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  • 1.
    Alvunger, David
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Variation in number of vertebrae in populations of pike (Esox lucius) in the south-east of Sweden2016Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Vertebral number (VN) is known to vary greatly across different taxa, but also within species orpopulations. Extensive research has shown that VN in fish is the result of interactions between geneticstructure and plastic responses to environmental cues during ontogeny. A frequently reported pattern is the tendency for VN to vary with body shape and/or length of the fish. The pike (Esox lucius) of the Baltic Sea has a complex population structure, with genetically distinct subpopulations consisting of homing anadromous individuals. Individuals belonging to these subpopulations are sympatric for most of their lives and become allopatric briefly during spawning each year. This study examined the distribution of VN in three anadromous sympatric subpopulations of pike in the Baltic. Significant differences in VN were found between juveniles and adults belonging to different subpopulations, but also across life-stageswithin all three subpopulations. Results from a common-garden experiment indicated that differences in VN among subpopulations were in part the result of genetic differences, indicative of evolutionary change. Furthermore, a quadratic regression revealed a curvilinear relationship between VN and bodylength of juveniles. Taken together, these results suggest that the combined effects of stabilizing and divergent selection might have played a role in shaping the distribution of VN in pike of the Baltic. The distribution of VN within subpopulations seems to be under the influence of stabilizing selection. Differences among subpopulations might instead reflect local adaptations driven by divergent selection. These findings signal the need for conservationists to view these subpopulations as unique units of management.

  • 2.
    Anderholm, Sofia
    et al.
    University of Gothenburg.
    Marshall, Rupert C
    Aberystwyth University, UK.
    van der Jeugd, Henk P
    SOVON Dutch Centre for Field Ornithology, The Netherlands ; Vogeltrekstation Dutch Centre for Avian Migration and Demography, The Netherlands.
    Waldeck, Peter
    University of Gothenburg.
    Larsson, Kjell
    Gotland University.
    Andersson, Malte
    University of Gothenburg.
    Nest parasitism in the barnacle goose: evidence from protein fingerprinting and microsatellites2009In: Animal Behaviour, ISSN 0003-3472, E-ISSN 1095-8282, Vol. 78, no 1, p. 167-174Article in journal (Refereed)
    Abstract [en]

    Geese are often seen as one of nature's best examples of monogamous relationships, and many social pairs stay together for life. However, when parents and young are screened genetically, some chicks do not match their social parents. Although this has often been explained as adoption of foreign young after hatching, conspecific nest parasitism is another possibility. We used nondestructive egg albumen sampling and protein fingerprinting to estimate the frequency and success of nest parasitism in a Baltic Sea population of barnacle geese, Branta leucopsis. Among the 86 nests for which we had the most complete information, 36% were parasitized, and 12% of the eggs were parasitic. Almost 80% of the parasitic eggs were laid after the host began incubation. Hatching of these eggs was limited to the few cases where the host female incubated longer than normally because her own eggs failed to hatch. Conspecific nest parasitism in this population therefore seems mainly to be an alternative reproductive tactic of lower fitness than normal nesting. Comparison with DNA profiling of chicks (with 10–14 microsatellites) and other evidence confirmed the suitability of protein fingerprinting for analysis of nest parasitism. It can often provide more data than microsatellites, if eggs are albumen-sampled soon after being laid, before most losses occur.

  • 3.
    Anderholm, Sofia
    et al.
    University of Gothenburg.
    Waldeck, Peter
    University of Gothenburg.
    van der Jeugd, Henk P
    Netherlands Institute for Ecology (NIOO-KNAW), The Netherlands.
    Marshall, Rupert C
    University of Gothenburg ; Aberystwyth University, UK.
    Larsson, Kjell
    Gotland University.
    Andersson, Malte
    University of Gothenburg.
    Colony kin structure and host-parasite relatedness in the barnacle goose2009In: Molecular Ecology, ISSN 0962-1083, E-ISSN 1365-294X, Vol. 18, no 23, p. 4955-4963Article in journal (Refereed)
    Abstract [en]

    Conspecific brood parasitism (CBP), females laying eggs in the nest of other 'host' females of the same species, is a common alternative reproductive tactic among birds. For hosts there are likely costs of incubating and rearing foreign offspring, but costs may be low in species with precocial chicks such as waterfowl, among which CBP is common. Waterfowl show strong female natal philopatry, and spatial relatedness among females may influence the evolution of CBP. Here we investigate fine-scale kin structure in a Baltic colony of barnacle geese, Branta leucopsis, estimating female spatial relatedness using protein fingerprints of egg albumen, and testing the performance of this estimator in known mother-daughter pairs. Relatedness was significantly higher between neighbour females (nesting ≤ 40 metres from each other) than between females nesting farther apart, but there was no further distance trend in relatedness. This pattern may be explained by earlier observations of females nesting close to their mother or brood sisters, even when far from the birth nest. Hosts and parasites were on average not more closely related than neighbour females. In 25 of 35 sampled parasitized nests, parasitic eggs were laid after the host female finished laying, too late to develop and hatch. Timely parasites, laying eggs in the host's laying sequence, had similar relatedness to hosts as that between neighbours. Females laying late parasitic eggs tended to be less related to the host, but not significantly so. Our results suggest that CBP in barnacle geese might represent different tactical life-history responses.

  • 4.
    Asano, Masanari
    et al.
    Tokyo University of Science.
    Basieva, Irina
    Linnaeus University, Faculty of Technology, Department of Mathematics.
    Khrennikov, Andrei
    Linnaeus University, Faculty of Technology, Department of Mathematics.
    Ohya, Masanori
    Tokyo University of Science.
    Tanaka, Yoshiharu
    Tokyo University of Science.
    Yamato, I.
    Tokyo University of Science.
    Lamarckian Evolution of Epigenome from Open Quantum Systems and Entanglement2014In: Quantum Interaction: 7th International Conference, QI 2013, Leicester, UK, July 25-27, 2013. Selected Papers / [ed] Harald Atmanspacher, Emmanuel Haven, Kirsty Kitto, Derek Raine, Springer, 2014, p. 324-334Conference paper (Refereed)
    Abstract [en]

    We develop a quantum-like (QL) model of cellular evolution based on the theory of open quantum systems and entanglement between epigenetic markers in a cell. This approach is applied to modeling of epigenetic evolution of cellular populations. We point out that recently experimental genetics discovered numerous phenomena of cellular evolution adaptive to the pressure of the environment. In such phenomena epigenetic changes are fixed in one generation and, hence, the Darwinian natural selection model cannot be applied. A number of prominent genetists stress the Lamarckian character of epigenetic evolution. In quantum physics the dynamics of the state of a system (e.g. electron) contacting with an environment (bath) is described by the theory of open quantum systems. Therefore it is natural to apply this theory to model adaptive changes in the epigenome. Since evolution of the Lamarckian type is very rapid – changes in the epigenome have to be inherited in one generation – we have to find a proper mathematical description of such a speed up. In our model this is the entanglement of different epigenetic markers.

