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  • 1.
    Abbey-Lee, Robin
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biologi. Linköpings universitet, Tekniska fakulteten. Max Planck Inst Ornithol, Germany.
    Dingemanse, Niels J.
    Ludwig Maximilians Univ Munchen, Germany.
    Adaptive individual variation in phenological responses to perceived predation levels2019Inngår i: Nature Communications, ISSN 2041-1723, E-ISSN 2041-1723, Vol. 10, artikkel-id 1601Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The adaptive evolution of timing of breeding (a component of phenology) in response to environmental change requires individual variation in phenotypic plasticity for selection to act upon. A major question is what processes generate this variation. Here we apply multi-year manipulations of perceived predation levels (PPL) in an avian predator-prey system, identifying phenotypic plasticity in phenology as a key component of alternative behavioral strategies with equal fitness payoffs. We show that under low-PPL, faster (versus slower) exploring birds breed late (versus early); the pattern is reversed under high-PPL, with breeding synchrony decreasing in conjunction. Timing of breeding affects reproductive success, yet behavioral types have equal fitness. The existence of alternative behavioral strategies thus explains variation in phenology and plasticity in reproductive behavior, which has implications for evolution in response to anthropogenic change.

  • 2.
    Abbey-Lee, Robin
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biologi. Linköpings universitet, Tekniska fakulteten.
    Uhrig, Emily
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biologi. Linköpings universitet, Tekniska fakulteten. Southern Oregon Univ, OR 97520 USA.
    Garnham, Laura
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biologi. Linköpings universitet, Tekniska fakulteten.
    Lundgren, Kristoffer
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biologi. Linköpings universitet, Tekniska fakulteten.
    Child, Sarah
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biologi. Linköpings universitet, Tekniska fakulteten. Univ Manchester, England.
    Lovlie, Hanne
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biologi. Linköpings universitet, Tekniska fakulteten.
    Experimental manipulation of monoamine levels alters personality in crickets2018Inngår i: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 8, artikkel-id 16211Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Animal personality has been described in a range of species with ecological and evolutionary consequences. Factors shaping and maintaining variation in personality are not fully understood, but monoaminergic systems are consistently linked to personality variation. We experimentally explored how personality was influenced by alterations in two key monoamine systems: dopamine and serotonin. This was done using ropinirole and fluoxetine, two common human pharmaceuticals. Using the Mediterranean field cricket (Gryllus bimaculatus), we focused on the personality traits activity, exploration, and aggression, with confirmed repeatability in our study. Dopamine manipulations explained little variation in the personality traits investigated, while serotonin manipulation reduced both activity and aggression. Due to limited previous research, we created a dose-response curve for ropinirole, ranging from concentrations measured in surface waters to human therapeutic doses. No ropinirole dose level strongly influenced cricket personality, suggesting our results did not come from a dose mismatch. Our results indicate that the serotonergic system explains more variation in personality than manipulations of the dopaminergic system. Additionally, they suggest that monoamine systems differ across taxa, and confirm the importance of the mode of action of pharmaceuticals in determining their effects on behaviour.

  • 3.
    Agnvall, Beatrix
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biologi. Linköpings universitet, Tekniska fakulteten.
    Early domestication?: Phenotypic alterations of Red Junglefowl selected for divergent fear of humans2016Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Domestication is the process through which animals adapt to conditions provided by humans. The domesticated phenotype differs from wild ancestors in a number of traits relating to physiology, morphology and behaviour. One of the most striking differences is the animals’ fear response towards humans, and reduced fear of humans is assumed to have been an early prerequisite for the success of domestication. The early alterations seen in the domesticated phenotype may be traits developed as a correlated selection response due to tameness rather than selected upon one by one.

    This thesis summarizes a project where Red Junglefowl were selected for divergent fear of humans during six generations. In every generation, fear response to human was assessed in a standardized test and, according to fear score, the animals were bred for either high fear of humans (H) or low fear of humans (L). The animals were, above that of the standardized selection test, behaviourally phenotyped in different tests in each generation mainly focusing on fear, exploration and social behaviour. In addition to behaviour, the animals were phenotyped for body weight, egg weight, metabolism, feed intake, plumage condition, blood plasma corticosterone and peripheral serotonin. After culling, vital organs and brains were harvested and weighed.

    In paper I, we demonstrated that the selection trait has a significant genetic heritability and is genetically correlated with other behavioural responses associated with fearfulness and exploration. In paper II, we concluded that animals from the L strain had better plumage condition, higher weight, laid larger eggs and also generated larger offspring. Furthermore, when tested in a social dominance test with a limited resource, they received less and performed more aggression regardless of whether the restricted source was edible or not. In paper III, we revealed that animals from the L strain had higher basal metabolic rate as chicks, gained more weight in relation to feed intake and were bolder in a Novel Object test. Furthermore, the L males had higher plasma levels of peripheral serotonin, but the corticosterone after a restraint stress test did not differ. In paper IV and V, we concluded the project by comparing brain and organ weights as well as behaviour of the parental generation (P0) with the fifth selected generation (S5). The absolute brain weight as well as the weight specific brain weight were larger in the animals selected on H than in the L-animals. The relative weight of telencephalon was significantly higher in H whereas relative weight of cerebellum was significantly lower. Heart, liver, spleen and testes were all relatively heavier in H animals than in L. Interestingly, the behaviours assessed in P0 and S5 seemed to be rather resilient to the selection with only small differences in S5.

    To summarize, the selection on divergent tameness in Red Junglefowl has affected several phenotypic traits associated with the domesticated phenotype. The results of this project indicate that tameness in Red Junglefowl could be an underlying factor driving trait modifications towards the domesticated phenotype.

    Delarbeid
    1. Heritability and Genetic Correlations of Fear-Related Behaviour in Red Jungelfowl -Possible Implications for Early Domestication
    Åpne denne publikasjonen i ny fane eller vindu >>Heritability and Genetic Correlations of Fear-Related Behaviour in Red Jungelfowl -Possible Implications for Early Domestication
    2012 (engelsk)Inngår i: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 7, nr 4, s. e35162-Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    Domesticated species differ from their wild ancestors in a number of traits, generally referred to as the domesticated phenotype. Reduced fear of humans is assumed to have been an early prerequisite for the successful domestication of virtually all species. We hypothesized that fear of humans is linked to other domestication related traits. For three generations, we selected Red Junglefowl (ancestors of domestic chickens) solely on the reaction in a standardized Fear of Human-test. In this, the birds were exposed for a gradually approaching human, and their behaviour was continuously scored. This generated three groups of animals, high (H), low (L) and intermediate (I) fearful birds. The birds in each generation were additionally tested in a battery of behaviour tests, measuring aspects of fearfulness, exploration, and sociality. The results demonstrate that the variation in fear response of Red Junglefowl towards humans has a significant genetic component and is genetically correlated to behavioural responses in other contexts, of which some are associated with fearfulness and others with exploration. Hence, selection of Red Junglefowl on low fear for humans can be expected to lead to a correlated change of other behavioural traits over generations. It is therefore likely that domestication may have caused an initial suite of behavioural modifications, even without selection on anything besides tameness.

    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-76833 (URN)10.1371/journal.pone.0035162 (DOI)000305336200026 ()
    Tilgjengelig fra: 2012-04-20 Laget: 2012-04-20 Sist oppdatert: 2017-12-07
    2. Red Junglefowl (Gallus gallus) selected for low fear of humans are larger, more dominant and produce larger offspring
    Åpne denne publikasjonen i ny fane eller vindu >>Red Junglefowl (Gallus gallus) selected for low fear of humans are larger, more dominant and produce larger offspring
    2014 (engelsk)Inngår i: animal, ISSN 1751-7311, Vol. 8, nr 9, s. 1498-1505Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    Many traits associated with domestication are suggested to have developed as correlated responses to reduced fear of humans. Tameness may have reduced the stress of living in human proximity and improved welfare in captivity. We selected Red Junglefowl (ancestors of all domestic chickens) for four generations on high or low fear towards humans, mimicking an important aspect of the earliest period of domestication, and tested birds from the third and fourth generation in three different social tests. Growth and plumage condition, as well as size of eggs and offspring were also recorded, as indicators of some aspects of welfare. Birds selected for low fear had higher weight, laid larger eggs and generated larger offspring, and had a better plumage condition. In a social dominance test they also performed more aggressive behaviour and received less of the same, regardless of whether the restricted resource was feed or not. Hence, dominance appeared to increase as a consequence of reduced fear of humans. Furthermore, egg size and the weight of the offspring were larger in the less fearful birds, and plumage condition better, which could be interpreted as the less fearful animals being better adapted to the environment in which they were selected.

    sted, utgiver, år, opplag, sider
    Cambridge University Press, 2014
    Emneord
    Red Junglefowl, domestication, fearfulness, selection, social behaviour
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-109499 (URN)10.1017/S1751731114001426 (DOI)000342219000013 ()24910136 (PubMedID)
    Tilgjengelig fra: 2014-08-20 Laget: 2014-08-20 Sist oppdatert: 2016-11-17
    3. Is domestication driven by reduced fear of humans? Boldness, metabolism and serotonin levels in divergently selected red junglefowl (Gallus gallus)
    Åpne denne publikasjonen i ny fane eller vindu >>Is domestication driven by reduced fear of humans? Boldness, metabolism and serotonin levels in divergently selected red junglefowl (Gallus gallus)
    2015 (engelsk)Inngår i: Biology Letters, ISSN 1744-9561, E-ISSN 1744-957X, Vol. 11, nr 9, artikkel-id 20150509Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    Domesticated animals tend to develop a coherent set of phenotypic traits. Tameness could be a central underlying factor driving this, and we therefore selected red junglefowl, ancestors of all domestic chickens, for high or low fear of humans during six generations. We measured basal metabolic rate (BMR), feed efficiency, boldness in a novel object (NO) test, corticosterone reactivity and basal serotonin levels (related to fearfulness) in birds from the fifth and sixth generation of the high- and low-fear lines, respectively (44-48 individuals). Corticosterone response to physical restraint did not differ between selection lines. However, BMR was higher in low-fear birds, as was feed efficiency. Low-fear males had higher plasma levels of serotonin and both low-fear males and females were bolder in an NO test. The results show that many aspects of the domesticated phenotype may have developed as correlated responses to reduced fear of humans, an essential trait for successful domestication.

    sted, utgiver, år, opplag, sider
    ROYAL SOC, 2015
    Emneord
    genetics; domestication; stress
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-123162 (URN)10.1098/rsbl.2015.0509 (DOI)000364772300009 ()26382075 (PubMedID)
    Merknad

    Funding Agencies|research council Formas; ERC [322206]

    Tilgjengelig fra: 2015-12-07 Laget: 2015-12-04 Sist oppdatert: 2019-10-07bibliografisk kontrollert
    4. Effects of Divergent Selection for Fear of Humans on Behaviour in Red Junglefowl
    Åpne denne publikasjonen i ny fane eller vindu >>Effects of Divergent Selection for Fear of Humans on Behaviour in Red Junglefowl
    2016 (engelsk)Inngår i: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 11, nr 11, s. 1-12Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    Domestication has caused a range of similar phenotypic changes across taxa, relating to physiology, morphology and behaviour. It has been suggested that this recurring domesticated phenotype may be a result of correlated responses to a central trait, namely increased tameness. We selected Red Junglefowl, the ancestors of domesticated chickens, during five generations for reduced fear of humans. This caused a marked and significant response in tameness, and previous studies have found correlated effects on growth, metabolism, reproduction, and some behaviour not directly selected for. Here, we report the results from a series of behavioural tests carried out on the initial parental generation (P0) and the fifth selected generation (S5), focusing on behaviour not functionally related to tameness, in order to study any correlated effects. Birds were tested for fear of humans, social reinstatement tendency, open field behaviour at two different ages, foraging/exploration, response to a simulated aerial predator attack and tonic immobility. In S5, there were no effects of selection on foraging/exploration or tonic immobility, while in the social reinstatement and open field tests there were significant interactions between selection and sex. In the aerial predator test, there were significant main effects of selection, indicating that fear of humans may represent a general wariness towards predators. In conclusion, we found only small correlated effects on behaviours not related to the tameness trait selected for, in spite of them showing high genetic correlations to fear of humans in a previous study on the same population. This suggests that species-specific behaviour is generally resilient to changes during domestication.

    sted, utgiver, år, opplag, sider
    PLOS, 2016
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-132742 (URN)10.1371/journal.pone.0166075 (DOI)000387909300035 ()27851792 (PubMedID)
    Merknad

    European Research Council [322206]; FORMAS [221-2007-838]; Vetenskapsradet [621-2008-5437]

    Tilgjengelig fra: 2016-11-22 Laget: 2016-11-22 Sist oppdatert: 2017-11-29bibliografisk kontrollert
  • 4.
    Agnvall, Beatrix
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biologi. Linköpings universitet, Tekniska fakulteten.
    Bélteky, Johan
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biologi. Linköpings universitet, Tekniska fakulteten.
    Jensen, Per
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biologi. Linköpings universitet, Tekniska fakulteten.
    Brain size is reduced by selectionfor tameness in Red Junglefowl–correlated effects in vital organs2017Inngår i: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 7, artikkel-id 3306Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    During domestication animals have undergone changes in size of brain and other vital organs. We hypothesize that this could be a correlated effect to increased tameness. Red Junglefowl (ancestors of domestic chickens) were selected for divergent levels of fear of humans for five generations. The parental (P0) and the fifth selected generation (S5) were culled when 48–54 weeks old and the brains were weighed before being divided into telencephalon, cerebellum, mid brain and optic lobes. Each single brain part as well as the liver, spleen, heart and testicles were also weighed. Brains of S5 birds with high fear scores (S5 high) were heavier both in absolute terms and when corrected for body weight. The relative weight of telencephalon (% of brain weight) was significantly higher in S5 high and relative weight of cerebellum was lower. Heart, liver, testes and spleen were all relatively heavier (% of body weight) in S5 high. Hence, selection for tameness has changed the size of the brain and other vital organs in this population and may have driven the domesticated phenotype as a correlated response.

