Zigaite Z.,Norbyvagen |
Zigaite Z.,University of Birmingham |
Richter M.,Natural History Museum in London |
Karatajute-Talimaa V.,Vilnius University |
Smith M.M.,King's College London
Historical Biology | Year: 2013
Previously described scale morphotypes of Silurian thelodonts, constrained by their representation as isolated dermal denticles are reassessed to provide a more robust character basis for their inclusion in future phylogenetic studies. As relatively common microfossils, thelodonts are important biostratigraphical markers, but their interrelationships with geologically younger species known by complete skeletons are still unresolved. We examined scales of 21 known morphotypes from north-eastern Europe, Siberia and central Asia and described their distinct tissue arrangements considering (1) thickness and direction of dentine tubules, (2) presence or absence of a pulp canal, (3) number and position of pulp canals, (4) the presence or absence of a distinct outer crown layer and (5) the extent of Sharpey's fibres penetrating the scale base. We correlated the traditional thelodont scale type morphologies with these distinct scale histologies, as found in Silurian thelodonts. In addition, a new histological type for thelodont scales, the Talimaalepis type, is described to represent a new taxon, from the Early-Mid Silurian. Our study suggests that, through time, there is a general trend of increasing complexity in thelodont dermal tissue structures. Three types of dentine and internal scale organisations were distinguished in Silurian species studied, namely (1) irregular, thin tubular dentine; (2) irregular, thick tubular dentine, with two subtypes as a function of pulp canal development and (3) regular, tubular dentine (orthodentine). © 2013 Copyright Taylor and Francis Group, LLC.
McFarlane S.E.,Norbyvagen |
Sirkia P.M.,University of Helsinki |
Sirkia P.M.,University of Turku |
Alund M.,Norbyvagen |
PLoS ONE | Year: 2016
Studies of ecological speciation are often biased towards extrinsic sources of selection against hybrids, resulting from intermediate hybrid morphology, but the knowledge of how genetic incompatibilities accumulate over time under natural conditions is limited. Here we focus on a physiological trait,metabolic rate, which is central to life history strategies and thermoregulation but is also likely to be sensitive to mismatched mitonuclear interactions. We measured the resting metabolic rate of male collared, and pied flycatchers as well as of naturally occurring F1 hybrid males, in a recent hybrid zone. We found that hybrid males had a higher rather than intermediate metabolic rate, which is indicative of hybrid physiological dysfunction. Fitness costs associated with elevated metabolic rate are typically environmentally dependent and exaggerated under harsh conditions. By focusing on male hybrid dysfunction in an eco-physiological trait, our results contribute to the general understanding of how combined extrinsic and intrinsic sources of hybrid dysfunction build up under natural conditions. © 2016 McFarlane et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Berglund E.C.,Norbyvagen |
Ehrenborg C.,Uppsala University Hospital |
Vinnere Pettersson O.,Norbyvagen |
Vinnere Pettersson O.,Uppsala University |
And 4 more authors.
BMC Genomics | Year: 2010
Background: Rodents represent a high-risk reservoir for the emergence of new human pathogens. The recent completion of the 2.3 Mb genome of Bartonella grahamii, one of the most prevalent blood-borne bacteria in wild rodents, revealed a higher abundance of genes for host-cell interaction systems than in the genomes of closely related human pathogens. The sequence variability within the global B. grahamii population was recently investigated by multi locus sequence typing, but no study on the variability of putative host-cell interaction systems has been performed.Results: To study the population dynamics of B. grahamii, we analyzed the genomic diversity on a whole-genome scale of 27 B. grahamii strains isolated from four different species of wild rodents in three geographic locations separated by less than 30 km. Even using highly variable spacer regions, only 3 sequence types were identified. This low sequence diversity contrasted with a high variability in genome content. Microarray comparative genome hybridizations identified genes for outer surface proteins, including a repeated region containing the fha gene for filamentous hemaggluttinin and a plasmid that encodes a type IV secretion system, as the most variable. The estimated generation times in liquid culture medium for a subset of strains ranged from 5 to 22 hours, but did not correlate with sequence type or presence/absence patterns of the fha gene or the plasmid.Conclusion: Our study has revealed a geographic microstructure of B. grahamii in wild rodents. Despite near-identity in nucleotide sequence, major differences were observed in gene presence/absence patterns that did not segregate with host species. This suggests that genetically similar strains can infect a range of different hosts. © 2010 Berglund et al; licensee BioMed Central Ltd.
