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  • 1301. Ravignani, Andrea
    et al.
    Madison, Guy
    Umeå universitet, Samhällsvetenskapliga fakulteten, Institutionen för psykologi.
    The Paradox of Isochrony in the Evolution of Human Rhythm2017Inngår i: Frontiers in Psychology, ISSN 1664-1078, E-ISSN 1664-1078, Vol. 8, artikkel-id 1820Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Isochrony is crucial to the rhythm of human music. Some neural, behavioral and anatomical traits underlying rhythm perception and production are shared with a broad range of species. These may either have a common evolutionary origin, or have evolved into similar traits under different evolutionary pressures. Other traits underlying rhythm are rare across species, only found in humans and few other animals. Isochrony, or stable periodicity, is common to most human music, but isochronous behaviors are also found in many species. It appears paradoxical that humans are particularly good at producing and perceiving isochronous patterns, although this ability does not conceivably confer any evolutionary advantage to modern humans. This article will attempt to solve this conundrum. To this end, we define the concept of isochrony from the present functional perspective of physiology, cognitive neuroscience, signal processing, and interactive behavior, and review available evidence on isochrony in the signals of humans and other animals. We then attempt to resolve the paradox of isochrony by expanding an evolutionary hypothesis about the function that isochronous behavior may have had in early hominids. Finally, we propose avenues for empirical research to examine this hypothesis and to understand the evolutionary origin of isochrony in general.

  • 1302.
    Razafimandimbison, Sylvain G.
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Botaniska institutionen.
    Kainulainen, Kent
    Stockholms universitet, Naturvetenskapliga fakulteten, Botaniska institutionen.
    Wong, Khoon M.
    Beaver, Katy
    Bremer, Birgitta
    Stockholms universitet, Naturvetenskapliga fakulteten, Botaniska institutionen.
    Molecular support for a basal grade of morphologically distinct, monotypic genera in the species-rich Vanguerieae alliance (Rubiaceae, Ixoroideae): Its systematic and conservation implications2011Inngår i: Taxon, ISSN 0040-0262, E-ISSN 1996-8175, Vol. 60, nr 4, s. 941-952Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Many monotypic genera with unique apomorphic characters have been difficult to place in the morphology-based classifications of the coffee family (Rubiaceae). We rigorously assessed the subfamilial phylogenetic position and generic status of three enigmatic genera, the Seychellois Glionnetia, the Southeast Asian Jackiopsis, and the Chinese Trailliaedoxa within Rubiaceae, using sequence data of four plastid markers (ndhF, rbcL, rps16, trnT-F). The present study provides molecular phylogenetic support for positions of these genera in the subfamily Ixoroideae, and reveals the presence of a basal grade of morphologically distinct, monotypic genera (Crossopteryx,Jackiopsis,Scyphiphora,Trailliaedoxa, and Glionnetia, respectively) in the species-rich Vanguerieae alliance. These five genera may represent sole representatives of their respective lineages and therefore may carry unique genetic information. Their conservation status was assessed, applying the criteria set in IUCN Red List Categories. We consider Glionnetia and Jackiopsis Endangered. Scyphiphora is recognized as Near Threatened despite its extensive range and Crossopteryx as Least Concern. Trailliaedoxa is poorly known (Data Deficient). Finally, the generic status of Glionnetia,Jackiopsis, and Trailliaedoxa and the monogeneric tribe Jackieae as defined by Ridsdale are supported.

  • 1303.
    Reardon, Erin E.
    et al.
    Biology Department Biology Department, McGill University, Montreal, Quebec, Canada.
    Thibert-Plante, Xavier
    Biology Department and Redpath Museum, McGill University, Montreal, Quebec, Canada.
    Optimal offspring size influenced by the interaction between dissolved oxygen and predation pressure2010Inngår i: Evolutionary Ecology Research, ISSN 1522-0613, E-ISSN 1937-3791, Vol. 12, nr 3, s. 377-387Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Question: How does optimal size at the beginning of the juvenile stage vary with dissolved oxygen and aquatic predator pressure?

    Mathematical methods: An implicit model based on earlier offspring size and number optimality models, using empirical observations to motivate and interpret the results.

    Key assumptions: A stable, density-independent system with high parental care that maximizes maternal fitness, with respect to offspring size and number.

    Predictions: The model predicts a positive relationship between juvenile size and aquatic dissolved oxygen, with respect to maternal fitness and predation pressure. This prediction is based on observations in the literature that smaller fish are less sensitive to low dissolved oxygen and may use low dissolved oxygen habitats as predator refuges.

  • 1304. Reber, A
    et al.
    Purcell, J
    Buechel, S D
    Buri, P
    Chapuisat, M
    The expression and impact of antifungal grooming in ants.2011Inngår i: Journal of Evolutionary Biology, ISSN 1010-061X, E-ISSN 1420-9101, Vol. 24, nr 5, s. 954-64Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Parasites can cause extensive damage to animal societies in which many related individuals frequently interact. In response, social animals have evolved diverse individual and collective defences. Here, we measured the expression and efficiency of self-grooming and allo-grooming when workers of the ant Formica selysi were contaminated with spores of the fungal entomopathogen Metarhizium anisopliae. The amount of self-grooming increased in the presence of fungal spores, which shows that the ants are able to detect the risk of infection. In contrast, the amount of allo-grooming did not depend on fungal contamination. Workers groomed all nestmate workers that were re-introduced into their groups. The amount of allo-grooming towards noncontaminated individuals was higher when the group had been previously exposed to the pathogen. Allo-grooming decreased the number of fungal spores on the surface of contaminated workers, but did not prevent infection in the conditions tested (high dose of spores and late allo-grooming). The rate of disease transmission to groomers and other nestmates was extremely low. The systematic allo-grooming of all individuals returning to the colony, be they contaminated or not, is probably a simple but robust prophylactic defence preventing the spread of fungal diseases in insect societies.

  • 1305.
    Reger, Julia
    et al.
    Univ Sheffield, Dept Anim & Plant Sci, Sheffield S10 2TN, S Yorkshire, England..
    Lind, Martin I.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Zooekologi.
    Robinson, Matthew R.
    Univ Lausanne, Dept Computat Biol, CH-1015 Lausanne, Switzerland.;Swiss Inst Bioinformat, CH-1015 Lausanne, Switzerland..
    Beckerman, Andrew P.
    Univ Sheffield, Dept Anim & Plant Sci, Sheffield S10 2TN, S Yorkshire, England..
    Predation drives local adaptation of phenotypic plasticity2018Inngår i: Nature Ecology & Evolution, E-ISSN 2397-334X, Vol. 2, nr 1, s. 100-107Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Phenotypic plasticity is the ability of an individual genotype to alter aspects of its phenotype depending on the current environment. It is central to the persistence, resistance and resilience of populations facing variation in physical or biological factors. Genetic variation in plasticity is pervasive, which suggests its local adaptation is plausible. Existing studies on the adaptation of plasticity typically focus on single traits and a few populations, while theory about interactions among genes (for example, pleiotropy) suggests that a multi-trait, landscape scale (for example, multiple populations) perspective is required. We present data from a landscape scale, replicated, multi-trait experiment using a classic predator-prey system centred on the water flea Daphnia pulex. We find predator regime-driven differences in genetic variation of multivariate plasticity. These differences are associated with strong divergent selection linked to a predation regime. Our findings are evidence for local adaptation of plasticity, suggesting that responses of populations to environmental variation depend on the conditions in which they evolved in the past.

  • 1306.
    Reichenberg, Abraham
    et al.
    Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, USA; Department of Preventive Medicine, Icahn School of Medicine at Mount Sinai, New York, USA.
    Cederlöf, Martin
    Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden.
    McMillan, Andrew
    Medical Research Council Social, Genetic and Developmental Psychiatry Centre, Institute of Psychiatry, Psychology & Neuroscience, King’s College London,London, United Kingdom.
    Trzaskowski, Maciej
    Medical Research Council Social, Genetic and Developmental Psychiatry Centre, Institute of Psychiatry, Psychology & Neuroscience, King’s College London,London, United Kingdom.
    Kapara, Ori
    Department of Psychiatry, Sheba Medical Center, Tel-Hashomer, Ramat Gan, Israel.
    Fruchter, Eyal
    Department of Mental Health, Israel Medical Corps, Tel-Hashomer, Israel .
    Ginat, Karen
    Department of Mental Health, Israel Medical Corps, Tel-Hashomer, Israel .
    Davidson, Michael
    Department of Psychiatry, Sheba Medical Center, Tel-Hashomer, Ramat Gan, Israel.
    Weiser, Mark
    Department of Psychiatry, Sheba Medical Center, Tel-Hashomer, Ramat Gan, Israel; Department of Mental Health, Israel Medical Corps, Tel-Hashomer, Israel .
    Larsson, Henrik
    Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden.
    Plomin, Robert
    Medical Research Council Social, Genetic and Developmental Psychiatry Centre, Institute of Psychiatry, Psychology & Neuroscience, King’s College London,London, United Kingdom.
    Lichtenstein, Paul
    Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden.
    Discontinuity in the genetic and environmental causes of the intellectual disability spectrum2016Inngår i: Proceedings of the National Academy of Sciences of the United States of America, ISSN 0027-8424, E-ISSN 1091-6490, Vol. 113, nr 4, s. 1098-1103Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Intellectual disability (ID) occurs in almost 3% of newborns. Despite substantial research, a fundamental question about its origin and links to intelligence (IQ) still remains. ID has been shown to be inherited and has been accepted as the extreme low of the normal IQ distribution. However, ID displays a complex pattern of inheritance. Previously, noninherited rare mutations were shown to contribute to severe ID risk in individual families, but in the majority of cases causes remain unknown. Common variants associated with ID risk in the population have not been systematically established. Here we evaluate the hypothesis, originally proposed almost 1 century ago, that most ID is caused by the same genetic and environmental influences responsible for the normal distribution of IQ, but that severe ID is not. We studied more than 1,000,000 sibling pairs and 9,000 twin pairs assessed for IQ and for the presence of ID. We evaluated whether genetic and environmental influences at the extremes of the distribution are different from those operating in the normal range. Here we show that factors influencing mild ID (lowest 3% of IQ distribution) were similar to those influencing IQ in the normal range. In contrast, the factors influencing severe ID (lowest 0.5% of IQ distribution) differ from those influencing mild ID or IQ scores in the normal range. Taken together, our results suggest that most severe ID is a distinct condition, qualitatively different from the preponderance of ID, which, in turn, represents the low extreme of the normal distribution of intelligence.