  • 5.
    Agnvall, Beatrix
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biologi. Linköpings universitet, Tekniska fakulteten.
    Katajamaa, Rebecca
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biologi.
    Altimiras, Jordi
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biologi. Linköpings universitet, Tekniska fakulteten.
    Jensen, Per
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biologi. Linköpings universitet, Tekniska fakulteten.
    Is domestication driven by reduced fear of humans? Boldness, metabolism and serotonin levels in divergently selected red junglefowl (Gallus gallus)2015Inngår i: Biology Letters, ISSN 1744-9561, E-ISSN 1744-957X, Vol. 11, nr 9, artikkel-id 20150509Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Domesticated animals tend to develop a coherent set of phenotypic traits. Tameness could be a central underlying factor driving this, and we therefore selected red junglefowl, ancestors of all domestic chickens, for high or low fear of humans during six generations. We measured basal metabolic rate (BMR), feed efficiency, boldness in a novel object (NO) test, corticosterone reactivity and basal serotonin levels (related to fearfulness) in birds from the fifth and sixth generation of the high- and low-fear lines, respectively (44-48 individuals). Corticosterone response to physical restraint did not differ between selection lines. However, BMR was higher in low-fear birds, as was feed efficiency. Low-fear males had higher plasma levels of serotonin and both low-fear males and females were bolder in an NO test. The results show that many aspects of the domesticated phenotype may have developed as correlated responses to reduced fear of humans, an essential trait for successful domestication.

  • 6.
    Arnqvist, Göran
    et al.
    Department of Ecology and Environmental Science, Animal Ecology, University of Umeå, Umeå, Sweden.
    Edvardsson, Martin
    Department of Ecology and Environmental Science, Animal Ecology, University of Umeå, Umeå, Sweden.
    Friberg, Urban
    Department of Ecology and Environmental Science, Animal Ecology, University of Umeå, Umeå, Sweden.
    Nilsson, Tina
    Department of Ecology and Environmental Science, Animal Ecology, University of Umeå, Umeå, Sweden.
    Sexual conflict promotes speciation in insects.2000Inngår i: Proceedings of the National Academy of Sciences of the United States of America, ISSN 0027-8424, E-ISSN 1091-6490, Vol. 97, nr 19, s. 10460-10464Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Speciation rates among extant lineages of organisms vary extensively, but our understanding of the causes of this variation and, therefore, the processes of speciation is still remarkably incomplete. Both theoretical and empirical studies have indicated that sexual selection is important in speciation, but earlier discussions have focused almost exclusively on the potential role of female mate choice. Recent findings of postmating reproductive conflicts of interest between the sexes suggest a quite different route to speciation. Such conflicts may lead to perpetual antagonistic coevolution between males and females and may thus generate rapid evolutionary divergence of traits involved in reproduction. Here, we assess this hypothesis by contrasting pairs of related groups of insect species differing in the opportunity for postmating sexual conflict. Groups where females mate with many males exhibited speciation rates four times as high as in related groups where females mate only once. Our results not only highlight the general importance of postmating sexual selection in speciation, but also support the recent suggestion that sexual conflict is a key engine of speciation.

  • 7.
    Bartoszek, Krzysztof
    Department of Mathematics, Uppsala University, Uppsala, Sweden.
    Phylogenetic effective sample size2016Inngår i: Journal of Theoretical Biology, ISSN 0022-5193, E-ISSN 1095-8541, Vol. 407, s. 371-386Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In this paper I address the question—how large is a phylogenetic sample? I propose a definition of a phylogenetic effective sample size for Brownian motion and Ornstein-Uhlenbeck processes-the regression effective sample size. I discuss how mutual information can be used to define an effective sample size in the non-normal process case and compare these two definitions to an already present concept of effective sample size (the mean effective sample size). Through a simulation study I find that the AICc is robust if one corrects for the number of species or effective number of species. Lastly I discuss how the concept of the phylogenetic effective sample size can be useful for biodiversity quantification, identification of interesting clades and deciding on the importance of phylogenetic correlations.

  • 8.
    Bartoszek, Krzysztof
    Mathematical Sciences, Chalmers University of Technology and the University of Gothenburg, Gothenburg, Sweden.
    Quantifying the effects of anagenetic and cladogenetic evolution2014Inngår i: Mathematical Biosciences, ISSN 0025-5564, E-ISSN 1879-3134, Vol. 254, s. 42-57Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    An ongoing debate in evolutionary biology is whether phenotypic change occurs predominantly around the time of speciation or whether it instead accumulates gradually over time. In this work I propose a general framework incorporating both types of change, quantify the effects of speciational change via the correlation between species and attribute the proportion of change to each type. I discuss results of parameter estimation of Hominoid body size in this light. I derive mathematical formulae related to this problem, the probability generating functions of the number of speciation events along a randomly drawn lineage and from the most recent common ancestor of two randomly chosen tip species for a conditioned Yule tree. Additionally I obtain in closed form the variance of the distance from the root to the most recent common ancestor of two randomly chosen tip species.

  • 9.
    Bartoszek, Krzysztof
    Department of Mathematical Sciences, Chalmers University of Technology and the University of Gothenburg, Göteborg Sweden.
    The Laplace Motion in Phylogenetic Comparative Methods2012Inngår i: Proceedings of the 18th National Conference on Applications of Mathematics in Biology and Medicine, 2012, s. 25-30Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The majority of current phylogenetic comparative methods assume that the stochastic evolutionaryprocess is homogeneous over the phylogeny or offer relaxations of this in rather limited and usually parameter expensive ways. Here we make a preliminary investigation, bymeans of a numerical experiment, whether the Laplace motion process can offer an alternative approach.

  • 10.
    Bartoszek, Krzysztof
    Linköpings universitet, Institutionen för datavetenskap, Statistik och maskininlärning. Linköpings universitet, Filosofiska fakulteten.
    Trait evolution with jumps: illusionary normality2017Inngår i: Proceedings of the XXIII National Conference on Applications of Mathematics in Biology and Medicine, 2017, s. 23-28Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Phylogenetic comparative methods for real-valued traits usually make use of stochastic process whose trajectories are continuous.This is despite biological intuition that evolution is rather punctuated thangradual. On the other hand, there has been a number of recent proposals of evolutionarymodels with jump components. However, as we are only beginning to understandthe behaviour of branching Ornstein-Uhlenbeck (OU) processes the asymptoticsof branching  OU processes with jumps is an even greater unknown. In thiswork we build up on a previous study concerning OU with jumps evolution on a pure birth tree.We introduce an extinction component and explore via simulations, its effects on the weak convergence of such a process.We furthermore, also use this work to illustrate the simulation and graphic generation possibilitiesof the mvSLOUCH package.

  • 11.
    Bartoszek, Krzysztof
    et al.
    Linköpings universitet, Institutionen för datavetenskap, Statistik och maskininlärning. Linköpings universitet, Filosofiska fakulteten. Uppsala University, Sweden.
    Glemin, Sylvain
    Uppsala University, Sweden; CNRS University of Montpellier IRD EPHE, France.
    Kaj, Ingemar
    Uppsala University, Sweden.
    Lascoux, Martin
    Uppsala University, Sweden.
    Using the Ornstein-Uhlenbeck process to model the evolution of interacting populations2017Inngår i: Journal of Theoretical Biology, ISSN 0022-5193, E-ISSN 1095-8541, Vol. 429, s. 35-45Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The Ornstein-Uhlenbeck (OU) process plays a major role in the analysis of the evolution of phenotypic traits along phylogenies. The standard OU process includes random perturbations and stabilizing selection and assumes that species evolve independently. However, evolving species may interact through various ecological process and also exchange genes especially in plants. This is particularly true if we want to study phenotypic evolution among diverging populations within species. In this work we present a straightforward statistical approach with analytical solutions that allows for the inclusion of adaptation and migration in a common phylogenetic framework, which can also be useful for studying local adaptation among populations within the same species. We furthermore present a detailed simulation study that clearly indicates the adverse effects of ignoring migration. Similarity between species due to migration could be misinterpreted as very strong convergent evolution without proper correction for these additional dependencies. Finally, we show that our model can be interpreted in terms of ecological interactions between species, providing a general framework for the evolution of traits between "interacting" species or populations.(C) 2017 Elsevier Ltd. All rights reserved.

  • 12.
    Bartoszek, Krzysztof
    et al.
    Mathematical Sciences, Chalmers University of Technology and the University of Gothenburg, Gothenburg, Sweden.
    Jones, Graham
    Mathematical Sciences, Chalmers University of Technology and the University of Gothenburg, Gothenburg, Sweden / Department of Biological and Environmental Science, University of Gothenburg, Gothenburg, Sweden.
    Oxelman, Bengt
    Department of Biological and Environmental Science, University of Gothenburg, Gothenburg, Sweden.
    Sagitov, Serik
    Mathematical Sciences, Chalmers University of Technology and the University of Gothenburg, Gothenburg, Sweden.
    Time to a single hybridization event in a group of species with unknown ancestral history2013Inngår i: Journal of Theoretical Biology, ISSN 0022-5193, E-ISSN 1095-8541, Vol. 322, s. 1-6Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We consider a stochastic process for the generation of species which combines a Yule process with a simple model for hybridization between pairs of co-existent species. We assume that the origin of the process, when there was one species, occurred at an unknown time in the past, and we condition the process on producing n species via the Yule process and a single hybridization event. We prove results about the distribution of the time of the hybridization event. In particular we calculate a formula for all moments, and show that under various conditions, the distribution tends to an exponential with rate twice that of the birth rate for the Yule process.

  • 13.
    Bartoszek, Krzysztof
    et al.
    Mathematical Sciences, Chalmers University of Technology and the University of Gothenburg, Sweden.
    Krzeminski, Michal
    Gdansk University of Technology.
    Critical case stochastic phylogenetic tree model via the Laplace transform2014Inngår i: Demonstratio Matematicae, ISSN 0420-1213, Vol. 47, nr 2, s. 474-481Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Birth-and-death models are now a common mathematical tool to describe branching patterns observed in real-world phylogenetic trees. Liggett and Schinazi (2009) is one such example. The authors propose a simple birth-and-death model that is compatible with phylogenetic trees of both in uenza and HIV, depending on the birth rate parameter. An interesting special case of this model is the critical case where the birth rate equals the death rate. This is a non-trivial situation and to study its asymptotic behaviour we employed the Laplace transform. With this we correct the proof of Liggett and Schinazi (2009) in the critical case.

  • 14.
    Bartoszek, Krzysztof
    et al.
    Mathematical Sciences, Chalmers University of Technology and the University of Gothenburg, Gothenburg, Sweden.
    Pienaar, Jason
    Department of Genetics, University of Pretoria, Pretoria 0002, South Africa.
    Mostad, Petter
    Mathematical Sciences, Chalmers University of Technology and the University of Gothenburg, Gothenburg, Sweden.
    Andersson, Staffan
    Department of Biological and Environmental Sciences, University of Gothenburg, Gothenburg, Sweden.
    Hansen, Thomas F.
    CEES, Department of Biology, University of Oslo, Oslo, Norway.
    A phylogenetic comparative method for studying multivariate adaptation2012Inngår i: Journal of Theoretical Biology, ISSN 0022-5193, E-ISSN 1095-8541, Vol. 314, s. 204-215Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Phylogenetic comparative methods have been limited in the way they model adaptation. Although some progress has been made, there are still no methods that can fully account for coadaptationbetween traits. Based on Ornstein-Uhlenbeck (OU) models of adaptive evolution, we present a method,with R implementation, in which multiple traits evolve both in response to each other and, as inprevious OU models, to fixed or randomly evolving predictor variables. We present the interpretation ofthe model parameters in terms of evolutionary and optimal regressions enabling the study of allometric and adaptive relationships between traits. To illustrate the method we reanalyze a data set of antlerand body-size evolution in deer (Cervidae).

  • 15.
    Bartoszek, Krzysztof
    et al.
    Department of Mathematics, Uppsala University, Uppsala, Sweden.
    Pietro, Lio'
    Computer Laboratory , University of Cambridge, Cambridge, Un ited Kingdom.
    A novel algorithm to reconstruct phylogenies using gene sequences and expression data2014Inngår i: International Proceedings of Chemical, Biological & Environmental Engineering; Environment, Energy and Biotechnology III, 2014, Vol. 70, s. 8-12Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Phylogenies based on single loci should be viewed with caution and the best approach for obtaining robust trees is to examine numerous loci across the genome. It often happens that for the same set of species trees derived from different genes are in conflict between each other. There are several methods that combine information from different genes in order to infer the species tree. One novel approach is to use informationfrom different -omics. Here we describe a phylogenetic method based on an Ornstein–Uhlenbeck process that combines sequence and gene expression data. We test our method on genes belonging to the histidine biosynthetic operon. We found that the method provides interesting insights into selection pressures and adaptive hypotheses concerning gene expression levels.

  • 16.
    Bartoszek, Krzysztof
    et al.
    Uppsala universitet, Tillämpad matematik och statistik.
    Sagitov, Serik
    A consistent estimator of the evolutionary rate2015Inngår i: Journal of Theoretical Biology, ISSN 0022-5193, E-ISSN 1095-8541, Vol. 371, s. 69-78Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We consider a branching particle system where particles reproduce according to the pure birth Yule process with the birth rate 2, conditioned on the observed number of particles to be equal to n. Particles are assumed to move independently on the real line according to the Brownian motion with the local variance sigma(2). In this paper we treat n particles as a sample of related species. The spatial Brownian motion of a particle describes the development of a trait value of interest (e.g. log-body-size). We propose an unbiased estimator 4 of the evolutionary rate rho(2) - sigma(2)/lambda. The estimator R-n(2) is proportional to the sample variance S-n(2) computed from n trait values. We find an approximate formula for the standard error of R-n(2), based on a neat asymptotic relation for the variance of S-n(2). (C) 2015 Elsevier Ltd. All rights reserved.

