Browsing NTNU Open by Author "Tufto, Jarle"
Now showing items 1-20 of 20
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A Continuous-Time, Discrete-Space Statistical Model for Estimating Dispersal Rate Applied to a Population of House Sparrows (Passer Domnesticus) in Northern Norway
Drahus, Kristin Mathilde (Master thesis, 2015)How individuals move and interact with each other is a complex matter. Even so, the knowledge of how such movements and interactions happen is important to understand in order to be able to keep genetic variation and ... -
A theoretical and empirical assessment of probabilistic multiple choice tests
Kval Bakken, Torunn (Master thesis, 2017)In this thesis, the probabilistic multiple choice test is analysed empirically and theoretically. It is suggested as an alternative to the traditional multiple choice test. The probabilistic multiple choice test has a long ... -
A time-series model for estimating temporal variation in phenotypic selection on laying dates in a Dutch great tit population
Cao, Yihan; Visser, Marcel E; Tufto, Jarle (Journal article; Peer reviewed, 2019)1. Temporal and spatial variation in phenotypic selection due to changing environmental conditions is of great interest to evolutionary biologists, but few existing methods estimating its magnitude take into account the ... -
Analysis of dominance hierarchies using generalized mixed models
Kristiansen, Thomas (Master thesis, 2011)This master s thesis investigates how well a generalized mixed model fits different dominance data sets. The data sets mainly represent disputes between individuals in a closed group, and the model to be used is an adjusted, ... -
Domestication and fitness in the wild: A multivariate view
Tufto, Jarle (Journal article; Peer reviewed, 2017)Domesticated species continually escaping and interbreeding with wild relatives impose a migration load on wild populations. As domesticated stocks become increasingly different as a result of artificial and natural selection ... -
Endoparasite infection has both short- and long-term negative effects on reproductive success of female house sparrows, as revealed by faecal parasitic egg counts
Holand, Håkon; Jensen, Henrik; Tufto, Jarle; Pärn, Henrik; Sæther, Bernt-Erik; Ringsby, Thor Harald (Journal article; Peer reviewed, 2015)Parasites have the potential to severely reduce host reproductive success. However, the effects of endoparasites on reproductive success have not received the same amount of attention as the effects of parasites on host ... -
Environmental drivers of varying selective optima in a small passerine: A multivariate, multiepisodic approach
Gamelon, Marlène; Tufto, Jarle; Nilsson, Anna; Jerstad, Kurt; Røstad, Ole Wiggo; Stenseth, Nils Christian; Sæther, Bernt-Erik (Journal article; Peer reviewed, 2018)In changing environments, phenotypic traits are shaped by numerous agents of selection. The optimal phenotypic value maximizing the fitness of an individual thus varies through time and space with various environmental ... -
Estimating the variation, autocorrelation, and environmental sensitivity of phenotypic selection
Chevin, Luis-Miguel; Visser, Marcel E.; Tufto, Jarle (Journal article; Peer reviewed, 2015)Despite considerable interest in temporal and spatial variation of phenotypic selection, very few methods allow quantifying this variation while correctly accounting for the error variance of each individual estimate. ... -
Genetic evolution, plasticity, and bet-hedging as adaptive responses to temporally autocorrelated fluctuating selection: A quantitative genetic model
Tufto, Jarle (Journal article; Peer reviewed, 2015)Adaptive responses to autocorrelated environmental fluctuations through evolution in mean reaction norm elevation and slope and an independent component of the phenotypic variance are analyzed using a quantitative genetic ... -
Genetic variation and structure of house sparrow populations: is there an island effect?
