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  • 1.
    Acerbi, Alberto
    et al.
    Stockholms universitet, Humanistiska fakulteten, Centrum för evolutionär kulturforskning.
    Ghirlanda, Stefano
    Stockholms universitet, Humanistiska fakulteten, Centrum för evolutionär kulturforskning. Brooklyn College, US.
    Enquist, Magnus
    Stockholms universitet, Humanistiska fakulteten, Centrum för evolutionär kulturforskning. Stockholms universitet, Naturvetenskapliga fakulteten, Zoologiska institutionen, Avdelningen för etologi.
    Regulatory Traits in Cultural Evolution2012Ingår i: Proceedings of WiVACE 2012, 2012, s. 1-9Konferensbidrag (Refereegranskat)
    Abstract [en]

    We call "regulatory traits" those cultural traits that are transmitted through cultural interactions and, at the same time, change individual behaviors directly influencing the outcome of future cultural interactions. The cultural dynamics of some of those traits are studied through simple simulations. In particular, we consider the cultural evolution of traits determining the propensity to copy, the number of potential demonstrators from whom one individual may copy, and conformist versus anti conformist attitudes. Our results show that regulatory traits generate peculiar dynamics that may explain complex human cultural phenomena. We discuss how the existence and importance of regulatory traits in cultural evolution impact on the analogy between genetic and cultural evolution and therefore on the possibility of using evolutionary biology inspired models to study human cultural dynamics.

  • 2.
    Ah-King, Malin
    et al.
    Stockholms universitet, Humanistiska fakulteten, Institutionen för etnologi, religionshistoria och genusvetenskap. Uppsala University, Sweden; University of California, USA.
    Gowaty, Patricia Adair
    A conceptual review of mate choice: stochastic demography, within-sex phenotypic plasticity, and individual flexibility2016Ingår i: Ecology and Evolution, ISSN 2045-7758, E-ISSN 2045-7758, Vol. 6, nr 14, s. 4607-4642Artikel, forskningsöversikt (Refereegranskat)
    Abstract [en]

    Mate choice hypotheses usually focus on trait variation of chosen individuals. Recently, mate choice studies have increasingly attended to the environmental circumstances affecting variation in choosers' behavior and choosers' traits. We reviewed the literature on phenotypic plasticity in mate choice with the goal of exploring whether phenotypic plasticity can be interpreted as individual flexibility in the context of the switch point theorem, SPT (Gowaty and Hubbell ). We found >3000 studies; 198 were empirical studies of within-sex phenotypic plasticity, and sixteen showed no evidence of mate choice plasticity. Most studies reported changes from choosy to indiscriminate behavior of subjects. Investigators attributed changes to one or more causes including operational sex ratio, adult sex ratio, potential reproductive rate, predation risk, disease risk, chooser's mating experience, chooser's age, chooser's condition, or chooser's resources. The studies together indicate that choosiness of potential mates is environmentally and socially labile, that is, induced - not fixed - in the choosy sex with results consistent with choosers' intrinsic characteristics or their ecological circumstances mattering more to mate choice than the traits of potential mates. We show that plasticity-associated variables factor into the simpler SPT variables. We propose that it is time to complete the move from questions about within-sex plasticity in the choosy sex to between- and within-individual flexibility in reproductive decision-making of both sexes simultaneously. Currently, unanswered empirical questions are about the force of alternative constraints and opportunities as inducers of individual flexibility in reproductive decision-making, and the ecological, social, and developmental sources of similarities and differences between individuals. To make progress, we need studies (1) of simultaneous and symmetric attention to individual mate preferences and subsequent behavior in both sexes, (2) controlled for within-individual variation in choice behavior as demography changes, and which (3) report effects on fitness from movement of individual's switch points.

  • 3. Allendorf, Fred W.
    et al.
    Berry, Oliver
    Ryman, Nils
    Stockholms universitet, Naturvetenskapliga fakulteten, Zoologiska institutionen.
    So long to genetic diversity, and thanks for all the fish2014Ingår i: Molecular Ecology, ISSN 0962-1083, E-ISSN 1365-294X, Vol. 23, nr 1, s. 23-25Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The world faces a global fishing crisis. Wild marine fisheries comprise nearly 15% of all animal protein in the human diet, but, according to the U.N. Food and Agriculture Organization, nearly 60% of all commercially important marine fish stocks are overexploited, recovering, or depleted (FAO 2012; Fig. 1). Some authors have suggested that the large population sizes of harvested marine fish make even collapsed populations resistant to the loss of genetic variation by genetic drift (e. g. Beverton 1990). In contrast, others have argued that the loss of alleles because of overfishing may actually be more dramatic in large populations than in small ones (Ryman et al. 1995). In this issue, Pinsky & Palumbi (2014) report that overfished populations have approximately 2% lower heterozygosity and 12% lower allelic richness than populations that are not overfished. They also performed simulations which suggest that their estimates likely underestimate the actual loss of rare alleles by a factor of three or four. This important paper shows that the harvesting of marine fish can have genetic effects that threaten the long-term sustainability of this valuable resource.

