Search results for "selection"
showing 10 items of 1940 documents
Sourcing practices in online journalism : an ethnographic study of the formation of trust in and the use of journalistic sources
2017
Arguably one of the most important factors of journalistic quality is careful source selection. Studies on online journalism have revealed working conditions which may lead to poor sourcing practices. This article seeks to answer the following questions: What sources do online journalists use, and how do they rationalize their sourcing practices? A total of 17 Finnish online journalists in 7 newsrooms were observed and interviewed over their practices of source searching, evaluation, and use. The study revealed five distinctive rationales of source use, which I call trust discourses: the ideological, the pragmatic, the cynically pragmatic, the consensual, and the contextual trust. Different…
Personality and musical preference using social-tagging in excerpt-selection.
2017
Music preference has been related to individual differences like social identity, cognitive style, and personality, but quantifying music preference can be a challenge. Self-report measures may be too presumptive of shared genre definitions between listeners, while listener ratings of expert-selected music may fail to reflect typical listeners’ genre boundaries. The current study aims to address this by using a social-tagging approach to select music for studying preference. In this study, 2,407 tracks were collected and subsampled from the Last.fm social-tagging service and the EchoNest platform based on attributes such as genre, tempo, and danceability. The set was further subsampled acco…
Data from: Harvest selection on multiple traits in the wild revealed by aquatic animal telemetry
2019
Harvesting can have profound impacts on the ecology and evolution of marine populations. However, little is known about the strength and direction of fisheries-induced selection acting on multiple traits in the wild. Here, we used acoustic telemetry to directly monitor individual behavior and fate in an intensively harvested species, the European lobster (Homarus gammarus, n = 100), in southern Norway. Overall, 24% of the tracked lobsters survived the two-month harvest season within the study area. Our results indicated that local survival was not random with respect to phenotype. We found no clear support for fisheries-induced selection acting directly on body size. However, lobsters with …
Data from: How do cuticular hydrocarbons evolve? Physiological constraints and climatic and biotic selection pressures act on a complex functional tr…
2016
Cuticular hydrocarbons (CHCs) cover the cuticles of virtually all insects, serving as a waterproofing agent and as a communication signal. The causes for the high CHC variation between species, and the factors influencing CHC profiles, are scarcely understood. Here, we compare CHC profiles of ant species from seven biogeographic regions, searching for physiological constraints and for climatic and biotic selection pressures. Molecule length constrained CHC composition: long-chain profiles contained fewer linear alkanes, but more hydrocarbons with disruptive features in the molecule. This is probably owing to selection on the physiology to build a semi-fluid cuticular layer, which is necessa…
Data from: Stable coexistence of genetically divergent Atlantic cod ecotypes at multiple spatial scales
2018
Coexistence in the same habitat of closely related yet genetically different populations is a phenomenon that challenges our understanding of local population structure and adaptation. Identifying the underlying mechanisms for such coexistence can yield new insight into adaptive evolution, diversification, and the potential for organisms to adapt and persist in response to a changing environment. Recent studies have documented cryptic, sympatric populations of Atlantic cod (Gadus morhua) in coastal areas. We analyzed genetic origin of 6483 individual cod sampled annually over 14 years from 125 locations along the Norwegian Skagerrak coast and document stable coexistence of two genetically d…
Data from: Do island plant populations really have lower genetic variation than mainland populations? Effects of selection and distribution range on …
2015
Ecological and evolutionary studies largely assume that island populations display low levels of neutral genetic variation. However, this notion has only been formally tested in a few cases involving plant taxa, and the confounding effect of selection on genetic diversity (GD) estimates based on putatively neutral markers has typically been overlooked. Here, we generated nuclear microsatellite and plastid DNA sequence data in Periploca laevigata, a plant taxon with an island-mainland distribution area, to (i) investigate whether selection affects GD estimates of populations across contrasting habitats and (ii) test the long-standing idea that island populations have lower GD than their main…
Data from: Positive selection in development and growth rate regulation genes involved in species divergence of the genus Radix
2015
Background: Life history traits like developmental time, age and size at maturity are directly related to fitness in all organisms and play a major role in adaptive evolution and speciation processes. Comparative genomic or transcriptomic approaches to identify positively selected genes involved in species divergence can help to generate hypotheses on the driving forces behind speciation. Here we use a bottom-up approach to investigate this hypothesis by comparative analysis of orthologous transcripts of four closely related European Radix species. Results: Snails of the genus Radix occupy species specific distribution ranges with distinct climatic niches, indicating a potential for natural…
Data from: Multiple quantitative trait loci influence intra-specific variation in genital morphology between phylogenetically distinct lines of Droso…
2011
The evolution of animal genitalia has gained renewed interest, because of their potential roles during sexual selection and early stages of species formation. Although central to understanding the evolutionary process, knowledge of the genetic basis of natural variation in genital morphology is limited to a very few species. Using an out-bred cross between phylogenetically distinct lines of Drosophila montana, we characterized quantitative trait loci (QTLs) affecting the size and shape of the distiphallus, a prominent part of the male intromittent organ. Our microsatellite-based linkage analysis shows that intra-specific variation of the distiphallus involves several QTLs of largely additiv…
Data from: No evidence for prezygotic postcopulatory avoidance of kin despite high inbreeding depression
2018
Offspring resulting from mating among close relatives can suffer from impaired fitness through the expression of recessive alleles with deleterious effects. Post-copulatory sperm selection (a pre-zygotic mechanism of cryptic female choice) has been suggested to be an effective way to avoid inbreeding. To investigate whether post-copulatory female choice allows avoiding fertilization by close kin, we performed artificial inseminations in a promiscuous bird, the houbara bustard (Chlamydotis undulata undulata). Females were inseminated with a mix of sperm from triads of males, each constituted of a male genetically unrelated to the female, a first cousin, and a half-sibling. When counting the …
Data from: Simultaneous age-dependent and age-independent sexual selection in the lekking black grouse (Lyrurus tetrix)
2016
Individuals' reproductive success is often strongly associated with their age, with typical patterns of early-life reproductive improvement and late-life senescence. These age-related patterns are due to the inherent trade-offs between life-history traits competing for a limited amount of resources available to the organisms. In males, such trade-offs are exacerbated by the resource requirements associated with the expression of costly sexual traits, leading to dynamic changes in trait expression throughout their life span. Due to the age dependency of male phenotypes, the relationship between the expression of male traits and mating success can also vary with male age. Hence, using longitu…