Browsing NTNU Open by Author "Pärn, Henrik"
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Characterizing morphological (co)variation using structural equation models: Body size, allometric relationships and evolvability in a house sparrow metapopulation
Araya-Ajoy, Yimen; Ranke, Peter Sjolte; Kvalnes, Thomas; Rønning, Bernt; Holand, Håkon; Myhre, Ane Marlene; Pärn, Henrik; Jensen, Henrik; Ringsby, Thor Harald; Sæther, Bernt-Erik; Wright, Jonathan (Peer reviewed; Journal article, 2019)Body size plays a key role in the ecology and evolution of all organisms. Therefore, quantifying the sources of morphological (co)variation, dependent and independent of body size, is of key importance when trying to ... -
Controlling for P-value inflation in allele frequency change in experimental evolution and artificial selection experiments
Kemppainen, Petri; Rønning, Bernt; Kvalnes, Thomas; Hagen, Ingerid Julie; Ringsby, Thor Harald; Billing, Anna Maria; Pärn, Henrik; Lien, Sigbjørn; Husby, Arild; Sæther, Bernt-Erik; Jensen, Henrik (Journal article; Peer reviewed, 2017)Experimental evolution studies can be used to explore genomic response to artificial and natural selection. In such studies, loci that display larger allele frequency change than expected by genetic drift alone are assumed ... -
Covarying Behaviours and Innovation in a House Sparrow Metapopulation - Implications for Social Foraging
Hammerås, John (Master thesis, 2016)Individuals in populations of many species have been found to differ consistently in suites of correlating behavioural measures. These phenomena appear to be heritable and subject to selection, thus making it as important ... -
Demographic influences of translocated individuals on a resident population of house sparrows
Ranke, Peter Sjolte; Skjelseth, Sigrun; Pärn, Henrik; Herfindal, Ivar; Borg Pedersen, Åsa Alexandra; Stokke, Bård Gunnar; Kvalnes, Thomas; Ringsby, Thor Harald; Sæther, Bernt-Erik; Jensen, Henrik (Journal article; Peer reviewed, 2017)Translocation of individuals from source populations to augment small populations facing risk of extinction is an important conservation tool. Here we examine sex-specific differences between resident and translocated house ... -
Dispersal in a house sparrow metapopulation: An integrative case study of genetic assignment calibrated with ecological data and pedigree information
Saatoglu, Fikriye Dilan; Niskanen, Alina Katariina; Kuismin, Markku; Ranke, Peter Sjolte; Hagen, Ingerid Julie; Araya-Ajoy, Yimen; Kvalnes, Thomas; Pärn, Henrik; Rønning, Bernt; Ringsby, Thor Harald; Sæther, Bernt-Erik; Husby, Arild; Sillanpää, Mikko J.; Jensen, Henrik (Peer reviewed; Journal article, 2021)Dispersal has a crucial role determining ecoevolutionary dynamics through both gene flow and population size regulation. However, to study dispersal and its consequences, one must distinguish immigrants from residents. ... -
DNA Metabarcoding Diet Analysis of Water Vole (Arvicola amphibius) in Northern Norway
Østby, Nina (Master thesis, 2019)Studier og kunnskap om hvilke faktorer som påvirker populasjonsdynamikk er svært viktig i økologi. Det gir viktig informasjon som er nyttig for blant annet bevaring av biodiversitet i en tid der den trues av globale ... -
Effects of population characteristics and structure on estimates of effective population size in a house sparrow metapopulation
Baalsrud, Helle Tessand; Sæther, Bernt-Erik; Hagen, Ingerid Julie; Myhre, Ane Marlene; Ringsby, Thor Harald; Pärn, Henrik; Jensen, Henrik (Journal article, 2014)Effective population size (Ne) is a key parameter to understand evolutionary processes and the viability of endangered populations as it determines the rate of genetic drift and inbreeding. Low Ne can lead to inbreeding ... -
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 ... -
Factors Affecting Juvenile Movement in a House Sparrow Metapopulation
Myhre, Ane Marlene (Master thesis, 2012)Dispersal propensity can vary considerably between individuals in a population. Understanding which individuals disperse- and under what circumstances these individuals disperse is valuable for conservation. Factors ... -
Fitness Consequences of Intra-Island dispersal in a House Sparrow (Passer domesticus) Population
Hansen, Ann-Katrine Esp (Master thesis, 2012)Dispersing individuals have the ability to link fragmented populations to each other, and influence a wide range of ecological and evolutionary processes. Understanding the fitness differences between resident and dispersing ... -
Inbreeding and inbreeding depression in water voles (Arvicola amphibious) in Northern Norway
Gabrielsen, Ida (Master thesis, 2020)Å forstå hvordan små og isolerte populasjoner kan bli påvirket av innavl er svært viktig innen bevaringsbiologi. Innavl kan ha alvorlige konsekvenser for fitness, både på individ- og populasjonsnivå, og kan øke sjansen for ... -
Inferences of genetic architecture of bill morphology in house sparrow using a high-density SNP array point to a polygenic basis
Lundregan, Sarah; Hagen, Ingerid Julie; Gohli, Jostein; Niskanen, Alina Katariina; Kemppainen, Petri; Ringsby, Thor Harald; Kvalnes, Thomas; Pärn, Henrik; Rønning, Bernt; Holand, Håkon; Ranke, Peter Sjolte; Båtnes, Anna Solvang; Selvik, Linn-Karina M.; Lien, Sigbjørn; Sæther, Bernt-Erik; Husby, Arild; Jensen, Henrik (Journal article; Peer reviewed, 2018)Understanding the genetic architecture of quantitative traits can provide insights into the mechanisms driving phenotypic evolution. Bill morphology is an ecologically important and phenotypically variable trait, which is ... -
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 ... -
Long-distance dispersal in the short-distance dispersing house sparrow (Passer domesticus)
Ranke, Peter Sjolte; Pepke, Michael Le; Søraker, Jørgen Skavdal; David, Gabriel; Araya Ajoy, Yimen Gerardo; Wright, Jonathan; Nafstad, Ådne Messel; Rønning, Bernt; Pärn, Henrik; Ringsby, Thor Harald; Jensen, Henrik; Sæther, Bernt-Erik (Journal article; Peer reviewed, 2024)The house sparrow (Passer domesticus) is a small passerine known to be highly sedentary. Throughout a 30-year capture–mark–recapture study, we have obtained occasional reports of recoveries far outside our main metapopulation ... -
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 ... -
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 ... -
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 ... -
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 ...