  • 4.
    Berger, David
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Zoologiska institutionen.
    Olofsson, Martin
    Stockholms universitet, Naturvetenskapliga fakulteten, Zoologiska institutionen.
    Gotthard, Karl
    Stockholms universitet, Naturvetenskapliga fakulteten, Zoologiska institutionen.
    Wiklund, Christer
    Stockholms universitet, Naturvetenskapliga fakulteten, Zoologiska institutionen.
    Friberg, Magne
    Stockholms universitet, Naturvetenskapliga fakulteten, Zoologiska institutionen.
    Ecological Constraints on Female Fitness in a Phytophagous Insect2012Ingår i: American Naturalist, ISSN 0003-0147, E-ISSN 1537-5323, Vol. 180, nr 4, s. 464-480Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Although understanding female reproduction is crucial for population demography, determining how and to what relative extent it is constrained by different ecological factors is complicated by difficulties in studying the links between individual behavior, life history, and fitness in nature. We present data on females in a natural population of the butterfly Leptidea sinapis. These data were combined with climate records and laboratory estimates of life-history parameters to predict the relative impact of different ecological constraints on female fitness in the wild. Using simulation models, we partitioned effects of male courtship, host plant availability, and temperature on female fitness. Results of these models indicate that temperature is the most constraining factor on female fitness, followed by host plant availability; the short-term negative effects of male courtship that were detected in the field study were less important in models predicting female reproductive success over the entire life span. In the simulations, females with more reproductive reserves were more limited by the ecological variables. Reproductive physiology and egg-laying behavior were therefore predicted to be co-optimized but reach different optima for females of different body sizes; this prediction is supported by the empirical data. This study thus highlights the need for studying behavioral and life-history variation in orchestration to achieve a more complete picture of both demographic and evolutionary processes in naturally variable and unpredictable environments.

  • 5. Boeger, Walter A.
    et al.
    Marteleto, Flávio M.
    Zagonel, Letícia
    Braga, Mariana P.
    Universidade Federal do Paraná, Brazil.
    Tracking the history of an invasion: the freshwater croakers (Teleostei: Sciaenidae) in South America2015Ingår i: Zoologica Scripta, ISSN 0300-3256, E-ISSN 1463-6409, Vol. 44, nr 3, s. 250-262Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In this study, the competing hypotheses of single vs. double colonisation events for freshwater Pachyurinae (Sciaenidae) in South America is tested and the historical biogeography of the expansion of this clade within the continent is reconstructed based on phylogenetic analysis. Parsimony and Bayesian inference (BI) for 19 marine and freshwater species assigned to Sciaenidae, Haemulidae and Polypteridae were determined based on partial sequences of the mitochondrial 16S and cytochrome b genes and fragments of the nuclear Tmo-4C4 and rhodopsin genes. A parsimonious ancestral character reconstruction of euryhalinity was performed on a clade of families of closely related fishes to evaluate the role of ecological fitting in the colonisation of freshwater by a marine sciaenid. The parsimony and BI phylogenetic hypotheses for the concatenated sequences supported the monophyly of the freshwater Sciaenidae. Divergence of the two freshwater clades of Sciaenidae, Pachyurinae and Plagioscion, occurred within the Amazon Basin. Within Pachyurinae, two clades were recovered: one composed of species from the Amazon and the Paraná Basin and a second with representatives from the São Francisco and south-eastern Atlantic basins. The results were compatible with the hypothesis of a single colonisation event of South American freshwater habitats by a marine lineage. The hypothesis of gradual adaptation to freshwater was rejected in favour of the hypothesis of ecological fitting. Sciaenidae, or a subordinate lineage within the family, is ancestrally capable of withstanding exposure to low-salinity habitats, which putatively facilitated the colonisation of freshwater habitats. The subsequent diversification and expansion of Pachyurinae across South America followed this colonisation and replicated the general pattern of the area relationships of South American river basins for several other fish groups.

  • 6.
    Bolinder, Kristina
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och botanik.
    Pollen and pollination in Ephedra (Gnetales)2017Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    Ephedra (Gnetales) is a gymnosperm genus with a long evolutionary history; the first dispersed pollen grains with affinity to the group are known already from the Permian. This thesis focuses on the evolutionary history of the group and different aspects of its pollination mechanisms. Despite the limited number of extant species of the genus (50-60), and a low morphological and genetic divergence among species, there is variation in pollination syndrome in the genus. The prevailing state in Ephedra, and most gymnosperms, is wind pollination. It is therefore surprising that one species, E. foeminea, is insect-pollinated. Together with co-workers I documented the pollination syndromes of E. foeminea and a sympatric species, E. distachya, based on long term field experiments in north-eastern Greece and aerodynamic investigations and calculations. Placing the results into an evolutionary framework reveals that the insect-pollinated species E. foeminea is sister to the remaining (mostly wind-pollinated) genus, and indicates that insect pollination is the ancestral state in the Gnetales. During the course of evolution of the group there has been a shift to wind pollination, which may have played a crucial role for the diversification of the crown group in the Paleogene. Pollination biology is often correlated with the morphology of the pollen such that pollen grains of anemophilous plants are small with a smooth surface, whereas pollen grains of entomophilous plants are larger with an ornamented surface and a covering of pollenkitt. The pollen morphology of Ephedra can be broadly divided into two types: an ancestral type with an unbranched pseudosulcus between each pair of plicae, and a derived type with a branched pseudosulcus between each pair of plicae. Further, the pollen morphology and ultrastructure of the pollen wall in Ephedra are to some degree correlated with the pollination syndrome and capability of long distance dispersal. Pollen of E. foeminea has a denser ultrastructure, as a result a higher settling velocity and is therefore capable of flying shorter distances than does pollen of the anemophilous E. distachya, and other investigated anemophilous species that show a more spacious ultrastructure of the pollen grain. These results can be useful in the reconstruction of the pollination mechanism of extinct taxa of the Ephedra-lineage in the future.

