Insecticide Resistance Mechanisms in the Green Peach Aphid Myzus persicae (Hemiptera: Aphididae) II: Costs and Benefits

feeds upon a huge diversity of hosts, it has been exposed to a wide variety of plant allelochemicals, which probably have promoted a wide range of detoxification systems. on both hosts, but they increased the transcriptional levels of two genes. than susceptible genotypes on radish, the more unfavorable host. Susceptible genotypes should be able to tolerate the defended host by up-regulating some metabolic genes that are also responding to insecticides. Hence, our results suggest that the trade-off among resistance mechanisms might be quite complex, with a multiplicity of costs and benefits depending on the environment

Impact of global warming at the range margins: Phenotypic plasticity and behavioral thermoregulation will buffer an endemic amphibian

© 2014 The Authors. Ecology and Evolution published by John Wiley & Sons Ltd. When dispersal is not an option to evade warming temperatures, compensation through behavior, plasticity, or evolutionary adaptation is essential to prevent extinction. In this work, we evaluated whether there is physiological plasticity in the thermal performance curve (TPC) of maximum jumping speed in individuals acclimated to current and projected temperatures and whether there is an opportunity for behavioral thermoregulation in the desert landscape where inhabits the northernmost population of the endemic frog Pleurodema thaul. Our results indicate that individuals acclimated to 20°C and 25°C increased the breath of their TPCs by shifting their upper limits with respect to when they were acclimated at 10°C. In addition, even when dispersal is not possible for this population, the landscape is heterogeneous enough to offer opportunities for behavioral thermoregulation. In particular, under current climatic conditions, behavioral thermoregulation is not compulsory as available operative temperatures are encompassed within the population TPC limits. However, for severe projected temperatures under climate change, behavioral thermoregulation will be required in the sunny patches. In overall, our results suggest that this population of Pleurodema thaul will be able to endure the worst projected scenario of climate warming as it has not only the physiological capacities but also the environmental opportunities to regulate its body temperature behaviorally.Link_to_subscribed_fulltex

Data from: Integrated and independent evolution of heteromorphic sperm types

Sperm are a simple cell type with few components, yet they exhibit tremendous between-species morphological variation in those components thought to reflect selection in different fertilization environments. However, within a species, sperm components are expected to be selected to be functionally integrated for optimal fertilization of eggs. Here, we take advantage of within-species variation in sperm form and function to test whether sperm components are functionally and genetically integrated both within and between sperm morphologies using a quantitative genetics approach. Drosophila pseudoobscura males produce two sperm types with different functions but which positively interact together in the same fertilization environment; the long eusperm fertilizes eggs and the short parasperm appear to protect eusperm from a hostile female reproductive tract. Our analysis found that all sperm traits were heritable, but short sperm components exhibited evolvabilities 10 times that of long sperm components. Genetic correlations indicated functional integration within, but not between, sperm morphs. These results suggest that sperm, despite sharing a common developmental process, can become developmentally and functionally non-integrated, evolving into separate modules with the potential for rapid and independent responses to selection

Drosophila_pseudoobscura_quantitativegenetics_sperm_length_data

Data collected from D. pseudoobscura derived from Tucson Arizona but cultured in the lab. Using a quantitative genetics design in which sires were mated to multiple dams, we measured sperm head and flagellum length of short, nonfertilizing sperm and long, fertilizing sperm from sons. Data are represented in six columns: sire ID, dam ID, short sperm head length, short sperm flagellum length, long sperm head length, long sperm flagellum length

Geography, temperature, and water: Interaction effects in a small native amphibian

Amphibian locomotor capacity is strongly linked to temperature and hydration. However, organisms in nature experience covariation of multiple environmental factors, and thus to better understand the effects of thermal and hydric conditions on physiological performance, it is critical not only to experimentally disentangle them but also to incorporate potential interactive effects due to geographic variation. To this end, we selected two populations of the small amphibianPleurodema thaulinhabiting highly contrasting temperatures and precipitation regimens. With these two populations, we evaluated the thermal and hydric sensitivities of locomotor performance. For both factors, performance increased with temperature as well as with hydration level, although performance reached a plateau between 25 degrees and 30 degrees C. In addition, the influence of dehydration on performance was independent of the temperature at which it was tested. Our results also showed that the population from the warmer environment has lower sensitivity of locomotor performance to dehydration, probably as a consequence of thermal adaptation, although further studies might be required to fully understand this.Comisión Nacional de Investigación Científica y Tecnológica (CONICYT) CONICYT FONDECYT FONDECYT-115002