  • 1307.
    Ressayre, Adrienne
    et al.
    INRA, UMR 0320, UMR Genet Quantitat & Evolut Le Moulon 8120, Gif Sur Yvette, France..
    Glemin, Sylvain
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Växtekologi och evolution. Univ Montpellier, CNRS IRD EPHE, UMR 5554, Inst Sci Evolut ISEM, Montpellier, France..
    Montalent, Pierre
    INRA, UMR 0320, UMR Genet Quantitat & Evolut Le Moulon 8120, Gif Sur Yvette, France..
    Serre-Giardi, Laurana
    Ctr Rech Angers Nantes, INRA, UMR IRHS Inst Rech Hort & Semences 1345, Beaucouse, France..
    Dillmann, Christine
    INRA, UMR 0320, UMR Genet Quantitat & Evolut Le Moulon 8120, Gif Sur Yvette, France..
    Joets, Johann
    INRA, UMR 0320, UMR Genet Quantitat & Evolut Le Moulon 8120, Gif Sur Yvette, France..
    Introns Structure Patterns of Variation in Nucleotide Composition in Arabidopsis thaliana and Rice Protein-Coding Genes2015Inngår i: Genome Biology and Evolution, ISSN 1759-6653, E-ISSN 1759-6653, Vol. 7, nr 10, s. 2913-2928Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Plant genomes present a continuous range of variation in nucleotide composition (G+C content). In coding regions, G+C-poor species tend to have unimodal distributions of G+C content among genes within genomes and slight 50-30 gradients along genes. In contrast, G+C-rich species display bimodal distributions of G+C content among genes and steep 50-30 decreasing gradients along genes. The causes of these peculiar patterns are still poorly understood. Within two species (Arabidopsis thaliana and rice), each representative of one side of the continuum, we studied the consequences of intron presence on coding region and intron G+C content at different scales. By properly taking intron structure into account, we showed that, in both species, intron presence is associated with step changes in nucleotide, codon, and amino acid composition. This suggests that introns have a barrier effect structuring G+C content along genes and that previous continuous characterizations of the 50-30 gradients were artifactual. In external gene regions (located upstream first or downstream last introns), species-specific factors, such as GC-biased gene conversion, are shaping G+C contentwhereas in internal gene regions (surrounded by introns), G+C content is likely constrained to remain within a range common to both species.

  • 1308.
    Rest, Joshua S
    et al.
    University of Michigan, Museum of Zoology and Department of Ecology and Evolutionary Biology.
    Ast, Jennifer C
    University of Michigan, Museum of Zoology and Department of Ecology and Evolutionary Biology.
    Austin, Christopher C
    Waddell, Peter J
    Tibbetts, Elizabeth A
    University of Michigan, Museum of Zoology and Department of Ecology and Evolutionary Biology.
    Hay, Jennifer M
    Mindell, David P
    University of Michigan, Museum of Zoology and Department of Ecology and Evolutionary Biology.
    Molecular systematics of primary reptilian lineages and the tuatara mitochondrial genome.2003Inngår i: Molecular Phylogenetics and Evolution, ISSN 1055-7903, E-ISSN 1095-9513, Vol. 29, nr 2, s. 289-97Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We provide phylogenetic analyses for primary Reptilia lineages including, for the first time, Sphenodon punctatus (tuatara) using data from whole mitochondrial genomes. Our analyses firmly support a sister relationship between Sphenodon and Squamata, which includes lizards and snakes. Using Sphenodon as an outgroup for select squamates, we found evidence indicating a sister relationship, among our study taxa, between Serpentes (represented by Dinodon) and Varanidae. Our analyses support monophyly of Archosauria, and a sister relationship between turtles and archosaurs. This latter relationship is congruent with a growing set of morphological and molecular analyses placing turtles within crown Diapsida and recognizing them as secondarily anapsid (lacking a skull fenestration). Inclusion of Sphenodon, as the only surviving member of Sphenodontia (with fossils from the mid-Triassic), helps to fill a sampling gap within previous analyses of reptilian phylogeny. We also report a unique configuration for the mitochondrial genome of Sphenodon, including two tRNA(Lys) copies and an absence of ND5, tRNA(His), and tRNA(Thr) genes.

  • 1309.
    Rettelbach, Agnes
    et al.
    University of Vienna.
    Kopp, Michael
    University of Vienna.
    Dieckmann, Ulf
    IIASA.
    Hermisson, Joachim
    University of Vienna.
    Effects of genetic architecture on the evolution of assortative mating under frequency-dependent disruptive selection2011Inngår i: Theoretical Population Biology, ISSN 0040-5809, E-ISSN 1096-0325, nr 79, s. 82-96Artikkel i tidsskrift (Fagfellevurdert)
  • 1310.
    Rettelbach, Agnes
    et al.
    University of Vienna.
    Kopp, Michael
    University of Vienna.
    Dieckmann, Ulf
    IIASA.
    Hermisson, Joachim
    University of Vienna.
    Three Modes of Adaptive Speciation in Spatially Structured Populations.2013Inngår i: American Naturalist, ISSN 0003-0147, E-ISSN 1537-5323, nr 182, s. E215-E234Artikkel i tidsskrift (Fagfellevurdert)
  • 1311.
    Rettelbach, Agnes
    et al.
    Univ Vienna, Dept Math, Vienna, Austria.
    Servedio, Maria
    Univ N Carolina, Dept Biol, Chapel Hill, NC USA.
    Hermisson, Joachim
    Univ Vienna, Dept Math, Vienna, Austria.; Univ Vienna, Max Perutz Labs, Vienna, Austria.
    Speciation in peripheral populations: effects of drift load and mating systems2016Inngår i: Journal of Evolutionary Biology, ISSN 1010-061X, E-ISSN 1420-9101, Vol. 29, nr 5, s. 1073-1090Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Speciation in peripheral populations has long been considered one of the most plausible scenarios for speciation with gene flow. In this study, however we identify two additional problems of peripatric speciation, as compared to the parapatric case, that may impede the completion of the speciation process for most parameter regions. First, with (predominantly) unidirectional gene flow, there is no selection pressure to evolve assortative mating on the continent. We discuss the implications of this for different mating schemes. Second, genetic load can build up in small populations. This can lead to extinction of the peripheral species, or generate selection pressure for lower assortative mating to avoid inbreeding. In this case, either a stable equilibrium with intermediate assortment evolves or there is cycling between phases of hybridization and phases of complete isolation.

  • 1312.
    Ribeiro, Luis
    et al.
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Industriell Produktion. Linköpings universitet, Tekniska fakulteten.
    Hochwallner, Martin
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Industriell Produktion. Linköpings universitet, Tekniska fakulteten.
    On the Design Complexity of Cyberphysical Production Systems2018Inngår i: Complexity, ISSN 1076-2787, E-ISSN 1099-0526, artikkel-id 4632195Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Establishing mass-customization practices, in a sustainable way, at a time of increased market uncertainty, is a pressing challenge for modern producing companies and one that traditional automation solutions cannot cope with. Industry 4.0 seeks to mitigate current practices limitations. It promotes a vision of a fully interconnected ecosystem of systems, machines, products, and many different stakeholders. In this environment, dynamically interconnected autonomous systems support humans in multifaceted decision-making. Industrial Internet of Things and cyberphysical systems (CPSs) are just two of the emerging concepts that embody the design and behavioral principles of these highly complex technical systems. The research within multiagent systems in manufacturing, by embodying most of the defining principles of industrial CPSs (ICPSs), is often regarded as a precursor for many of todays emerging ICPS architectures. However, the domain has been fuzzy in specifying clear-cut design objectives and rules. Designs have been proposed with different positioning, creating confusion in concepts and supporting technologies. This paper contributes by providing clear definitions and interpretations of the main functional traits spread across the literature. A characterization of the defining functional requirements of ICPSs follows, in the form of a scale, rating systems according to the degree of implementation of the different functions.