  • 7.
    Braga, Mariana P.
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Zoologiska institutionen.
    Guimarães Jr, Paulo R.
    Wheat, Christopher W.
    Stockholms universitet, Naturvetenskapliga fakulteten, Zoologiska institutionen.
    Nylin, Sören
    Stockholms universitet, Naturvetenskapliga fakulteten, Zoologiska institutionen.
    Janz, Niklas
    Stockholms universitet, Naturvetenskapliga fakulteten, Zoologiska institutionen.
    Unifying host-associated diversification processes using butterfly-plant networks2018Ingår i: Nature Communications, ISSN 2041-1723, E-ISSN 2041-1723, Vol. 9, artikel-id 5155Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Explaining the exceptional diversity of herbivorous insects is an old problem in evolutionary ecology. Here we focus on the two prominent hypothesised drivers of their diversification, radiations after major host switch or variability in host use due to continuous probing of new hosts. Unfortunately, current methods cannot distinguish between these hypotheses, causing controversy in the literature. Here we present an approach combining network and phylogenetic analyses, which directly quantifies support for these opposing hypotheses. After demonstrating that each hypothesis produces divergent network structures, we then investigate the contribution of each to diversification in two butterfly families: Pieridae and Nymphalidae. Overall, we find that variability in host use is essential for butterfly diversification, while radiations following colonisation of a new host are rare but can produce high diversity. Beyond providing an important reconciliation of alternative hypotheses for butterfly diversification, our approach has potential to test many other hypotheses in evolutionary biology.

  • 8.
    Braga, Mariana P.
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Zoologiska institutionen.
    Landis, Michael
    Nylin, Sören
    Stockholms universitet, Naturvetenskapliga fakulteten, Zoologiska institutionen.
    Janz, Niklas
    Stockholms universitet, Naturvetenskapliga fakulteten, Zoologiska institutionen.
    Ronquist, Fredrik
    Bayesian analysis of host repertoire evolutionManuskript (preprint) (Övrigt vetenskapligt)
  • 9.
    Braga, Mariana P.
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Zoologiska institutionen.
    Landis, Michael
    Nylin, Sören
    Stockholms universitet, Naturvetenskapliga fakulteten, Zoologiska institutionen.
    Janz, Niklas
    Stockholms universitet, Naturvetenskapliga fakulteten, Zoologiska institutionen.
    Ronquist, Fredrik
    Evolution of butterfly-plant networks revealed by Bayesian inference of host repertoireManuskript (preprint) (Övrigt vetenskapligt)
  • 10.
    Braga, Mariana Pires
    Stockholms universitet, Naturvetenskapliga fakulteten, Zoologiska institutionen.
    Evolution of host repertoires and the diversification of butterflies2019Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    All herbivorous insects are specialized to some extent to their host plants, but the level of specialization varies greatly. Insect-plant coevolution is often invoked to explain the large diversity of herbivorous insects, but the role of specialization during diversification is still controversial. Although well-studied, our understanding of the evolution of species interactions is still improving, and recent theoretical developments have highlighted the role of generalization (via colonization of new hosts) on diversification. In this thesis, various approaches are combined for a detailed study of the origins of macroevolutionary patterns of host use and butterfly diversity. Chapter I provides a mechanistic basis for such patterns through simulations of lineages evolved in silico. By separating the effects of the number of hosts used by a parasite lineage and the diversity of resources they encompass, we found that resource diversity, rather than host range per se, was the main driver of parasite species richness in both simulated and empirical systems. In Chapter II, we combined network and phylogenetic analyses to quantify support for the two main hypothesized drivers of diversification of herbivorous insects. Based on analyses of two butterfly families, Nymphalidae and Pieridae, we found that variability in host use is essential for diversification, while radiation following the colonization of a new host is rare but can produce high diversity. We then reconciled the two alternative hypotheses into a unified process of host-associated diversification where continuous probing of new hosts and retention of the ability to use hosts colonized in the past are the main factors shaping butterfly-plant networks. While network analysis is a powerful tool for investigating patterns of interaction, other methods are necessary to directly test the mechanisms generating the observed patterns. Therefore, in Chapter III we describe a model of host repertoire evolution we developed for Bayesian inference of evolution of host-parasite interactions. The approach was validated with both simulated and empirical data sets. Finally, in Chapter IV we used the method described in Chapter III to explicitly test the predictions made in Chapter II about the evolution of butterfly-plant networks. We found direct evidence for the role of expansion of fundamental host repertoire and phylogenetic conservatism as important drivers of host repertoire evolution. Thus, using three different approaches, we found overall support for the idea that variation in host use accumulated over evolutionary time is essential for butterfly diversification.

  • 11.
    Buechel, Séverine D.
    et al.
    University of Lausanne, Switzerland; Institute of Integrative Biology (IBZ), Switzerland.
    Wurm, Yanick
    Keller, Laurent
    Social chromosome variants differentially affect queen determination and the survival of workers in the fire ant Solenopsis invicta2014Ingår i: Molecular Ecology, ISSN 0962-1083, E-ISSN 1365-294X, Vol. 23, nr 20, s. 5117-5127Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Intraspecific variation in social organization is common, yet the underlying causes are rarely known. An exception is the fire ant Solenopsis invicta in which the existence of two distinct forms of social colony organization is under the control of the two variants of a pair of social chromosomes, SB and Sb. Colonies containing exclusively SB/SB workers accept only one single queen and she must be SB/SB. By contrast, when colonies contain more than 10% of SB/Sb workers, they accept several queens but only SB/Sb queens. The variants of the social chromosome are associated with several additional important phenotypic differences, including the size, fecundity and dispersal strategies of queens, aggressiveness of workers, and sperm count in males. However, little is known about whether social chromosome variants affect fitness in other life stages. Here, we perform experiments to determine whether differential selection occurs during development and in adult workers. We find evidence that the Sb variant of the social chromosome increases the likelihood of female brood to develop into queens and that adult SB/Sb workers, the workers that cull SB/SB queens, are overrepresented in comparison to SB/SB workers. This demonstrates that supergenes such as the social chromosome can have complex effects on phenotypes at various stages of development.

