It has been widely reported that isoprene emissions from the Arctic ecosystem have a strong temperature response. Here we identify sedges (Carex spp. and Eriophorum spp.
View Article and Find Full Text PDFGlobally, human activities have resulted in rapid environmental changes that present unique challenges for wildlife. However, investigations of local adaptation in response to simultaneous exposure to multiple anthropogenic selection pressures are rare and often generate conflicting results. We used an in situ reciprocal transplant design within a quantitative genetic framework to examine how adaptive evolution and phenotypic plasticity contribute to the persistence of an amphibian population inhabiting an environment characterized by high levels of multiple toxic trace elements.
View Article and Find Full Text PDFAlthough pharmaceutical pollution is a global environmental concern, much remains unknown about the transformation of pharmaceuticals in the wild and their effects on wildlife. In the environment, pharmaceuticals typically transform to some extent into different, structurally related compounds. Pharmaceutical transformation products resulting from exposure to sunlight (i.
View Article and Find Full Text PDFDevelopment can play a critical role in how organisms respond to changes in the environment. Tolerance to environmental challenges can vary during ontogeny, with individual- and population-level impacts that are associated with the timing of exposure relative to the timing of vulnerability. In addition, the life history consequences of different stressors can vary with the timing of exposure to stress.
View Article and Find Full Text PDFBecause habitats are increasingly exposed to multiple stressors simultaneously, assessing the interactive effects of stressors is crucial for understanding how populations respond to human-altered habitats. Salinization of freshwater habitats is increasing and has the potential to interact with other stressors. Chemical pollutants also contribute to habitat degradation in freshwater environments, and both salinity and various pesticides can harm amphibians.
View Article and Find Full Text PDFGenetic variation in sexual displays is crucial for an evolutionary response to sexual selection, but can be eroded by strong selection. Identifying the magnitude and sources of additive genetic variance underlying sexually selected traits is thus an important issue in evolutionary biology. We conducted a quantitative genetics experiment with gray treefrogs (Hyla versicolor) to investigate genetic variances and covariances among features of the male advertisement call.
View Article and Find Full Text PDFAmphibian populations around the world have been declining at an alarming rate due to factors such as habitat destruction, pollution, and infectious diseases. Between May and July 2008, we investigated a fungal pathogen in the critically endangered Morelet's treefrog (Agalychnis moreletii) at sites in El Salvador. Larvae were screened with a hand lens for indications of infection with Batrachochytrium dendrobatidis (Bd), a fungus that can cause lethal chytridiomycosis in amphibians.
View Article and Find Full Text PDF"Good genes" models of sexual selection predict that male courtship displays can advertise genetic quality and that, by mating with males with extreme displays, females can obtain genetic benefits for their offspring. However, because the relative performance of different genotypes can vary across environments, these genetic benefits may depend on the environmental context; in which case, static mating preferences may not be adaptive. To better understand how selection acts on the preference that female gray tree frogs (Hyla versicolor) express for long advertisement calls, I tested for genetic benefits in two realistic natural environments, by comparing the performance of half-sibling offspring sired by males with long versus short calls.
View Article and Find Full Text PDFBotanophila flies act as "pollinating" parasites of the ascomycetous fungus, Epichloë elymi. Flies transfer fungal spermatia (gametes) among fungi as they visit their hosts for oviposition. Fly larvae consume the products of cross-fertilization (ascospores).
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