  • 1313.
    Ribeiro, Maria Margarida
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Växtekologi och evolution. Inst Politecn Castelo Branco, Escola Super Agr, Dept Recursos Nat & Desenvolvimento Sustentavel, Castelo Branco, Portugal.;Univ Lisbon, Sch Agr, Forest Res Ctr, Lisbon, Portugal..
    Piotti, Andrea
    CNR, Inst Biosci & BioResources, Via Madonna del Piano 10, Florence, Italy..
    Ricardo, Alexandra
    Inst Politecn Castelo Branco, Escola Super Agr, Dept Recursos Nat & Desenvolvimento Sustentavel, Castelo Branco, Portugal..
    Gaspar, Daniel
    Inst Nacl Invest Agr Vet IP, INIAV, Av Republ, Quinta Do Marques Oeiras, Portugal..
    Costa, Rita
    Univ Lisbon, Sch Agr, Forest Res Ctr, Lisbon, Portugal.;Inst Nacl Invest Agr Vet IP, INIAV, Av Republ, Quinta Do Marques Oeiras, Portugal..
    Parducci, Laura
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Växtekologi och evolution.
    Vendramin, Giovanni Giuseppe
    CNR, Inst Biosci & BioResources, Via Madonna del Piano 10, Florence, Italy..
    Genetic diversity and divergence at the Arbutus unedo L. (Ericaceae) westernmost distribution limit2017Inngår i: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 12, nr 4, artikkel-id e0175239Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Mediterranean forests are fragile ecosystems vulnerable to recent global warming and reduction of precipitation, and a long-term negative effect is expected on vegetation with increasing drought and in areas burnt by fires. We investigated the spatial distribution of genetic variation of Arbutus unedo in the western Iberia Peninsula, using plastid markers with conservation and provenance regions design purposes. This species is currently undergoing an intense domestication process in the region, and, like other species, is increasingly under the threat from climate change, habitat fragmentation and wildfires. We sampled 451 trees from 15 natural populations from different ecological conditions spanning the whole species' distribution range in the region. We applied Bayesian analysis and identified four clusters ( north, centre, south, and a single-population cluster). Hierarchical AMOVA showed higher differentiation among clusters than among populations within clusters. The relatively low within-clusters differentiation can be explained by a common postglacial history of nearby populations. The genetic structure found, supported by the few available palaeobotanical records, cannot exclude the hypothesis of two independent A. unedo refugia in western Iberia Peninsula during the Last Glacial Maximum. Based on the results we recommend a conservation strategy by selecting populations for conservation based on their allelic richness and diversity and careful seed transfer consistent with current species' genetic structure.

  • 1314. Ricci, Marco
    et al.
    Peona, Valentina
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Evolutionsbiologi. University of Bologna.
    Guichard, Etienne
    Taccioli, Cristian
    Boattini, Alessio
    Transposable Elements Activity is Positively Related to Rate of Speciation in Mammals2018Inngår i: Journal of Molecular Evolution, ISSN 0022-2844, E-ISSN 1432-1432, Vol. 86, nr 5, s. 303-310Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Transposable elements (TEs) play an essential role in shaping eukaryotic genomes and generating variability. Speciation and TE activity bursts could be strongly related in mammals, in which simple gradualistic models of differentiation do not account for the currently observed species variability. In order to test this hypothesis, we designed two parameters: the Density of insertion (DI) and the Relative rate of speciation (RRS). DI is the ratio between the number of TE insertions in a genome and its size, whereas the RRS is a conditional parameter designed to identify potential speciation bursts. Thus, by analyzing TE insertions in mammals, we defined the genomes as "hot" (high DI) and "cold" (low DI). Then, comparing TE activity among 29 taxonomical families of the whole Mammalia class, 16 intra-order pairs of mammalian species, and four superorders of Eutheria, we showed that taxa with high rates of speciation are associated with "hot" genomes, whereas taxa with low ones are associated with "cold" genomes. These results suggest a remarkable correlation between TE activity and speciation, also being consistent with patterns describing variable rates of differentiation and accounting for the different time frames of the speciation bursts.

  • 1315.
    Rice, William
    et al.
    Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara.
    Linder, Jodell
    Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara.
    Friberg, Urban
    Umeå universitet, Institutionen för ekologi, miljö och geovetenskap.
    Lew, Timothy
    Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara.
    Morrow, Edward
    Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara.
    Stewart, Andrew
    Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara.
    Inter-locus antagonistic coevolution as an engine of speciation: assessment with hemiclonal analysis2005Inngår i: Proceedings of the National Academy of Sciences of the United States of America, ISSN 0027-8424, E-ISSN 1091-6490, Vol. 102, nr Suppl. 1, s. 6527-6534Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    One of Ernst Mayr's legacies is the consensus that the allopatry model is the predominant mode of speciation in most sexually reproducing lineages. In this model, reproductive isolation develops as a pleiotropic byproduct of the genetic divergence that develops among physically isolated populations. Presently, there is no consensus concerning which, if any, evolutionary process is primarily responsible for driving the specific genetic divergence that leads to reproductive isolation. Here, we focus on the hypothesis that inter-locus antagonistic coevolution drives rapid genetic divergence among allopatric populations and thereby acts as an important “engine” of speciation. We assert that only data from studies of experimental evolution, rather than descriptive patterns of molecular evolution, can provide definitive evidence for this hypothesis. We describe and use an experimental approach, called hemiclonal analysis, that can be used in theDrosophila melanogaster laboratory model system to simultaneously screen nearly the entire genome for both standing genetic variation within a population and the net-selection gradient acting on the variation. Hemiclonal analysis has four stages: (i) creation of a laboratory “island population”; (ii) cytogenetic cloning of nearly genome-wide haplotypes to construct hemiclones; (iii) measurement of additive genetic variation among hemiclones; and (iv) measurement of the selection gradient acting on phenotypic variation among hemiclones. We apply hemiclonal analysis to test the hypothesis that there is ongoing antagonistic coevolution between the sexes in the D. melanogaster laboratory model system and then discuss the relevance of this analysis to natural systems.

  • 1316.
    Rice, William R.
    et al.
    Department of Ecology, Evolution and Marine Biology, University of California, 93106-9610, Santa Barbara, CA, USA.
    Friberg, Urban
    Department of Ecology, Evolution and Marine Biology, University of California, 93106-9610, Santa Barbara, CA, USA.
    A Graphical Approach to Lineage Selection Between Clonals and Sexuals2009Inngår i: Lost Sex: The Evolutionary Biology of Parthenogenesis / [ed] Isa Schön, Koen Martens and Peter Dijk, Springer Netherlands, 2009, s. 75-97Kapittel i bok, del av antologi (Fagfellevurdert)
    Abstract [en]

    Theories for the evolutionary advantages and disadvantages of sex address two fundamentally different questions: (i) Why does the genome of sexual lineages not “congeal,” (i.e., move toward a lowered recombination rate)?, and (ii) When there is a mixture of reproductively isolated clonal and sexual lineages, why do the clonals not accumulate and lead to a predominance of asexual reproduction within a clade? Here, we focus on the latter question. The relevant theory in this case is necessarily based on a special form of “lineage” selection between sexuals and clonals that do not share a common gene pool. We first briefly review the major genetic costs and benefits of clonal reproduction and conclude that the extant assemblage of theories provides an essentially complete description of the phenomenon. We next set out to combine and simplify these seemingly disparate theories by graphically representing the frameworks previously developed by Felsenstein (Genetics 78: 737–756, 1974) and Kimura and Maruyama (Genetics 54: 1337–1351, 1966) to show that the all of the proposed disadvantages to clonal reproduction can be expressed by a single factor: a decreased efficiency of natural selection in non-recombining lineages. This reduced efficiency derives from two distinct processes that only operate in clonal lineages: (i) background-trapping and (ii) the compensatory linkage disequilibrium that accrues in response to epistatic selection.

  • 1317.
    Rice, William R
    et al.
    Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, CA 93106, USA.
    Friberg, Urban
    Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, CA 93106, USA.
    Genomic clues to an ancient asexual scandal.2007Inngår i: Genome Biology, ISSN 1465-6906, E-ISSN 1474-760X, Vol. 8, nr 12, artikkel-id 232Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Despite abandoning meiosis, the bdelloid rotifers have persisted for millions of years and given rise to hundreds of species. Several mechanisms - allelic variants with different functions, high effective population size, and resistance to radiation - may contribute to their success.

    Bdelloid rotifers are diploid aquatic microinvertebrates that live in fresh or brackish water, especially in ephemeral habitats prone to periodic desiccation. They are the only well documented lineage that has eliminated meiosis yet has persisted for many millions of years (more than 35 million years [1]) and undergone an adaptive radiation - nearly 400 species in three families. Maynard Smith [2] referred to them as an "evolutionary scandal" because they are the exception to the usual pattern that asexual lineages die out before undergoing extensive speciation.

    The fact that asexuals are composed entirely of offspring-producing females gives them an intrinsic demographic advantage over sexual competitors whenever males do not help to produce offspring (referred to as the 'two-fold cost of sex' or the 'cost of producing males'). Evolutionary theory predicts, however, that obligate asexuals have a long-term evolutionary disadvantage, compared with sexuals, owing to a more pronounced 'Hill-Robertson effect', a reduction in the efficacy of natural selection that occurs because finite populations accumulate associations of linked genes (haplotypes) that interfere with selection [3, 4] (Figure 1).