  • 12.
    Bukontaite, Rasa
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Zoologiska institutionen. Swedish Museum of Natural History, Sweden.
    Miller, Kelly B.
    Bergsten, Johannes
    The utility of CAD in recovering Gondwanan vicariance events and the evolutionary history of Aciliini (Coleoptera: Dytiscidae)2014Ingår i: BMC Evolutionary Biology, ISSN 1471-2148, E-ISSN 1471-2148, Vol. 14, s. 5-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Background: Aciliini presently includes 69 species of medium-sized water beetles distributed on all continents except Antarctica. The pattern of distribution with several genera confined to different continents of the Southern Hemisphere raises the yet untested hypothesis of a Gondwana vicariance origin. The monophyly of Aciliini has been questioned with regard to Eretini, and there are competing hypotheses about the intergeneric relationship in the tribe. This study is the first comprehensive phylogenetic analysis focused on the tribe Aciliini and it is based on eight gene fragments. The aims of the present study are: 1) to test the monophyly of Aciliini and clarify the position of the tribe Eretini and to resolve the relationship among genera within Aciliini, 2) to calibrate the divergence times within Aciliini and test different biogeographical scenarios, and 3) to evaluate the utility of the gene CAD for phylogenetic analysis in Dytiscidae. Results: Our analyses confirm monophyly of Aciliini with Eretini as its sister group. Each of six genera which have multiple species are also supported as monophyletic. The origin of the tribe is firmly based in the Southern Hemisphere with the arrangement of Neotropical and Afrotropical taxa as the most basal clades suggesting a Gondwana vicariance origin. However, the uncertainty as to whether a fossil can be used as a stem-or crowngroup calibration point for Acilius influenced the result: as crowngroup calibration, the 95% HPD interval for the basal nodes included the geological age estimate for the Gondwana break-up, but as a stem group calibration the basal nodes were too young. Our study suggests CAD to be the most informative marker between 15 and 50 Ma. Notably, the 2000 bp CAD fragment analyzed alone fully resolved the tree with high support. Conclusions: 1) Molecular data confirmed Aciliini as a monophyletic group. 2) Bayesian optimizations of the biogeographical history are consistent with an influence of Gondwana break-up history, but were dependent on the calibration method. 3) The evaluation using a method of phylogenetic signal per base pair indicated Wnt and CAD as the most informative of our sampled genes.

  • 13. Burger, Joep M. S.
    et al.
    Buechel, Séverine D.
    University of Lausanne, Switzerland.
    Kawecki, Tadeusz J.
    Dietary restriction affects lifespan but not cognitive aging in Drosophila melanogaster2010Ingår i: Aging Cell, ISSN 1474-9718, E-ISSN 1474-9726, Vol. 9, nr 3, s. 327-335Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Dietary restriction extends lifespan in a wide variety of animals, including Drosophila, but its relationship to functional and cognitive aging is unclear. Here, we study the effects of dietary yeast content on fly performance in an aversive learning task (association between odor and mechanical shock). Learning performance declined at old age, but 50-day-old dietary-restricted flies learned as poorly as equal-aged flies maintained on yeast-rich diet, even though the former lived on average 9 days (14%) longer. Furthermore, at the middle age of 21 days, flies on low-yeast diets showed poorer short-term (5 min) memory than flies on rich diet. In contrast, dietary restriction enhanced 60-min memory of young (5 days old) flies. Thus, while dietary restriction had complex effects on learning performance in young to middle-aged flies, it did not attenuate aging-related decline of aversive learning performance. These results are consistent with the hypothesis that, in Drosophila, dietary restriction reduces mortality and thus leads to lifespan extension, but does not affect the rate with which somatic damage relevant for cognitive performance accumulates with age.

  • 14.
    Caputo, Andrea
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och botanik.
    Genomic and morphological diversity of marine planktonic diatom-diazotroph associations: a continuum of integration and diversification through geological time2019Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    Symbioses between eukaryotes and nitrogen (N2)-fixing cyanobacteria (or diazotrophs) are quite common in the plankton community. A few genera of diatoms (Bacillariophyceae) such as Rhizosolenia, Hemiaulus and Chaetoceros are well known to form symbioses with the heterocystous diazotrophic cyanobacteria Richelia intracellularis and Calothrix rhizosoleniae. The latter are also called diatom-diazotroph associations, or DDAs. Up to now, the prokaryotic partners have been morphologically and genetically characterized, and the phylogenetic reconstruction of the well conserved nifH gene (encodes for the nitrogenase enzyme) placed the symbionts in 3 clusters based on their host-specificity, i.e. het-1 (Rhizosolenia-R. intracellularis), het-2 (Hemiaulus-R. intracellularis), and het-3 (Chaetoceros-C- rhizosoleniae). Conversely, the diatom-hosts, major representative of the phytoplankton community and crucial contributors to the carbon (C) biogeochemical cycle, have been understudied.

    The first aim of this thesis was to genetically and morphologically characterize the diatom-hosts, and to reconstruct the evolutionary background of the partnerships and the symbiont integration in the host. The molecular-clock analysis reconstruction showed the ancient appearance of the DDAs, and the traits characterizing the ancestors. In addition, diatom-hosts bearing internal symbionts (with more eroded draft genomes) appeared earlier than diatom-hosts with external symbionts. Finally a blast survey highlighted a broader distribution of the DDAs than expected.

    The second aim of this thesis was to compare genetic and physiological characteristics of the DDAs symbionts with the other eukaryote-diazotroph symbiosis, i.e. prymnesiophyte-UCYN-A (or Candidatus Atelocyanobacterium thalassa). The genome comparison highlighted more genes for transporters in het-3 (external symbiont) and in the UCYN-A based symbiosis, suggesting that symbiont location might be relevant also for metabolic exchanges and interactions with the host and/or environment. Moreover, a summary of methodological biases that brought to an underestimation of the DDAs is reported.