Malmstrom H.,Norbyvagen |
Vretemark M.,Vastergotlands Museum |
Tillmar A.,National Board of Forensic Medicine |
Durling M.B.,Swedish University of Agricultural Sciences |
And 5 more authors.
Annals of Anatomy | Year: 2012
Historical records claim that Birger Magnusson (died 1266), famous regent of Sweden and the founder of Stockholm, was buried in Varnhem Abbey in Västergötland. After being lost for centuries, his putative grave was rediscovered during restoration work in the 1920s. Morphological analyses of the three individuals in the grave concluded that the older male, the female and the younger male found in the grave were likely to be Birger, his second wife Mechtild of Holstein and his son Erik from a previous marriage. More recent evaluations of the data from the 1920s seriously questioned these conclusions, ultimately leading to the reopening and reexamination of the grave in 2002. Ancient DNA-analyses were performed to investigate if the relationship between the three individuals matched what we would expect if the individuals were Birger, Erik and Mechtild. We used pyrosequencing of Y-chromosomal and autosomal SNPs and compared the results with haplogroup frequencies of modern Swedes to investigate paternal relations. Possible maternal kinship was investigated by deep FLX-sequencing of overlapping mtDNA amplicons. The authenticity of the sequences was examined using data from independent extractions, massive clonal data, the c-statistics, and real-time quantitative data. We show that the males carry the same Y-chromosomal haplogroup and thus we cannot reject a father-son type of relation. Further, as shown by the mtDNA analyses, none of the individuals are maternally related. We conclude that the graves indeed belong to Birger, Erik and Mechtild, or to three individuals with the exact same kind of biological relatedness. © 2011 Elsevier GmbH.
Chen D.,Norbyvagen |
Janvier P.,French Natural History Museum |
Ahlberg P.E.,Norbyvagen |
Historical Biology | Year: 2012
The origin of osteichthyans (bony fishes and tetrapods) dates back to the Late Silurian, but the early evolution of the group is poorly understood. Andreolepis is one of the oldest known osteichthyans, but exclusively documented by detached and fragmentary dermal microremains. A large data-set of Andreolepis scales from the Silurian of Gotland has been used to explore the scale morphology on different parts of the body. Landmark-based geometric morphometrics together with comparative anatomy and functional morphology has allowed 10 morphotypes to be identified and incorporated into a squamation model, in which scales are allocated to anterior-mid lateral flank scales, posterior lateral flank scales, caudal peduncle scales, pectoral peduncle scales, dorsal flank scales, dorsal fulcral scales, caudal fulcral scales, ventral flank scales, medioventral scales and cranial scales. The scale morphology and squamation pattern of Andreolepis may be primitive for the Osteichthyes and thus informative about the acquisition of the osteichthyan body plan. © 2012 Copyright Taylor and Francis Group, LLC.
Zigaite Z.,Norbyvagen |
Karatajute-Talimaa V.,Vilnius University |
Goujet D.,CNRS Center for Research on Palaeobiodiversity and Palaeoenvironments |
GFF | Year: 2013
Scales of six thelodont taxa are described from the Devonian of Spitsbergen. Numerous samples from localities widely dispersed on Spitsbergen yield several assemblages considered to represent different depositional phases of the late Lower lower Middle Devonian of the Andrée Land Group, but also support the view that certain lithostratigraphic units of the Andrée Land Group should be regarded as contemporaneous lithofacies subjected to different sedimentary environments, rather than as separate stratigraphic members. The description of Woodfjordia collisa gen. et sp. nov., Talivalia svalbardia sp. nov., Canonia cf. C. grossi, Amaltheolepis montiwatsonia sp. nov., Amaltheolepis winsnesi and Amaltheolepis austfjordia sp. nov. also allows for a comparison with similar faunas from other regions of the Northern Hemisphere and motivates further elaboration of Early-Middle Devonian thelodont biostratigraphy. © 2013 Copyright OPA (Overseas Publishers Association) N.V. Published by license under the Harwood Academic Publishers imprint, 2013.
