Search results for "C lo"
showing 10 items of 794 documents
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.
Clutch-size variation in Western Palaearctic secondary hole-nesting passerine birds in relation to nest box design.
2014
Møller, A.P. [et al.]
Extinction and recolonization of maritime Antarctica in the limpet Nacella concinna (Strebel, 1908) during the last glacial cycle: toward a model of …
2013
Quaternary glaciations in Antarctica drastically modified geographical ranges and population sizes of marine benthic invertebrates and thus affected the amount and distribution of intraspecific genetic variation. Here, we present new genetic information in the Antarctic limpet Nacella concinna, a dominant Antarctic benthic species along shallow ice-free rocky ecosystems. We examined the patterns of genetic diversity and structure in this broadcast spawner along maritime Antarctica and from the peri-Antarctic island of South Georgia. Genetic analyses showed that N. concinna represents a single panmictic unit in maritime Antarctic. Low levels of genetic diversity characterized this population…
Linking extreme seasonality and gene expression in arctic marine protists
2021
ABSTRACTAt high latitudes, strong seasonal differences in light availability affect marine organisms and restrict the timing of ecosystem processes. Marine protists are key players in Arctic aquatic ecosystems, yet little is known about their ecological roles over yearly cycles. This is especially true for the dark polar night period, which up until recently was assumed to be devoid of biological activity. A 12 million transcripts catalogue was built from 0.45-10 μm protist assemblages sampled over 13 months in a time series station in an arctic fjord in Svalbard. Community gene expression was correlated with seasonality, with light as the main driving factor. Transcript diversity and evenn…
Effects of global warming on reproduction and potential dispersal of Mediterranean Cnidarians
2019
Water temperature directly affects life cycles, reproductive periods, and metabolism of organisms living the oceans, especially in the surface zones. Due to the ocean warming, changes in water stratification and primary productivity are affecting trophic chains in sensitive world areas, such as the Mediterranean Sea. Benthic and pelagic cnidarians exhibit complex responses to climatic conditions. For example, the structure and phenology of the Mediterranean hydrozoan community displayed marked changes in species composition, bathymetric distribution, and reproductive timing over the last decades. The regional species pool remained stable in terms of species numbers but not in terms of speci…
Ocean acidification impairs vermetid reef recruitment
2014
Vermetids form reefs in sub-tropical and warm-temperate waters that protect coasts from erosion, regulate sediment transport and accumulation, serve as carbon sinks and provide habitat for other species. The gastropods that form these reefs brood encapsulated larvae; they are threatened by rapid environmental changes since their ability to disperse is very limited. We used transplant experiments along a natural CO2 gradient to assess ocean acidification effects on the reef-building gastropod Dendropoma petraeum. We found that although D. petraeum were able to reproduce and brood at elevated levels of CO2, recruitment success was adversely affected. Long-term exposure to acidified conditions…
Climate change and the ecology and evolution of Arctic vertebrates
2012
Climate change is taking place more rapidly and severely in the Arctic than anywhere on the globe, exposing Arctic vertebrates to a host of impacts. Changes in the cryosphere dominate the physical changes that already affect these animals, but increasing air temperatures, changes in precipitation, and ocean acidification will also affect Arctic ecosystems in the future. Adaptation via natural selection is problematic in such a rapidly changing environment. Adjustment via phenotypic plasticity is therefore likely to dominate Arctic vertebrate responses in the short term, and many such adjustments have already been documented. Changes in phenology and range will occur for most species but wil…
Reproductive timing and individual fitness
2002
Estimation of individual fitness – i.e. description of the extent to which an individual's genes are represented in future generations – is a feature central to most evolutionary studies. Lifetime reproductive success (LRS) is a commonly used estimate of individual fitness, but because it is rate-insensitive (i.e. timing of reproductive events is not incorporated), it may give a biased estimate of fitness when reproductive timing is an important component of fitness. A review of all empirical studies which have used a recently derived, rate-sensitive estimate of individual fitness, λind revealed that λind ranks the fitness of phenotypes differently from LRS, and that this difference may lea…
Thompson Sampling Based Active Learning in Probabilistic Programs with Application to Travel Time Estimation
2019
The pertinent problem of Traveling Time Estimation (TTE) is to estimate the travel time, given a start location and a destination, solely based on the coordinates of the points under consideration. This is typically solved by fitting a function based on a sequence of observations. However, it can be expensive or slow to obtain labeled data or measurements to calibrate the estimation function. Active Learning tries to alleviate this problem by actively selecting samples that minimize the total number of samples needed to do accurate inference. Probabilistic Programming Languages (PPL) give us the opportunities to apply powerful Bayesian inference to model problems that involve uncertainties.…
Disentangling phylogeography, polyploid evolution and taxonomy of a woodland herb (Veronica chamaedrys group, Plantaginaceae s.l.) in southeastern Eu…
2010
Southeastern Europe is a centre of European biodiversity, but very little is known about factors causing the observed richness. Here, we contribute to fill this gap by reconstructing the spatio-temporal diversification of the cytologically variable and taxonomically intricate complex of Veronica chamaedrys (Plantaginaceae s.l.), growing in open forests, forest edges and grasslands, with flow cytometry, molecular markers (AFLPs, plastid DNA sequences) and morphometry. Our results show that both diploid and tetraploid cytotypes are widespread, but diploids predominate on the southern Balkan Peninsula. Plastid sequences suggest a first split into three main lineages in the mid-Pleistocene and …