    The third aim of this thesis was to determine the distribution of the DDAs in the South Pacific Ocean using a quantitative polymerase chain reaction (qPCR) approach and to outline the environmental drivers of such distribution. Among the het-groups, het-1 was the most abundant/detected and co-occurred with the other 2 symbiotic strains, all responding similarly to the influence of abiotic factors, such as temperature and salinity (positive and negative correlation, respectively). Globally, Trichodesmium dominated the qPCR detections, followed by UCYN-B. UCYN-A phylotypes (A-1, A-2) were detected without their proposed hosts, for which new oligonucleotides were designed. The latter suggested a facultative symbiosis. Finally, microscopy observations of the het-groups highlighted a discrepancy with the qPCR counts (i.e. the former were several order of magnitudes lower), leading to the idea of developing a new approach to quantify the DDAs.  

    The fourth aim of this thesis was to develop highly specific in situ hybridization assays (CARD-FISH) to determine the presence of alternative life-stages and/or free-living partners. The new assays were applied to samples collected in the South China Sea and compared with abundance estimates from qPCR assays for the 3 symbiotic strains. Free-living cells were indeed detected along the transect, mainly at deeper depths. Free-living symbionts had two morphotypes: trichomes and single-cells. The latter were interpreted as temporary life-stages. Consistent co-occurrence of the 3 het-groups was also found in the SCS and application of a SEM model predicted positive interactions between the het groups. We interpreted the positive interaction as absence of intra-specific competition, and consistent with the previous study, temperature and salinity were predicted as major drivers of the DDAs distribution.

  • 15. Conroy-Beam, Daniel
    et al.
    Roney, James R.
    Lukaszewski, Aaron W.
    Buss, David M.
    Asao, Kelly
    Sorokowska, Agnieszka
    Sorokowski, Piotr
    Aavik, Toivo
    Akello, Grace
    Alhabahba, Mohammad Madallh
    Alm, Charlotte
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Psykologiska institutionen, Personlighets-, social- och utvecklingspsykologi.
    Amjad, Naumana
    Anjum, Afifa
    Atama, Chiemezie S.
    Duyar, Derya Atamturk
    Ayebare, Richard
    Batres, Carlota
    Bendixen, Mons
    Bensafia, Aicha
    Bertoni, Anna
    Bizumic, Boris
    Boussena, Mahmoud
    Butovskaya, Marina
    Can, Seda
    Cantarero, Katarzyna
    Carrier, Antonin
    Cetinkaya, Hakan
    Croy, Ilona
    Maria Cueto, Rosa
    Czub, Marcin
    Donato, Silvia
    Dronova, Daria
    Dural, Seda
    Duyar, Izzet
    Ertugrul, Berna
    Espinosa, Agustin
    Estevan, Ignacio
    Esteves, Carla Sofia
    Fang, Luxi
    Frackowiak, Tomasz
    Garduno, Jorge Contreras
    Ugalde Gonzalez, Karina
    Guemaz, Farida
    Gyuris, Petra
    Halamova, Maria
    Herak, Iskra
    Horvat, Marina
    Hromatko, Ivana
    Hui, Chin-Ming
    Iafrate, Raffaella
    Jaafar, Jas Laile
    Jiang, Feng
    Kafetsios, Konstantinos
    Kavcic, Tina
    Kennair, Leif Edward Ottesen
    Kervyn, Nicolas
    Truong, Thi
    Khilji, Imran Ahmed
    Kobis, Nils C.
    Hoang, Moc
    Lang, Andras
    Lennard, Georgina R.
    Leon, Ernesto
    Lindholm, Torun
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Psykologiska institutionen, Personlighets-, social- och utvecklingspsykologi.
    Trinh, Thi
    Lopez, Giulia
    Nguyen, Van
    Mailhos, Alvaro
    Manesi, Zoi
    Martinez, Rocio
    McKerchar, Sarah L.
    Mesko, Norbert
    Misra, Girishwar
    Monaghan, Conal
    Mora, Emanuel C.
    Moya-Garofano, Alba
    Musil, Bojan
    Natividade, Jean Carlos
    Niemczyk, Agnieszka
    Nizharadze, George
    Oberzaucher, Elisabeth
    Oleszkiewicz, Anna
    Omar-Fauzee, Mohd Sofian
    Onyishi, Ike E.
    Ozener, Baris
    Pagani, Ariela Francesca
    Pakalniskiene, Vilmante
    Parise, Miriam
    Pazhoohi, Farid
    Pisanski, Annette
    Pisanski, Katarzyna
    Ponciano, Edna
    Popa, Camelia
    Prokop, Pavol
    Rizwan, Muhammad
    Sainz, Mario
    Salkicevic, Svjetlana
    Sargautyte, Ruta
    Sarmany-Schuller, Ivan
    Schmehl, Susanne
    Sharad, Shivantika
    Siddiqui, Razi Sultan
    Simonetti, Franco
    Stoyanova, Stanislava Yordanova
    Tadinac, Meri
    Correa Varella, Marco Antonio
    Vauclair, Christin-Melanie
    Diego Vega, Luis
    Widarini, Dwi Ajeng
    Yoo, Gyesook
    Zatkova, Marta
    Zupancic, Maja
    Assortative mating and the evolution of desirability covariation2019Ingår i: Evolution and human behavior, ISSN 1090-5138, E-ISSN 1879-0607, Vol. 40, nr 5, s. 479-491Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Mate choice lies dose to differential reproduction, the engine of evolution. Patterns of mate choice consequently have power to direct the course of evolution. Here we provide evidence suggesting one pattern of human mate choice-the tendency for mates to be similar in overall desirability-caused the evolution of a structure of correlations that we call the d factor. We use agent-based models to demonstrate that assortative mating causes the evolution of a positive manifold of desirability, d, such that an individual who is desirable as a mate along any one dimension tends to be desirable across all other dimensions. Further, we use a large cross-cultural sample with n = 14,478 from 45 countries around the world to show that this d-factor emerges in human samples, is a cross-cultural universal, and is patterned in a way consistent with an evolutionary history of assortative mating. Our results suggest that assortative mating can explain the evolution of a broad structure of human trait covariation.