  • 5. Barber, I.
    et al.
    Svensson, P. A.
    Effects of experimental Schistocephalus solidus infections on growth, morphology and sexual development of female three-spined sticklebacks, Gasterosteus aculeatus2003In: Parasitology, ISSN 0031-1820, E-ISSN 1469-8161, Vol. 126, p. 359-367Article in journal (Refereed)
    Abstract [en]

    The use of naturally infected hosts in studies attempting to identify parasite-induced changes in host biology is problematical because it does not eliminate the possibility that infection may be a consequence, rather than a cause, of host trait variation. In addition, uncontrolled concomitant infections may confound results. In this study we experimentally infected individual laboratory-bred female three-spined sticklebacks Gasterosteus aculeatus L. with the pseudophyllidean cestode Schistocephalus solidus [Muller], and compared the morphology and growth patterns of infected females with sham-exposed controls over a 16-week period. Fish were fed a ration of 8% body weight per day. Non-invasive image analysis techniques allowed the growth of individual plerocercoids to be tracked in vivo throughout the course of infection, and patterns of host and parasite growth were determined. Females that developed infections diverged morphometrically from unexposed control females and exposed-uninfected females at 6 weeks post-infection, with the width of the body at the pectoral fins giving the earliest indication of infection success. When including the plerocercoid, infected females gained weight more quickly than controls, but when plerocercoid weight was removed this trend was reversed. There was no effect of infection on the increase in fish length. Plerocercoids grew at different rates in individual hosts, and exhibited measurable sustained weight increases of up to 10% per day. Final estimates of plerocercoid weight from morphometric analysis prior to autopsy were accurate to within +/-17% of actual plerocercoid weight. At autopsy, infected female sticklebacks had significantly lower perivisceral fat reserves but had developed significantly larger ovaries than controls. The results are discussed in relation to previous studies examining natural infections, and the value of utilizing experimental infections to examine ecological aspects of host-parasite interactions is discussed.

  • 6. Barber, I.
    et al.
    Svensson, P. Andreas
    Synchrony between parasite development and host behaviour change2003In: Journal of Fish Biology, ISSN 0022-1112, E-ISSN 1095-8649, Vol. 63 Supp A, p. 246-Article in journal (Refereed)
  • 7. Barber, I.
    et al.
    Walker, P.
    Svensson, P. A.
    Behavioural responses to simulated avian predation in female three spined sticklebacks the effect of experimental Schistocephalus solidus infections2004In: Behaviour, ISSN 0005-7959, E-ISSN 1568-539X, Vol. 141, p. 1425-1440Article in journal (Refereed)
    Abstract [en]

    Plerocercoid larvae of Schistocephalus solidus are common parasites of three-spined sticklebacks that require the ingestion of stickleback hosts by birds to complete their life cycle. Amongst wild-caught sticklebacks, infection is associated with a reduction in antipredator behaviour; however, to date no study has examined the escape responses of experimentally infected sticklebacks, and thus assigning causality remains difficult. Here, we compare aspects of the antipredator behaviour of five experimentally infected female sticklebacks with shamexposed controls over a 16 post-exposure week period. During weeks 1-7 post-exposure, the escape responses of infected fish did not differ significantly from those of sham-exposed fish. However, over weeks 9-15, when infected fish had developed plerocercoids of >50 mg—the size at which they become infective to birds —a lower proportion of infected fish performed directional responses and reached cover within 2 s of the strike. Infected fish also performed a lower frequency of ‘staggered dashes’, and a higher frequency of ‘slow swims’, than shamexposed fish over weeks 9-15. Amongst sham-exposed fish, re-emergence from cover was uncommon throughout the study, but infected fish regularly left cover during weeks 9-15. Our results support those of previous studies examining behavioural change in naturally infected fish and, although other explanations remain possible, our finding that behaviour change in experimentally-infected fish is limited to hosts harbouring single infective parasites provides further evidence that the behaviour changes may be parasite adaptations.

  • 8.
    Berggren, Hanna
    et al.
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Nordahl, Oscar
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Tibblin, Petter
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Larsson, Per
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Forsman, Anders
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Testing for local adaptation to spawning habitat in sympatric subpopulations of northern pike by reciprocal translocation of embryos2016In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 11, no 5, article id e0154488Article in journal (Refereed)
    Abstract [en]

    We tested for local adaption in early life-history traits by performing a reciprocal translocation experiment with approximately 2500 embryos of pike (Esox lucius) divided in paired split-family batches. The experiment indicated local adaptation in one of the two subpopulations manifested as enhanced hatching success of eggs in the native habitat, both when compared to siblings transferred to a non-native habitat, and when compared to immigrant genotypes from the other subpopulation. Gene-by-environment effects on viability of eggs and larvae were evident in both subpopulations, showing that there existed genetic variation allowing for evolutionary responses to divergent selection, and indicating a capacity for plastic responses to environmental change. Next, we tested for differences in female life-history traits. Results uncovered that females from one population invested more resources into reproduction and also produced more (but smaller) eggs in relation to their body size compared to females from the other population. We suggest that these females have adjusted their reproductive strategies as a counter-adaptation because a high amount of sedimentation on the eggs in that subpopulations spawning habitat might benefit smaller eggs. Collectively, our findings point to adaptive divergence among sympatric subpopulations that are physically separated only for a short period during reproduction and early development – which is rare. These results illustrate how combinations of translocation experiments and field studies of life-history traits might infer about local adaptation and evolutionary divergence among populations. Local adaptations in subdivided populations are important to consider in management and conservation of biodiversity, because they may otherwise be negatively affected by harvesting, supplementation, and reintroduction efforts targeted at endangered populations.

  • 9.
    Berggren, Hanna
    et al.
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Tinnert, Jon
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Forsman, Anders
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Spatial sorting may explain evolutionary dynamics of wing polymorphism in pygmy grasshoppers.2012In: Journal of Evolutionary Biology, ISSN 1010-061X, E-ISSN 1420-9101, Vol. 25, no 10, p. 2126-2138Article in journal (Refereed)
    Abstract [en]

    Wing polymorphism in insects provides a good model system for investigating evolutionary dynamics and population divergence in dispersal-enhancing traits. This study investigates the contribution of divergent selection, trade-offs, behaviour and spatial sorting to the evolutionary dynamics of wing polymorphism in the pygmy grasshopper Tetrix subulata (Tetrigidae: Orthoptera). We use data for > 2800 wild-caught individuals from 13 populations and demonstrate that the incidence of the long-winged (macropterous) morph is higher and changes faster between years in disturbed habitats characterized by succession than in stable habitats. Common garden and mother-offspring resemblance studies indicate that variation among populations and families is genetically determined and not influenced to any important degree by developmental plasticity in response to maternal condition, rearing density or individual growth rate. Performance trials show that only the macropterous morph is capable of flight and that propensity to fly differs according to environment. Markrecapture data reveal no difference in the distance moved between free-ranging long- and short-winged individuals. There is no consistent difference across populations and years in number of hatchlings produced by long- and shorter-winged females. Our findings suggest that the variable frequency of the long-winged morph among and within pygmy grasshopper populations may reflect evolutionary modifications driven by spatial sorting due to phenotype- and habitat typedependent emigration and immigration.

  • 10.
    Betzholtz, Per-Eric
    et al.
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Franzén, Markus
    Helmholtz Centre for Environmental Research, Germany.
    Ecological characteristics associated with high mobility in night-active moths2013In: Basic and Applied Ecology, ISSN 1439-1791, E-ISSN 1618-0089, Vol. 14, no 3, p. 271-279Article in journal (Refereed)
    Abstract [en]

    Mobility is an important factor influencing the range and persistence of local populations. However, mobility is very difficult to measure empirically and thus is poorly known in most taxa. Since ecological characteristics have been suggested as good estimators of mobility, we here explore the association between ecological characteristics and mobility. We surveyed night-active moths on a Swedish island, situated 16 km from the mainland, and compared ecological characteristics of the non-resident moths found on the island with those of a species pool of assumed potential vagrants from the neighbouring mainland. Species associated with high mobility were characterised by a large range, a high population density, an activity period during warm temperatures and by being habitat generalists or preferring open habitats. The generally assumed view of poly- and oligophagous species being more mobile than monophagous species was obscured by the effect of population density. Poly- and oligophagous species had higher population densities than did monophagous species, which probably explain their higher mobility found in this study. Our result highlights the need to consider the influence of ecological characteristics on mobility. This in turn will have implications for an increased understanding of distribution patterns, population persistence and how to prioritise conservation actions, especially since habitats and climate are under dramatic changes. In taxa where data on mobility are poor, ecological characteristics can be used as a proxy for mobility.

