Blar i NTNU Open på forfatter "Jensen, Henrik"
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Insights into the genetic architecture of morphological and sexually selected traits in two passerine bird species
Silva, Catarina; McFarlane, S. Eryn; Hagen, Ingerid Julie; Rönnegård, Lars; Billing, Anna; Kvalnes, Thomas; Kemppainen, Petri; Rønning, Bernt; Ringsby, Thor Harald; Sæther, Bernt-Erik; Qvarnström, Anna; Ellegren, Hans; Jensen, Henrik; Husby, Arild (Journal article; Peer reviewed, 2017)Knowledge about the underlying genetic architecture of phenotypic traits is needed to understand and predict their evolutionary dynamics. The number of causal loci underlying most phenotypic traits, the magnitude of their ... -
Is basal metabolic rate associated with recruit production and survival in free-living house sparrows?
Rønning, Bernt; Broggi, Juli; Bech, Claus; Moe, Børge; Ringsby, Thor Harald; Pärn, Henrik; Hagen, Ingerid Julie; Sæther, Bernt-Erik; Jensen, Henrik (Journal article; Peer reviewed, 2016)Life history theory predicts that available energy is limited and needs to be allocated among different processes such as growth, reproduction and self-maintenance. Basal metabolic rate (BMR), a common measure of an animal's ... -
Linking variation in personality and behavioural syndromes to social foraging and producer-scrounger effects in house sparrows (Passer domesticus)
Olsen, Mirja Carola (Master thesis, 2016)Consistent behavioural differences between individuals across time and situations are referred to as animal personality. Associated with this are behavioural syndromes , which are suites of correlated behaviours across ... -
Longitudinal telomere dynamics within natural lifespans of a wild bird
Pepke, Michael Le; Kvalnes, Thomas; Wright, Jonathan; Araya Ajoy, Yimen Gerardo; Ranke, Peter Sjolte; Boner, Winnie; Monaghan, Pat; Sæther, Bernt-Erik; Jensen, Henrik; Ringsby, Thor Harald (Peer reviewed; Journal article, 2023)Telomeres, the nucleotide sequences that protect the ends of eukaryotic chromosomes, shorten with each cell division and telomere loss may be influenced by environmental factors. Telomere length (TL) decreases with age in ... -
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 ... -
Molecular Genetics of Sex Identification, Breed Ancestry and Polydactyly in the Norwegian Lundehund Breed
Kropatsch, Regina; Melis, Claudia; Stronen, Astrid V.; Jensen, Henrik; Eppelen, Joerg T. (Journal article, 2015)The Norwegian Lundehund breed of dog has undergone a severe loss of genetic diversity as a result of inbreeding and epizootics of canine distemper. As a consequence, the breed is extremely homogeneous and accurate sex ... -
Multi-generation genetic and fitness effects of immigration in a natural meta-population of song sparrows (Melospiza melodia)
Dickel, Lisa (Doctoral theses at NTNU;2024:105, Doctoral thesis, 2024)Fragmentation leads to smaller habitat patches and population sizes, endangering population fitness and persistence, including through inbreeding depression and loss of genetic diversity. These effects can be mitigated ... -
Multiple aspects of plasticity in clutch size vary among populations of a globally distributed songbird
Westneat, David; Bokony, Veronika; Burke, Terry; Chastel, Olivier; Jensen, Henrik; Kvalnes, Thomas; Lendvai, Adam Z.; Liker, Andras; Mock, Douglas; Schroeder, Julia; Schwagmeyer, P. L.; Sorci, Gabriele; Stewart, Ian R. K. (Journal article, 2014)Plasticity in life-history characteristics can influence many ecological and evolutionary phenomena, including how invading organisms cope with novel conditions in new locations or how environmental change affects organisms ... -
NR1D1 methylation as an epigenetic response during Syngamus trachea infection in the house sparrow
Buer, Amberly (Master thesis, 2022)Climate change may increase host-parasite interactions as temperature and precipitation levels become more favorable for parasite reproduction, survival, and transmission. Consequently, increased parasite prevalence as a ... -
Offspring fitness and the optimal propagule size in a fluctuating environment