  • 16.
    Corral López, Alberto
    Stockholms universitet, Naturvetenskapliga fakulteten, Zoologiska institutionen.
    The link between brain size, cognitive ability, mate choice and sexual behaviour in the guppy (Poecilia reticulata)2017Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    Competition over access for mates has led to the evolution of many striking examples of morphological traits and behaviour in animals. The rapid development of the sexual selection field in recent decades have dramatically advanced our understanding of what traits make individuals more successful in attracting mates and how preferences for mates evolve over time. However, till now, research in this field has put less emphasis on the mechanisms that underlie variation in mate choice and sexual behaviour. Cognitive processes could potentially be key drivers of individual variation in mating preferences and sexual behaviours and therefore deserve further investigation. In this thesis, I used guppies artificially selected for relative brain size as the model system to study the association between brain size, cognitive ability and various aspects of mate choice. Previous studies in this model system showed that large-brained individuals of both sexes outperformed small-brained individuals in cognitive tests. Here I quantified their sexual behaviours and mating preferences to provide novel empirical data concerning the association between brain size, cognitive ability and sexual selection. In dichotomous choice preference tests based on visual cues, comparisons between large-brained and small-brained guppies showed important differences in their assessment of mate quality. These results are not driven by pre-existing visual biases caused by the artificial selection since further investigation of the visual capacity of these fish detected no differences between large-brained and small-brained individuals in their sensitivity to colour or in their capacity to resolve spatial detail. I also quantified sexual behaviour in male guppies artificially selected for relative brain size and found no difference in the behaviours of large-brained and small-brained males in a single male-single female non-competitive scenario. On the contrary, in a more complex social setting I found a reduction in large-brained males in the rate of courtship towards females and dominance displays towards other males when exposed to different degrees of predation threat and different numbers of male competitors. However, this reduction in behavioural intensity did not result in a lower access to copulation with females for large-brained males. I likewise evaluated female sexual behaviour and found that large-brained females had higher behavioural flexibility such that they decreased their receptiveness towards males more strongly under higher levels of predation threat. Together, these results provide novel empirical evidence that brain size and cognitive ability are tightly linked to mating preferences and sexual behaviours. These findings suggest that brain size and cognitive ability might be important mechanisms behind variation in mating preferences and in sexually selected traits across and within species.

  • 17.
    Corral-López, Alberto
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Zoologiska institutionen.
    Bloch, Natasha I.
    Kotrschal, Alexander
    Stockholms universitet, Naturvetenskapliga fakulteten, Zoologiska institutionen.
    van der Bijl, Wouter
    Stockholms universitet, Naturvetenskapliga fakulteten, Zoologiska institutionen.
    Buechel, Severine D.
    Stockholms universitet, Naturvetenskapliga fakulteten, Zoologiska institutionen.
    Mank, Judith E.
    Kolm, Niclas
    Stockholms universitet, Naturvetenskapliga fakulteten, Zoologiska institutionen.
    Female brain size affects the assessment of male attractiveness during mate choice2017Ingår i: Science Advances, ISSN 0036-8156, E-ISSN 2375-2548, Vol. 3, nr 3, artikel-id e1601990Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Mate choice decisions are central in sexual selection theory aimed to understand how sexual traits evolve and their role in evolutionary diversification. We test the hypothesis that brain size and cognitive ability are important for accurate assessment of partner quality and that variation in brain size and cognitive ability underlies variation in mate choice. We compared sexual preference in guppy female lines selected for divergence in relative brain size, which we have previously shown to have substantial differences in cognitive ability. In a dichotomous choice test, large-brained and wild-type females showed strong preference for males with color traits that predict attractiveness in this species. In contrast, small-brained females showed no preference for males with these traits. In-depth analysis of optomotor response to color cues and gene expression of key opsins in the eye revealed that the observed differences were not due to differences in visual perception of color, indicating that differences in the ability to process indicators of attractiveness are responsible. We thus provide the first experimental support that individual variation in brain size affects mate choice decisions and conclude that differences in cognitive ability may be an important underlying mechanism behind variation in female mate choice.

  • 18. Dalin, Peter
    et al.
    Nylin, Sören
    Stockholms universitet, Naturvetenskapliga fakulteten, Zoologiska institutionen.
    Host-plant quality adaptively affects the diapause threshold: evidence from leaf beetles in willow plantations2012Ingår i: Ecological Entomology, ISSN 0307-6946, E-ISSN 1365-2311, Vol. 37, nr 6, s. 490-499Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    1. Voltinism of herbivorous insects can vary depending on environmental conditions. The leaf beetle Phratora vulgatissima L. is univoltine in Sweden but will sometimes initiate a second generation in short-rotation coppice (SRC) willow plantations. 2. The study investigated whether increased voltinism by P. vulgatissima in plantations can be explained by (i) rapid life-cycle development allowing two generations, or (ii) postponed diapause induction on coppiced willows. 3. In the field, no difference was found in the phenology or development of first-generation broods between plantations (S. viminalis) and natural willow habitats (S. cinerea). However, the induction of diapause occurred 12 weeks later in SRC willow plantations. 4. Laboratory experiments indicated no genetic difference in the critical day-length for diapause induction between beetles originating from plantations and natural habitats. Development time was unaffected by host-plant quality but critical day-length was prolonged by almost an hour when the beetles were reared on a non-preferred willow species (S. phylicifolia). When reared on new leaves from re-sprouting shoots of recently coppiced willow plants, diapause incidence was significantly less than when the beetles were reared on mature leaves from uncoppiced plants. 5. The study suggests that P. vulgatissima has a plastic diapause threshold influenced by host-plant quality. The use of host-plant quality as a diapause-inducing stimulus is likely to be adaptive in cases where food resources are unpredictable, such as when new host-plant tissue is produced after a disturbance. SRC willows may allow two beetle generations due to longer growing seasons of coppiced plants that grow vigorously.