  • 11.
    Betzholtz, Per-Eric
    et al.
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Franzén, Markus
    Department of Community Ecology, UFZ Centre for Environmental Research, Halle, Germany.
    Mobility is related to species traits in noctuid moths2011In: Ecological Entomology, ISSN 0307-6946, E-ISSN 1365-2311, Vol. 36, p. 369-376Article in journal (Refereed)
    Abstract [en]

    Abstract. 1. Mobility is important for the understanding of how species survive infragmented landscapes and cope with increasing rates of habitat and climate change.However, mobility is a difficult trait to explore and is poorly known in most taxa.Species traits have been studied in relation to range shifts, extinction risks, andresponses to habitat area and isolation, and have also been suggested as good estimatorsof mobility. Here we explore the relation between mobility and species traits in noctuidmoths.2. We sampled noctuid moths by an automatic light-trap on an island far out in theBaltic Sea. We compared traits of the non-resident species on the island with traits ofa species pool of assumed potential migrants from the Swedish mainland.3. Mobility was significantly related to adult activity period, length of flightperiod, and the interaction between host-plant specificity and distribution area. Widelydistributed host-plant generalists were more mobile than host-plant specialists withmore restricted distribution, and species with an adult activity period in August toSeptember moved to the island to a higher extent than species with an adult activityperiod in May to July. Our results remained qualitatively robust in additional analyses,after controlling for phylogeny and including all species recorded on the island, exceptfor the trait ‘length of flight period’.4. Our results highlight the importance of the relation between mobility and speciestraits. Noctuid moths with certain traits move over longer distances than earlier known.This finding is important to include when predicting range dynamics in fragmentedand changing landscapes, and when conservation measures of species are devised.

  • 12.
    Caesar, Sofia
    et al.
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Forsman, Anders
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Do polyandrous pygmy grasshopper females obtain fitness benefits for their offspring?2009In: Behavioral Ecology, ISSN 1045-2249, E-ISSN 1465-7279, Vol. 20, no 2, p. 354-361Article in journal (Refereed)
    Abstract [en]

    Explanations for polyandry in insects invoke material and genetic benefits that enhance female fitness via the production of more viable or more variable offspring. Here we use the color polymorphic pygmy grasshopper, Tetrix subulata, to evaluate effects of male quality, mate color morph resemblance (a proxy for compatibility), and polyandry on offspring performance. We experimentally mated females with different numbers and color morph combinations of males and reared offspring under either sun-exposed or shaded conditions using a split-brood design. We find a significant male identity effect on egg hatchability, consistent with the hypothesis that males vary in paternal quality. Offspring viability posthatching varied in a complex manner with solar regime, mating treatment, and parental resemblance. The effects of parental color morph resemblance on offspring performance suggest a potential role of compatibility and offspring variability. Monandrous females produced more viable offspring than polyandrous females (under shaded conditions) and we suggest as a hypothesis that the expected positive influence of polyandry on offspring performance may have been outweighed by more intense competition and antagonistic interactions among half-siblings. That an effect of mating treatment was evident under shaded but not under sun-exposed conditions suggests that great care is called for when making inferences from studies that show negative results.

  • 13.
    Chapman, Joanne R.
    et al.
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Hellgren, Olof
    Lund University.
    Helin, Anu S.
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Kraus, Robert H. S.
    Univ Konstanz, Germany;Max Planck Inst Ornithology, Germany.
    Cromie, Ruth L.
    Wildfowl & Wetlands Trust, UK.
    Waldenström, Jonas
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    The Evolution of Innate Immune Genes: Purifying and Balancing Selection on beta-Defensins in Waterfowl2016In: Molecular biology and evolution, ISSN 0737-4038, E-ISSN 1537-1719, Vol. 33, no 12, p. 3075-3087Article in journal (Refereed)
    Abstract [en]

    In disease dynamics, high immune gene diversity can confer a selective advantage to hosts in the face of a rapidly evolving and diverse pathogen fauna. This is supported empirically for genes involved in pathogen recognition and signalling. In contrast, effector genes involved in pathogen clearance may be more constrained. beta-Defensins are innate immune effector genes; their main mode of action is via disruption of microbial membranes. Here, five beta-defensin genes were characterized in mallards (Anas platyrhynchos) and other waterfowl; key reservoir species for many zoonotic diseases. All five genes showed remarkably low diversity at the individual-, population-, and species-level. Furthermore, there was widespread sharing of identical alleles across species divides. Thus, specific beta-defensin alleles were maintained not only spatially but also over long temporal scales, with many amino acid residues being fixed across all species investigated. Purifying selection to maintain individual, highly efficacious alleles was the primary evolutionary driver of these genes in waterfowl. However, we also found evidence for balancing selection acting on the most recently duplicated beta-defensin gene (AvBD3b). For this gene, we found that amino acid replacements were more likely to be radical changes, suggesting that duplication of beta-defensin genes allows exploration of wider functional space. Structural conservation to maintain function appears to be crucial for avian beta-defensin effector molecules, resulting in low tolerance for new allelic variants. This contrasts with other types of innate immune genes, such as receptor and signalling molecules, where balancing selection to maintain allelic diversity has been shown to be a strong evolutionary force.

  • 14.
    Dwivedi, Bhakti
    et al.
    University of South Florida, USA.
    Xue, Bingjie
    University of South Florida, USA.
    Lundin, Daniel
    KTH Royal Institute of Technology.
    Edwards, Robert A.
    San Diego State University, USA.
    Breitbart, Mya
    University of South Florida, USA.
    A bioinformatic analysis of ribonucleotide reductase genes in phage genomes and metagenomes2013In: BMC Evolutionary Biology, ISSN 1471-2148, E-ISSN 1471-2148, Vol. 13, no 1, p. 1-17, article id 33Article in journal (Refereed)
    Abstract [en]

    BackgroundRibonucleotide reductase (RNR), the enzyme responsible for the formation of deoxyribonucleotides from ribonucleotides, is found in all domains of life and many viral genomes. RNRs are also amongst the most abundant genes identified in environmental metagenomes. This study focused on understanding the distribution, diversity, and evolution of RNRs in phages (viruses that infect bacteria). Hidden Markov Model profiles were used to analyze the proteins encoded by 685 completely sequenced double-stranded DNA phages and 22 environmental viral metagenomes to identify RNR homologs in cultured phages and uncultured viral communities, respectively.

    ResultsRNRs were identified in 128 phage genomes, nearly tripling the number of phages known to encode RNRs. Class I RNR was the most common RNR class observed in phages (70%), followed by class II (29%) and class III (28%). Twenty-eight percent of the phages contained genes belonging to multiple RNR classes. RNR class distribution varied according to phage type, isolation environment, and the host’s ability to utilize oxygen. The majority of the phages containing RNRs are Myoviridae (65%), followed by Siphoviridae (30%) and Podoviridae (3%). The phylogeny and genomic organization of phage and host RNRs reveal several distinct evolutionary scenarios involving horizontal gene transfer, co-evolution, and differential selection pressure. Several putative split RNR genes interrupted by self-splicing introns or inteins were identified, providing further evidence for the role of frequent genetic exchange. Finally, viral metagenomic data indicate that RNRs are prevalent and highly dynamic in uncultured viral communities, necessitating future research to determine the environmental conditions under which RNRs provide a selective advantage.

    ConclusionsThis comprehensive study describes the distribution, diversity, and evolution of RNRs in phage genomes and environmental viral metagenomes. The distinct distributions of specific RNR classes amongst phages, combined with the various evolutionary scenarios predicted from RNR phylogenies suggest multiple inheritance sources and different selective forces for RNRs in phages. This study significantly improves our understanding of phage RNRs, providing insight into the diversity and evolution of this important auxiliary metabolic gene as well as the evolution of phages in response to their bacterial hosts and environments.