Jensen, Henrik; Moe, Rune; Hagen, Ingerid Julie; Holand, Anna Marie; Kekkonen, Jaana; Tufto, Jarle; Sæther, Bernt-Erik (Journal article; Peer reviewed, 2013)Population genetic structure and intrapopulation levels of genetic variation have important implications for population dynamics and evolutionary processes. Habitat fragmentation is one of the major threats to biodiversity. ... -
Lower survival probability of house sparrows severely infected by the gapeworm parasite
Holand, Håkon; Jensen, Henrik; Tufto, Jarle; Soliman, Mustafa M.; Pärn, Henrik; Sæther, Bernt-Erik; Ringsby, Thor Harald (Journal article; Peer reviewed, 2014)The effect of parasites in natural populations has received increasing attention in recent years. Studies have shown that parasites may play an important part in population ecology due to their potential effects on host ... -
Parasite prevalence increases with temperature in an avian metapopulation in northern Norway
Holand, Håkon; Jensen, Henrik; Kvalnes, Thomas; Tufto, Jarle; Pärn, Henrik; Sæther, Bernt-Erik; Ringsby, Thor Harald (Peer reviewed; Journal article, 2019)Climate and weather conditions may have substantial effects on the ecology of both parasites and hosts in natural populations. The strength and shape of the effects of weather on parasites and hosts are likely to change ... -
Pre-adaptation or genetic shift after introduction in the invasive species Impatiens glandulifera?
Elst, Evelyne M.; Acharya, Kamal Prasad; Dar, Pervaiz A.; Reshi, Zafar A.; Tufto, Jarle; Nijs, Ivan; Graae, Bente Jessen (Journal article, 2016)Invasive exotic plants often grow fast, reproduce rapidly and display considerable phenotypic plasticity in their invasive range, which may be essential characteristics for successful invasion. However, it remains unclear ... -
Short‐term insurance versus long‐term bet‐hedging strategies as adaptations to variable environments
Haaland, Thomas; Wright, Jonathan; Tufto, Jarle; Ratikainen, Irja Ida (Journal article; Peer reviewed, 2018)Understanding how organisms adapt to environmental variation is a key challenge of biology. Central to this are bet‐hedging strategies that maximize geometric mean fitness across generations, either by being conservative ... -
Spatial variation in senescence rates in a bird metapopulation
Holand, Håkon; Kvalnes, Thomas; Gamelon, Marlène; Tufto, Jarle; Jensen, Henrik; Pärn, Henrik; Ringsby, Thor Harald; Sæther, Bernt-Erik (Journal article, 2016)Investigating factors which affect the decline in survival with age, i.e. actuarial senescence, is important in order to understand how demographic rates vary in wild populations. Although the evidence for the occurrence ... -
Spatiotemporal variation in laying date and its impact on reproductive success in house sparrows (Passer domesticus)
Johansen, Sonja Kristina Norum (Master thesis, 2018)Timing of breeding is an important determinant of reproductive success for animals living in seasonal environments. Understanding the factors affecting reproductive processes are necessary to predict how populations may ... -
Statistical methods for estimating fluctuating selection
Cao, Yihan (Doctoral theses at NTNU;2020:99, Doctoral thesis, 2020) -
Temporal and spatial variation in prevalence of the parasite Syngamus trachea in a metapopulation of House Sparrows (Passer domesticus)
Holand, Håkon; Jensen, Henrik; Tufto, Jarle; Sæther, Bernt-Erik; Ringsby, Thor Harald (Journal article, 2013)When investigating parasite–host dynamics in wild populations, a fundamental parameter to investigate is prevalence. This quantifies the percentage of individuals infected in the population. Investigating how prevalence ... -
Ungulate population monitoring in an open tundra landscape:distance sampling versus total counts
Le Moullec, Mathilde; Pedersen, Åshild Ønvik; Yoccoz, Nigel Gilles; Aanes, Ronny; Tufto, Jarle; Hansen, Brage Bremset (Journal article; Peer reviewed, 2017)Researchers and wildlife managers strive for low bias and high precision (i.e. high accuracy) when estimating animal population sizes. Distance sampling is currently one of the most widely used monitoring methods. However, ... -
Varying disease-mediated selection at different life-history stages of Atlantic salmon in fresh water
de Eyto, E; McGinnity, P; Huisman, Jisca; Coughlan, J; Consuegra, S; Farrell, K; O´Toole, C; Tufto, Jarle; Megens, HJ; Jordan, W; Cross, T.; Stet, Rene J.M. (Journal article; Peer reviewed, 2011)Laboratory studies on associations between disease resistance and susceptibility and major histocompatibility (MH) genes in Atlantic salmon Salmo salar have shown the importance of immunogenetics in understanding the ...