  • 19.
    Dalsätt, Johan
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för geologiska vetenskaper.
    Fossil birds: Contributions to the understanding of avian evolution2012Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    The study of the evolution of birds began about 150 years ago with the finding of Archaeopteryx. Yet, many unsolved questions about avian evolution remain to be answered. This thesis aims at addressing some of these questions.

    The Early Cretaceous Confusiusornis is the most well-represented Mesozoic bird in the fossil record. The abundance of fossils facilitates a study of the preservation of specimens in the two geological formations in which this taxon is found. It was demonstrated that specimens in the Yixiang Formation always are represented by complete, articulated skeletons, while those in the Jiofutang Formation often lack the pectoral girdle and the wings.

    Despite the many specimens available of Confusiusornis few clues to the diet of this taxon have been found. We describe a Confusiusornis specimen with a pellet of fish remains preserved in the throat region.

    The enantiornithid birds probably constituted the most species-rich and diverse bird group during the Cretaceous. Several well-preserved specimens have been found in China, e.g. Grabauornis lingyuanensis described herein.

    The mass extinction at the end of the Cretaceous probably gave the only surviving group of birds,Neornithes,chance to radiate and evolve into new niches. One such group is the Strigiformes (owls). We describe a new species from the Eocene Green River Formation in USAthat we suggest is closely related to the contemporary European Prosybris antique and P. medius.

    Although birds are known from several Miocene localities in Europe, the discovery of vertebrate fossils in the Hambach opencast lignite mine was thus unexpected and remarkable. The most significant bird found in Hambach is a specimen of darter, genus Anhinga. It agrees in size, proportions and morphology the fossil species Anhinga pannonica to which we refer the Hambach specimen. Fossils of ducks and galliforms have also been found in deposits at Hambach dated to the Pliocene.

  • 20.
    Dalsätt, Johan
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för geologiska vetenskaper. Swedish Museum of National History, Sweden.
    Ericson, Per G. P.
    Zhou, Zhonge
    A New Enantiornithes (Aves) from the Early Cretaceous of China2014Ingår i: Acta Geologica Sinica, ISSN 1000-9515, E-ISSN 1755-6724, Vol. 88, nr 4, s. 1034-1040Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A new bird from the early Cretaceous Yixian Formation of Liaoning, China is described. This new species, Grabauornis lingyuanensis, shares several synapomorphies with the Enantiornithes. The specimen is relatively well preserved. The skeletal morphology of Grabauornis bears close resemblance to that of other Chinese members of this clade. The brachial index (the ratio between the lengths of humerus and ulna) is 0.95, which is close to the average for enantiornithine birds. It indicates that Grabauornis was a rather good flyer, and the presence of an alula in the wing further testifies to this.

  • 21.
    Dalsätt, Johan
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för geologiska vetenskaper.
    Ericson, Per P. G.
    A new species of owl (Aves: Strigiformes) from the Eocene Wasatch Formation, WyomingArtikel i tidskrift (Övrigt vetenskapligt)
  • 22.
    Dalsätt, Johan
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för geologiska vetenskaper.
    Ericson, Per
    Zhou, Z.
    Differential preservation of Confuciusornis specimens in the Yixian and Jiufotang formationsArtikel i tidskrift (Övrigt vetenskapligt)
  • 23.
    Dalsätt, Johan
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för geologi och geokemi.
    Mörs, Thomas
    Ericson, Per G. P.
    Fossil birds from the Miocene and Pliocene of Hambach (NW Germany)2006Ingår i: Palaeontographica. Abteilung A, Palaozoologie, Stratigraphie, ISSN 0375-0442, Vol. 277, nr 1-6, s. 113-121Artikel i tidskrift (Refereegranskat)
  • 24.
    Dalsätt, Johan
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för geologi och geokemi.
    Zhou, Z.
    Zhang, F.
    Ericson, Per G. P.
    Food remains in Confuciusornis sanctus suggest a fish diet2006Ingår i: Die Naturwissenschaften, ISSN 0028-1042, E-ISSN 1432-1904, Vol. 93, nr 9, s. 444-446Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Despite hundreds of excellent fossils of Confuciusornis, the most abundant group of birds in the Early Cretaceous, ‘Jehol Biota’ in China, there is yet no indication of the food choice of these birds. Here, we describe fish remains preserved in the alimentary system of a specimen of Confuciusornis sanctus from the Jiufotang Formation. This find is about five million years younger than all previously published confuciusornithid birds from the Yixian Formation. Although it is unknown how common fish was in the diet of Confuciusornis, the find does not support previous hypotheses that it fed on plants or grain.

  • 25.
    de Barra, Mícheál
    et al.
    Stockholms universitet, Humanistiska fakulteten, Centrum för evolutionär kulturforskning. University of London, England.
    DeBruine, Lisa M.
    Jones, Benedict C.
    Mahmud, Zahid Hayat
    Curtis, Valerie A.
    Illness in childhood predicts face preferences in adulthood2013Ingår i: Evolution and human behavior, ISSN 1090-5138, E-ISSN 1879-0607, Vol. 34, nr 6, s. 384-389Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The value of different mate choices may depend on the local pathogen ecology and on personal infection susceptibility: when there is a high risk of infection, choosing a healthy or immunocompetent mate may be particularly important. Frequency of childhood illness may act as a cue of the ecological and immunological factors relevant to mate preferences. Consistent with this proposal, we found that childhood illness - and frequency of diarrhea in particular - was positively correlated with preferences for exaggerated sex-typical characteristics in opposite-sex, but not same-sex, faces. Moreover, this relationship was stronger among individuals with poorer current health. These data suggest that childhood illness may play a role in calibrating adult mate preferences and have implications for theories of disease-avoidance psychology, life-history strategy and cross-cultural differences in mate preferences.