  • 15.
    Flink, Henrik
    et al.
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Svensson, P. Andreas
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Nest size preferences and aggression in sand gobies (Pomatoschistus minutus)2015In: Behavioral Ecology and Sociobiology, ISSN 0340-5443, E-ISSN 1432-0762, Vol. 69, no 9, p. 1519-1525Article in journal (Refereed)
    Abstract [en]

    In animal competition, resource holding potential (RHP) and resource value are two important factors determining the level of aggression and the outcome of contests. One valuable resource among nest-brooding animals that is subject to intense competition is a suitable nest substrate. Sand goby males (Pomatoschistus minutus) rely on finding good nest substrates, but the strategies vary between regions. We first investigated the nest size preferences in sand gobies from Kalmar Sound, a brackish area of the Baltic Sea with a shortage of suitable shells for nest construction and few invertebrate nest predators. Males expressed clear preference for larger nest substrates regardless of the male’s own size. To manipulate resource value, we provided males with large or small nests and tested if this and/or RHP affected aggression during nest defence. Resource value (a preferred large nest vs an unpreferred small nest) had no effect on aggression. However, RHP (total length of the resident male) had a significant effect. Larger males were more aggressive than smaller ones when matched against an opponent of the same size, suggesting that resident males acted according to own RHP.

  • 16.
    Forslund, Pär
    et al.
    Uppsala University, Sweden.
    Larsson, Kjell
    Uppsala University, Sweden.
    Intraspecific nest parasitism in the barnacle gooseFjärrlån IN: behavioural tactics of parasites and hosts1995In: Animal Behaviour, ISSN 0003-3472, E-ISSN 1095-8282, Vol. 50, no 2, p. 509-517Article in journal (Refereed)
    Abstract [en]

    Intraspecific nest parasitism in the barnacle goose,Branta leucopsis, was recorded by direct observations of females trying to lay eggs in the nests of other females. This was observed on 36 occasions. Parasitic egg-laying attempts were observed both in mornings and evenings, and lasted on average at least 20 min. Parasitic females approached host nests very fast and immediately sat down on or close to the nest. Host females attacked parasitic females intensively, but host males were much less aggressive. Males paired to the parasitic females were sometimes seen, but they never took any active part in the parasitic egg-laying attempts. Parasitic females probably successfully laid an egg most of the times, as the clutch size in host nests was on average 0·9 eggs larger than in nests where parasitic egg-laying attempts were not observed. Host females were observed to retrieve eggs laid outside the nest cup. Of 27 known cases, parasitic females made their egg-laying attempts before or at the host's start of incubation on 12 occasions, and after the start of incubation 15 times. It is suggested that parasitic females exploited features in the behaviour of potential hosts, such as egg retrieval and low aggressiveness in host males, to succeed in their egg-laying attempts. Nest parasitism seems to be a facultative, ‘best-of-a-bad-job’ tactic in barnacle geese, as parasitic females were observed to have nests of their own before or after the year they behaved parasitically, but never in that particular year.

  • 17.
    Forsman, Anders
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Effects of genotypic and phenotypic variation on establishment are important for conservation, invasion and infection biology.2014In: Proceedings of the National Academy of Sciences of the United States of America, ISSN 0027-8424, E-ISSN 1091-6490, Vol. 111, no 1, p. 302-307Article in journal (Refereed)
    Abstract [en]

    There is abundant evidence that the probability of successful establishment in novel environments increases with number of individuals in founder groups and with number of repeated introductions. Theory posits that the genotypic and phenotypic variation among individuals should also be important, but few studies have examined whether founder diversity influences establishment independent of propagule pressure, nor whether the effect is model or context dependent. I summarize the results of 18 experimental studies and report on a metaanalysis that provides strong evidence that higher levels of genotypic and phenotypic diversity in founder groups increase establishment success in plants and animals. The effect of diversity is stronger in experiments carried out under natural conditions in the wild than under seminatural or standardized laboratory conditions. The realization that genetic and phenotypic variation is key to successful establishment may improve the outcome of reintroduction and translocation programs used to vitalize or restore declining and extinct populations. Founder diversity may also improve the ability of invasive species to establish and subsequently spread in environments outside of their native community, and enhance the ability of pathogens and parasites to colonize and invade the environment constituted by their hosts. It is argued that exchange of ideas, methodological approaches, and insights of the role of diversity for establishment in different contexts may further our knowledge, vitalize future research, and improve management plans in different disciplines.

  • 18.
    Forsman, Anders
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Growth and survival of Vipera berus in a variable environment1997In: Venomous snakes: ecology, evolution and snakebite / [ed] Thorpe, Roger S., Oxford: Oxford University Press, 1997, p. 143-154Chapter in book (Other academic)
  • 19.
    Forsman, Anders
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Is colour polymorphism advantageous to populations and species?2016In: Molecular Ecology, ISSN 0962-1083, E-ISSN 1365-294X, Vol. 25, no 12, p. 2693-2698Article, review/survey (Refereed)
    Abstract [en]

    I am writing in response to an article by Bolton, Rollinsand Griffith (2015) entitled ‘The danger within: the roleof genetic, behavioural and ecological factors in populationpersistence of colour polymorphic species’ that wasrecently published as an Opinion under the NEWS ANDVIEWS section in Molecular Ecology. Bolton et al.(Molecular Ecology, 2015, 24, 2907) argue that colour polymorphismmay reduce population fitness and increaseextinction risk and emphasize that this is contrary to predictionsput forward by Forsman et al. (Ecology, 89, 2008,34) and Wennersten & Forsman (Biological Reviews 87,2012, 756) that the existence of multiple colour morphswith co-adapted gene complexes and associated trait valuesmay increase the ecological and evolutionary successof polymorphic populations and species. Bolton et al.(Molecular Ecology, 2015, 24, 2907) further state that thereis no clear evidence from studies of ‘true polymorphicspecies’ that polymorphism promotes population persistence.In response, I (i) challenge their classifications ofpolymorphisms and revisit the traditional definitions recognizingthe dynamic nature of polymorphisms, (ii)review empirical studies that have examined whetherand how polymorphism is associated with extinction risk,(iii) discuss the roles of trait correlations between colourpattern and other phenotypic dimensions for populationfitness and (iv) highlight that the causes and mechanismsthat influence the composition and maintenance of polymorphismsare different from the consequences of thepolymorphic condition and how it may impact on aspectsof ecological success and long-term persistence of populationsand species.

  • 20.
    Forsman, Anders
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    On the role of sex differences for evolution in heterogeneous and changing fitness landscapes: insights from pygmy grasshoppers2018In: Philosophical Transactions of the Royal Society of London. Biological Sciences, ISSN 0962-8436, E-ISSN 1471-2970, Vol. 373, no 1757, article id 20170429Article, review/survey (Refereed)
    Abstract [en]

    Much research has been devoted to study evolution of local adaptations by natural selection, and to explore the roles of neutral processes and developmental plasticity for patterns of diversity among individuals, populations and species. Some aspects, such as evolution of adaptive variation in phenotypic traits in stable environments, and the role of plasticity in predictable changing environments, are well understood. Other aspects, such as the role of sex differences for evolution in spatially heterogeneous and temporally changing environments and dynamic fitness landscapes, remain elusive. An increased understanding of evolution requires that sex differences in development, physiology, morphology, life-history and behaviours are more broadly considered. Studies of selection should take into consideration that the relationships linking phenotypes to fitness may vary not only according to environmental conditions but also differ between males and females. Such opposing selection, sex-by-environment interaction effects of selection and sex-specific developmental plasticity can have consequences for population differentiation, local adaptations and for the dynamics of polymorphisms. Integrating sex differences in analytical frameworks and population comparisons can therefore illuminate neglected evolutionary drivers and reconcile unexpected patterns. Here, I illustrate these issues using empirical examples from over 20 years of research on colour polymorphic Tetrix subulata and Tetrix undulata pygmy grasshoppers, and summarize findings from observational field studies, manipulation experiments, common garden breeding experiments and population genetics studies. This article is part of the theme issue 'Linking local adaptation with the evolution of sex differences'.