    Figure 1

    The effect of genetic linkage on the effectiveness of selection. Consider two closely linked single nucleotide polymorphisms (SNPs A and B) with one of the 'alleles' at each site favored by selection (denoted by a superscript +). Selection acts more weakly on the 'interfering' haplotypes (A+B- and A-B+), where positive selection on one SNP is counterbalanced by negative selection on the other, compared with the 'reinforcing' haplotypes (A+B+ and A-B-), where selection on the two SNPs is complementary. This disparity causes interfering haplotypes to persist longer after they have accumulated by chance in finite populations. See Box 1 for further details.

    The Hill-Robertson effect arises when selection acts simultaneously at multiple linked sites (Figure 1). In this case, the fate of a mutation depends not only on its own selective value but also on that of its genetic backgrounds. Selection on genetic backgrounds introduces 'noise', which makes selection on a mutation less efficient. A similar interaction occurs between selection and random genetic drift, with smaller population sizes increasing the noise generated by drift. The cost of the Hill-Robertson effect in asexuals can be expressed as a reduced effective population size (N e , the size of an idealized, random-mating population with only chance fluctuations in family sizes) compared with the actual population size (census size, N; see Box 1 for further details). Because the strength of the Hill-Robertson effect increases with tighter linkage, non-meiotic species like bdelloid rotifers, in which 'interfering' haplotypes cannot be routinely broken up, should have a much reduced N e compared with their sexual competitors with similar census sizes, and should hence experience less effective selection. All else being equal, the bdelloids' ability to compete with sexuals should erode over time, leading to their eventual extinction. This has not happened, so the bdelloids must have one or more compensating advantages. Several recent studies indicate how bdelloids may have achieved their "scandalous" status.

  • 1318.
    Rice, William R.
    et al.
    Department of Ecology, Evolution & Marine Biology, University of California, Santa Barbara, CA, USA.
    Friberg, Urban
    Department of Evolutionary Biology, Uppsala University, Uppsala, Sweden.
    Gavrilets, Sergey
    Department of Ecology and Evolutionary Biology, Department of Mathematics, National Institute for Mathematical and Biological Synthesis (NIMBioS), University of Tennessee, Knoxville, TN, USA.
    Homosexuality via canalized sexual development: A testing protocol for a new epigenetic model2013Inngår i: Bioessays, ISSN 0265-9247, E-ISSN 1521-1878, Vol. 35, nr 9, s. 764-770Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We recently synthesized and reinterpreted published studies to advance an epigenetic model for the development of homosexuality (HS). The model is based on epigenetic marks laid down in response to the XX vs. XY karyotype in embryonic stem cells. These marks boost sensitivity to testosterone in XY fetuses and lower it in XX fetuses, thereby canalizing sexual development. Our model predicts that a subset of these canalizing epigenetic marks stochastically carry over across generations and lead to mosaicism for sexual development in opposite-sex offspring - the homosexual phenotype being one such outcome. Here, we begin by outlining why HS has been under-appreciated as a commonplace phenomenon in nature, and how this trend is currently being reversed in the field of neurobiology. We next briefly describe our epigenetic model of HS, develop a set of predictions, and describe how epigenetic profiles of human stem cells can provide for a strong test of the model.

  • 1319.
    Richter-Boix, Alex
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Populationsbiologi och naturvårdsbiologi.
    Tejedo, Miguel
    Rezende, Enrico L.
    Evolution and plasticity of anuran larval development in response to desiccation: A comparative analysis2011Inngår i: Ecology and Evolution, ISSN 2045-7758, E-ISSN 2045-7758, Vol. 1, nr 1, s. 15-25Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Anurans breed in a variety of aquatic habitats with contrasting levels of desiccation risk, which may result in selection for faster development during larval stages. Previous studies suggest that species in ephemeral ponds reduce their developmental times to minimize desiccation risks, although it is not clear how variation in desiccation risk affects developmental strategies in different species. Employing a comparative phylogenetic approach including data from published and unpublished studies encompassing 62 observations across 30 species, we tested if species breeding in ephemeral ponds (High risk) develop faster than those from permanent ponds (Low risk) and/or show increased developmental plasticity in response to drying conditions. Our analyses support shorter developmental times in High risk, primarily by decreasing body mass at metamorphosis. Plasticity in developmental times was small and did not differ between groups. However, accelerated development in High risk species generally resulted in reduced sizes at metamorphosis, while some Low risk species were able compensate this effect by increasing mean growth rates. Taken together, our results suggest that plastic responses in species breeding in ephemeral ponds are constrained by a general trade-off between development and growth rates.

  • 1320. Ritchie, Euan G.
    et al.
    Elmhagen, Bodil
    Stockholms universitet, Naturvetenskapliga fakulteten, Zoologiska institutionen.
    Glen, Alistair S.
    Letnic, Mike
    Ludwig, Gilbert
    McDonald, Robbie A.
    Ecosystem restoration with teeth: what role for predators?2012Inngår i: Trends in Ecology & Evolution, ISSN 0169-5347, E-ISSN 1872-8383, Vol. 27, nr 5, s. 265-271Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Recent advances highlight the potential for predators to restore ecosystems and confer resilience against globally threatening processes, including climate change and biological invasions. However, releasing the ecological benefits of predators entails significant challenges. Here, we discuss the economic, environmental and social considerations affecting predator-driven ecological restoration programmes, and suggest approaches for reducing the undesirable impacts of predators. Because the roles of predators are context dependent, we argue for increased emphasis on predator functionality in ecosystems and less on the identities and origins of species and genotypes. We emphasise that insufficient attention is currently given to the importance of variation in the social structures and behaviours of predators in influencing the dynamics of trophic interactions. Lastly, we outline experiments specifically designed to clarify the ecological roles of predators and their potential utility in ecosystem restoration.

  • 1321.
    Rojas, Danny
    et al.
    Univ Aveiro, Dept Biol, P-3810193 Aveiro, Portugal.;Univ Aveiro, Ctr Environm & Marine Studies, P-3810193 Aveiro, Portugal.;SUNY Stony Brook, Dept Ecol & Evolut, 650 Life Sci Bldg, Stony Brook, NY 11794 USA..
    Warsi, Omar M.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för medicinsk biokemi och mikrobiologi. SUNY Stony Brook, Dept Ecol & Evolut, 650 Life Sci Bldg, Stony Brook, NY 11794 USA..
    Davalos, Liliana M.
    SUNY Stony Brook, Dept Ecol & Evolut, 650 Life Sci Bldg, Stony Brook, NY 11794 USA.;SUNY Stony Brook, Sch Marine & Atmospher Sci, Consortium Interdisciplinary Environm Res, 129 Dana Hall, Stony Brook, NY 11794 USA..
    Bats (Chiroptera:Noctilionoidea) Challenge a Recent Origin of Extant Neotropical Diversity2016Inngår i: Systematic Biology, ISSN 1063-5157, E-ISSN 1076-836X, Vol. 65, nr 3, s. 432-448Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The mechanisms underlying the high extant biodiversity in the Neotropics have been controversial since the 19th century. Support for the influence of period-specific changes on diversification often rests on detecting more speciation events during a particular period. The timing of speciation events may reflect the influence of incomplete taxon sampling, protracted speciation, and null processes of lineage accumulation. Here we assess the influence of these factors on the timing of speciation with new multilocus data for New World noctilionoid bats (Chiroptera: Noctilionoidea). Biogeographic analyses revealed the importance of the Neotropics in noctilionoid diversification, and the critical role of dispersal. We detected no shift in speciation rate associated with the Quaternary or pre-Quaternary periods, and instead found an increase in speciation linked to the evolution of the subfamily Stenodermatinae (similar to 18 Ma). Simulations modeling constant speciation and extinction rates for the phylogeny systematically showed more speciation events in the Quaternary. Since recording more divergence events in the Quaternary can result from lineage accumulation, the age of extant sister species cannot be interpreted as supporting higher speciation rates during this period. Instead, analyzing the factors that influence speciation requires modeling lineage-specific traits and environmental, spatial, and ecological drivers of speciation.

  • 1322.
    Ronquist, Fredrik
    et al.
    Naturhistoriska riksmuseet, Enheten för bioinformatik och genetik.
    Lartillot, Nicolas
    Phillips, Matthew J.
    Closing the gap between rocks and clocks using total-evidence dating2016Inngår i: Philosophical Transactions of the Royal Society of London. Biological Sciences, ISSN 0962-8436, E-ISSN 1471-2970, Vol. 371, artikkel-id 20150136Artikkel i tidsskrift (Fagfellevurdert)
  • 1323. Ronquist, Fredrik
    et al.
    Teslenko, Maxim
    van der Mark, Paul
    Ayres, Daniel L.
    Darling, Aaron
    Höhna, Sebastian
    Stockholms universitet, Naturvetenskapliga fakulteten, Matematiska institutionen.
    Larget, Bret
    Liu, Liang
    Suchard, Marc A.
    Huelsenbeck, John P.
    MrBayes 3.2: Efficient Bayesian Phylogenetic Inference and Model Choice Across a Large Model Space2012Inngår i: Systematic Biology, ISSN 1063-5157, E-ISSN 1076-836X, Vol. 61, nr 3, s. 539-542Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Since its introduction in 2001, MrBayes has grown in popularity as a software package for Bayesian phylogenetic inference using Markov chain Monte Carlo (MCMC) methods. With this note, we announce the release of version 3.2, a major upgrade to the latest official release presented in 2003. The new version provides convergence diagnostics and allows multiple analyses to be run in parallel with convergence progress monitored on the fly. The introduction of new proposals and automatic optimization of tuning parameters has improved convergence for many problems. The new version also sports significantly faster likelihood calculations through streaming single-instruction-multiple-data extensions (SSE) and support of the BEAGLE library, allowing likelihood calculations to be delegated to graphics processing units (GPUs) on compatible hardware. Speedup factors range from around 2 with SSE code to more than 50 with BEAGLE for codon problems. Checkpointing across all models allows long runs to be completed even when an analysis is prematurely terminated. New models include relaxed clocks, dating, model averaging across time-reversible substitution models, and support for hard, negative, and partial (backbone) tree constraints. Inference of species trees from gene trees is supported by full incorporation of the Bayesian estimation of species trees (BEST) algorithms. Marginal model likelihoods for Bayes factor tests can be estimated accurately across the entire model space using the stepping stone method. The new version provides more output options than previously, including samples of ancestral states, site rates, site d(N)/d(S) rations, branch rates, and node dates. A wide range of statistics on tree parameters can also be output for visualization in FigTree and compatible software.

