes, Mark C. Belk, Jerald B. Johnson
Faculty Publications
Outside of anadromous salmonids and a few endangered species, biology of native freshwater fishes of western North America is poorly known. What do we need to know to effectively manage native species and avoid decline and extinction? A recent analysis of the role of science in the Pacific salmon controversy outlines a clear framework for biological evaluation and management of native species. This framework has three components: (1) determine status of populations based on genetic and ecological variation, (2) identify and quantify threats to populations, and (3) determine actions to alleviate threats and promote conservation of populations. We use our …