  • 21.
    Forsman, Anders
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Rethinking the thermal melanism hypothesis: rearing temperature and coloration in pygmy grasshoppers2011In: Evolutionary Ecology, ISSN 0269-7653, E-ISSN 1573-8477, Vol. 25, no 6, p. 1247-1257Article in journal (Refereed)
    Abstract [en]

    Selection for efficient conversion of solar radiation to body heat has favored theevolution of dark coloration in many ectotherms. The thermal melanism hypothesis positsthat dark coloration is beneficial under conditions of low ambient temperatures because itresults in faster heating rates and higher body temperatures. Fast heating rates, however,may come at a cost of overheating unless compensated for by thermal physiology orbehaviour. Pygmy grasshopper (Orthoptera, Tetrigidae) populations that inhabit fire-ravagedareas characterized by blackened backgrounds and hot surface temperatures due tohigh absorbance of solar radiation show an increased frequency of black phenotypes. Iraised the progeny of wild-captured Tetrix undulata in cold and hot temperatures and useddata on color patterns and survival in a greenhouse to examine whether a cold thermalenvironment triggered the development of melanic coloration or differently affected survivalof melanic versus non-melanic individuals. My results indicate that melanism was notinfluenced by rearing temperature but by genes or epigenetic maternal effects. Temperaturealso did not affect survival. However, melanic individuals produced by melanic motherssurvived longer than melanic individuals produced by non- melanic mothers, whereas nonmelanicindividuals produced by non-black mothers survived longer than melanic individualsproduced by non-black mothers. This suggests a mismatch between color andphysiology in offspring belonging to a different color morph than their mother. Futureinvestigations into the evolution of melanism should consider conflicting selection pressureson thermal capacity and camouflage as well as the influence of correlated responsesto selection on traits associated with coloration.

  • 22.
    Forsman, Anders
    et al.
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Berggren, Hanna
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Åström, Mats E.
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Larsson, Per
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    To what extent can existing research help project climate change impacts on biodiversity in aquatic environments?: A review of methodological approaches2016In: Journal of Marine Science and Engineering, E-ISSN 2077-1312, Vol. 4, no 4, article id 75Article, review/survey (Refereed)
    Abstract [en]

    It is broadly accepted that continued global warming will pose a major threat to biodiversity in the 21st century. But how reliable are current projections regarding consequences of future climate change for biodiversity? To address this issue, we review the methodological approaches in published studies of how life in marine and freshwater environments responds to temperature shifts. We analyze and compare observational field surveys and experiments performed either in the laboratory or under natural conditions in the wild, the type of response variables considered, the number of species investigated, study duration, and the nature and magnitude of experimental temperature manipulations. The observed patterns indicate that, due to limitations of study design, ecological and evolutionary responses of individuals, populations, species, and ecosystems to temperature change were in many cases difficult to establish, and causal mechanism(s) often remained ambiguous. We also discovered that the thermal challenge in experimental studies was 10,000 times more severe than reconstructed estimates of past and projections of future warming of the oceans, and that temperature manipulations also tended to increase in magnitude in more recent studies. These findings raise some concerns regarding the extent to which existing research can increase our understanding of how higher temperatures associated with climate change will affect life in aquatic environments. In view of our review findings, we discuss the trade-off between realism and methodological tractability. We also propose a series of suggestions and directions towards developing a scientific agenda for improving the validity and inference space of future research efforts.

  • 23.
    Forsman, Anders
    et al.
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Betzholtz, Per-Eric
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Franzén, Markus
    Helmholtz Centre for Environmental Research, Germany.
    Faster poleward range shifts in moths with more variable colour patterns2016In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 6, article id 36265Article in journal (Refereed)
    Abstract [en]

    Range shifts have been documented in many organisms, and climate change has been implicated asa contributing driver of latitudinal and altitudinal range modifications. However, little is known aboutwhat species trait(s) allow for faster environmental tracking and improved capacity for distributionexpansions. We used data for 416 species of moths, and show that range limits in Sweden have shifted tothe north by on average 52.4 km per decade between 1973 and 2014. When also including non-expandingspecies, average expansion rate was 23.2 km per decade. The rate of boundary shifts increased withincreasing levels of inter-individual variation in colour patterns and decreased with increasing latitude. Theassociation with colour patterns indicate that variation in this functionally important trait enables speciesto cope with novel and changing conditions. Northern range limits also increased with average abundanceand decreased with increasing year-to-year abundance fluctuations, implicating production of dispersersas a driver of range dynamics. Studies of terrestrial animals show that rates of poleward shifts differbetween taxonomic groups, increase over time, and depend on study duration and latitude. Knowledge ofhow distribution shifts change with time, location, and species characteristics may improve projections ofresponses to climate change and aid the protection of biodiversity

  • 24.
    Forsman, Anders
    et al.
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Hagman, Mattias
    Association of coloration mode with population declines and endangerment in Australian frogs2009In: Conservation Biology, ISSN 0888-8892, E-ISSN 1523-1739, Vol. 23, no 6, p. 1535-1543Article in journal (Refereed)
    Abstract [en]

    Successful protection of biodiversity requires increased understanding of the ecological characteristics that predispose some species to endangerment. Theory posits that species with polymorphic or variable coloration should have larger distributions, use more diverse resources, and be less vulnerable to population declines and extinctions, compared with taxa that do not vary in color. We used information from literature on 194 species of Australian frogs to search for associations of coloration mode with ecological variables. In general, species with variable or polymorphic color patterns had larger ranges, used more habitats, were less prone to have a negative population trend, and were estimated as less vulnerable to extinction compared with nonvariable species. An association of variable coloration with lower endangerment was also evident when we controlled statistically for the effects of range size. Nonvariable coloration was not a strong predictor of endangerment, and information on several characteristics is needed to reliably identify and protect species that are prone to decline and may become threatened by extinction in the near future. Analyses based on phylogenetic-independent contrasts did not support the hypothesis that evolutionary transitions between nonvariable and variable or polymorphic coloration have been accompanied by changes in the ecological variables we examined. Irrefutable demonstration of a role of color pattern variation in amphibian decline and in the dynamics and persistence of populations in general will require a manipulative experimental approach.

  • 25.
    Forsman, Anders
    et al.
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Wennersten, Lena
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Inter-individual variation promotes ecological success of populations and species: evidence from experimental and comparative studies2016In: Ecography, ISSN 0906-7590, E-ISSN 1600-0587, Vol. 39, no 7, p. 630-648Article, review/survey (Refereed)
    Abstract [en]

    Biological diversity is threatened by exploitation, fragmentation of natural habitats, pollution, climatechange, and anthropogenic spread of species. The question of how among-individual variation influencesthe performance of populations and species is a poorly explored but currently growing field of research.Here, we review 31 experimental and 14 comparative studies and first investigate whether there is empiricalsupport for the propositions that higher levels of among-individual phenotypic and genetic variationpromote the ecological and evolutionary success of populations and species in the face of environmentalchange. Next, we examine whether and how the effect of diversity depends on environmental conditions.Finally, we explore whether the relationship linking population fitness to diversity is typically linear,asymptotic, or whether the benefits peak at intermediate diversity. The reviewed studies provide strong,almost invariable, evidence that more variable populations are less vulnerable to environmental changes,show decreased fluctuations in population size, have superior establishment success, larger distributionranges, and are less extinction prone, compared with less variable populations or species. Given theoverwhelming evidence that variation promotes population performance, it is important to identifyconditions when increased variation does not have the theoretically expected effect, a question ofconsiderable importance in biodiversity management, where there are many other practical constraints. Wefind that experimental outcomes generally support the notion that genetic and phenotypic variation is ofgreater importance under more stressful than under benign conditions. Finally, population performanceincreased linearly with increasing diversity in the majority (10 of 12) of manipulation studies that includedfour or more diversity levels; only two experiments detected curvilinear relationships.