  • 1324.
    Roufidou, Chrysoula
    et al.
    Stockholm Univ, Dept Zool, SE-10691 Stockholm, Sweden..
    Sebire, Marion
    Ctr Environm Fisheries & Aquaculture Sci Cefas, Weymouth, England..
    Katsiadaki, Ioanna
    Ctr Environm Fisheries & Aquaculture Sci Cefas, Weymouth, England..
    Mustafa, Arshi
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för organismbiologi. Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för neurovetenskap, Fysiologi.
    Schmitz, Monika
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för organismbiologi.
    Mayer, Ian
    Norwegian Univ Life Sci, Fac Vet Med & Biosci, Oslo, Norway..
    Shao, Yi Ta
    Natl Taiwan Ocean Univ, Inst Marine Biol, Keelung, Taiwan..
    Borg, Bertil
    Stockholm Univ, Dept Zool, SE-10691 Stockholm, Sweden..
    Overripening of eggs and changes in reproductive hormones in the threespine stickleback, Gasterosteus aculeatus2016Inngår i: Evolutionary Ecology Research, ISSN 1522-0613, E-ISSN 1937-3791, Vol. 17, nr 3, s. 583-601Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Background: Female threespine sticklebacks, Gasterosteus aculeatus, are batch spawners. As in most teleosts, the ovulated eggs are kept in the ovarian cavity until spawning. If spawning or spontaneous release of the eggs does not take place, they can become overripe and harden, and in most cases remain in the ovary. The overripe eggs are lost for reproduction and also block further spawnings. Reproductive hormones regulate egg production and may be involved in the mechanism of overripening. Question: What are the reproductive endocrinological parameters characterizing overripening of ovulated eggs in the threespine stickleback? Organism: Wild-caught adult threespine sticklebacks from the southern Baltic at Skare in southern Sweden and the island of Asko in northwestern Baltic Proper in Sweden. Experiments: We collected blood samples for hormone measurements, as well as pituitaries and brains for measurement of mRNA from both sexually mature non-overripe (non-ovulated and/or ovulated) and overripe (egg-bound) females. For the Skare fish, sexual maturation was induced under laboratory conditions by exposure to a long photoperiod and we compared the non-overripe (including non-ovulated, with oocytes in different maturing or ripening stages, and ovulated females) with the overripe females. The Asko fish were sampled directly from nature, during the natural summer breeding season and we compared the non-overripe (including non-ovulated, with oocytes in different maturing or ripening stages, and ovulated females) with the overripe females. Methods: In the fish collected from Skare, we used radioimmunoassay to measure the plasma levels of four steroids: testosterone, estradiol, 17,20 beta-dihydroxypregn-4-en-3-one (17,20 beta-P), and 17,20 beta, 21-trihydroxypregn-4-en-3-one (17,20 beta,21-P). We also measured the mRNA levels of gonadotropins [GTHs: follicle-stimulating hormone (fsh-beta) and luteinizing hormone (lh-beta)] in the pituitary, and of gonadotropin-releasing hormones (GnRHs: gnrh2, gnrh3) and kisspeptin (kiss2) and its G protein-coupled receptor (gpr54) in the brain by real-time quantitative PCR. In the fish collected from Asko, we measured only progestogens (17,20 beta-P and 17,20 beta,21-P). Results: In the fish from Skare, overripe female sticklebacks had significantly lower levels of circulating plasma steroid hormones (testosterone, estradiol, 17,20 beta-P), as well as of pituitary lh-beta and brain kiss2 and gpr54 mRNA than the non-overripe females. In the fish caught from Asko, overripe females had lower 17,20 beta-P levels than the non-overripe non-ovulated females, but there was no difference between the non-overripe ovulated and the overripe females. The 17,20 beta,21-P plasma levels were under the limit of detection in all groups.

  • 1325. Roulin, Alexandre
    et al.
    Antoniazza, S
    Burri, Reto
    Department of Ecology and Evolution, University of Lausanne, Lausanne.
    Spatial variation in the temporal change of male and female melanic ornamentation in the barn owl2011Inngår i: Journal of Evolutionary Biology, ISSN 1010-061X, E-ISSN 1420-9101, Vol. 24, nr 7, s. 1403-14099Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Because the magnitude of selection can vary between sexes and in space and time, sexually antagonistic selection is difficult to demonstrate. In a Swiss population of barn owls (Tyto alba), a heritable eumelanic colour trait (size of black spots on ventral feathers) was positively selected with respect to yearling survival only in females. It remains unclear whether the absence of negative selection in males is typical in this species. To tackle this issue indirectly, we measured the size of black spots in 1733 skin specimens collected by museums from 1816 to 2001 in seven European countries and in the Middle-East. The temporal change in spot size was sex- and country-specific. In males, spots became smaller particularly in three countries (Middle-East, Italy and Switzerland). In females, the size of spots increased significantly in two countries (UK and Spain) and decreased in two others (Germany and Switzerland). Because migration and phenotypic plasticity cannot explain these results, selection is the most likely cause. The weaker temporal change in spot size in females than males may be because of the combined effect of strong genetic correlation between the sexes and stronger negative selection in males than positive selection in females. We thus suggest that in the barn owl, spot size (or genetically correlated traits) is sexually antagonistically selected and that its pattern of selection may account for the maintenance of its variation and sexual dimorphism.

  • 1326.
    Roulin, Alexandre
    et al.
    Department of Ecology and Evolution, Biophore, University of Lausanne.
    Burri, Reto
    Department of Ecology and Evolution, Biophore, University of Lausanne.
    Antoniazza, Sylvain
    Department of Ecology and Evolution, Biophore, University of Lausanne.
    Owl melanin-based plumage redness is more frequent near than away from the equator: implications on the effect of climate change on biodiversity2011Inngår i: Biological Journal of the Linnean Society, ISSN 0024-4066, E-ISSN 1095-8312, Vol. 102, nr 3, s. 573-582Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Climate change acts as a major new selective agent on many organisms, particularly at high latitudes where climate change is more pronounced than at lower latitudes. Studies are required to predict which species are at a high risk of extinction and whether certain phenotypes may be more affected by climate change than others. The identification of susceptible phenotypes is important for evaluating the potential negative effect of climate change on biodiversity at the inter- and intraspecific levels. Melanin-based coloration is an interesting and easily accessible candidate trait because, within certain species, reddish pheomelanin-based coloration is associated with adaptations to warm climates. However, it is unclear whether the same holds among species. We tested one prediction of this hypothesis in four owl genera (wood, scops, screech, and pygmy owls), namely that darker reddish species are more prevalent near the equator than polewards. Our comparative analysis is consistent with this prediction for the northern hemisphere, suggesting that pale reddish species may be adapted to cold climates and dark reddish species to warmer climates. Thus, climate change may have a larger negative impact on pale pheomelanic owls and favour dark pheomelanic species.

  • 1327. Rowe, L
    et al.
    Arnqvist, Göran
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Zooekologi.
    Sexually antagonistic coevolution in a mating system: Combining experimental and comparative approaches to address evolutionary processes2002Inngår i: Evolution, ISSN 0014-3820, E-ISSN 1558-5646, Vol. 56, nr 4, s. 754-767Artikkel i tidsskrift (Fagfellevurdert)
  • 1328. Roy, Justin
    et al.
    Arandjelovic, Mimi
    Bradley, Brenda J.
    Guschanski, Katerina
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Zooekologi. Max Planck Inst Evolutionary Anthropol, Dept Primatol, Leipzig, Germany.
    Stephens, Colleen R.
    Bucknell, Dan
    Cirhuza, Henry
    Kusamba, Chifundera
    Kyungu, Jean Claude
    Smith, Vince
    Robbins, Martha M.
    Vigilant, Linda
    Recent divergences and size decreases of eastern gorilla populations2014Inngår i: Biology Letters, ISSN 1744-9561, E-ISSN 1744-957X, Vol. 10, nr 11, artikkel-id 20140811Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Compared with other African apes, eastern gorillas (Gorilla beringei) have been little studied genetically. We used analysis of autosomal DNA genotypes obtained from non-invasively collected faecal samples to estimate the evolutionary histories of the two extant mountain gorilla populations and the closely related eastern lowland gorillas. Our results suggest that eastern lowland gorillas and mountain gorillas split beginning some 10 000 years ago, followed 5000 years ago by the split of the two mountain gorilla populations of Bwindi Impenetrable National Park and the Virungas Massif. All three populations have decreased in effective population size, with particularly substantial 10- fold decreases for the mountain gorillas. These dynamics probably reflect responses to habitat changes resulting from climate fluctuations over the past 20 000 years as well as increasing human influence in this densely populated region in the last several thousand years.