  • 17.
    Bartoszek, Krzysztof
    et al.
    Department of Mathematics, Uppsala University, Uppsala, Sweden.
    Sagitov, Serik
    Chalmers University of Technology and the Unversity of Gothenburg, Sweden.
    Phylogenetic confidence intervals for the optimal trait value2015Inngår i: Journal of Applied Probability, ISSN 0021-9002, E-ISSN 1475-6072, Vol. 52, nr 4, s. 1115-1132Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We consider a stochastic evolutionary model for a phenotype developing amongst n related species with unknown phylogeny. The unknown tree ismodelled by a Yule process conditioned on n contemporary nodes. The trait value is assumed to evolve along lineages as an Ornstein–Uhlenbeck process. As a result, the trait values of the n species form a sample with dependent observations. We establish three limit theorems for the samplemean corresponding to three domains for the adaptation rate. In the case of fast adaptation, we show that for large n the normalized sample mean isapproximately normally distributed. Using these limit theorems, we develop novel confidence interval formulae for the optimal trait value.

  • 18.
    Bohlin, Gustav
    et al.
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Medie- och Informationsteknik. Linköpings universitet, Tekniska högskolan.
    Göransson, Andreas C.
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Medie- och Informationsteknik. Linköpings universitet, Tekniska högskolan.
    Tibell, Lena A. E.
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Medie- och Informationsteknik. Linköpings universitet, Tekniska högskolan.
    Diverse use of threshold concepts - A content analysis of online dynamic visualizations describing evolution.2015Konferansepaper (Fagfellevurdert)
    Abstract [en]

    There is an abundance of dynamic visualizations (animations, videos and simulations) that claim to explain evolution available on the Internet. The present study explores what aspects of evolution that are represented in these potential learning tools. A criteria catalogue covering 40 operationalized variables was used as a content analysis grid in the analysis of 71 dynamic visualizations. The concepts, derived from research literature, were operationalized into variables sorted into four different categories: (a) content-specific concepts (such as limited resources or inherited variation), (b) threshold concepts (core concepts that transform and integrate understanding within a subject), (c) alternative conceptions (such as teleological explanations or anthropomorphism), and (d) model organism. The results indicate that some concepts are dominantly communicated while others are seldom or never included in online visualizations. Regarding the proposed threshold concepts, evolutionary events happening on small time- and spatial scales, such as subcellular processes, were seldom observed. Rather, the focus was on events happening at a population level in time scales spanning from years and longer. This echoes with an observed lack of explanations regarding randomly occurring mutations providing the basis for variation. Implications include that there are components of evolution that would benefit from being addressed with an increased focus in biology teaching and science education research. The results may also serve as a useful toolkit in the design of new educational material.

  • 19.
    Bravo, Gustavo A.
    et al.
    Harvard Univ, MA 02138 USA.
    Antonelli, Alexandre
    Harvard Univ, MA 02138 USA; Gothenburg Global Biodivers Ctr, Sweden; Univ Gothenburg, Sweden; Gothenburg Bot Garden, Sweden.
    Bacon, Christine D.
    Gothenburg Global Biodivers Ctr, Sweden; Univ Gothenburg, Sweden.
    Bartoszek, Krzysztof
    Linköpings universitet, Institutionen för datavetenskap, Statistik och maskininlärning. Linköpings universitet, Filosofiska fakulteten.
    Blom, Mozes P. K.
    Swedish Museum Nat Hist, Sweden.
    Huynh, Stella
    Univ Neuchatel, Switzerland.
    Jones, Graham
    Univ Gothenburg, Sweden.
    Knowles, L. Lacey
    Univ Michigan, MI 48109 USA.
    Lamichhaney, Sangeet
    Harvard Univ, MA 02138 USA.
    Marcussen, Thomas
    Univ Oslo, Norway.
    Morlon, Helene
    Ecole Normale Super Paris, France.
    Nakhleh, Luay K.
    Rice Univ, TX USA.
    Oxelman, Bengt
    Gothenburg Global Biodivers Ctr, Sweden; Univ Gothenburg, Sweden.
    Pfeil, Bernard
    Univ Gothenburg, Sweden.
    Schliep, Alexander
    Chalmers Univ Technol, Sweden; Univ Gothenburg, Sweden.
    Wahlberg, Niklas
    Lund Univ, Sweden.
    Werneck, Fernanda P.
    Inst Nacl de Pesquisas da Amazonia, Brazil.
    Wiedenhoeft, John
    Chalmers Univ Technol, Sweden; Univ Gothenburg, Sweden; Rutgers State Univ, NJ USA.
    Willows-Munro, Sandi
    Univ Kwazulu Natal, South Africa.
    Edwards, Scott V
    Harvard Univ, MA 02138 USA; Univ Gothenburg, Sweden; Chalmers Univ Technol, Sweden.
    Embracing heterogeneity: coalescing the Tree of Life and the future of phylogenomics2019Inngår i: PeerJ, ISSN 2167-8359, E-ISSN 2167-8359, Vol. 7, artikkel-id e6399Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Building the Tree of Life (ToL) is a major challenge of modern biology, requiring advances in cyberinfrastructure, data collection, theory, and more. Here, we argue that phylogenomics stands to benefit by embracing the many heterogeneous genomic signals emerging from the first decade of large-scale phylogenetic analysis spawned by high-throughput sequencing (HTS). Such signals include those most commonly encountered in phylogenomic datasets, such as incomplete lineage sorting, but also those reticulate processes emerging with greater frequency, such as recombination and introgression. Here we focus specifically on how phylogenetic methods can accommodate the heterogeneity incurred by such population genetic processes; we do not discuss phylogenetic methods that ignore such processes, such as concatenation or supermatrix approaches or supertrees. We suggest that methods of data acquisition and the types of markers used in phylogenomics will remain restricted until a posteriori methods of marker choice are made possible with routine whole-genome sequencing of taxa of interest. We discuss limitations and potential extensions of a model supporting innovation in phylogenomics today, the multispecies coalescent model (MSC). Macroevolutionary models that use phylogenies, such as character mapping, often ignore the heterogeneity on which building phylogenies increasingly rely and suggest that assimilating such heterogeneity is an important goal moving forward. Finally, we argue that an integrative cyberinfrastructure linking all steps of the process of building the ToL, from specimen acquisition in the field to publication and tracking of phylogenomic data, as well as a culture that values contributors at each step, are essential for progress.

  • 20.
    Brengdahl, Martin
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biologi. Linköpings universitet, Tekniska högskolan.
    Differentiation of dispersive traits under a fluctuating range distribution in Asellus aquaticus2014Independent thesis Basic level (degree of Bachelor), 10,5 poäng / 16 hpOppgave
    Abstract [en]

    Knowledge about dispersion is of utmost importance for understanding populations’ reaction to changes in the environment. Expansion of a population range brings with it both spatial sorting and over time, spatial selection. This means that dispersion rates increases over time at the expanding edge. Most studies have so far been performed on continuously expanding populations. This study aims to bring more knowledge about dispersal biology in dynamic systems. I studied dispersal traits in two permanent and two seasonal vegetation habitats of an isopod (Asellus aquaticus), for which differentiation between habitat types has previously been shown. I quantified differences in displacement (dispersal rate) and three morphological traits, head angle (body streamline) and leg of the third and seventh pair of legs. Isopods from the seasonal vegetation had higher displacement rates than animals from permanent vegetation. This inclines that mechanisms driving spatial selection in expanding population ranges also exist in dynamic systems. The more streamlined isopods found in seasonal sites further points towards spatial sorting by dispersion capability. Because no effect of permanence was found on leg length and there was no correlation between streamlining and displacement, the higher dispersion among animals from seasonal habitats most likely derives from behavioral differences.

  • 21.
    Brengdahl, Martin
    Linköpings universitet, Institutionen för fysik, kemi och biologi. Linköpings universitet, Tekniska fakulteten.
    Dispersive trait expression of Asellus aquaticus from a rare cave habitat2016Independent thesis Advanced level (degree of Master (Two Years)), 40 poäng / 60 hpOppgave
    Abstract [en]

    Dispersal influences several ecological and evolutionary processes, such as intraspecific competition, genetic drift and inbreeding. It can lead to phenotypic mismatch with the habitat when a locally adapted individual winds up in an environment with a divergent selection regime compared to the source habitat. The aim of this project was to compare dispersive traits in the freshwater isopod Asellus aquaticus from a cave habitat, with surface dwelling isopods collected upstream and downstream from the cave system. The subterranean stream (cave) represents a rare, geographically limited habitat which has a divergent selective pressure compared to the surrounding habitats. Experiments on dispersal were performed in the laboratory, in darkness with IR-equipment for visualization. Displacement was measured using one-dimensional test arenas. Compared to the surface phenotype, the cave phenotype was expected to have reduced fitness outside of the cave and unlikely to successfully disperse to new areas of similar suitable conditions. The results did not follow my main hypothesis that isopods from the cave would be less dispersive than individuals from the surface. The inconclusive results might derive from large variation in the data and divergent adaptations which yield similar expression of dispersal.

  • 22.
    Brengdahl, Martin
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biologi. Linköpings universitet, Tekniska fakulteten.
    Kimber, Christopher
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biologi. Linköpings universitet, Tekniska fakulteten.
    Maguire-Baxter, Jack
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biologi. Linköpings universitet, Tekniska fakulteten.
    Friberg, Urban
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biologi. Linköpings universitet, Tekniska fakulteten.
    Sex differences in life span: Females homozygous for the X chromosome do not suffer the shorter life span predicted by the unguarded X hypothesis2018Inngår i: Evolution, ISSN 0014-3820, E-ISSN 1558-5646, Vol. 72, nr 3, s. 568-577Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Life span differs between the sexes in many species. Three hypotheses to explain this interesting pattern have been proposed, involving different drivers: sexual selection, asymmetrical inheritance of cytoplasmic genomes, and hemizygosity of the X(Z) chromosome (the unguarded X hypothesis). Of these, the unguarded X has received the least experimental attention. This hypothesis suggests that the heterogametic sex suffers a shortened life span because recessive deleterious alleles on its single X(Z) chromosome are expressed unconditionally. In Drosophila melanogaster, the X chromosome is unusually large (approximate to 20% of the genome), providing a powerful model for evaluating theories involving the X. Here, we test the unguarded X hypothesis by forcing D. melanogaster females from a laboratory population to express recessive X-linked alleles to the same degree as males, using females exclusively made homozygous for the X chromosome. We find no evidence for reduced life span or egg-to-adult viability due to X homozygozity. In contrast, males and females homozygous for an autosome both suffer similar, significant reductions in those traits. The logic of the unguarded X hypothesis is indisputable, but our results suggest that the degree to which recessive deleterious X-linked alleles depress performance in the heterogametic sex appears too small to explain general sex differences in life span.

  • 23.
    Brengdahl, Martin
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biologi. Linköpings universitet, Tekniska fakulteten.
    Kimber, Christopher
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biologi. Linköpings universitet, Tekniska fakulteten.
    Maguire-Baxter, Jack
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biologi. Linköpings universitet, Tekniska fakulteten.
    Malacrinò, Antonino
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biologi. Linköpings universitet, Tekniska fakulteten.
    Friberg, Urban
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biologi. Linköpings universitet, Tekniska fakulteten.
    Genetic Quality Affects the Rate of Male and Female Reproductive Aging Differently in Drosophila melanogaster2018Inngår i: American Naturalist, ISSN 0003-0147, E-ISSN 1537-5323, Vol. 192, nr 6, s. 761-772Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Males and females often maximize fitness by pursuing different reproductive strategies, with males commonly assumed to benefit more from increased resource allocation into current reproduction. Such investment should trade off with somatic maintenance and may explain why males frequently live shorter than females. It also predicts that males should experience faster reproductive aging. Here we investigate whether reproductive aging and life span respond to condition differently in male and female Drosophila melanogaster, as predicted if sexual selection has shaped male and female resource-allocation patterns. We manipulate condition through genetic quality by comparing individuals inbred or outbred for a major autosome. While genetic quality had a similar effect on condition in both sexes, condition had a much larger general effect on male reproductive output than on female reproductive output, as expected when sexual selection on vigor acts more strongly on males. We find no differences in reproductive aging between the sexes in low condition, but in high condition reproductive aging is relatively faster in males. No corresponding sex-specific change was found for life span. The sex difference in reproductive aging appearing in high condition was specifically due to a decreased aging rate in females rather than any change in males. Our results suggest that females age slower than males in high condition primarily because sexual selection has favored sex differences in resource allocation under high condition, with females allocating relatively more toward somatic maintenance than males.

  • 24.
    Bélteky, Johan
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biologi. Linköpings universitet, Tekniska fakulteten.
    Chicken domestication: Effects of tameness on brain gene expression and DNA methylation2016Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Domestication greatly increases phenotypic variation in a short time span, with selection for a single phenotype and a plethora of associated phenotypic changes as an outcome of the process. The domestication process influences the underlying genomic architecture of a species, and the success and speed of the process is likely influenced by it. The main aims of my thesis was to study how domestication affects the brain of chickens: specifically changes in morphology, gene expression, and DNA methylation. Differences in gene expression and DNA methylation between White Leghorn and Red Junglefowl chickens were mapped, and inheritance of these patterns were quantified, indicating a faithful transmission of breed-specific epigenetic markers. Selection on the behavioral trait fearfulness, generated high and low fearful lines of Red Junglefowl. Both the parental population and the fifth selected generation were used for the analyses in this thesis. One experiment studied morphological changes in the brain and other vital organs, and found that relative total brain size increased in high fearful birds, as a consequence of an increase in cerebral hemisphere size in high fearful birds and not in low fearful birds. Also, the relative heart, liver, spleen and testis size increased in high fearful birds, indicating correlated morphological changes with selection for fearfulness. Two additional experiments examined differential gene expression in the hypothalamus and the anterior cerebral hemisphere. The hypothalamus differed in expression of genes with reproductive and immunological functions, whilst the cerebral hemisphere differed in expression of genes related to social behaviors and neurological functions especially those upregulated in low fearful birds.  These results indicate the occurrence of tissue- and species-specific changes in gene expression as overlap with other domestication events were nearly nonexistent. A fourth experiment sought to associate the change in fear levels and gene expression differences with DNA methylation. Chromosomal regions with differential DNA methylation between high and low fearful birds were identified, and genes in these regions had annotated functions relevant to phenotypic differences between the selection lines. This thesis is the first to study the genetic alterations of domestication using the wild ancestor of an already domesticated species to repeat the domestication process selecting against fear of humans. The findings corroborate results from previous comparisons of wild and domestic animals, and further support the theory that rigorous selection for a behavioral trait can cause a cascade of genetic and epigenetic changes facilitating the domestication of a population.