Lundgren M.,Norbyvagen |
GFF | Year: 2013
The present analysis investigates for the first time the phylogenetic relationships of the cyathaspidid heterostracans by the principle of global parsimony on the basis of 36 species and 1 outgroup taxon. In this study, which assumes cyathaspidid monophyly, states for 61 characters were compiled and analysed using maximum parsimony methods, resulting in nine shortest trees of 122 steps each. The strict consensus tree shows a high degree of homoplasy and challenges previous classification schemes. The consensus topology supports previous arguments that the tolypelepids with their characteristic scale-like ornament occupy a basal position among the cyathaspidids. © 2013 Copyright OPA (Overseas Publishers Association) N.V. Published by license under the Harwood Academic Publishers imprint, 2013.
Ostman O.,Norbyvagen |
Stuart-Fox D.,University of Melbourne
Journal of Evolutionary Biology | Year: 2011
Natural and sexual selection shape the evolution of species but the interplay between them is poorly understood. Two phylogenetic studies on birds have suggested that species with greater sexual dichromatism have a broader habitat use. We show that in agamid lizards, species with more elaborate secondary sexual traits are also ecologically more opportunistic. Species with greater dimorphism in head size and ornamentation have greater altitudinal range and broader habitat use, respectively, and species with greater sexual dichromatism have wider microhabitat use. Body size was positively associated with sexual and ecological generalism, but associations between ecological and sexual traits remained after accounting for body size. We suggest that sexual and natural selection may be linked either because sexual selection can promote generalism at the population level by favouring 'good genes', or because higher population densities may be associated with both stronger sexual selection and broader resource use. © 2011 The Authors. Journal of Evolutionary Biology © 2011 European Society For Evolutionary Biology.
Palaeontology | Year: 2012
A new possible stem gnathostome, Kerreralepis carinata gen. et sp. nov., is described on the basis of a single specimen from the Lower Devonian of the island of Kerrera in the Inner Hebrides, Scotland. It is recognized as an anaspid by the chevron-like arranged rod-shaped scales on the trunk, gill openings extending behind the orbits in a slanting row and a series of median dorsal ridge scales. This specimen also has a series of median ventral plates, indicating the presence of a preanal fin-fold, which in turn has consequences for interpretations of other problematic stem gnathostomes and their phylogenetic context. A cladistic analysis supports a monophyletic Anaspida including the scale-covered birkeniids but excluding Lasanius as well as anaspid-like forms such as Euphanerops and Jamoytius. The establishment of a new genus and species increases the diversity of anaspids and allows for a more detailed study of anaspid interrelationships. An ingroup analysis using Lasanius as an outgroup resolves Birkenia as a rather basal anaspid, sister to all other anaspids, alternatively sister to a clade represented by the taxa from Ringerike, Norway, and the closely associated taxon from Saaremaa Island, Estonia. These topologies agree rather well with the present fossil record of anaspids. © The Palaeontological Association.
PubMed | Norbyvagen
Type: Journal Article | Journal: Molecular ecology | Year: 2012
There is ample evidence that organisms adapt to their native environment when gene flow is restricted. However, evolution of plastic responses across discrete environments is less well examined. We studied divergence in means and plasticity across wild and hatchery populations of sea-run brown trout (Salmo trutta) in a common garden experiment with two rearing environments (hatchery and a nearly natural experimental stream). Since natural and hatchery environments differ, this arrangement provides an experiment in contemporary adaptation across the two environments. A Q(ST) - F(ST) approach was used to investigate local adaptation in survival and growth over the first summer. We found evidence for divergent selection in survival in 1 year and in body length in both years and rearing environments. In general, the hatchery populations had higher survival and larger body size in both environments. Q(ST) in body size did not differ between the rearing environments, and constitutive divergence in the means was in all cases stronger than divergence in the plastic responses. These results suggest that in this system, constitutive changes in mean trait values are more important for local adaptation than increased plasticity. In addition, ex situ rearing conditions induce changes in trait means that are adaptive in the hatchery, but potentially harmful in the wild, suggesting that hatchery rearing is likely to be a suboptimal management strategy for trout populations facing selection in the stream environment.