  • 1329.
    Rudh, Andreas
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Zooekologi.
    Aposematism, Crypsis and Population Differentiation in the Strawberry Poison Frog2012Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Evolutionary transitions between the two major predator avoidance strategies aposematism and crypsis are expected to be associated with changes in many important traits of animals. However, empirical studies on populations experiencing ongoing or recent transitions between these strategies are rare. This thesis investigates the co-evolution of traits among populations of the Strawberry poison frog D.pumilio in Bocas del Toro, Panama. I found that all investigated populations were genetically distinct but that colour and pattern did not correlate with genetic or geographic distance, which suggests that selection needs to be invoked to explain the observed variation. Based on the chromatic contrast between frog dorsal colour and the natural habitat substrates used by the frogs, the populations were defined as bright or dull coloured. I found that frogs from bright coloured populations were larger. This is expected if aposematism is enhanced by large signals while crypsis is enhanced by small size. Further, individuals from bright coloured populations had a coarser black dorsal pattern, which is expected if crypsis is impaired by a bold pattern. The importance of pattern coarseness was confirmed by an avian detection experiment showing that coarse patterned dark green prey were more easily detected than dark green prey without pattern or with fine pattern. I put forward the hypothesis that enhanced protection, gained by aposematism, may affect behaviours that influence dispersal and pairing patterns. Indeed, males from bright coloured populations displayed at more exposed sites and showed a tendency to be more explorative and aggressive. In summary, my results show that the bright and dull coloured populations most likely represent an aposematic and a cryptic strategy, respectively. Furthermore, I show that evolutionary changes between aposematism and crypsis can be associated with coevolution of both morphology and behaviour. I argue that this coevolution may increase the likelihood of both pre- and post-zygotic reproductive isolation. This is because greater phenotypic differences between populations increase the likelihood of selection against badly adapted migrants and hybrids with intermediate traits.

  • 1330.
    Rudh, Andreas
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Zooekologi.
    Loss of conspicuous colouration has co-evolved with decreasing body size in populations of a poison dart frogManuskript (preprint) (Annet vitenskapelig)
  • 1331.
    Rudh, Andreas
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Zooekologi.
    Breed, Martin F.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Växtekologi och evolution.
    Qvarnström, Anna
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Zooekologi.
    Does aggression and explorative behaviour decrease with lost warning colouration?2013Inngår i: Biological Journal of the Linnean Society, ISSN 0024-4066, E-ISSN 1095-8312, Vol. 108, nr 1, s. 116-126Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    For prey, many behavioural traits are constrained by the risk of predation. Therefore, shifts between warning and cryptic coloration have been suggested to result in parallel changes in several behaviours. In the present study, we tested whether changes in chromatic contrast among eight populations of the strawberry poison-dart frog, Dendrobates pumilio, co-vary with behaviour, as expected if selection is imposed by predators relying on visual detection of prey. These eight populations are geographically isolated on different island in the Bocas del Toro region of Panama and have recently diverged morphologically and genetically. We found that aggression and explorative behaviour were strongly correlated and also that males tended to be more aggressive and explorative if they belonged to populations with conspicuously coloured individuals. We discuss how evolutionary switches between predator avoidance strategies and associated behavioural divergence between populations may affect reproductive isolation.

  • 1332.
    Rudh, Andreas
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Zooekologi.
    Edström, Torkel
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Zooekologi.
    Ödeen, Anders
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Zooekologi.
    Løvlie, Hanne
    IFM, Biology, Linköping University.
    Tullberg, Birgitta
    Department of Zoology. Stockholm University.
    Qvarnström, Anna
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Zooekologi.
    Pattern coarseness affects detectability of dull but not of conspicuously coloured poison frogs by an avian predator - implications for evolutionary transitions between aposematism and crypsisManuskript (preprint) (Annet vitenskapelig)
  • 1333.
    Ryberg, Martin
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för organismbiologi, Systematisk biologi.
    Molecular operational taxonomic units as approximations of species in the light of evolutionary models and empirical data from Fungi2015Inngår i: Molecular Ecology, ISSN 0962-1083, E-ISSN 1365-294X, Vol. 24, nr 23, s. 5770-5777Artikkel i tidsskrift (Annet vitenskapelig)
    Abstract [en]

    During the last couple of decades, an increasing number of studies use sequence clusters as units for taxonomic diversity. It is well known that such molecular operational taxonomic units (MOTUs) do not necessarily correspond to species, but they are treated as such when measuring diversity and testing theories. Here, I show that data from studies of molecular evolution and species diversification of fungi indicate that commonly used cut-offs are likely to lump species in many cases. At the same time, empirical studies show that the mean within-species variation is close to these cut-offs. That the within-species variation estimates are plausible is supported by coalescence modelling under a range of parameter settings. In addition, studies using crossing tests to delimit species show that there often is an overlap in within- and between-species distances. The available data therefore indicate that sequence clusters are likely to misrepresent species. However, to keep a biological relevance, MOTUs should be kept in close agreement with species. Studies using them should therefore asses how sensitive the results are to differences between MOTUs and species - something that is rarely done. An even better solution is to directly include the uncertainty in species delimitation in the analyses, but in many cases, we need to increase our knowledge of taxonomy and evolution to do this accurately. Even if the empirical data referred to here pertain to the barcoding region of rDNA in fungi, there is nothing indicating that the situation is substantially better for other taxa or genes.

  • 1334. Ryberg, Martin
    et al.
    Matheny, P Brandon
    Asynchronous origins of ectomycorrhizal clades of Agaricales.2012Inngår i: Proceedings of the Royal Society of London. Biological Sciences, ISSN 0962-8452, E-ISSN 1471-2954, Vol. 279, nr 1735, s. 2003-11Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The ectomycorrhizal (ECM) symbiosis is the most widespread biotrophic nutritional mode in mushroom-forming fungi. ECM fungi include, though are not limited to, about 5000 described species of Agaricales from numerous, independently evolved lineages. Two central hypotheses suggest different explanations for the origin of ECM fungal diversity: (i) dual origins, initially with the Pinaceae in the Jurassic and later with angiosperms during the Late Cretaceous, and (ii) a simultaneous and convergent radiation of ECM lineages in response to cooling climate during the Palaeogene and advancing temperate ECM plant communities. Neither of these hypotheses is supported here. While we demonstrate support for asynchronous origins of ECM Agaricales, the timing of such events appears to have occurred more recently than suggested by the first hypothesis, first during the Cretaceous and later during the Palaeogene. We are also unable to reject models of rate constancy, which suggests that the diversity of ECM Agaricales is not a consequence of convergent rapid radiations following evolutionary transitions from saprotrophic to ECM habits. ECM lineages of Agaricales differ not only in age, but also in rates of diversification and rate of substitution at nuclear ribosomal RNA loci. These results question the biological uniformity of the ECM guild.

  • 1335. Ryberg, Martin
    et al.
    Matheny, Patrick Brandon
    Dealing with incomplete taxon sampling and diversification of a large clade of mushroom-forming fungi.2011Inngår i: Evolution, ISSN 0014-3820, E-ISSN 1558-5646, Vol. 65, nr 7, s. 1862-78Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The absence of an adequate fossil record can hinder understanding the process of diversification that underlies the evolutionary history of a given group. In such cases, investigators have used ultrametric trees derived from molecular data from extant taxa to gain insights into processes of speciation and extinction over time. Inadequate taxon sampling, however, impairs such inferences. In this study, we use simulations to investigate the effect of incomplete taxon sampling on the accumulation of lineages through time for a clade of mushroom-forming fungi, the Hebelomateae. To achieve complete taxon sampling, we use a new Bayesian approach that incorporates substitute lineages to estimate diversification rates. Unlike many studies of animals and plants, we find no evidence of a slowdown in speciation. This indicates the Hebelomateae has not undergone an adaptive radiation. Rather, these fungi have evolved under a relatively constant rate of diversification since their most recent common ancestor, which we date back to the Eocene. The estimated net diversification rate (0.08-0.19 spp./lineage/Ma) is comparable with that of many plants and animals. We suggest that continuous diversification in the Hebelomateae has been facilitated by climatic and vegetation changes throughout the Cenozoic. We also caution against modeling multiple genes as a single partition when performing phylogenetic dating analyses.