    Delarbeid
    1. Heritable genome-wide variation of gene expression and promoter methylation between wild and domesticated chickens
    Åpne denne publikasjonen i ny fane eller vindu >>Heritable genome-wide variation of gene expression and promoter methylation between wild and domesticated chickens
    Vise andre…
    2012 (engelsk)Inngår i: BMC Genomics, ISSN 1471-2164, E-ISSN 1471-2164, Vol. 13, nr 59Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    Variations in gene expression, mediated by epigenetic mechanisms, may cause broad phenotypic effects in animals. However, it has been debated to what extent expression variation and epigenetic modifications, such as patterns of DNA methylation, are transferred across generations, and therefore it is uncertain what role epigenetic variation may play in adaptation. Here, we show that in Red Junglefowl, ancestor of domestic chickens, gene expression and methylation profiles in thalamus/hypothalamus differ substantially from that of a domesticated egg laying breed. Expression as well as methylation differences are largely maintained in the offspring, demonstrating reliable inheritance of epigenetic variation. Some of the inherited methylation differences are tissue-specific, and the differential methylation at specific loci are little changed after eight generations of intercrossing between Red Junglefowl and domesticated laying hens. There was an over-representation of differentially expressed and methylated genes in selective sweep regions associated with chicken domestication. Hence, our results show that epigenetic variation is inherited in chickens, and we suggest that selection of favourable epigenomes, either by selection of genotypes affecting epigenetic states, or by selection of methylation states which are inherited independently of sequence differences, may have been an important aspect of chicken domestication.

    sted, utgiver, år, opplag, sider
    BioMed Central, 2012
    Emneord
    Domestication, gene expression, tiling array, behaviour, methylation
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-70159 (URN)10.1186/1471-2164-13-59 (DOI)000301440800001 ()
    Merknad

    funding agencies|Swedish Research Council| 2008-14496-59340-36 |Swedish Research Council for Environment, Agricultural Sciences and Spatial Planning| 221 2007 838 |

    Tilgjengelig fra: 2011-08-22 Laget: 2011-08-22 Sist oppdatert: 2019-03-05bibliografisk kontrollert
    2. Domestication and tameness: brain geneexpression in red junglefowl selected for less fear of humans suggests effects on reproduction and immunology
    Åpne denne publikasjonen i ny fane eller vindu >>Domestication and tameness: brain geneexpression in red junglefowl selected for less fear of humans suggests effects on reproduction and immunology
    Vise andre…
    2016 (engelsk)Inngår i: Royal Society Open Science, E-ISSN 2054-5703, nr 3, artikkel-id 160033Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    The domestication of animals has generated a set of phenotypicmodifications, affecting behaviour, appearance, physiologyand reproduction, which are consistent across a range ofspecies. We hypothesized that some of these phenotypes couldhave evolved because of genetic correlation to tameness,an essential trait for successful domestication. Starting froman outbred population of red junglefowl, ancestor of alldomestic chickens, we selected birds for either high or lowfear of humans for five generations. Birds from the fifthselected generation (S5) showed a divergent pattern of growthand reproduction, where low fear chickens grew larger andproduced larger offspring. To examine underlying geneticmechanisms, we used microarrays to study gene expressionin thalamus/hypothalamus, a brain region involved in fearand stress, in both the parental generation and the S5. Whileparents of the selection lines did not show any differentiallyexpressed genes, there were a total of 33 genes with adjustedp-values below 0.1 in S5. These were mainly related to spermfunction,immunological functions, with only a few known tobe relevant to behaviour. Hence, five generations of divergentselection for fear of humans produced changes in hypothalamicgene expression profiles related to pathways associated withmale reproduction and to immunology. This may be linked to the effects seen on growth and size of offspring. These results support the hypothesis thatdomesticated phenotypes may evolve because of correlated effects related to reduced fear of humans.

    sted, utgiver, år, opplag, sider
    Royal Society Publishing, 2016
    Emneord
    artificial selection, gene expression, microarray, chicken, fearfulness
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-130501 (URN)10.1098/rsos.160033 (DOI)000384411000002 ()
    Merknad

    Funding agencies:  Research council Formas; Vetenskapsradet; ERC [322206]

    Tilgjengelig fra: 2016-08-11 Laget: 2016-08-11 Sist oppdatert: 2017-11-28
  • 25.
    Cauchoix, M.
    et al.
    CNRS, France; Inst Adv Study Toulouse, France.
    Chow, P. K. Y.
    Univ Exeter, England; Hokkaido Univ, Japan.
    van Horik, J. O.
    Univ Exeter, England.
    Atance, C. M.
    Univ Ottawa, Canada.
    Barbeau, E. J.
    UPS, France.
    Barragan-Jason, G.
    Inst Adv Study Toulouse, France.
    Bize, P.
    Univ Aberdeen, Scotland.
    Boussard, A.
    Stockholm Univ, Sweden.
    Buechel, S. D.
    Stockholm Univ, Sweden.
    Cabirol, A.
    Univ Paul Sabatier, France.
    Cauchard, L.
    Univ Montreal, Canada.
    Claidiere, N.
    Aix Marseille Univ, France.
    Dalesman, S.
    Aberystwyth Univ, Wales.
    Devaud, J. M.
    Univ Paul Sabatier, France.
    Didic, M.
    AP HM Timone, France; Inst Neurosci Syst, France.
    Doligez, B.
    Univ Lyon 1, France.
    Fagot, J.
    Aix Marseille Univ, France.
    Fichtel, C.
    German Primate Ctr, Germany; Univ Gottingen, Germany; Leibniz Sci Campus Primate Cognit, Germany.
    Henke-von der Malsburg, J.
    German Primate Ctr, Germany; Univ Gottingen, Germany; Leibniz Sci Campus Primate Cognit, Germany.
    Hermer, E.
    Univ Gottingen, Germany.
    Huber, L.
    Leibniz Sci Campus Primate Cognit, Germany.
    Huebner, F.
    German Primate Ctr, Germany; Univ Gottingen, Germany; Leibniz Sci Campus Primate Cognit, Germany.
    Kappeler, P. M.
    German Primate Ctr, Germany; Univ Gottingen, Germany; Leibniz Sci Campus Primate Cognit, Germany.
    Klein, S.
    Univ Paul Sabatier, France.
    Langbein, J.
    Leibniz Inst Farm Anim Biol, Germany.
    Langley, E. J. G.
    Univ Exeter, England.
    Lea, S. E. G.
    Univ Exeter, England.
    Lihoreau, M.
    Univ Paul Sabatier, France.
    Lovlie, Hanne
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biologi. Linköpings universitet, Tekniska fakulteten.
    Matzel, L. D.
    Rutgers State Univ, NJ USA.
    Nakagawa, S.
    Univ New South Wales, Australia; Univ New South Wales, Australia.
    Nawroth, C.
    Leibniz Inst Farm Anim Biol, Germany.
    Oesterwind, S.
    Univ Rostock, Germany.
    Sauce, B.
    Rutgers State Univ, NJ USA.
    Smith, E. A.
    Univ Lincoln, England.
    Sorato, Enrico
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biologi. Linköpings universitet, Tekniska fakulteten.
    Tebbich, S.
    Univ Vienna, Austria.
    Wallis, L. J.
    Univ Vienna, Austria; Eotvos Lorand Univ, Hungary.
    Whiteside, M. A.
    Univ Exeter, England.
    Wilkinson, A.
    Univ Lincoln, England.
    Chaine, A. S.
    CNRS, France; Inst Adv Study Toulouse, France.
    Morand-Ferron, J.
    Univ Ottawa, Canada.
    The repeatability of cognitive performance: a meta-analysis2018Inngår i: Philosophical Transactions of the Royal Society of London. Biological Sciences, ISSN 0962-8436, E-ISSN 1471-2970, Vol. 373, nr 1756, artikkel-id 20170281Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Behavioural and cognitive processes play important roles in mediating an individuals interactions with its environment. Yet, while there is a vast literature on repeatable individual differences in behaviour, relatively little is known about the repeatability of cognitive performance. To further our understanding of the evolution of cognition, we gathered 44 studies on individual performance of 25 species across six animal classes and used meta-analysis to assess whether cognitive performance is repeatable. We compared repeatability (R) in performance (1) on the same task presented at different times (temporal repeatability), and (2) on different tasks that measured the same putative cognitive ability (contextual repeatability). We also addressed whether R estimates were influenced by seven extrinsic factors (moderators): type of cognitive performance measurement, type of cognitive task, delay between tests, origin of the subjects, experimental context, taxonomic class and publication status. We found support for both temporal and contextual repeatability of cognitive performance, with mean R estimates ranging between 0.15 and 0.28. Repeatability estimates were mostly influenced by the type of cognitive performance measures and publication status. Our findings highlight the widespread occurrence of consistent inter-individual variation in cognition across a range of taxa which, like behaviour, may be associated with fitness outcomes. This article is part of the theme issue Causes and consequences of individual differences in cognitive abilities.

  • 26.
    Eklöf, Anna
    et al.
    Department of Ecology and Evolution, University of Chicago, Chicago, IL 60637, USA.
    Helmus, Matthew R.
    Department of Ecology and Evolution, University of Chicago, Chicago, IL 60637, USA.
    Moore, M.
    Department of Ecology and Evolution, University of Chicago, Chicago, IL 60637, USA.
    Allesina, Stefano
    Department of Ecology and Evolution, and Computation Institute, University of Chicago, Chicago, IL 60637, USA.
    Relevance of evolutionary history for food web structure2012Inngår i: Proceedings of the Royal Society of London. Biological Sciences, ISSN 0962-8452, E-ISSN 1471-2954, Vol. 279, nr 1733, s. 1588-1596Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Explaining the structure of ecosystems is one of the great challenges of ecology. Simple models for foodweb structure aim at disentangling the complexity of ecological interaction networks and detect the main forces that are responsible for their shape. Trophic interactions are influenced by species traits, which in turn are largely determined by evolutionary history. Closely related species are more likely to share similar traits, such as body size, feeding mode and habitat preference than distant ones. Here, we present a theoretical framework for analysing whether evolutionary history—represented by taxonomic classification—provides valuable information on food web structure. In doing so, we measure which taxonomic ranks better explain species interactions. Our analysis is based on partitioning of the species into taxonomic units. For each partition, we compute the likelihood that a probabilistic model for food web structurere produces the data using this information. We find that taxonomic partitions produce significantly higher likelihoods than expected at random. Marginal likelihoods (Bayes factors) are used to perform model selection among taxonomic ranks. We show that food webs are best explained by the coarser taxonomic ranks (kingdom to class). Our methods provide a way to explicitly include evolutionary history in models for food web structure.

  • 27.
    Fallahshahroudi, Amir
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biologi. Linköpings universitet, Tekniska fakulteten.
    Domestication Effects on the Stress Response in Chickens: Genetics, Physiology, and Behaviour2017Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Animal domestication, the process where animals become adapted to living in proximity to humans, is associated with the alteration of multiple traits, including decreased fearfulness and stress response. With an estimated population of 50 billion, the domesticated chicken is the most populous avian species in the world. Hundreds of chicken breeds have been developed for meat and egg production, hobby or research purposes. Multidirectional selection and the relaxation of natural selection in captivity have created immense phenotypic diversity amongst domesticates in a relatively short evolutionary time. The extensive phenotypic diversity, existence of the wild ancestor, and feasibility of intercrossing various breeds makes the chicken a suitable model animal for deciphering genetic determinants of complex traits such as stress response. We used chicken domestication as a model to gain insights about the mechanisms that regulate stress response in an avian species. We studied behavioural and physiological stress response in the ancestral Red Junglefowl and one of its domesticated progenies, White Leghorn. An advanced intercross between the aforementioned breeds was later used to map genetic loci underlying modification of stress response. The general pattern of the stress response in chickens was comparable with that reported in mammals, however we identified distinctive differences in the stress modulatory pathways in chickens. We showed that changes in the expression levels of several stress modulatory genes in the brain, the pituitary and the adrenal glands underlie the observed modified stress response in domesticated chickens. Using quantitative trait loci (QTL) mapping, several QTL underlying stress induced corticosterone, aldosterone and baseline dehydroepiandrosterone (DHEA) levels were detected. As a next step, we combined QTL mapping with gene expression (eQTL) mapping and narrowed two QTL down to the putative causal genes, SERPINA10 and PDE1C. Both of these genes were differentially expressed in the adrenal glands of White Leghorn and the Red Junglefowl, had overlapping eQTL with hormonal QTL, and their expression levels in the adrenal glands were correlated with plasma levels of corticosterone and al-dosterone. These two genes thus serve as strong candidates for further functional investigation concerning modification of the stress response during domestication. This dissertation increase the knowledge about genetics and physiology of the stress response in an avian species and its modification during domestication. Our findings expand the basic knowledge about the stress response in chicken, which can potentially be used to improve welfare through appropriate genetic selection.