  • 26.
    Forsman, Anders
    et al.
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Wennersten, Lena
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Karlsson, Magnus
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Caesar, Sofia
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Variation in founder groups promotes establishment success in the wild2012In: Proceedings of the Royal Society of London. Biological Sciences, ISSN 0962-8452, E-ISSN 1471-2954, Vol. 279, no 1739, p. 2800-2806Article in journal (Refereed)
    Abstract [en]

    Environmental changes currently pose severe threats to biodiversity, and reintroductions and translocations are increasingly used to protect declining populations and species from extinction. Theory predicts that establishment success should be higher for more variable groups of dissimilar individuals. To test this ‘diversity promotes establishment’ hypothesis, we introduced colour polymorphic pygmy grasshoppers (Tetrix subulata) to different sites in the wild. The number of descendants found at the release sites the subsequent year increased with increasing number of colour morphs in the founder group, and variation in founder groups also positively affected colour morph diversity in the established populations. Since colour morphs differ in morphology, physiology, behaviour, reproductive life history and types of niche used, these findings demonstrate that variation among individuals in functionally important traits promotes establishment success under natural conditions, and further indicate that founder diversity may contribute to evolutionary rescue and increased population persistence.

  • 27. Franzén, Markus
    et al.
    Betzholtz, Per-Eric
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Species traits predict island occupancy in noctuid moths2012In: Journal of Insect Conservation, ISSN 1366-638X, E-ISSN 1572-9753, Vol. 16, no 2, p. 155-163Article in journal (Refereed)
    Abstract [en]

    Knowing how species’ traits relate to processes that underlie occupancy patterns such as colonisation and population persistence, is important for our understanding of how species survive in fragmented and changing landscapes. We used automatic UV light-traps to sample noctuidmoths on two remote islands, and compared traits of island occupants with those of a species pool from mainland southeast Sweden. Widely distributed species, generalist species, species with a long adult activity period and species active late in the summer had higher probability of occupancy on the remote islands. The results were consistent between islands. The traits of host plant specificity and species with an adult activity period during late summer remained robust and were statistically significant after controlling for any possible phylogenetic bias. This indicates that species exhibiting those traits survive better when habitat and climate changes. It is crucial to includeour results in; (1) conservation planning, e.g. when devising conservation measures in fragmented landscapes; (2) for predictions of future occupancy patterns; and (3) ecosystem impact assessments, e.g. the importance of moths as pollinators, herbivores and being the functional link between parasitoids, plants, consumers and predators.

  • 28. Guevara-Fiore, P.
    et al.
    Svensson, P. Andreas
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Endler, J.A.
    Sex as moderator of early life experiences: interaction between rearing environment and sexual experience in male guppies2012In: Animal Behaviour, ISSN 0003-3472, E-ISSN 1095-8282, Vol. 84, no 4, p. 1023-1029Article in journal (Refereed)
    Abstract [en]

    The effects of learning have been neglected in studies of sexual selection because previous researchers have assumed, implicitly or explicitly, that sexual behaviour is genetically fixed. To understand the role of learning in sexual selection, it is important to investigate how early experience interacts with adult experience to determine the use of different mating strategies. We explored this interaction by comparing the sexual behaviour of male guppies, Poecilia reticulata, raised in different social environments before and after they gained sexual experience. Males raised with other males performed long courtship displays at first, but decreased their courtship after they had gained sexual experience. However, for males raised only with females, sexual experience did not modify courtship duration. Males raised exclusively with females exhibited high rates of forced copulation attempts in their first encounter with a female, but reduced this behaviour after sexual experience. In contrast, males raised with other males did not modify their forced copulations. Adult sexual experience appeared to mitigate the behavioural differences caused by variation in rearing environment. Sexual experience helps males to find an optimal balance between courtship displays and forced copulation attempts. We also show that more males exhibited male–male aggression after sexual experience if they had social interactions with other males early in life. This study highlights that courtship and other sexual strategies are not fixed, and that several potential sources of variation exist in the development of an animal's sexual behaviour. Importantly, juvenile and adult experiences can interact to shape sexual behaviour in males.

  • 29.
    Gärdenfors, Peter
    et al.
    Lund University; Wallenberg Research Centre at Stellenbosch University, South Africa.
    Högberg, Anders
    Linnaeus University, Faculty of Arts and Humanities, Department of Cultural Sciences. Wallenberg Research Centre at Stellenbosch University, South Africa.
    Evolutionary mechanisms of teaching2015In: Behavioral and Brain Sciences, ISSN 0140-525X, E-ISSN 1469-1825, Vol. 38, p. 25-26, article id e41Article in journal (Refereed)
    Abstract [en]

    We argue that Kline’s analysis does not account for the evolutionary mechanisms that can explain the uniqueness of human teaching. We suggest that data should be complemented by an analysis of archaeological material with respect to what forms of teaching are required for the transmission of technologies over generations.

  • 30.
    Helin, Anu S.
    et al.
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Aarts, Lauren
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Bususu, Isaya
    Linnaeus University, Faculty of Health and Life Sciences, Department of Chemistry and Biomedical Sciences.
    Andersson, Håkan S.
    Linnaeus University, Faculty of Health and Life Sciences, Department of Chemistry and Biomedical Sciences.
    Rosengren, Johan
    University of Queensland, Australia‎.
    Chapman, Joanne R.
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science. University of Kansas, USA.
    Waldenström, Jonas
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Antimicrobial activity differences in reduced vs. oxidized AvBD3b peptides in mallards (Anas platyrhynchos).2017Conference paper (Other academic)
  • 31.
    Helin, Anu S.
    et al.
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Aarts, Lauren
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Bususu, Isaya
    Linnaeus University, Faculty of Health and Life Sciences, Department of Chemistry and Biomedical Sciences.
    Andersson, Håkan S.
    Linnaeus University, Faculty of Health and Life Sciences, Department of Chemistry and Biomedical Sciences.
    Rosengren, Johan
    University of Queensland, Australia.
    Chapman, Joanne R.
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Waldenström, Jonas
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Antimicrobial differences between AvBDs in mallards (Anas platyrhynchos)2018Conference paper (Other academic)
  • 32.
    Helin, Anu S.
    et al.
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Aarts, Lauren
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Chapman, Joanne R.
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Andersson, Håkan S.
    Linnaeus University, Faculty of Health and Life Sciences, Department of Chemistry and Biomedical Sciences.
    Waldenström, Jonas
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Bactericidal tests of mallard (Anas plathyrynchos) ß-defensin alleles2017Conference paper (Other academic)
  • 33.
    Härlin, Carina
    et al.
    University of Gothenburg.
    Härlin, Mikael
    Södertörn University College.
    Towards a historization of aposematism2003In: Evolutionary Ecology, ISSN 0269-7653, E-ISSN 1573-8477, Vol. 17, no 2, p. 197-212Article in journal (Refereed)
    Abstract [en]

    Aposematism is one of the oldest phenomena in evolutionary biology and still a major puzzle to biologists. Despite its evolutionary nature, most attempts to understand aposematism are devoid of phylogenetic components. In addition, most studies that do take phylogeny into account need to bring the analysis even further. We argue that in order to fully understand aposematism we must have a clear picture of the evolutionary history behind present behaviours. In this paper we frame aposematism in a phylogenetic context and argue that most studies still are wanting in terms of demonstrating aposematism. Aposematism is not an end product but rather evolutionary scenarios including character transformations as well as prey-predator interactions. Finally, we suggest that, regardless how we restrict the concept of aposematism, knowing the directions of events facilitate all kinds of comparisons with a promise of uniting functional and evolutionary aspects into a historization of aposematism.