  • 1336.
    Rybinski, Jakub
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Zooekologi. Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för biologisk grundutbildning.
    Should I stay or should I go?: Breeding dispersal decisions in a young avian hybrid zone2012Independent thesis Advanced level (degree of Master (Two Years)), 30 poäng / 45 hpOppgave
  • 1337.
    Rybinski, Jakub
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Zooekologi.
    Sirkia, Paivi M.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Zooekologi. Univ Helsinki, Zool Unit, Finnish Museum Nat Hist, FIN-00014 Helsinki, Finland..
    McFarlane, S. Eryn
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Zooekologi.
    Vallin, Niclas
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Zooekologi.
    Wheatcroft, David
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Zooekologi.
    Ålund, Murielle
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Zooekologi.
    Qvarnström, Anna
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Zooekologi.
    Competition-driven build-up of habitat isolation and selection favoring modified dispersal patterns in a young avian hybrid zone2016Inngår i: Evolution, ISSN 0014-3820, E-ISSN 1558-5646, Vol. 70, nr 10, s. 2226-2238Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Competition-driven evolution of habitat isolation is an important mechanism of ecological speciation but empirical support for this process is often indirect. We examined how an on-going displacement of pied flycatchers from their preferred breeding habitat by collared flycatchers in a young secondary contact zone is associated with (a) access to an important food resource (caterpillar larvae), (b) immigration of pied flycatchers in relation to habitat quality, and (c) the risk of hybridization in relation to habitat quality. Over the past 12 years, the estimated access to caterpillar larvae biomass in the habitat surrounding the nests of pied flycatchers has decreased by a fifth due to shifted establishment possibilities, especially for immigrants. However, breeding in the high quality habitat has become associated with such a high risk of hybridization for pied flycatchers that overall selection currently favors pied flycatchers that were forced to immigrate into the poorer habitats (despite lower access to preferred food items). Our results show that competition-driven habitat segregation can lead to fast habitat isolation, which per se caused an opportunity for selection to act in favor of future "voluntarily" altered immigration patterns and possibly strengthened habitat isolation through reinforcement.

  • 1338.
    Rydin, Håkan
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Växtekologi och evolution.
    Emanuelsson, Urban
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Centrum för biologisk mångfald.
    Kautsky, Lena
    Stockholm University.
    3. Ecology and Ecosystems2003Inngår i: Environmental Science: Understanding, protecting and managing the environment in the Baltic Sea Region / [ed] Lars Rydén, Pawel Migula and Magnus Andersson, Uppsala: Baltic University Press , 2003, 1, s. 68-91Kapittel i bok, del av antologi (Annet (populærvitenskap, debatt, mm))
  • 1339.
    Ryll, Bettina
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för organismbiologi, Evolution och utvecklingsbiologi.
    Sanchez, Sophie
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för organismbiologi, Evolution och utvecklingsbiologi.
    Haitina, Tatjana
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för organismbiologi, Evolution och utvecklingsbiologi.
    Tafforeau, Paul
    Ahlberg, Per Erik
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för organismbiologi, Evolution och utvecklingsbiologi.
    The genome of Callorhinchus and the fossil record: a new perspective on SCPP gene evolution in gnathostomes2014Inngår i: Evolution & Development, ISSN 1520-541X, E-ISSN 1525-142X, Vol. 16, nr 3, s. 123-124Artikkel i tidsskrift (Annet vitenskapelig)
  • 1340.
    Récapet, Charlotte
    et al.
    Univ Lyon, Univ Claude Bernard Lyon 1, Lab Biometr & Biol Evolut, CNRS,UMR 5558, 43 Bd 11 Novembre 1918, F-69622 Villeurbanne, France.;Univ Lausanne Sorge, Dept Ecol & Evolut, CH-1015 Lausanne, Switzerland..
    Bize, Pierre
    Univ Aberdeen, Sch Biol Sci, Tillydrone Ave, Aberdeen AB24 2TZ, Scotland..
    Doligez, Blandine
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Evolutionsbiologi. Univ Lyon, Univ Claude Bernard Lyon 1, Lab Biometr & Biol Evolut, CNRS,UMR 5558, 43 Bd 11 Novembre 1918, F-69622 Villeurbanne, France..
    Food availability modulates differences in parental effort between dispersing and philopatric birds2017Inngår i: Behavioral Ecology, ISSN 1045-2249, E-ISSN 1465-7279, Vol. 28, nr 3, s. 688-697Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Dispersal entails costs and might have to be traded off against other life-history traits. Dispersing and philopatric individuals may thus exhibit alternative life-history strategies. Importantly, these differences could also partly be modulated by environmental variation. Our previous results in a patchy population of a small passerine, the collared flycatcher, suggest that, as breeding density, a proxy of habitat quality, decreases, dispersing individuals invest less in reproduction but maintain a stable oxidative balance, whereas philopatric individuals maintain a high reproductive investment at the expense of increased oxidative stress. In this study, we aimed at experimentally testing whether these observed differences between dispersing and philopatric individuals across a habitat quality gradient were due to food availability, a major component of habitat quality in this system. We provided additional food for the parents to use during the nestling rearing period and we measured subsequent parental reproductive effort (through provisioning rate, adult body mass, and plasmatic markers of oxidative balance) and reproductive output. Density-dependent differences between dispersing and philopatric parents in body mass and fledging success were observed in control nests but not in supplemented nests. However, density-dependent differences in oxidative state were not altered by the supplementation. Altogether, our results support our hypothesis that food availability is responsible for some of the density-dependent differences observed in our population between dispersing and philopatric individuals but other mechanisms are also at play. Our study further emphasizes the need to account for environmental variation when studying the association between dispersal and other traits.

  • 1341.
    Rózsa, Jani
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Evolutionsbiologi.
    Strand, Tanja
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för medicinsk biokemi och mikrobiologi. Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik.
    Montadert, Marc
    Univ Franche Comte, UC INRA, MRT, Lab Ecol & Ecophysiol,EA 3184, Pl Leclercq, F-25300 Besancon, France.
    Kozma, Radoslav
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Zooekologi.
    Höglund, Jacob
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Zooekologi.
    Effects of a range expansion on adaptive and neutral genetic diversity in dispersal limited Hazel grouse (Bonasa bonasia) in the French Alps2016Inngår i: Conservation Genetics, ISSN 1566-0621, E-ISSN 1572-9737, Vol. 17, nr 2, s. 401-412Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Biogeographic range expansions, when related to dispersal limitation, may have counter intuitive effects on genetic diversity. At range margins the relative roles of demographic changes, connectivity and genetic diversity need to be integrated for a successful assessment of population viability. Historically the Hazel grouse (Bonasa bonasia) in France was found in the north of the French Alps and also in a disjunct population in the nearby Jura Mountains. The species has recently undergone a range expansion in a north to south axis in the Alps. Local population size estimates and migration patterns during expansion have previously been studied. In this study, we performed genotyping at neutral (microsatellite) and adaptive (MHC) genetic markers in Hazel grouse. We compared diversity and differentiation (FST and DEST) at three sampling localities along the expansion axis in the French Alps and Jura, as well as at two sampling localities in Sweden, where the population has had a long-term continuous and stable distribution. Strong serial founder effects were found between the French localities, resulting in stronger isolation further south, with a relatively high neutral differentiation (pair-wise FST = 0.117). However, the loss of adaptive diversity MHC was slight. No adaptive differentiation (MHC DEST = −0.015) was observed, thus, the French localities can be considered uniform units with regard to MHC diversity, a criterion to treat populations in these localities as a management unit.

  • 1342.
    Rödin Mörch, Patrik
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för biologisk grundutbildning.
    Recombination, Diversity and Differentiation at the MHC-B Region in Two Populations of Black Grouse (Tetrao tetrix)2014Independent thesis Advanced level (degree of Master (Two Years)), 30 poäng / 45 hpOppgave
    Abstract [en]

    The genes of the major histocompatibility complex (MHC) encode proteins that are involved in the adaptive immune system. They are among the most polymorphic genes known in vertebrates and are mainly responsible for the presentation of antigens to T-cells in order to initiate an immune response. Evidence indicates that balancing selection is behind this extraordinary polymorphism. Known for it’s more compact and streamlined organization black grouse and other galliform birds have what is called a minimal essential MHC. Here, I investigate the patterns of recombination and linkage disequilibrium, genetic diversity, differentiation and signs of positive natural selection in two demographically distinct populations of black grouse (Tetrao tetrix). Using MHC linked microsatellites and MHC-BLB single locus sequences I showed that a small isolated population from the Netherlands is significantly differentiated from a large population from Finland , that the Dutch population has lower levels of genetic variation and a smaller number, but more divergent BLB alleles. Both populations also show signs of historical balancing selection acting on the codons responsible for the antigen binding site of the BLB genes. Lastly, the Dutch population shows overall signs of higher linkage disequilibrium resulting in lower population recombination rates compared to the Finnish population. Based on the estimated ratio between the population recombination rate and the population mutation rate I showed that mutations have been more prevalent in shaping diversity at the black grouse MHC-B region than recombination has been. The differences in variation, selection and recombination between the Dutch and Finnish population are likely a reflection of their very different demographic histories.

  • 1343.
    Sagitov, Serik
    et al.
    Chalmers University of Technology and the University of Gothenburg.
    Bartoszek, Krzysztof
    Mathematical Sciences, Chalmers University of Technology and the University of Gothenburg.
    Interspecies correlation for neutrally evolving traits2012Inngår i: Journal of Theoretical Biology, ISSN 0022-5193, E-ISSN 1095-8541, Vol. 309, s. 11-19Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A simple way to model phenotypic evolution is to assume that after splitting, the trait values of the sister species diverge as independent Brownian motions. Relying only on a prior distribution for the underlying species tree (conditioned on the number, n, of extant species) we study the random vector (X1,…,Xn) of the observed trait values. In this paper we derive compact formulae for the variance of the sample mean and the mean of the sample variance for the vector (X1,…,Xn).