    Delarbeid
    1. Domestication effects on behavioural and hormonal responses to acute stress in chickens
    Åpne denne publikasjonen i ny fane eller vindu >>Domestication effects on behavioural and hormonal responses to acute stress in chickens
    Vise andre…
    2014 (engelsk)Inngår i: Physiology and Behavior, ISSN 0031-9384, E-ISSN 1873-507X, Vol. 133, s. 161-169Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    Comparative studies have shown that alterations in physiology, morphology and behaviour have arisen due tothe domestication. A driving factor behind many of the changes could be a shift in stress responses,withmodifiedendocrine and behavioural profiles. In the present study we compared two breeds of chicken (Gallus gallus), thedomesticWhite Leghorn (WL) egg laying breed and its ancestor, the Red Junglefowl (RJF). Birds were exposed toan acute stress event, invoked by 3 or 10 min of physical restraint. Theywere then continuouslymonitored for theeffects on a wide range of behaviours during a 60 min recovery phase. Blood samples were collected from thechicken at baseline, and after 10 and 60 min following a similar restraint stress, and the samples wereanalyzed for nine endogenous steroids of the HPA and HPG axes. Concentration of the steroids was determinedusing validated liquid chromatography tandem mass spectrometry methods. In RJF, an immediate behaviouralresponse was observed after release from restraint in several behaviours, with a relatively fast return to baselinewithin 1 h. In WL, somebehaviourswere affected for a longer period of time, and others not at all. Concentrationsof corticosterone increasedmore in RJF, but returned faster to baseline compared toWL. A range of baseline levelsfor HPG-related steroids differed between the breeds, and they were generally more affected by the stress in WLthan in RJF. In conclusion, RJF reacted stronger both behaviourally and physiologically to the restraint stress, butalso recovered faster. This would appear to be adaptive under natural conditions, whereas the stress recovery ofdomesticated birds has been altered by domestication and breeding for increased reproductive output.

    sted, utgiver, år, opplag, sider
    Elsevier, 2014
    Emneord
    Corticosterone Recovery Restraint White Leghorn Red Junglefowl
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-107167 (URN)10.1016/j.physbeh.2014.05.024 (DOI)000340315100022 ()
    Merknad

    Funders: Swedish Research Council (VR) [621-2011-4731]; Swedish Research Council for Environment, Agricultural Sciences and Spatial Planning (FORMAS) [221-2011-1088]; ERC (project Genewell) [322206]; Swedish Centre of Excellence in Animal Welfare; ARUP Institute for Clinical and Experimental Pathology

    Tilgjengelig fra: 2014-06-09 Laget: 2014-06-09 Sist oppdatert: 2017-12-05
    2. Domestication Effects on Stress Induced Steroid Secretion and Adrenal Gene Expression in Chickens
    Åpne denne publikasjonen i ny fane eller vindu >>Domestication Effects on Stress Induced Steroid Secretion and Adrenal Gene Expression in Chickens
    Vise andre…
    2015 (engelsk)Inngår i: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 5, s. 1-10, artikkel-id 15345Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    Understanding the genetic basis of phenotypic diversity is a challenge in contemporary biology. Domestication provides a model for unravelling aspects of the genetic basis of stress sensitivity. The ancestral Red Junglefowl (RJF) exhibits greater fear-related behaviour and a more pronounced HPA-axis reactivity than its domesticated counterpart, the White Leghorn (WL). By comparing hormones (plasmatic) and adrenal global gene transcription profiles between WL and RJF in response to an acute stress event, we investigated the molecular basis for the altered physiological stress responsiveness in domesticated chickens. Basal levels of pregnenolone and dehydroepiandrosterone as well as corticosterone response were lower in WL. Microarray analysis of gene expression in adrenal glands showed a significant breed effect in a large number of transcripts with over-representation of genes in the channel activity pathway. The expression of the best-known steroidogenesis genes were similar across the breeds used. Transcription levels of acute stress response genes such as StAR, CH25 and POMC were upregulated in response to acute stress. Dampened HPA reactivity in domesticated chickens was associated with changes in the expression of several genes that presents potentially minor regulatory effects rather than by means of change in expression of critical steroidogenic genes in the adrenal.

    sted, utgiver, år, opplag, sider
    Nature Publishing Group, 2015
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-122305 (URN)10.1038/srep15345 (DOI)000362885300001 ()26471470 (PubMedID)
    Merknad

    Funding agencies: Swedish Research Council (VR) [621-2011-4731]; Swedish Research Council for Environment, Agricultural Sciences and Spatial Planning (FORMAS) [221-2011-1088]; SRC [621-2011-5523]; ERC [322206]; Swedish Centre of Excellence in Animal Welfare

    Tilgjengelig fra: 2015-10-28 Laget: 2015-10-28 Sist oppdatert: 2017-12-01
    3. Genetic and Targeted eQTL Mapping Reveals Strong Candidate Genes Modulating the Stress Response During Chicken Domestication.
    Åpne denne publikasjonen i ny fane eller vindu >>Genetic and Targeted eQTL Mapping Reveals Strong Candidate Genes Modulating the Stress Response During Chicken Domestication.
    Vise andre…
    2017 (engelsk)Inngår i: G3: Genes, Genomes, Genetics, ISSN 2160-1836, E-ISSN 2160-1836, Vol. 7, nr 2Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    The stress response has been largely modified in all domesticated animals, offering a strong tool for genetic mapping. In chickens, ancestral Red Junglefowl react stronger both in terms of physiology and behavior to a brief restraint stress than domesticated White Leghorn, demonstrating modified functions of the hypothalamic-pituitary-adrenal (HPA) axis. We mapped quantitative trait loci (QTL) underlying variations in stress-induced hormone levels using 232 birds from the 12th generation of an advanced intercross between White Leghorn and Red Junglefowl, genotyped for 739 genetic markers. Plasma levels of corticosterone, dehydroepiandrosterone (DHEA), and pregnenolone (PREG) were measured using LC-MS/MS in all genotyped birds. Transcription levels of the candidate genes were measured in the adrenal glands or hypothalamus of 88 out of the 232 birds used for hormone assessment. Genes were targeted for expression analysis when they were located in a hormone QTL region and were differentially expressed in the pure breed birds. One genome-wide significant QTL on chromosome 5 and two suggestive QTL together explained 20% of the variance in corticosterone response. Two significant QTL for aldosterone on chromosome 2 and 5 (explaining 19% of the variance), and one QTL for DHEA on chromosome 4 (explaining 5% of the variance), were detected. Orthologous DNA regions to the significant corticosterone QTL have been previously associated with the physiological stress response in other species but, to our knowledge, the underlying gene(s) have not been identified. SERPINA10 had an expression QTL (eQTL) colocalized with the corticosterone QTL on chromosome 5 and PDE1C had an eQTL colocalized with the aldosterone QTL on chromosome 2. Furthermore, in both cases, the expression levels of the genes were correlated with the plasma levels of the hormones. Hence, both these genes are strong putative candidates for the domestication-induced modifications of the stress response in chickens. Improved understanding of the genes associated with HPA-axis reactivity can provide insights into the pathways and mechanisms causing stress-related pathologies.

    sted, utgiver, år, opplag, sider
    The Genetics Society, 2017
    Emneord
    animal, domestication, quantitative trait, genes, corticosterone, aldosterone
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-134649 (URN)10.1534/g3.116.037721 (DOI)000394357100015 ()27974436 (PubMedID)
    Merknad

    Funding agencies: Swedish Research Council (SRC) (Vetenskapsradet) [621-2011-4731]; Swedish Research Council for Environment, Agricultural Sciences and Spatial Planning (Forskningsradet for Miljo, Areella Naringar och Samhallsbyggande) [221-2011-1088]; European Research Co

    Tilgjengelig fra: 2017-02-21 Laget: 2017-02-21 Sist oppdatert: 2017-11-29
    4. QTL mapping of stress related gene expression in a cross between domesticated chickens and ancestral red junglefowl.
    Åpne denne publikasjonen i ny fane eller vindu >>QTL mapping of stress related gene expression in a cross between domesticated chickens and ancestral red junglefowl.
    Vise andre…
    2017 (engelsk)Inngår i: Molecular and Cellular Endocrinology, ISSN 0303-7207, E-ISSN 1872-8057, Vol. 446, s. 52-58, artikkel-id S0303-7207(17)30090-4Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    Domestication of animals is associated with numerous alterations in physiology, morphology, and behavior. Lower reactivity of the hypothalamic-pituitary-adrenal (HPA) axis and reduced fearfulness is seen in most studied domesticates, including chickens. Previously we have shown that the physiological stress response as well as expression levels of hundreds of genes in the hypothalamus and adrenal glands are different between domesticated White Leghorn and the progenitor of modern chickens, the Red Junglefowl. To map genetic loci associated with the transcription levels of genes involved in the physiological stress response, we conducted an eQTL analysis in the F12 generation of an inter-cross between White Leghorn and Red Junglefowl. We selected genes for further studies based on their known function in the regulation of the HPA axis or sympathoadrenal (SA) system, and measured their expression levels in the hypothalamus and the adrenal glands after a brief stress exposure (physical restraint). The expression values were treated as quantitative traits for the eQTL mapping. The plasma levels of corticosterone were also assessed. We analyzed the correlation between gene expression and corticosterone levels and mapped eQTL and their potential effects on corticosterone levels. The effects on gene transcription of a previously found QTL for corticosterone response were also investigated. The expression levels of the glucocorticoid receptor (GR) in the hypothalamus and several genes in the adrenal glands were correlated with the post-stress levels of corticosterone in plasma. We found several cis- and trans-acting eQTL for stress-related genes in both hypothalamus and adrenal. In the hypothalamus, one eQTL for c-FOS and one QTL for expression of GR were found. In the adrenal tissue, we identified eQTL for the genes NR0B1, RGS4, DBH, MAOA, GRIN1, GABRB2, GABRB3, and HSF1. None of the found eQTL were significant predictors of corticosterone levels. The previously found QTL for corticosterone was associated with GR expression in hypothalamus. Our data suggests that domestication related modification in the stress response is driven by changes in the transcription levels of several modulators of the HPA and SA systems in hypothalamus and adrenal glands and not by changes in the expression of the steroidogenic genes. The presence of eQTL for GR in hypothalamus combined with the negative correlation between GR expression and corticosterone response suggests GR as a candidate for further functional studies regarding modification of stress response during chicken domestication.

    Emneord
    Animal domestication, HPA axis, QTL, Stress response, eQTL
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-136027 (URN)10.1016/j.mce.2017.02.010 (DOI)000399509600006 ()28189567 (PubMedID)
    Merknad

    Funding agencies: Swedish Research Council (VR) [621-2011-4731]; Swedish Research Council for Environment, Agricultural Sciences and Spatial Planning (FORMAS) [221-2011-1088]; ERC [Genewell 322206]; SRC grant [VR 621-2011-4423, 2015-4870]; Swedish Centre of Excellence in A

    Tilgjengelig fra: 2017-03-27 Laget: 2017-03-27 Sist oppdatert: 2018-09-27
  • 28.
    Favati, Anna
    et al.
    Stockholm University, Sweden.
    Leimar, Olof
    Stockholm University, Sweden.
    Radesäter, Tommy
    Stockholm University, Sweden.
    Løvlie, Hanne
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biologi. Linköpings universitet, Tekniska högskolan. Stockholm University, Sweden.
    Social status and personality: stability in social state can promote consistency of behavioural responses2014Inngår i: Proceedings of the Royal Society of London. Biological Sciences, ISSN 0962-8452, E-ISSN 1471-2954, Vol. 281, nr 1774, s. 20132531-Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Stability of ‘state’ has been suggested as an underlying factor explainingbehavioural stability and animal personality (i.e. variation among, andconsistency within individuals in behavioural responses), but the possibilitythat stable social relationships represent such states remains unexplored.Here, we investigated the influence of social status on the expression andconsistency of behaviours by experimentally changing social status betweenrepeated personality assays. We used male domestic fowl (Gallus gallusdomesticus), a social species that forms relatively stable dominance hierarchies,and showed that behavioural responses were strongly affected bysocial status, but also by individual characteristics. The level of vigilance,activity and exploration changed with social status, whereas boldnessappeared as a stable individual property, independent of status. Furthermore,variation in vocalization predicted future social status, indicatingthat individual behaviours can both be a predictor and a consequence ofsocial status, depending on the aspect in focus. Our results illustrate thatsocial states contribute to both variation and stability in behaviouralresponses, and should therefore be taken into account when investigatingand interpreting variation in personality.

  • 29.
    Favati, Anna
    et al.
    Department of Zoology, Stockholm University, Stockholm, Sweden.
    Zidar, Josefina
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biologi. Linköpings universitet, Tekniska fakulteten.
    Thorpe, Hanne
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biologi. Linköpings universitet, Tekniska fakulteten.
    Jensen, Per
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biologi. Linköpings universitet, Tekniska fakulteten.
    Lovlie, Hanne
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biologi. Linköpings universitet, Tekniska fakulteten.
    The ontogeny of personality traits in the redjunglefowl, Gallus gallus2016Inngår i: Behavioral Ecology, ISSN 1045-2249, E-ISSN 1465-7279, Vol. 27, nr 2, s. 484-493Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Consistent behavioral differences among individuals, that is, personality, are described in numerous species. Nevertheless, thedevelopment of behavioral consistency over ontogeny remains unclear, including whether the personality of individuals is consistentthroughout life, and if adult personality can be predicted already at young age. We investigated the ontogeny of personality in thered junglefowl (Gallus gallus) by scoring personality of hatchlings at 5 time points through adulthood, including before and after themajor developmental stages of becoming independent and sexual mature. We use the conceptual framework laid out by Stamps andGroothuis (2010a) to holistically investigate the observed changes in behavioral response over ontogeny. We demonstrate that meanvalues of behavioral responses changed across ontogeny and stabilized after independence. Rank-order consistencies of behavioralresponses were overall low across independence and sexual maturation. Only in 1 case could low rank-order consistencies potentiallybe explained by different phenotypes displaying different amounts of change in behavior; more explorative individuals decreased inexploration after independence, while less explorative individuals remained so. Correlations among behavior varied across ontogenyand weakened after sexual maturation. Our results demonstrate that both absolute values and consistency of behavioral traits maychange across ontogeny and that individual developmental trajectories and adult personality only to some extent can be predictedearly in life. These results have implications for future studies on personality, highlighting that the life stage at which individuals arescored affects the observed consistency of behavioral responses.

  • 30.
    Friberg, Urban
    Department of Ecology and Environmental Science, Section of Animal Ecology, Umeå University, Umeå , Sweden.
    Genetic variation in male and female reproductive characters associated with sexual conflict in Drosophila melanogaster2005Inngår i: Behavior Genetics, ISSN 0001-8244, E-ISSN 1573-3297, Vol. 35, nr 4, s. 455-462Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Recent studies have shown that elevated mating, courtship and seminal substances affect female fitness negatively in Drosophila melanogaster. It has also been shown that males vary with respect to these characters and that male harm to females correlates positively with components of male fitness. These results suggest that there is sexual conflict over the effect of such male characters. An important component of this scenario is that females have evolved counteradaptations to male harm, but so far there is limited evidence for this. Here I define female resistance as the ability to withstand an increased exposure to males. Across 10 genetically differentiated lines of D. melanogaster, I found genetic variation among females in the reduction of lifespan that followed from exposure to males of different durations. There was also genetic variation among males with regards to the degree to which they decrease the lifespan of their mates. These results suggest that genetic variation for female ability to endure male sexually antagonistic adaptations exists and may play an important role in male–female coevolution.