Kvalnes, Thomas; Røberg, Anja Ås; Jensen, Henrik; Holand, Håkon; Pärn, Henrik; Sæther, Bernt-Erik; Ringsby, Thor Harald (Journal article; Peer reviewed, 2018) -
On being the right size: Increased body size is associated with reduced telomere length under natural conditions
Ringsby, Thor Harald; Jensen, Henrik; Pärn, Henrik; Kvalnes, Thomas; Boner, Winnie; Gillespie, Robert; Holand, Håkon; Hagen, Ingerid Julie; Rønning, Bernt; Sæther, Bernt-Erik; Monaghan, Pat (Journal article, 2015)Evolution of body size is likely to involve trade-offs between body size, growth rate and longevity. Within species, larger body size is associated with faster growth and ageing, and reduced longevity, but the cellular ... -
On estimation and identifiability issues of sex-linked inheritance with a case study of pigmentation in Swiss barn owl (Tyto alba)
Larsen, Camilla Thorrud; Holand, Anna Marie; Jensen, Henrik; Steinsland, Ingelin; Roulin, Alexandre (Journal article; Peer reviewed, 2014)Genetic evaluation using animal models or pedigree-based models generally assume only autosomal inheritance. Bayesian animal models provide a flexible framework for genetic evaluation, and we show how the model readily can ... -
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 ... -
Personality and Innovation in House Sparrows - Evolutionary and Demographic Consequences of Individual Phenotypic Differences
Sommerli, Sindre Lysfjord (Master thesis, 2015)Atferdssyndromer, og kovarians mellom trekk er essensielle for forståelse av fenotypisk struktur og fenotypisk variasjon. Nyere forskning viser at atferdssyndromer ikke bare eksisterer, men at disse varierer i struktur ... -
Population characteristics and estimates of effective population size in a house sparrow metapopulation
Baalsrud, Helle Tessand (Master thesis, 2011)Effective population size (Ne) is a fundamental concept within biology and can be defined as the size of an ideal Wright-Fisher population in which the rate of genetic drift is the same as in the observed population. Natural ... -
Possible Effects of Persistent Organic Pollutants on Steroid Hormone Homeostasis in House Sparrows (Passer domesticus) from Helgeland, Norway
Nossen, Ida (Master thesis, 2014)Over the last decades, declines have occurred in the range and abundance of several passerines and farmland bird species and even though several possible causes have been suggested, the exposure to environmental contaminants ... -
Quantitative genetic modeling and inference in the presence of nonignorable missing data
Steinsland, Ingelin; Larsen, Camilla Thorrud; Roulin, Alexandre; Jensen, Henrik (Journal article; Peer reviewed, 2014)Natural selection is typically exerted at some specific life stages. If natural selection takes place before a trait can be measured, using conventional models can cause wrong inference about population parameters. When ... -
Reversal of response to artificial selection on body size in a wild passerine bird
Kvalnes, Thomas; Ringsby, Thor Harald; Jensen, Henrik; Hagen, Ingerid Julie; Rønning, Bernt; Pärn, Henrik; Holand, Håkon; Engen, Steinar; Sæther, Bernt-Erik (Journal article, 2017)A general assumption in quantitative genetics is the existence of an intermediate phenotype with higher mean individual fitness in the average environment than more extreme phenotypes. Here we investigate the evolvability ... -
Sensitivity Analysis of Effective Population Size to Demographic Parameters in House Sparrow Populations
Stubberud, Marlene Wæge (Master thesis, 2015)In population management, the effective population size, Ne, can be viewed in tandem with actual population size, N, as the main factors determining a population s long-term viability and sustainability. Ne is the number ... -
Sensitivity analysis of effective population size to demographic parameters in house sparrow populations
Stubberud, Marlene Wæge; Myhre, Ane Marlene; Holand, Håkon; Kvalnes, Thomas; Ringsby, Thor Harald; Sæther, Bernt-Erik; Jensen, Henrik (Journal article, 2017)The ratio between the effective and the census population size, (math formula), is an important measure of the long-term viability and sustainability of a population. Understanding which demographic processes that affect ...