    The key ingredient of these formulae is the correlation coefficient between two trait values randomly chosen from (X1,…,Xn). This interspecies correlation coefficient takes into account not only variation due to the random sampling of two species out of n and the stochastic nature of Brownian motion but also the uncertainty in the phylogenetic tree. The latter is modeled by a (supercritical or critical) conditioned branching process. In the critical case we modify the Aldous-Popovic model by assuming a proper prior for the time of origin.

  • 1344.
    Sagitov, Serik
    et al.
    Chalmers University of Technology and the University of Gothenburg.
    Bartoszek, Krzysztof
    Mathematical Sciences, Chalmers University of Technology and the University of Gothenburg.
    Interspecies correlation for neutrally evolving traits2012Inngår i: Journal of Theoretical Biology, ISSN 0022-5193, E-ISSN 1095-8541, Vol. 309, s. 11-19Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A simple way to model phenotypic evolution is to assume that after splitting, the trait values of the sister species diverge as independent Brownian motions. Relying only on a prior distribution for the underlying species tree (conditioned on the number, n, of extant species) we study the random vector (X1,…,Xn) of the observed trait values. In this paper we derive compact formulae for the variance of the sample mean and the mean of the sample variance for the vector (X1,…,Xn).

    The key ingredient of these formulae is the correlation coefficient between two trait values randomly chosen from (X1,…,Xn). This interspecies correlation coefficient takes into account not only variation due to the random sampling of two species out of n and the stochastic nature of Brownian motion but also the uncertainty in the phylogenetic tree. The latter is modeled by a (supercritical or critical) conditioned branching process. In the critical case we modify the Aldous-Popovic model by assuming a proper prior for the time of origin.

  • 1345.
    Salakka, Seela
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Geovetenskapliga sektionen, Institutionen för geovetenskaper, Paleobiologi.
    Tooth Replacement of Euhelopus zdanskyi (Dinosauria: Sauropoda) and the Evolution of Titanosaurian Tooth Morphology2014Independent thesis Advanced level (degree of Master (Two Years)), 80 poäng / 120 hpOppgave
    Abstract [en]

    Sauropod tooth morphologies and tooth replacement patterns bear important information on feeding habits and sauropod evolution. Euhelopus zdanskyi is an Early Cretaceous neosauropod, and belongs to the group Euhelopodidae, which is the sister group of Titanosauria. Euhelopus is a key taxon in the evolution of sauropod teeth, because it displays a very conservative tooth morphology compared to that seen in Titanosauria, despite being a close relative. The teeth of Euhelopus resemble those of Camarasaurus, as well as many basal sauropods that are not closely related to Euhelopus. The teeth of Euhelopus are spoon-shaped, and they have approximately two replacement teeth for each functional tooth. Their robust morphology and low number of replacement teeth suggest that they were worn down a lot more slowly than the pencil-shaped teeth of Titanosauria and Diplodocoidea. Diplodocoids, whose teeth have been studied widely, especially show very rapid tooth replacement rates, and the tooth morphology of titanosaurs suggests that they might have had similar replacement rates. On the contrary, Euhelopus was likely to have replacement rates similar to the relatively low rates of Camarasaurus, whose tooth battery is much like that of Euhelopus. Furthermore, some euhelopodids are known to have had pencil-shaped teeth, which indicates that there was a strong evolutionary pressure towards the development of narrow teeth during the Late Cretaceous. This pressure may have been caused by a change in vegetation or may merely represent somphospondylans occupying the niches vacated by the diplodocoids, which appear to have gone extinct before the end of the Cretaceous. This study uses 3D modelling for inspecting tooth replacement of Euhelopus and evolution of sauropod teeth.

  • 1346. Samils, Nicklas
    et al.
    Oliva, Jonas
    Johannesson, Hanna
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Evolutionsbiologi.
    Nuclear interactions in a heterokaryon: insight from the model Neurospora tetrasperma2014Inngår i: Proceedings of the Royal Society of London. Biological Sciences, ISSN 0962-8452, E-ISSN 1471-2954, Vol. 281, nr 1786, s. UNSP 20140084-Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A heterokaryon is a tissue type composed of cells containing genetically different nuclei. Although heterokaryosis is commonly found in nature, an understanding of the evolutionary implications of this phenomenon is largely lacking. Here, we use the filamentous ascomycete Neurospora tetrasperma to study the interplay between nuclei in heterokaryons across vegetative and sexual developmental stages. This fungus harbours nuclei of two opposite mating types (mat A and mat a) in the same cell and is thereby self-fertile. We used pyrosequencing of mat-linked SNPs of three heterokaryons to demonstrate that the nuclear ratio is consistently biased for mat A-nuclei during mycelial growth (mean mat A/mat a ratio 87%), but evens out during sexual development (ratio ranging from 40 to 57%). Furthermore, we investigated the association between nuclear ratio and expression of alleles of mat-linked genes and found that expression is coregulated to obtain a tissue-specific bias in expression ratio: during mycelial extension, we found a strong bias in expression for mat A-linked genes, that was independent of nuclear ratio, whereas at the sexual stage we found an expression bias for genes of the mat a nuclei. Taken together, our data indicate that nuclei cooperate to optimize the fitness of the heterokaryon, via both altering their nuclear ratios and coregulation genes expressed in the different nuclei.

  • 1347.
    Sanchez, Sophie
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för organismbiologi, Evolution och utvecklingsbiologi.
    Dupret, Vincent
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för organismbiologi, Evolution och utvecklingsbiologi.
    Ryll, Bettina
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för organismbiologi, Evolution och utvecklingsbiologi.
    Trinajstic, Kate
    Curtin University, Western Australia.
    Wretman, Lovisa
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för organismbiologi, Evolution och utvecklingsbiologi.
    Zylberberg, Louise
    Université Pierre et Marie Curie, UPMC, Paris, France.
    Tafforeau, Paul
    European Synchrotron Radiation Facility, Grenoble, France.
    Ahlberg, Per
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för organismbiologi, Evolution och utvecklingsbiologi.
    Fossil bone histology revealed in 3D thanks to the synchrotron light: palaeobiological implications2011Konferansepaper (Fagfellevurdert)
  • 1348.
    Sanchez, Sophie
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för organismbiologi, Evolution och utvecklingsbiologi.
    Dupret, Vincent
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för organismbiologi, Evolution och utvecklingsbiologi.
    Ryll, Bettina
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för organismbiologi, Evolution och utvecklingsbiologi.
    Trinajstic, Kate
    Curti University, Western Australia.
    Wretman, Lovisa
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för organismbiologi, Evolution och utvecklingsbiologi.
    Zylberberg, Louise
    Université Pierre et Marie Curie, UPMC, Paris, France.
    Tafforeau, Paul
    European Synchrotron Radiation Facility, Grenoble, France.
    Ahlberg, Per
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för organismbiologi, Evolution och utvecklingsbiologi.
    Synchrotron virtual palaeohistology: a new tool for studying the evolution of bone microstructures in 3D2011Konferansepaper (Fagfellevurdert)
  • 1349.
    Sanchez, Sophie
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för organismbiologi.
    Schoch, Rainer
    Environmental and metabolic plasticity revealed by bonehistology as a successful evolutionary strategy in a long-lived homeostatic triassic temnospondyl2013Konferansepaper (Annet vitenskapelig)
  • 1350.
    Sanchez, Sophie
    et al.
    Uppsala universitet, Science for Life Laboratory, SciLifeLab. Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för organismbiologi, Evolution och utvecklingsbiologi. European Synchrotron Radiat Facil, 71 Ave Martyrs,CS 40220, F-38043 Grenoble, France..
    Tafforeau, Paul
    European Synchrotron Radiat Facil, 71 Ave Martyrs,CS 40220, F-38043 Grenoble, France..
    Clack, Jennifer A.
    Univ Cambridge, Univ Museum Zool, Dept Zool, Downing St, Cambridge CB2 3EJ, England..
    Ahlberg, Per E.
    Uppsala universitet, Science for Life Laboratory, SciLifeLab. Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för organismbiologi, Evolution och utvecklingsbiologi.
    Life history of the stem tetrapod Acanthostega revealed by synchrotron microtomography2016Inngår i: Nature, ISSN 0028-0836, E-ISSN 1476-4687, Vol. 537, nr 7620, s. 408-+Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The transition from fish to tetrapod was arguably the most radical series of adaptive shifts in vertebrate evolutionary history. Data are accumulating rapidly for most aspects of these events(1-5), but the life histories of the earliest tetrapods remain completely unknown, leaving a major gap in our understanding of these organisms as living animals. Symptomatic of this problem is the unspoken assumption that the largest known Devonian tetrapod fossils represent adult individuals. Here we present the first, to our knowledge, life history data for a Devonian tetrapod, from the Acanthostega mass-death deposit of Stensio Bjerg, East Greenland(6,7). Using propagation phase-contrast synchrotron microtomography (PPC-SR mu CT)(8) to visualize the histology of humeri (upper arm bones) and infer their growth histories, we show that even the largest individuals from this deposit are juveniles. A long early juvenile stage with unossified limb bones, during which individuals grew to almost final size, was followed by a slow-growing late juvenile stage with ossified limbs that lasted for at least six years in some individuals. The late onset of limb ossification suggests that the juveniles were exclusively aquatic, and the predominance of juveniles in the sample suggests segregated distributions of juveniles and adults at least at certain times. The absolute size at which limb ossification began differs greatly between individuals, suggesting the possibility of sexual dimorphism, adaptive strategies or competition-related size variation.

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