  • 31.
    Friberg, Urban
    et al.
    Department of Ecology and Environmental Science, Umeå University, Umeå, Sweden / Department of Ecology, Evolution and Marine Biology, University of California, Santa Barbara, California, USA.
    Lew, Timothy
    Department of Ecology, Evolution and Marine Biology, University of California, Santa Barbara, California, USA.
    Byrne, Pillip
    Department of Ecology, Evolution and Marine Biology, University of California, Santa Barbara, California, USA / School of Botany and Zoology, Australian National University, Canberra, Australian Capital Territory 0200, Australia.
    Rice, William
    Department of Ecology, Evolution and Marine Biology, University of California, Santa Barbara, California, USA.
    Assessing the potential for an ongoing arms race within and between the sexes: selection and heritable variation2005Inngår i: Evolution, ISSN 0014-3820, E-ISSN 1558-5646, Vol. 59, nr 7, s. 1540-1551Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In promiscuous species, sexual selection generates two opposing male traits: offense (acquiring new mates and supplanting stored sperm) and defense (enforcing fidelity on one's mates and preventing sperm displacement when this fails). Coevolution between these traits requires both additive genetic variation and associated natural selection. Previous work with Drosophila melanogaster found autosomal genetic variation for these traits among inbred lines from a mixture of populations, but only nonheritable genetic variation was found within a single outbred population. These results do not support ongoing antagonistic coevolution between offense and defense, nor between either of these male traits and female reproductive characters. Here we use a new method (hemiclonal analysis) to study genomewide genetic variation in a large outbred laboratory population of D. melanogaster. Hemiclonal analysis estimates the additive genetic variation among random, genomewide haplotypes taken from a large, outbred, locally adapted laboratory population and determines the direction of the selection gradient on this variation. In contrast to earlier studies, we found low but biologically significant heritable variation for defensive and offensive offspring production as well as all their components (P1, fidelity, P2, and remating). Genetic correlations between these traits were substantially different from those reported for inbred lines. A positive genetic correlation was found between defense and offense, demonstrating that some shared genes influence both traits. In addition to this common variation, evidence for unique genetic variation for each trait was also found, supporting an ongoing coevolutionary arms race between defense and offense. Reproductive conflict between males can strongly influence female fitness. Correspondingly, we found genetic variation in both defense and offense that affected female fitness. No evidence was found for intersexual conflict in the context of male defense, but we found substantial intersexual conflict in the context of male offensive sperm competitive ability. These results indicate that conflict between competing males also promotes an associated arms race between the sexes.

  • 32.
    Friesen, Christopher R.
    et al.
    University of Sydney, Australia; Oregon State University, OR 97330 USA.
    Uhrig, Emily
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biologi. Linköpings universitet, Tekniska fakulteten. Oregon State University, OR 97330 USA.
    Bentz, Ehren J.
    Oregon State University, OR 97330 USA.
    Blakemore, Leslie A.
    Oregon State University, OR 97330 USA.
    Mason, Robert T.
    Oregon State University, OR 97330 USA.
    Correlated evolution of sexually selected traits: interspecific variation in ejaculates, sperm morphology, copulatory mate guarding, and body size in two sympatric species of garter snakes2017Inngår i: Behavioral Ecology and Sociobiology, ISSN 0340-5443, E-ISSN 1432-0762, Vol. 71, nr 12, artikkel-id UNSP 180Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Male reproductive success is dependent on a correlated suite of traits related to a species ecology and mating system dynamics. Closely related species differing in their mating systems and ecology, such as the garter snakes (Thamnophis), are ideal for studying the correlated evolution of sexually selected traits. Here, we compare the degree of sexual size dimorphism (SSD), copulatory behavior, copulatory plug size, and traits associated with sperm competition between two sympatric and closely related Thamnophis species, T. sirtalis and T. radix with divergent mating aggregation size and density. Our findings indicate that T. sirtalis has greater female-biased SSD, shorter copulations, and larger, more strongly adhering copulatory plugs than T. radix. Our finding that T. sirtalis have longer sperm and higher numbers of sperm per ejaculate is further evidence of more intense sperm competition in this species than in T. radix. However, this reduced number of sperm in the ejaculate means that T. radix males are likely capable of more matings per season than T. sirtalis. This result may reflect differences in feeding during the breeding season (obligate aphagy in T. sirtalis) and the potential for sperm loss in T. radix during prolonged copulations that are prevented in T. sirtlais by their substantial copulatory plugs. Our findings demonstrate that ecological and mating system dynamics have the capacity to strongly influence correlated selection of pre- and postcopulatory traits.

  • 33.
    Gavrilets, Sergey
    et al.
    Departments of Ecology and Evolutionary Biology and Mathematics, University of Tennessee, Knoxville,USA.
    Arnqvist, Göran
    Department of Ecology and Environmental Science, University of Umeå, Sweden.
    Friberg, Urban
    Department of Ecology and Environmental Science, University of Umeå, Sweden.
    The evolution of female mate choice by sexual conflict2001Inngår i: Proceedings of the Royal Society of London Series B, ISSN 0080-4649, Vol. 268, nr 1466, s. 531-539Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Although empirical evidence has shown that many male traits have evolved via sexual selection by female mate choice, our understanding of the adaptive value of female mating preferences is still very incomplete. It has recently been suggested that female mate choice may result from females evolving resistance rather than attraction to males, but this has been disputed. Here, we develop a quantitative genetic model showing that sexual conflict over mating indeed results in the joint evolution of costly female mate choice and exaggerated male traits under a wide range of circumstances. In contrast to traditional explanations of costly female mate choice, which rely on indirect genetic benefits, our model shows that mate choice can be generated as a side–effect of females evolving to reduce the direct costs of mating.

  • 34.
    Gering, E.
    et al.
    Kellogg Biological Station, Michigan State Universiry, 3700 East Gull Lake Road, Hickory Corners, MI 49060, USA.
    Johnsson, Martin
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biologi. Linköpings universitet, Tekniska högskolan.
    Willis, P.
    Department of Biology, University of Victoria, Cunningham 202, 3800 Finnerty Road, Victoria, BC V8P 5C2, Canada.
    Getty, T.
    Kellogg Biological Station, Michigan State Universiry, 3700 East Gull Lake Road, Hickory Corners, MI 49060, USA.
    Wright, Dominic
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biologi. Linköpings universitet, Tekniska högskolan.
    Mixed ancestry and admixture in Kauai's feral chickens: invasion of domestic genes into ancient Red Junglefowl reserviors2015Inngår i: Molecular Ecology, ISSN 0962-1083, E-ISSN 1365-294X, Vol. 24, nr 9, s. 2112-2124Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A major goal of invasion genetics is to determine how establishment histories shape non-native organisms' genotypes and phenotypes. While domesticated species commonly escape cultivation to invade feral habitats, few studies have examined how this process shapes feral gene pools and traits. We collected genomic and phenotypic data from feral chickens (Gallus gallus) on the Hawaiian island of Kauai to (i) ascertain their origins and (ii) measure standing variation in feral genomes, morphology and behaviour. Mitochondrial phylogenies (D-loop & whole Mt genome) revealed two divergent clades within our samples. The rare clade also contains sequences from Red Junglefowl (the domestic chicken's progenitor) and ancient DNA sequences from Kauai that predate European contact. This lineage appears to have been dispersed into the east Pacific by ancient Polynesian colonists. The more prevalent MtDNA clade occurs worldwide and includes domesticated breeds developed recently in Europe that are farmed within Hawaii. We hypothesize this lineage originates from recently feralized livestock and found supporting evidence for increased G. gallus density on Kauai within the last few decades. SNPs obtained from whole-genome sequencing were consistent with historic admixture between Kauai's divergent (G. gallus) lineages. Additionally, analyses of plumage, skin colour and vocalizations revealed that Kauai birds' behaviours and morphologies overlap with those of domestic chickens and Red Junglefowl, suggesting hybrid origins. Together, our data support the hypotheses that (i) Kauai's feral G. gallus descend from recent invasion(s) of domestic chickens into an ancient Red Junglefowl reservoir and (ii) feral chickens exhibit greater phenotypic diversity than candidate source populations. These findings complicate management objectives for Pacific feral chickens, while highlighting the potential of this and other feral systems for evolutionary studies of invasions.

  • 35.
    Gering, Eben
    et al.
    Michigan State Univ, MI 48824 USA.
    Incorvaia, Darren
    Michigan State Univ, MI 48824 USA.
    Henriksen, Rie
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biologi. Linköpings universitet, Tekniska fakulteten.
    Wright, Dominic
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biologi. Linköpings universitet, Tekniska fakulteten.
    Getty, Thomas
    Michigan State Univ, MI 48824 USA.
    Maladaptation in feral and domesticated animals2019Inngår i: Evolutionary Applications, ISSN 1752-4571, E-ISSN 1752-4571, Vol. 12, nr 7, s. 1274-1286Artikkel, forskningsoversikt (Fagfellevurdert)
    Abstract [en]

    Selection regimes and population structures can be powerfully changed by domestication and feralization, and these changes can modulate animal fitness in both captive and natural environments. In this review, we synthesize recent studies of these two processes and consider their impacts on organismal and population fitness. Domestication and feralization offer multiple windows into the forms and mechanisms of maladaptation. Firstly, domestic and feral organisms that exhibit suboptimal traits or fitness allow us to identify their underlying causes within tractable research systems. This has facilitated significant progress in our general understandings of genotype-phenotype relationships, fitness trade-offs, and the roles of population structure and artificial selection in shaping domestic and formerly domestic organisms. Additionally, feralization of artificially selected gene variants and organisms can reveal or produce maladaptation in other inhabitants of an invaded biotic community. In these instances, feral animals often show similar fitness advantages to other invasive species, but they are also unique in their capacities to modify natural ecosystems through introductions of artificially selected traits. We conclude with a brief consideration of how emerging technologies such as genome editing could change the tempos, trajectories, and ecological consequences of both domestication and feralization. In addition to providing basic evolutionary insights, our growing understanding of mechanisms through which artificial selection can modulate fitness has diverse and important applications-from enhancing the welfare, sustainability, and efficiency of agroindustry, to mitigating biotic invasions.

  • 36.
    Griffin, Robert M
    et al.
    Department of Evolutionary Biology, Evolutionary Biology Centre, Uppsala, Sweden.
    Dean, Rebecca
    Department of Evolutionary Biology, Evolutionary Biology Centre, Uppsala, Sweden.
    Grace, Jaime L
    Department of Evolutionary Biology, Evolutionary Biology Centre, Uppsala, Sweden.
    Rydén, Patrik
    Department of Mathematics and Mathematical Statistics, Umeå University, Umeå ,Sweden / Computational Life Science Cluster (CLiC), Umeå University, Umeå , Sweden.
    Friberg, Urban
    Department of Evolutionary Biology, Evolutionary Biology Centre, Uppsala, Sweden.
    The shared genome is a pervasive constraint on the evolution of sex-biased gene expression.2013Inngår i: Molecular biology and evolution, ISSN 0737-4038, E-ISSN 1537-1719, Vol. 30, nr 9, s. 2168-76Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Males and females share most of their genomes, and differences between the sexes can therefore not evolve through sequence divergence in protein coding genes. Sexual dimorphism is instead restricted to occur through sex-specific expression and splicing of gene products. Evolution of sexual dimorphism through these mechanisms should, however, also be constrained when the sexes share the genetic architecture for regulation of gene expression. Despite these obstacles, sexual dimorphism is prevalent in the animal kingdom and commonly evolves rapidly. Here, we ask whether the genetic architecture of gene expression is plastic and easily molded by sex-specific selection, or if sexual dimorphism evolves rapidly despite pervasive genetic constraint. To address this question, we explore the relationship between the intersexual genetic correlation for gene expression (rMF), which captures how independently genes are regulated in the sexes, and the evolution of sex-biased gene expression. Using transcriptome data from Drosophila melanogaster, we find that most genes have a high rMF and that genes currently exposed to sexually antagonistic selection have a higher average rMF than other genes. We further show that genes with a high rMF have less pronounced sex-biased gene expression than genes with a low rMF within D. melanogaster and that the strength of the rMF in D. melanogaster predicts the degree to which the sex bias of a gene's expression has changed between D. melanogaster and six other species in the Drosophila genus. In sum, our results show that a shared genome constrains both short- and long-term evolution of sexual dimorphism.

  • 37.
    Griffin, Robert M.
    et al.
    Uppsala University, Sweden; University of Turku, Finland.
    Schielzeth, Holger
    University of Bielefeld, Germany; Friedrich Schiller University of Jena, Germany.
    Friberg, Urban
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biologi. Linköpings universitet, Tekniska fakulteten.
    Autosomal and X-Linked Additive Genetic Variation for Lifespan and Aging: Comparisons Within and Between the Sexes in Drosophila melanogaster2016Inngår i: G3-GENES GENOMES GENETICS, ISSN 2160-1836, Vol. 6, nr 12, s. 3903-3911Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Theory makes several predictions concerning differences in genetic variation between the X chromosome and the autosomes due to male X hemizygosity. The X chromosome should: (i) typically show relatively less standing genetic variation than the autosomes, (ii) exhibit more variation in males compared to females because of dosage compensation, and (iii) potentially be enriched with sex-specific genetic variation. Here, we address each of these predictions for lifespan and aging in Drosophila melanogaster. To achieve unbiased estimates of X and autosomal additive genetic variance, we use 80 chromosome substitution lines; 40 for the X chromosome and 40 combining the two major autosomes, which we assay for sex-specific and cross-sex genetic (co)variation. We find significant X and autosomal additive genetic variance for both traits in both sexes (with reservation for X-linked variation of aging in females), but no conclusive evidence for depletion of X-linked variation (measured through females). Males display more X-linked variation for lifespan than females, but it is unclear if this is due to dosage compensation since also autosomal variation is larger in males. Finally, our results suggest that the X chromosome is enriched for sex-specific genetic variation in lifespan but results were less conclusive for aging overall. Collectively, these results suggest that the X chromosome has reduced capacity to respond to sexually concordant selection on lifespan from standing genetic variation, while its ability to respond to sexually antagonistic selection may be augmented.