Sphagnum magellanicum growth and productivity in Chilean anthropogenic peatlands

Sphagnum peatlands are threatened at a global scale, not only by peat extraction, but also by Sphagnum harvesting. In Chile, dry Sphagnum moss is mainly exported for use as substrate for horticulture and orchids. Although the use of Sphagnum within Chile is limited, there are no data about its productivity and growth. These peatlands have a special microtopography with hummocks, hollows and lawns, which vary the distance of moss to the water table level. In these ecosystems, the water table is almost all year near the surface. We measured cumulative and relative growth rates and productivity during approximately one annual cycle in private Sphagnum peatlands that are being yearly harvested for commercial purposes. We evaluated the relationship between Sphagnum magellanicum growth and productivity with microtopography and water table depth. Productivity, cumulative and relative growths were higher in lawns than in hummocks. Overall and relative growth of S. magellanicum showed a negative relationship with depth of the water table. There were also differences between sites, some of them showed high growth rates, but low productivity. Sphagnum extraction in Chile, is now at low scale, but the growing international market demands constitute a real threat to the resource.Las turberas de Sphagnum están amenazadas a escala global, no solo por la extracción de turba, sino también por la cosecha de Sphagnum. En Chile, el musgo seco es importado principalemente para su uso como sustrato para la horticultura y cultivo de orquídeas. Aunque el uso del musgo en Chile es limitado, no existen datos sobre su productividad y crecimiento. Las turberas de Sphagnum tienen una microtopografía especial con cojines, zonas planas y zonas bajas o depresiones en el terreno, las que varían en la distancia del musgo a la napa freática. En estos ecosistemas, el nivel freático se encuentra gran parte del año muy cercano a la superfi cie. Se midieron las tasas de crecimiento acumulado y relativo por aproximadamente un ciclo anual en turberas de Sphagnum que se cosechan periódicamente para fi nes comerciales. Se evaluó la relación entre el crecimiento de Sphagnum magellanicum y la productividad con la microtopografía y la profundidad de la napa freática. La productividad, el crecimiento acumulado y relativo fueron mayores en zonas bajas que en cojines. El crecimiento total y relativo de S. magellanicum mostró una relación negativa con la profundidad de la napa freática. También se encontraron diferencias entre sitios, algunos mostraron mayores tasas de crecimiento en altura, pero menor productividad. La extracción de Sphagnum en Chile aún se realiza a baja escala, pero la creciente demanda del mercado internacional constituye una real amenaza para el musgo

Could plasticity mediate highlands lizards’ resilience to climate change? A case study of the leopard iguana (Diplolaemus leopardinus) in Central Andes of Argentina

The predicted rise of global temperatures is of major concern for ectotherms because of its direct impact on their behavior and physiology. As physiological performance mediates a species’ resilience to warming exposure, physiological plasticity could greatly reduce the susceptibility to climate change. We studied the degree to which Diplolaemus leopardinus lizards are able to adjust behavioral and physiological traits in response to short periods of temperature change. We used a split cross design to measure the acclimation response of preferred body temperature (Tp), and the thermal performance curve of resting metabolic rate (RMR) and evaporative water loss (EWL). Our results showed that plasticity differs among traits: whereas Tp and EWL showed lower values in warm conditions, the body temperature at which RMR was highest increased. Moreover, RMR was affected by thermal history, showing a large increase in response to cold exposure in the group initially acclimated to warm temperatures. The reduction of EWL and the increase in optimal temperature will give lizards the potential to partially mitigate the impact of rising temperatures in the energy cost and water balance. However, the decrease in Tp and the sensitivity to the warm thermal history of RMR could be detrimental to the energy net gain, increasing the species’ vulnerability, especially considering the increase of heat waves predicted for the next 50 years. The integration of acclimation responses in behavioral and physiological traits provides a better understanding of the range of possible responses of lizards to cope with the upcoming climatic and environmental modifications expected as a result of climate change.Fil: Vicenzi, Nadia Pamela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Investigaciones de las Zonas Áridas. Provincia de Mendoza. Instituto Argentino de Investigaciones de las Zonas Áridas. Universidad Nacional de Cuyo. Instituto Argentino de Investigaciones de las Zonas Áridas; ArgentinaFil: Bacigalupe, Leonardo D.. Universidad Austral de Chile; ChileFil: Laspiur, Julio Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; ArgentinaFil: Ibarguengoytía, Nora. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; ArgentinaFil: Sassi, Paola Lorena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Investigaciones de las Zonas Áridas. Provincia de Mendoza. Instituto Argentino de Investigaciones de las Zonas Áridas. Universidad Nacional de Cuyo. Instituto Argentino de Investigaciones de las Zonas Áridas; Argentin

Jacknife statistics of model performance and relative importance of each variable.

<p>For each species, the table shows the area under the curve (AUC) and regularized training gain (Gain). For each variable first value correspond to the gain of a model fitted using all variables except the focal one. The more important variable according to this criterion is marked with *. The second value corresponds to the gain of a model fitted using just the focal variable. The more important variable according to this criterion is marked with ^†, (see methods for details). Abbreviations as in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0102592#pone-0102592-t001" target="_blank">table 1</a>.</p

Geographical gradients in selection can reveal genetic constraints for evolutionary responses to ocean acidification

Geographical gradients in selection can shape different genetic architectures in natural populations, reflecting potential genetic constraints for adaptive evolution under climate change. Investigation of natural pH/pCO(2) variation in upwelling regions reveals different spatio-temporal patterns of natural selection, generating genetic and phenotypic clines in populations, and potentially leading to local adaptation, relevant to understanding effects of ocean acidification (OA). Strong directional selection, associated with intense and continuous upwellings, may have depleted genetic variation in populations within these upwelling regions, favouring increased tolerances to low pH but with an associated cost in other traits. In contrast, diversifying or weak directional selection in populations with seasonal upwellings or outside major upwelling regions may have resulted in higher genetic variances and the lack of genetic correlations among traits. Testing this hypothesis in geographical regions with similar environmental conditions to those predicted under climate change will build insights into how selection may act in the future and how populations may respond to stressors such as OA