Search results for "PHI"
showing 10 items of 28259 documents
Microevolutionary relationships between phylogeographical history, climate change and morphological variability in the common vole (Microtus arvalis)…
2011
Aim In this study, we analyse microevolutionary processes in common voles (Microtus arvalis) through the investigation of tooth morphological structure, in order to assess the relative impact of climate and phylogeographical history. Microevolutionary studies have shown that climate change may play a role in both population phylogeography and phenotypic differentiation. However, relatively little is known about the precise relationship between phylogeography and phenotypic variability and about how organisms respond to climate change. Location France, from sea level to the Alps (5 to > 2300 m a.s.l.). Methods This morphological analysis is based on first lower molar measurements from 16 geo…
PERMANENT GENETIC RESOURCES: Polymorphic microsatellite loci and interspecific cross-amplification in the parasitoid wasps Megastigmus stigmatizans a…
2008
We isolated and characterized 19 polymorphic microsatellite loci in the congeneric parasitoid wasps Megastigmus stigmatizans and Megastigmus dorsalis associated with cynipid oak galls. Loci isolated from species-specific libraries showed extensive cross-amplification, resulting in a total of 15 polymorphic loci for M. stigmatizans and 13 for M. dorsalis.
Blood parasites mediate morph-specific maintenance costs in a colour polymorphic wild bird
2011
Parasites can mediate profound negative effects on host fitness. Colour polymorphism has been suggested to covary genetically with intrinsic physiological properties. Tawny owl colour polymorphism is highly heritable with two main morphs, grey and brown. We show that experimental medication acts to reduce blood parasites and that medicated grey females maintain body mass during breeding, whereas medicated brown females decline in body mass similar to control females of both morphs. We find no effect of medication on general immunoglobulin levels, antigen-specific humoral response or H/L ratio. In the descriptive data, both morphs have similar blood parasite infection rates, but blood parasi…
Do colour morphs of wall lizards express different personalities?
2021
Abstract Colour morphs sometimes have different behavioural strategies which may be maintained by frequency or density dependence mechanisms. We investigated temporal changes in behavioural reaction to a novel environment among colour morphs (yellow, orange, white) of the European wall lizard (Podarcis muralis). Adult males were given two 15 min experimental trials, and their locomotion was highly consistent between the two trials. Boldness, freezing and escape behaviour were less repeatable. Colour morphs differed in their locomotion and freezing behaviour. Boldness was similar among the morphs, whereas escape behaviour was lowest in yellow morph. Consequently, yellow morph males tended to…
Fight or flight trade-offs and the defensive behaviour of the mountain katydid, Acripeza reticulata
2020
The defensive repertoires of prey are shaped by diverse ecological and evolutionary demands. This can generate trade-offs between the components of defences, as in the classic ‘fight or flight’ dichotomy, or dedicated investment in a singular end, allowing individuals in better condition to mount a more effective defence all round. Further, sexual dimorphism may drive sex differences in such responses, although our understanding of the interaction between sexual selection and defensive behaviour is in its infancy. Deimatic, or ‘startle’, defences typically combine multiple protective strategies, such as camouflage and aposematism, with a rapid transition between them, and thus offer unique …
Defoliation and patchy nutrient return drive grazing effects on plant and soil properties in a dairy cow pasture
2009
Large herbivores can influence plant and soil properties in grassland ecosystems, but especially for belowground biota and processes, the mechanisms that explain these effects are not fully understood. Here, we examine the capability of three grazing mechanisms-plant defoliation, dung and urine return, and physical presence of animals (causing trampling and excreta return in patches)-to explain grazing effects in Phleum pratense-Festuca pratensis dairy cow pasture in Finland. Comparison of control plots and plots grazed by cows showed that grazing maintained original plant-community structure, decreased shoot mass and root N and P concentrations, increased shoot N and P concentrations, and …
Coastal Research Seen Through an Early Career Lens—A Perspective on Barriers to Interdisciplinarity in Norway
2021
The value of interdisciplinarity for solving complex coastal problems is widely recognized. Many early career researchers (ECRs) therefore actively seek this type of collaboration through choice or necessity, for professional development or project funding. However, establishing and conducting interdisciplinary research collaborations as an ECR has many challenges. Here, we identify these challenges through the lens of ECRs working in different disciplines on a common ecosystem, the Norwegian Skagerrak coast. The most densely populated coastline in Norway, the Skagerrak coast, is experiencing a multitude of anthropogenic stressors including fishing, aquaculture, eutrophication, climate chan…
Advancing Through the Pandemic From the Perspective of Marine Graduate Researchers: Challenges, Solutions, and Opportunities
2020
The ongoing COVID-19 pandemic has brought about a new social and academic reality to researchers worldwide. The field of marine science, our own topic of interest, has also been impacted in multiple ways, from cancelation of laboratory and field activities to postponement of onboard research. As graduate researchers, we have a time-sensitive academic path, and our current situation may constrain our academic future. At the same time, the pandemic demands revised strategies to deal with the ongoing difficulties and tackle similar future situations. In this perspective, we have gathered information on the challenges, solutions and opportunities for graduate researchers in the field of marine …
50,000 years of ice and seals: Impacts of the Last Glacial Maximum on Antarctic fur seals
2021
Abstract Ice is one of the most important drivers of population dynamics in polar organisms, influencing the locations, sizes, and connectivity of populations. Antarctic fur seals, Arctocephalus gazella, are particularly interesting in this regard, as they are concomitantly reliant on both ice‐associated prey and ice‐free coastal breeding areas. We reconstructed the history of this species through the Last Glacial Maximum (LGM) using genomic sequence data from seals across their range. Population size trends and divergence events were investigated using continuous‐time size estimation analysis and divergence time estimation models. The combined results indicated that a panmictic population …
Phylogenomics Identifies an Ancestral Burst of Gene Duplications Predating the Diversification of Aphidomorpha
2019
Aphids (Aphidoidea) are a diverse group of hemipteran insects that feed on plant phloem sap. A common finding in studies of aphid genomes is the presence of a large number of duplicated genes. However, when these duplications occurred remains unclear, partly due to the high relatedness of sequenced species. To better understand the origin of aphid duplications we sequenced and assembled the genome of Cinara cedri, an early branching lineage (Lachninae) of the Aphididae family. We performed a phylogenomic comparison of this genome with 20 other sequenced genomes, including the available genomes of five other aphids, along with the transcriptomes of two species belonging to Adelgidae (a close…