  • 38.
    Guerrero-Bosagna, Carlos
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biologi. Linköpings universitet, Tekniska fakulteten.
    Epigenetics, evolution and the survival of the non-unfit2017Inngår i: The Biochemist, ISSN 0954-982X, Vol. 39, nr 5, s. 8-11Artikkel i tidsskrift (Annet vitenskapelig)
    Abstract [en]

    The transition that occurred in vertebrates moving from water to land was a major step in the evolution of terrestrial animals. This is an evolutionary step that has always fascinated scientists and the general public. The land-to-water vertebrate transition happened around the Devonian period and involved structural changes such as the transition from fin to limb, a reduction of the gill arch, loss of the mid-fin and a reduction in the number of scales, among others. I will use this interesting example to depict how the same evolutionary process can be seen through two different lenses. One view, which is the most widespread way of seeing evolution, is the 'survival of the fittest'. The other is intentionally stated in the title as the double negative 'survival of the non-unfit'. Only semantic differences? Not in my view.

  • 39.
    Gustavsson, Emelie
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biologi.
    Kjellgren, Sofie
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biologi.
    En uppdatering om människans evolution: med betoning på forskning från de senaste fem åren samt koppling till kurslitteratur för gymnasiet2018Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [sv]

    början av 2000-talet sekvenserades det första hela mänskliga genomet och sedan dess har teknikerna förfinats, effektiviserats och förbättrats, så att utvecklingen på många områden, däribland forskningen om människans evolution, går fortare än någonsin tidigare. Från att ha sekvenserat en molekyl i taget är det idag möjligt att sekvensera miljontals molekyler parallellt och dessutom till ett så lågt pris att fler nu har möjlighet att använda sig av teknikerna. Bara under de senaste fem åren har det hänt mycket på området människans evolution och det är detta som vi kommer redogöra för i den här studien. Vi redovisar nya upptäckter –såsom att Homo naledi artbestämdes 2015 –, stärker gamla hypoteser –såsom att Homo sapiens utvandrade ur Afrika –samt stryker andra hypoteser –såsom att Australopithecus afarensis skulle vara den saknade länken mellan släktet Australopithecus och släktet Homo. Mycket har skett inom forskningen på människans evolution. Tillgång till nya biologiska tekniker har tillsammans med paleontologiska upptäckter bidragit till att skapa en större samstämmighet inom båda områden. Genom att teknikerna utvecklas och kompletterar varandra kan en större konsensus i resultaten skapas.

    Att utvecklingen av forskningen går fort fram har konsekvenser även för kurslitteraturen i gymnasieskolan. Vi analyserar därför om gymnasielitteraturen hinner med samt om förenklingarna som görs i den är rimlig. Det är svårt att avgöra om kurslitteraturen uppdateras i tillräcklig takt då förenklingarna är så pass stora. Vi anser att flera av de jämförda böckerna är tvetydiga i sina beskrivningar och framställer fakta som säkerställd, vilket inte alltid stämmer överens med hur området ser ut i verkligheten.

  • 40.
    Hansen, Thomas F.
    et al.
    Department of Biology, Centre for Ecological and Evolutionary Synthesis, University of Oslo, Norway.
    Bartoszek, Krzysztof
    Department of Mathematical Sciences, Chalmers University of Technology and the University of Gothenburg, Gothenburg, Sweden.
    Interpreting the evolutionary regression: The interplay between observational and biological errors in phylogenetic comparative studies2012Inngår i: Systematic Biology, ISSN 1063-5157, E-ISSN 1076-836X, Vol. 61, nr 3, s. 413-425Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Regressions of biological variables across species are rarely perfect. Usually, there are residual deviations fromthe estimated model relationship, and such deviations commonly show a pattern of phylogenetic correlations indicatingthat they have biological causes. We discuss the origins and effects of phylogenetically correlated biological variation inregression studies. In particular, we discuss the interplay of biological deviations with deviations due to observationalor measurement errors, which are also important in comparative studies based on estimated species means. We showhow bias in estimated evolutionary regressions can arise from several sources, including phylogenetic inertia and eitherobservational or biological error in the predictor variables. We show how all these biases can be estimated and correctedfor in the presence of phylogenetic correlations.We present general formulas for incorporating measurement error in linearmodels with correlated data. We also show how alternative regression models, such as major axis and reduced major axisregression, which are often recommended when there is error in predictor variables, are strongly biased when there isbiological variation in any part of the model.We argue that such methods should never be used to estimate evolutionary orallometric regression slopes.

  • 41.
    Hedlund, Louise
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Zoologi. Linköpings universitet, Tekniska högskolan.
    Personality and production in dairy cows2013Independent thesis Advanced level (degree of Master (Two Years)), 40 poäng / 60 hpOppgave
    Abstract [en]

    Variation in animal personality, in other words, behavioural responses consistent within individuals over time and/or across contexts, is predicted to be related to life-history traits, such as growth rate and investment in reproduction. How this translates into relationships between personality and milk production in dairy cows is however scarcely investigated and previous studies are showing contradicting results. To further investigate this relationship, individual consistencies in behaviour were related to milk production in two breeds of dairy cows (Swedish red and white cattle, SRB, and Holstein). Variation was found among the breeds in consistency of behaviours and both SRB and Holstein cows were highly consistent over time in stepping behaviour during milking and frequency of performed abnormal behaviours in home pen. Overall were Holstein cows consistent in more observed behaviours than SRB. Variation in neophobia and responses to social separation were more flexible, both among breeds and over time. Nevertheless, behaviour showed limited relationship with milk production. To conclude, the tests here carried out are useful in describing personality in cows; however, personality showed no relationship with milk production, encouraging future studies to explore this expected relationship further in other breeds and species.

  • 42.
    Herman, Jeremy S.
    et al.
    Natl Museums Scotland, Scotland.
    Stojak, Joanna
    Polish Acad Sci, Poland.
    Pauperio, Joana
    Univ Porto, Portugal.
    Jaarola, Maarit
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Centrum för social och affektiv neurovetenskap. Linköpings universitet, Medicinska fakulteten.
    Wojcik, Jan M.
    Polish Acad Sci, Poland.
    Searle, Jeremy B.
    Cornell Univ, NY USA.
    Genetic variation in field voles (Microtus agrestis) from the British Isles: selective sweeps or population bottlenecks?2019Inngår i: Biological Journal of the Linnean Society, ISSN 0024-4066, E-ISSN 1095-8312, Vol. 126, nr 4, s. 852-865Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The Eurasian field vole (Microtus agrestis) comprises three evolutionarily significant units (ESUs). The northern ESU is found at higher latitudes across the western Palaearctic region and includes six, largely allopatric, mitochondrial DNA lineages that were derived from population bottlenecks. One of these lineages is found in southern Britain and nearby areas of continental Europe. A prominent sub-lineage is nested within, and therefore derived from, the part of this lineage occupying southern Britain. The sub-lineage consists of an abundant central haplotype together with a series of closely related haplotypes, a distribution that would result from either a recent population bottleneck or a selective sweep. To distinguish between these, we sequenced a Y-chromosome marker in 167 field voles from Britain and Europe, and analysed a panel of 13 autosomal microsatellite loci in 144 field voles from eight populations in Britain. The Y-chromosome marker showed a continental-scale pattern of variation that was not aligned with that of the mitochondrial marker, while microsatellite variation did not show any evidence for a bottleneck, tentatively favouring selection instead. This implies a role for both stochastic and selective processes in generating phylogeographical patterns at different scales in the field vole.

  • 43.
    Jansson, Fredrik
    Linköpings universitet, Institutet för analytisk sociologi, IAS. Linköpings universitet, Filosofiska fakulteten. Centrum för evolutionär kulturforskning, Stockholms universitet; Centre for the Study of Cultural Evolution, Stockholm University.
    What Games Support the Evolution of an Ingroup Bias?2015Inngår i: Journal of Theoretical Biology, ISSN 0022-5193, E-ISSN 1095-8541, Vol. 373, s. 100-110Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    There is an increasing wealth of models trying to explain the evolution of group discrimination and an ingroup bias. This paper sets out to systematically investigate the most fundamental assumption in these models: in what kind of situations do the interactions take place? What strategic structures – games – support the evolution of an ingroup bias? More specifically, the aim here is to find the prerequisites for when a bias also with respect to minimal groups – arbitrarily defined groups void of group-specific qualities – is selected for, and which cannot be ascribed to kin selection.

    Through analyses and simulations of minimal models of two-person games, this paper indicates that only some games are conducive to the evolution of ingroup favouritism. In particular, this class does not contain the prisoners' dilemma, but it does contain anti-co-ordination and co-ordination games. Contrasting to the prisoners' dilemma, these are games where it is not a matter of whether to behave altruistically, but rather one of predicting what the other person will be doing, and where I would benefit from you knowing my intentions.

    In anti-co-ordination games, on average, not only will agents discriminate between groups, but also in such a way that their choices maximise the sum of the available payoffs towards the ingroup more often than towards the outgroup. And in co-ordination games, even if agents do manage to co-ordinate with the whole population, they are more likely to co-ordinate on the socially optimal equilibrium within their group. Simulations show that this occurs most often in games where there is a component of risk-taking, and thus trust, involved. A typical such game is the stag hunt or assurance game.

  • 44.
    Koch, Franziska
    et al.
    School of Life Sciences, Institute for Chemistry and Bioanalytics, University of Applied Sciences and Arts Northwestern Switzerland, Muttenz, Switzerland.
    Muller, Michael
    Department for Health Science and Technology, Cartilage Engineering and Regeneration Laboratory, ETH Zurich, Zurich, Switzerland.
    König, Finja
    Linköpings universitet.
    Meyer, Nina
    Department for Chemistry and Biotechnology, Tissue Engineering, Zurich University of Applied Sciences, Wädenswil, Switzerland.
    Gattlen, Jasmin
    Department for Chemistry and Biotechnology, Tissue Engineering, Zurich University of Applied Sciences, Wädenswil, Switzerland.
    Pieles, Uwe
    School of Life Sciences, Institute for Chemistry and Bioanalytics, University of Applied Sciences and Arts Northwestern Switzerland, Muttenz, Switzerland.
    Peters, Kirsten
    Department of Cell Biology, University Medicine Rostock, Rostock, Germany.
    Kreikemeyer, Bernd
    Institute of Medical Microbiology, Virology and Hygiene, University Medicine Rostock, Rostock, Germany.
    Mathes, Stephanie
    Department for Chemistry and Biotechnology, Tissue Engineering, Zurich University of Applied Sciences, Wädenswil, Switzerland.
    Saxer, Sina
    School of Life Sciences, Institute for Chemistry and Bioanalytics, University of Applied Sciences and Arts Northwestern Switzerland, Muttenz, Switzerland.
    Mechanical characteristics of beta sheet-forming peptide hydrogels are dependent on peptide sequence, concentration and buffer composition2018Inngår i: Royal Society Open Science, E-ISSN 2054-5703, Vol. 5, nr 3, artikkel-id 171562Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Self-assembling peptide hydrogels can be modified regarding their biodegradability, their chemical and mechanical properties and their nanofibrillar structure. Thus, self assembling peptide hydrogels might be suitable scaffolds for regenerative therapies and tissue engineering. Owing to the use of various peptide concentrations and buffer compositions, the self-assembling peptide hydrogels might be influenced regarding their mechanical characteristics. Therefore, the mechanical properties and stability of a set of self-assembling peptide hydrogels, consisting of 11 amino acids, made from four beta sheet self-assembling peptides in various peptide concentrations and buffer compositions were studied. The formed self-assembling peptide hydrogels exhibited stiffnesses ranging from 0.6 to 205 kPa. The hydrogel stiffeness affected by peptide sequence followed by peptide concentration and buffer composition. All self-assembling peptide hydrogels examined provided a nanofibrillar network formation. A maximum self-assembling peptide hydrogel dissolution of 20% was observed for different buffers solution after 7 days. The stability regarding enzymatic and bacterial digestion showed less degradation in comparison to the self-assembling peptide hydrogel dissolution rate in buffer. The tested set of self-assembling peptide hydrogels were able to form stable scaffolds and provided a broad spectrum of tissue-specific stiffnesses that are suitable for a regenerative therapy.

  • 45.
    Kylin, Henrik
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    Hypotesdriven forskning: inte enda alternativet2018Inngår i: Universitetsläraren, ISSN 0282-4973, nr 7, s. 44-Artikkel i tidsskrift (Annet (populærvitenskap, debatt, mm))
  • 46.
    Lahger, Christian
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biologi. Linköpings universitet, Tekniska fakulteten.
    Laska, Matthias
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biologi. Linköpings universitet, Tekniska fakulteten.
    Behavioral responses of CD-1 mice to conspecific and heterospecific blood odors and to a blood odor component2018Inngår i: Physiology and Behavior, ISSN 0031-9384, E-ISSN 1873-507X, Vol. 184, s. 205-210Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The odor of blood may have both aversive and attractive properties for mammals, depending on the species of the odor donor and the species perceiving the odor. To better understand the informational content of blood odor for a prey species we assessed behavioral responses of male CD-1 mice (n = 60) to the odor of blood of same-sex and opposite-sex conspecifics, of a natural predator of mice (cat), and of a herbivore (horse) and an omnivore (human) non-predator of mice. Further, we assessed their behavior towards the mammalian blood odor component trans-4,5-epoxy-(E)-2-decenal which recent studies have shown to be as attractive to mammalian predators as the odor of real blood. A two-compartment test arena was used to record approach/avoidance behavior when the animals were presented with an odor in one compartment and a blank control in the other compartment. We found that both conspecific and heterospecific blood odors elicited significant avoidance behavior in the mice whereas a control odor (n-pentyl acetate) did not. The blood odor component trans-4,5-epoxy-(E)-2-decenal was also significantly avoided and thus appears to play an important role in the perception of mammalian blood odor in this prey species. These results support the notion that mammalian blood odor contains an olfactory warning signal which elicits an adaptive behavioral avoidance response in a prey species, the mouse. Our finding that the mice avoided the mammalian blood odor component trans-4,5-epoxy-(E)-2-decenal to the same degree as the odor of real blood suggests that this volatile compound might be (part of) this warning signal.

