Following human occupation, the house mouse has colonized numerous islands, exposing the species to a wide variety of environments. Such a colonization process, involving successive founder events and bottlenecks, may either promote random evolution or facilitate adaptation, making the relative importance of adaptive and stochastic processes in insular evolution difficult to assess. Here, we jointly analyse genetic and morphometric variation in the house mice (Mus musculus domesticus) from the Orkney archipelago. Genetic analyses, based on...

4 dataset corresponding to the four models described.

Although the diversity of bacterial endosymbionts in arthropods is well documented, whether and how such diversity is maintained remains an open question. We investigated the temporal changes occurring in the prevalence and composition of endosymbionts after transferring natural populations of Tetranychus spider-mites from the field to the laboratory. These populations, belonging to three different Tetranychus species (T. urticae, T. ludeni and T. evansi) carried variable infection frequencies of Wolbachia, Cardinium, and Rickettsia. We report a...

Aerobic metabolism of aquatic ectotherms is highly sensitive to fluctuating climates. Many mitochondrial traits exhibit phenotypic plasticity in response to acute variations in temperature and oxygen availability. These responses are critical for understanding the effects of environmental variations on aquatic ectotherms performance. Using the European seabass, Dicentrarchus labrax, we determined the effects of acute warming and deoxygenation in vitro on mitochondrial respiratory capacities and mitochondrial efficiency to produce ATP (ATP/O ratio). We show that acute...

Most birds incubate their eggs to allow embryo development. This behaviour limits the ability of adults to perform other activities. Hence, incubating adults trade-off incubation and nest protection with foraging to meet their own needs. Parents can either cooperate to sustain this trade-off or incubate alone. The main cause of reproductive failure at this reproductive stage is predation and adults reduce this risk by keeping the nest location secret. Arctic sandpipers are interesting biological models...

Territorial animals are expected to adjust their response to intruders according to the perceived threat-level. One of the factors that drives threat-level is the identity of the intruder. The dear enemy phenomenon theory postulates that individuals should respond with lower intensity to neighbors, already possessing a territory, than to strangers that may fight to evict them. In social species, the hierarchical status of the intruder might also mediate this response. Such behavioral adjustments presuppose a...

1. Trophic selectivity has major influences on consumers’ fitness, stability of predator and prey populations, and nutrient fluxes in food webs. Trophic selectivity occurs when the relative abundances of resources in a consumer's diet differ from their relative abundances in the environment. This discrepancy between resources abundance and use has been predicted to increase with the availability of resources in the environment. Trophic selectivity has also been predicted to increase with the heterogeneity of resources...

Changes in climate can alter individual body size, and the resulting shifts in reproduction and survival are expected to impact population dynamics and viability. However, appropriate methods to account for size-dependent demographic changes are needed, especially in understudied yet threatened groups such as amphibians. We investigated individual and population-level demographic effects of changes in body size for a terrestrial salamander using capture-mark-recapture data. For our analysis, we implemented an integral projection model parameterized with capture-recapture...

Widespread preservation of fossilized biomolecules in many fossil animals has recently been reported in six studies, based on Raman microspectroscopy. Here, we show that the putative Raman signatures of organic compounds in these fossils are actually instrumental artefacts resulting from intense background luminescence. Raman spectroscopy is based on the detection of photons scattered inelastically by matter upon its interaction with a laser beam. For many natural materials, this interaction also generates a luminescence signal that...