  • 34.
    Härlin, Mikael
    Linnaeus University, The University Administration.
    Arterna är inte vad de varit2014In: Forskning & Framsteg, ISSN 0015-7937, no 5, p. 48-52Article in journal (Other (popular science, discussion, etc.))
    Abstract [sv]

    När Kristofer Helgen under ett besök på Field museum i Chicago drog ut en låda med vad han trodde var en samling kända tvättbjörnsarter blev han rejält överraskad.

    – Jag tittade på pälsen, skallen, tänderna, hörselbenen. Inget i anatomin liknade något jag sett tidigare, säger Kristofer Helgen, som är zoolog vid Smithsonian museum i USA.

    Det starkt rödfärgade skinnen han såg ledde till beskrivningen av en ny köttätande däggdjursart.

  • 35.
    Härlin, Mikael
    University of Gothenburg.
    Biogeographic patterns and the evolution of eureptantic nemerteans1996In: Biological Journal of the Linnean Society, ISSN 0024-4066, E-ISSN 1095-8312, Vol. 58, no 3, p. 325-342Article in journal (Refereed)
    Abstract [en]

    The origin and evolution of the eureptantic nemerteans is discussed from a biogeographic point of view. It is most likely that East Indian Ocean was part of the ancestral distribution of the Eureptantia. The area cladogram estimated by Brooks parsimony analysis (BPA) is to a high degree congruent with a vicariance explanation of the evolution of the Eureptantia and suggests an ancestral distribution concordant with the Tethys Sea. A general area cladogram based on a combined BPA analysis of eureptantic nemerteans and acanthuroid fishes is reconstructed and suggested as a hypothesis of the relationships between east Indian Ocean, west Indian Ocean, west Pacific Ocean, east Atlantic Ocean, west Atlantic Ocean, and the Mediterranean. This tree is compared with cladograms from the same areas based on other taxa.

  • 36.
    Härlin, Mikael
    Linnaeus University, The University Administration.
    Den mänskliga naturen?2014In: Sans, ISSN 2000-9690, no 2, p. 82-85Article in journal (Other (popular science, discussion, etc.))
  • 37. Härlin, Mikael
    Fossil och molekylära klockor ger nya ledtrådar till livets ursprung: Jordens första livstecken2014In: Allt om vetenskap, ISSN 1652-3318, no 6, p. 60-66Article in journal (Other (popular science, discussion, etc.))
  • 38. Härlin, Mikael
    Miljoner arter som söker sin plats: Livets snårskog2014In: Allt om vetenskap, ISSN 1652-3318, no 3, p. 44-52Article in journal (Other (popular science, discussion, etc.))
  • 39.
    Härlin, Mikael
    Växjö University, Faculty of Mathematics/Science/Technology, Institutionen för biovetenskaper och processteknik.
    Phylogenetic approaches to nomenclature: a comparison based on a nemertean case study.1999In: Proceedings of the Royal Society of London. Biological Sciences, ISSN 0962-8452, E-ISSN 1471-2954, Vol. 266, no 1434, p. 2201-2207Article in journal (Refereed)
    Abstract [en]

    Phylogenetic approaches to biological nomenclature are becoming increasingly common. Here I compare the behaviour of two such approaches, the phylogenetic system of definition and the phylogenetic system of reference, when there is a shift in the preference of phylogenetic hypotheses. The comparison is based on a case study from nemertean systematics and is the first to compare two different phylogenetic approaches throughout three stages of change, including two stages of phylogenetic nomenclature. It is concluded that a phylogenetic system of reference in combination with uninomials is superior in conveying phylogenetic information.

  • 40.
    Härlin, Mikael
    Södertörn University College.
    Taxon names as paradigms: the structure of nomenclatural revolutions2003In: Cladistics, ISSN 0748-3007, E-ISSN 1096-0031, Vol. 19, no 2, p. 138-143Article in journal (Refereed)
    Abstract [en]

    In the present paper I argue that the two systems of phylogenetic nomenclature hitherto proposed represent, in a generalized sense, two different philosophies for how science develops and progresses. The phylogenetic system of definition. initially proposed by de Queiroz and Gauthier [Syst. Zool. 39 (1990) 307], and later labeled PSD, is typically Popperian in the 'sense that science progresses toward truth by An accumulation of knowledge. Phylogenetic definitions of taxon names are assumed to adapt automatically to each new hypothesis of phylogeny, thereby reflecting better and better hypotheses. The phylogenetic system of reference proposed by Harlin [Zool. Scr. 27 (1998a) 381], on the other hand, is more Kuhnian, because it is built on the idea that successive hypotheses are incommensurable (and thus not cumulative) and that taxon names might be equalled with low-level paradigms.

  • 41.
    Härlin, Mikael
    Växjö University, Faculty of Mathematics/Science/Technology, Institutionen för biovetenskaper och processteknik.
    The logical priority of the tree over characters and some of its consequences for taxonomy1999In: Biological Journal of the Linnean Society, ISSN 0024-4066, E-ISSN 1095-8312, Vol. 68, no 4, p. 497-503Article in journal (Refereed)
    Abstract [en]

    The aim of the present paper is to explore the role of the character in phylogenetic systematics. I argue that too much emphasis is put on particular characters rather than congruence both in the choice of phylogenetic hypotheses and in taxonomic decisions. This means that the logical priority of the tree over the characters is neglected. To a large extent, this is a result of not paying enough attention to the individuality thesis which states that clades are historical individuals and hence contingent in nature.

  • 42.
    Högberg, Anders
    Linnaeus University, Faculty of Arts and Humanities, Department of Cultural Sciences.
    På plats – Symposium i Sydafrika: Svenska bidrag till forskingen om människans evolution2018In: Respons : recensionstidskrift för humaniora & samhällsvetenskap, ISSN 2001-2292, no 1, p. 14-14Article in journal (Other (popular science, discussion, etc.))
  • 43.
    Högberg, Anders
    Linnaeus University, Faculty of Arts and Humanities, Department of Cultural Sciences.
    [recension av] Clive Gamble & John Gowlett & Robin Dunbar: Thinking big: how the evolution of social life shaped the human mind2015In: Respons: recensionstidskrift för humaniora & samhällsvetenskap, ISSN 2001-2292, no 1, p. 66-68Article, book review (Other (popular science, discussion, etc.))
  • 44.
    Johansson, Jenny
    et al.
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Caesar, Sofia
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Forsman, Anders
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Multiple paternity increases phenotypic diversity in Tetrix subulata pygmy grasshoppers2013In: Journal of Orthoptera Research, ISSN 1082-6467, Vol. 22, no 2, p. 79-85Article in journal (Refereed)
    Abstract [en]

    Multiple paternity within clutches has been recorded among a variety of organisms. The degree of genetic similarity between parents may influence the number and viability of offspring. Females may therefore mate with several males as an insurance against sterile, low quality or genetically incompatible mates, but also to obtain half sibling offspring that are genetically and phenotypically more diverse. We examine the links between polyandry, multiple paternity and offspring phenotypic diversity in the color polymorphic pygmy grasshopper Tetrix subulata. By experimentally mating virgin females and genotyping the resulting offspring using microsatellite markers, we demonstrate that polyandrous females can produce offspring sired by different males. Analyses of microsatellite data and color patterns of captive reared families produced by wild caught females that were not mated in the laboratory, confirmed that multiple paternity occurs in the wild, and that it may increase color morph diversity among half-siblings. Polyandrous mating behavior may thus influence the evolutionary dynamics and maintenance of color polymorphism in this species.