  • 47.
    Larsson, Angelica
    Linköpings universitet, Institutionen för fysik, kemi och biologi.
    Läroböckers behandling av alternativa uppfattningar angående evolution2016Independent thesis Advanced level (degree of Master (One Year)), 10 poäng / 15 hpOppgave
    Abstract [sv]

    I denna studie gör jag en analys av evolutionskapitlet i tre läroböcker som är utformade för gymnasiekursen Biologi 1. Fokus för analysen är hur läroböcker lyfter och kommenterar olika typar av alternativa uppfattningar. Dessutom intresserar jag mig för hur man beskriver uppkomsten av variation samt hur stort utrymme som ges för detta. Detta då jag menar att en svag förståelse för variation ligger till grund för flera av de alternativa uppfattningar forskningen har pekat på. De fyra alternativa uppfattningar som behandlas i studien är teleologiska resonemang, antropomorfa förklaringar, Lamarckistiska förklaringar samt att naturlig selektion beskrivs som den enda mekanismen för evolution. Studien visar att selektion ges ett större utrymme i läroböckerna samt att ingen av böckerna ger en grundlig förklaring av mutationer som uppkomst till variation. Detta menar jag kan bidra till att elever får en svag förståelse för variationens betydelse för evolution. Vidare visade analysen att alternativa uppfattningar sällan beskriv men i viss mån bemöts i enskilda meningar i kapitlet. Främst påpekar man bara att ett påstående är felaktigt och säger hur det faktiskt är. En beskrivning av varför påståendet är felaktig uteblir. Jag uppmanar lärare att komplettera läroboken med läsning av refutational texts för att stödja elevernas inlärning.

  • 48.
    Larsson, Angelica
    Linköpings universitet, Institutionen för fysik, kemi och biologi. Linköpings universitet, Tekniska fakulteten.
    Påverkar slumpen evolutionsundervisningen?: En litteraturstudie angående hur förståelse för slump och sannolikhet påverkar förståelsen för evolution.2015Independent thesis Advanced level (degree of Master (One Year)), 10 poäng / 15 hpOppgave
    Abstract [sv]

    Syftet med denna systematiska litteraturstudie var att undersöka om slump och sannolikhet kan vara det Ross och kollegor kallar för tröskelbegrepp. Detta undersöktes genom en kvalitativ analys av 11 publicerade artiklar. Dessa analyserades utifrån tre frågeställningar.  Hur resonerar elever angående slump och sannolikhet inom matematikundervisningen? Hur resonerar elever angående slump och sannolikhet inom evolutionsundervisningen? Återfinns liknande resonemang angående slump och sannolikhet inom matematik- och evolutionsundervisningen? Utifrån sammanställningen granskades resonemangen för att se om de liknade varandra. Efter detta drogs slutsatser om huruvida slump och sannolikhet skulle kunna vara så kallade tröskelbegrepp. Resonemangen verkade påminna om varandra och flera av de kriterier som Ross och kollegor har ställt upp för tröskelbegrepp är uppfyllda. Denna studie stödjer deras förslag angående att slump och sannolikhet är tröskelbegrepp.

  • 49.
    Lehtovaara, Anne
    et al.
    Ageing Research Group, Department of Evolutionary Biology, Uppsala University, Uppsala, Sweden.
    Schielzeth, Holger
    Ageing Research Group, Department of Evolutionary Biology, Uppsala University, Uppsala, Sweden, Department of Evolutionary Biology, Bielefeld University, Bielefeld, Germany.
    Flis, Ilona
    Ageing Research Group, Department of Evolutionary Biology, Uppsala University, Uppsala, Sweden.
    Friberg, Urban
    Ageing Research Group, Department of Evolutionary Biology, Uppsala University, Uppsala, Sweden.
    Heritability of life span is largely sex limited in Drosophila.2013Inngår i: American Naturalist, ISSN 0003-0147, E-ISSN 1537-5323, Vol. 182, nr 5, s. 653-65Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Males and females differ with respect to life span and rate of aging in most animal species. Such sexual dimorphism can be associated with a complex genetic architecture, where only part of the genetic variation is shared between the sexes. However, the extent to which this is true for life span and aging is not known, because studies of life span have given contradictory results and aging has not been studied from this perspective. Here we investigate the additive genetic architecture of life span and aging in Drosophila melanogaster. We find substantial amounts of additive genetic variation for both traits, with more than three-quarters of this variation available for sex-specific evolutionary change. This result shows that the sexes have a profoundly different additive genetic basis for these traits, which has several implications. First, it translates into an, on average, three-times-higher heritability of life span within, compared to between, the sexes. Second, it implies that the sexes are relatively free to evolve with respect to these traits. And third, as life span and aging are traits that integrate over all genetic factors that contribute to mortal disease, it also implies that the genetics of heritable disease differs vastly between the sexes.

  • 50.
    Lundström, Maria
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biologi. Linköpings universitet, Tekniska fakulteten.
    Exploring Fennoscandian agricultural history through genetic analysis of aged crop materials2018Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Crop plants have undergone a multitude of genetic changes during and following their domestication. The spread of agriculture brought the crops to new geographic regions exposing them to new environments and selection pressures along the way. This gave rise to many local variants with traits favoured both by agricultural practices and the environment.

    Agriculture was introduced in Fennoscandia (Norway, Sweden, Finland and Denmark) around 4000 BC. The composition of the archaeobotanical record gives some clues as to which species were cultivated, but macroscale analyses rarely reach beyond that. Therefore, methods like genetic analysis are necessary to expand our knowledge about the history of crop cultivation. Under optimal conditions, DNA can survive in biological samples for several hundred thousand years. The preservation of plant specimens in the Fennoscandian climate has, however, rarely been explored. This thesis therefore attempts to dive deeper into the Fennoscandian cultivation history through genetic analyses of aged plant materials from both museum collections and archaeological sources. Cereal grains from a range of preservation conditions were evaluated to find which ones might be of interest for genetic investigations. Desiccated materials gave the highest success rates, in agreement with previous studies. Waterlogged materials appeared to contain small amounts of endogenous DNA, whereas genetic analysis of charred cereals failed completely in all samples.

    Population structure was investigated in 17-19th century materials of both barley and rye from Sweden and Finland. Northern and southern populations of Finnish six-row barley were distinct from one another. In southern Sweden, genetic analysis suggested conserved population structure extending over 200 years. The genetic composition of rye also seemed mostly conserved, but rye did not show geographic population structure across the investigated region in Sweden and Finland.

    A long-standing question in Fennoscandian crop history has been the interpretation of historical written records mentioning Brassica (cole crops, turnips and mustards), as well as the species identity of archaeobotanical finds of Brassica seeds. Thus, Next Generation Sequencing (NGS) was applied to identify which Brassica types that were cultivated in 17th century Kalmar, Sweden. The analysis corroborated morphological species classification in two of the investigated subfossil seeds, whereas no conclusions could be drawn from the remaining samples. The genome coverages were too low to allow subspecies identification.

    Wheat has been cultivated in Fennoscandia since the introduction of agriculture but has increased dramatically in importance over the last century. The functional allele of the wheat nutrition gene NAM-B1 was found to be particularly prominent in Fennoscandian wheats, likely associated with its effect on grain maturation time. Here the evolutionary history of NAM-B1 was investigated to see if it could truly be considered a domestication gene as suggested in a previous study. By studying extant landrace materials of Mediterranean tetraploid wheat, it was found that the non-functional allele showed signs indicative of a selective sweep. This selection did not, however, appear to have occurred during domestication.

    In conclusion, aged plant specimens from both museum and archaeological contexts could contribute greatly to our knowledge about historical cultivation, extending the investigated period into the mid 17th century. Subfossil and waterlogged archaeobotanical materials do contain endogenous DNA, suggesting that they are better suited for genetic analysis than charred ones, at least as far as cereals are concerned. There is potential for classifying archaeological Brassica remains using NGS, even though further optimisation of sample and library preparation may be necessary. And finally, despite NAM-B1 showing signs of selection it should not be considered a domestication gene in tetraploid wheat.

    Delarbeid
    1. Genetic analyses of Scandinavian desiccated, charred and waterlogged remains of barley (Hordeum vulgare L.)
    Åpne denne publikasjonen i ny fane eller vindu >>Genetic analyses of Scandinavian desiccated, charred and waterlogged remains of barley (Hordeum vulgare L.)
    Vise andre…
    2018 (engelsk)Inngår i: Journal of Archaeological Science: Reports, ISSN 2352-409X, Vol. 22, s. 11-20Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    Barley, Hordeum vulgare L., has been cultivated in Fennoscandia (Denmark, Norway, Sweden, Finland) since the start of the Neolithic around 4000 years BCE. Genetic studies of extant and 19th century barley landraces from the area have previously shown that distinct genetic groups exist with geographic structure according to latitude, suggesting strong local adaptation of cultivated crops. It is, however, not known what time depth these patterns reflect. Here we evaluate different archaeobotanical specimens of barley, extending several centuries in time, for their potential to answer this question by analysis of aDNA. Forty-six charred grains, nineteen waterlogged specimens and nine desiccated grains were evaluated by PCR and KASP genotyping. The charred samples did not contain any detectable endogenous DNA. Some waterlogged samples permitted amplification of endogenous DNA, however not sufficient for subsequent analysis. Desiccated plant materials provided the highest genotyping success rates of the materials analysed here in agreement with previous studies. Five desiccated grains from a grave from 1679 in southern Sweden were genotyped with 100 SNP markers and data compared to genotypes of 19th century landraces from Fennoscandia. The results showed that the genetic composition of barley grown in southern Sweden changed very little from late 17th to late 19th century and farmers stayed true to locally adapted crops in spite of societal and agricultural development.

    sted, utgiver, år, opplag, sider
    Elsevier, 2018
    Emneord
    Ancient DNA, Barley, Population structure, 17th century, Landraces
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-151282 (URN)10.1016/j.jasrep.2018.09.006 (DOI)
    Tilgjengelig fra: 2018-09-14 Laget: 2018-09-14 Sist oppdatert: 2019-08-02bibliografisk kontrollert
    2. Archaeological and Historical Materials as a Means to Explore Finnish Crop History
    Åpne denne publikasjonen i ny fane eller vindu >>Archaeological and Historical Materials as a Means to Explore Finnish Crop History
    Vise andre…
    2018 (engelsk)Inngår i: Environmental Archaeology, ISSN 1461-4103, E-ISSN 1749-6314Artikkel i tidsskrift (Fagfellevurdert) Epub ahead of print
    Abstract [en]

    In Northern Europe, barley (Hordeum vulgare L.) has been cultivated for almost 6000 years. Thus far, 150-year-old grains from historical collections have been used to investigate the distribution of barley diversity and how the species has spread across the region. Genetic studies of archaeobotanical material from agrarian sites could potentially clarify earlier migration patterns and cast further light on the origin of barley landraces. In this study, we aimed to evaluate different archaeological and historical materials with respect to DNA content, and to explore connections between Late Iron Age and medieval barley populations and historical samples of barley landraces in north-west Europe. The material analysed consisted of archaeological samples of charred barley grains from four sites in southern Finland, and historical material, with 33 samples obtained from two herbaria and the seed collections of the Swedish museum of cultural history.

    The DNA concentrations obtained from charred archaeological barley remains were too low for successful KASP genotyping confirming previously reported difficulties in obtaining aDNA from charred remains. Historical samples from herbaria and seed collection confirmed previously shown strong genetic differentiation between two-row and six-row barley. Six-row barley accessions from northern and southern Finland tended to cluster apart, while no geographical structuring was observed among two-row barley. Genotyping of functional markers revealed that the majority of barley cultivated in Finland in the late nineteenth and early twentieth century was late-flowering under increasing day-length, supporting previous findings from northern European barley.

    sted, utgiver, år, opplag, sider
    Routledge, 2018
    Emneord
    aDNA, archaeobotany, barley, genetic diversity, Hordeum vulgare, KASP, landraces
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-151277 (URN)10.1080/14614103.2018.1482598 (DOI)2-s2.0-85048366875 (Scopus ID)
    Tilgjengelig fra: 2018-09-14 Laget: 2018-09-14 Sist oppdatert: 2018-12-11bibliografisk kontrollert
    3. Evolutionary history of the NAM-B1 gene in wild and domesticated tetraploid wheat
    Åpne denne publikasjonen i ny fane eller vindu >>Evolutionary history of the NAM-B1 gene in wild and domesticated tetraploid wheat
    2017 (engelsk)Inngår i: BMC Genetics, ISSN 1471-2156, E-ISSN 1471-2156, Vol. 18, artikkel-id 118Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    Background

    The NAM-B1 gene in wheat has for almost three decades been extensively studied and utilized in breeding programs because of its significant impact on grain protein and mineral content and pleiotropic effects on senescence rate and grain size. First detected in wild emmer wheat, the wild-type allele of the gene has been introgressed into durum and bread wheat. Later studies have, however, also found the presence of the wild-type allele in some domesticated subspecies. In this study we trace the evolutionary history of the NAM-B1 in tetraploid wheat species and evaluate it as a putative domestication gene.

    Results

    Genotyping of wild and landrace tetraploid accessions showed presence of only null alleles in durum. Domesticated emmer wheats contained both null alleles and the wild-type allele while wild emmers, with one exception, only carried the wild-type allele. One of the null alleles consists of a deletion that covers several 100 kb. The other null-allele, a one-basepair frame-shift insertion, likely arose among wild emmer. This allele was the target of a selective sweep, extending over several 100 kb.

    Conclusions

    The NAM-B1 gene fulfils some criteria for being a domestication gene by encoding a trait of domestication relevance (seed size) and is here shown to have been under positive selection. The presence of both wild-type and null alleles in domesticated emmer does, however, suggest the gene to be a diversification gene in this species. Further studies of genotype-environment interactions are needed to find out under what conditions selection on different NAM-B1 alleles have been beneficial.

    sted, utgiver, år, opplag, sider
    BioMed Central, 2017
    Emneord
    Selective sweep, Grain protein content (GPC), Emmer, Durum, Domestication gene
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-144103 (URN)10.1186/s12863-017-0566-7 (DOI)000418687000001 ()
    Tilgjengelig fra: 2018-01-05 Laget: 2018-01-05 Sist oppdatert: 2019-08-02bibliografisk kontrollert
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