  • 45. Jonker, R.M.
    et al.
    Kraus, R.H.S.
    Zhang, Q.
    Van Hooft, P.
    Larsson, Kjell
    Linnaeus University, Faculty of Technology, Kalmar Maritime Academy.
    Van der Jeugd, H.P.
    Kurvers, R.H.J.M.
    Van Wieren, S.E.
    Loonen, M.J.J.E.
    Crooijmans, R.P.M.A.
    Ydenberg, R.C.
    Groenen, M.A.M.
    Prins, H.H.T.
    Genetic consequences of breaking migratory traditions in barnacle geese Branta leucopsis2013In: Molecular Ecology, ISSN 0962-1083, E-ISSN 1365-294X, Vol. 22, no 23, p. 5835-5847Article in journal (Refereed)
    Abstract [en]

    Cultural transmission of migratory traditions enables species to deal with their environment based on experiences from earlier generations. Also, it allows a more adequate and rapid response to rapidly changing environments. When individuals break with their migratory traditions, new population structures can emerge that may affect gene flow. Recently, the migratory traditions of the Barnacle Goose Branta leucopsis changed, and new populations differing in migratory distance emerged. Here, we investigate the population genetic structure of the Barnacle Goose to evaluate the consequences of altered migratory traditions. We used a set of 358 single nucleotide polymorphism (SNP) markers to genotype 418 individuals from breeding populations in Greenland, Spitsbergen, Russia, Sweden and the Netherlands, the latter two being newly emerged populations. We used discriminant analysis of principal components, FST, linkage disequilibrium and a comparison of geneflow models using MIGRATE-N to show that there is significant population structure, but that relatively many pairs of SNPs are in linkage disequilibrium, suggesting recent admixture between these populations. Despite the assumed traditions of migration within populations, we also show that genetic exchange occurs between all populations. The newly established nonmigratory population in the Netherlands is characterized by high emigration into other populations, which suggests more exploratory behaviour, possibly as a result of shortened parental care. These results suggest that migratory traditions in populations are subject to change in geese and that such changes have population genetic consequences. We argue that the emergence of nonmigration probably resulted from developmental plasticity.

  • 46.
    Karpestam, Einat
    et al.
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Forsman, Anders
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Dietary differences among colour morphs of pygmy grasshoppers revealed by behavioural experiments and stable isotopes.2011In: Evolutionary Ecology Research, ISSN 1522-0613, E-ISSN 1937-3791, Vol. 13, p. 461-477Article in journal (Refereed)
  • 47.
    Karpestam, Einat
    et al.
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Forsman, Anders
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Stable isotopes reveal dietary divergence between dispersal phenotypes in Tetrix subulata pygmy grasshoppers (Orthoptera: Tetrigidae)2013In: European Journal of Entomology, ISSN 1210-5759, E-ISSN 1802-8829, Vol. 110, no 1, p. 65-70Article in journal (Refereed)
    Abstract [en]

    In some species of insects, individuals with fully developed wings and capable of flying coexist with flightless individuals that lack functional wings. Their diets may differ if long-winged individuals are more mobile and therefore likely to be better at finding and utilizing high quality food resources, or if they have different food preferences or physiological requirements. Despite its potential importance, differences in the diet of dispersal phenotypes have not been unequivocally demonstrated under natural conditions. To test for dietary divergence, we compared natural abundances of carbon and nitrogen stable isotope ratios (d13C and d15N) in long- and short-winged free ranging Tetrix subulata pygmy grasshoppers collected as adults from two natural populations. Overall, this comparison of stable isotopes indicated long-term differences in the diet of the two wing morphs in both populations, but not between males and females of the same morph. We conclude that it is likely that the dietary niches of the long winged and flightless individuals differ under natural conditions. This may reduce intra-specific competition, offset the expected trade-off between flight capacity and reproduction and promote ecological speciation.

  • 48.
    Karpestam, Einat
    et al.
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Merilaita, Sami
    Åbo Akademi University, Finland.
    Forsman, Anders
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Colour polymorphism protects prey individuals and populations against predation2016In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 6, article id 22122Article in journal (Refereed)
    Abstract [en]

    Colour pattern polymorphism in animals can influence and be influenced by interactions between predators and prey. However, few studies have examined whether polymorphism is adaptive, and there is no evidence that the co-occurrence of two or more natural prey colour variants can increase survival of populations. Here we show that visual predators that exploit polymorphic prey suffer from reduced performance, and further provide rare evidence in support of the hypothesis that prey colour polymorphism may afford protection against predators for both individuals and populations. This protective effect provides a probable explanation for the longstanding, evolutionary puzzle of the existence of colour polymorphisms. We also propose that this protective effect can provide an adaptive explanation for search image formation in predators rather than search image formation explaining polymorphism.

  • 49.
    Karpestam, Einat
    et al.
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Merilaita, Sami
    Department of Biosciences, Åbo Akademi University, Turku 780 FI-20520, Finland..
    Forsman, Anders
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Detection experiments with humans implicate visual predation as a driver of colour polymorphism dynamics in pygmy grasshoppers2013In: BMC Ecology, ISSN 1472-6785, E-ISSN 1472-6785, Vol. 13, p. Article number 17-Article in journal (Refereed)
    Abstract [en]

    Background: Animal colour patterns offer good model systems for studies of biodiversity and evolution of local adaptations. An increasingly popular approach to study the role of selection for camouflage for evolutionary trajectories of animal colour patterns is to present images of prey on paper or computer screens to human 'predators'. Yet, few attempts have been made to confirm that rates of detection by humans can predict patterns of selection and evolutionary modifications of prey colour patterns in nature. In this study, we first analyzed encounters between human 'predators' and images of natural black, grey and striped colour morphs of the polymorphic Tetrix subulata pygmy grasshoppers presented on background images of unburnt, intermediate or completely burnt natural habitats. Next, we compared detection rates with estimates of capture probabilities and survival of free-ranging grasshoppers, and with estimates of relative morph frequencies in natural populations. Results: The proportion of grasshoppers that were detected and time to detection depended on both the colour pattern of the prey and on the type of visual background. Grasshoppers were detected more often and faster on unburnt backgrounds than on 50% and 100% burnt backgrounds. Striped prey were detected less often than grey or black prey on unburnt backgrounds; grey prey were detected more often than black or striped prey on 50% burnt backgrounds; and black prey were detected less often than grey prey on 100% burnt backgrounds. Rates of detection mirrored previously reported rates of capture by humans of free-ranging grasshoppers, as well as morph specific survival in the wild. Rates of detection were also correlated with frequencies of striped, black and grey morphs in samples of T. subulata from natural populations that occupied the three habitat types used for the detection experiment. Conclusions: Our findings demonstrate that crypsis is background-dependent, and implicate visual predation as an important driver of evolutionary modifications of colour polymorphism in pygmy grasshoppers. Our study provides the clearest evidence to date that using humans as 'predators' in detection experiments may provide reliable information on the protective values of prey colour patterns and of natural selection and microevolution of camouflage in the wild.

  • 50.
    Karpestam, Einat
    et al.
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Merilaita, Sami
    Åbo Akademi University, Finland.
    Forsman, Anders
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Reduced predation risk for melanistic pygmy grasshoppers in post-fire environments2012In: Ecology and Evolution, ISSN 2045-7758, E-ISSN 2045-7758, Vol. 2, no 9, p. 2204-2212Article in journal (Refereed)
    Abstract [en]

    The existence of melanistic (black) color forms in many species represents interesting model systems that have played important roles for our understanding of selective processes, evolution of adaptations, and the maintenance of variation. A recent study reported on rapid evolutionary shifts in frequencies of the melanistic forms in replicated populations of Tetrix subulata pygmy grasshoppers; the incidence of the melanistic form was higher in recently burned areas with backgrounds blackened by fire than in nonburned areas, and it declined over time in postfire environments. Here, we tested the hypothesis that the frequency shifts of the black color variant were driven, at least in part, by changes in the selective regime imposed by visual predators. To study detectability of the melanistic form, we presented human “predators” with images of black grasshoppers and samples of the natural habitat on computer screens. We demonstrate that the protective value of black coloration differs between burnt and nonburnt environments and gradually increases in habitats that have been more blackened by fire. These findings support the notion that a black color pattern provides improved protection from visually oriented predators against blackened backgrounds and implicate camouflage and predation as important drivers of fire melanism in pygmy grasshoppers.

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