  • 26.
    de Boer, Raïssa A.
    et al.
    University of Antwerp, Belgium.
    Eens, Marcel
    Fransen, Erik
    Müller, Wendt
    Hatching asynchrony aggravates inbreeding depression in a songbird (Serinus canaria): An inbreeding–environment interaction2015Ingår i: Evolution, ISSN 0014-3820, E-ISSN 1558-5646, Vol. 69, nr 4, s. 1063-1068Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Understanding how the intensity of inbreeding depression is influenced by stressful environmental conditions is an important area of enquiry in various fields of biology. In birds, environmental stress during early development is often related to hatching asynchrony; differences in age, and thus size, impose a gradient in conditions ranging from benign (first hatched chick) to harsh (last hatched chick). Here, we compared the effect of hatching order on growth rate in inbred (parents are full siblings) and outbred (parents are unrelated) canary chicks (Serinus canaria). We found that inbreeding depression was more severe under more stressful conditions, being most evident in later hatched chicks. Thus, consideration of inbreeding‐environment interactions is of vital importance for our understanding of the biological significance of inbreeding depression and hatching asynchrony. The latter is particularly relevant given that hatching asynchrony is a widespread phenomenon, occurring in many bird species. The exact causes of the observed inbreeding‐environment interaction are as yet unknown, but may be related to a decrease in maternal investment in egg contents with laying position (i.e. prehatching environment), or to performance of the chicks during sibling competition and/or their resilience to food shortage (i.e. posthatching environment).

  • 27.
    de Boer, Raïssa A.
    et al.
    University of Antwerp, Belgium.
    Eens, Marcel
    Müller, Wendt
    A loss of heterozygosity, a loss in competition? The effects of inbreeding, pre- and postnatal conditions on nestling development.2016Ingår i: Ecology and Evolution, ISSN 2045-7758, E-ISSN 2045-7758, Vol. 6, nr 21, s. 7921-7930Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The early developmental trajectory is affected by genetic and environmental factors that co-depend and interact often in a complex way. In order to distinguish their respective roles, we used canaries (Serinus canaria) of different genetic backgrounds (inbred and outbred birds). An artificial size hierarchy was created to provoke within-nest competition, manipulating postnatal conditions. To this end, inbred birds were weight-matched with outbred birds into duos, and each nest contained one duo of size-advantaged, and one duo of size-disadvantaged inbred and outbred nestlings. Prenatal (maternal) effects were taken into account also, enabling us to study the separate as well as the interactive effects of inbreeding, pre- and postnatal conditions on nestling development. We find that postnatal conditions were the most important determinant of early growth, with size-advantaged nestlings growing faster and obtaining larger size/body mass at fledging in comparison with size-disadvantaged nestlings. Prenatal conditions were important too, with birds that hatched from eggs that were laid late in the laying order obtaining a larger size at fledging than those hatched from early laid eggs. Inbreeding inhibited growth, but surprisingly this did not depend on (dis)advantageous pre- or postnatal conditions. Our findings imply that inbred individuals lose when they are in direct competition with same-sized outbred individuals regardless of the rearing conditions, and we thus propose that reduced competitiveness is one of the driving forces of inbreeding depression.

  • 28.
    de Boer, Raïssa A.
    et al.
    University of Antwerp, Belgium.
    Eens, Marcel
    Müller, Wendt
    An experimental study: Does inbreeding increase the motivation to mate?2018Ingår i: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 13, nr 6, artikel-id e0199182Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Inbreeding is a central topic in evolutionary biology and ecology and is of major concern for the conservation of endangered species. Yet, it remains challenging to comprehend the fitness consequences of inbreeding, because studies typically focus only on short-term effects on inbreeding in the offspring (e.g. survival until independence). However, there is no a priori reason to assume that inbreeding has no more effects in adulthood. Specifically, inbred males should have lower reproductive success than outbred males among other things because of inbreeding depression in attractiveness to females and a reduced lifespan. Such differences in future reproductive value should affect male mating behaviour, such that an inbred male of a given age should be more motivated to seize a current mating opportunity than an outbred male of the same age. We used an inventive experimental set-up that enabled us to assess male behaviour in relation to an apparent mating opportunity while excluding potential confounding effects of female preference. Age-, weight-, and size-matched inbred and outbred male canaries (Serinus canaria) were presented with a female that only one male at a time could access visually via a ‘peephole’ and thus when both males were equally interested in seizing the apparent mating opportunity this would result in contest. We find that inbred males spent more than twice as much time ‘peeping’ at the female than outbred males, suggesting that inbreeding indeed causes different behavioural responses to an apparent mating opportunity. Our study is among the first to highlight that inbreeding affects male mating behaviour, and therewith potentially male-male competition, which should be taken into account in order to understand the full range of inbreeding effects on fitness.

  • 29.
    de Boer, Raïssa A.
    et al.
    University of Antwerp, Belgium.
    Eens, Marcel
    Müller, Wendt
    'Out of tune': consequences of inbreeding on bird song2016Ingår i: Proceedings of the Royal Society of London. Biological Sciences, ISSN 0962-8452, E-ISSN 1471-2954, Vol. 283, nr 1835, artikel-id 20161142Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The expression of bird song is expected to signal male quality to females. 'Quality' is determined by genetic and environmental factors, but, surprisingly, there is very limited evidence if and how genetic aspects of male quality are reflected in song. Here, we manipulated the genetic make-up of canaries (Serinus canaria) via inbreeding, and studied its effects upon song output, complexity, phonetics and, for the first time, song learning. To this end, we created weight-matched inbred and outbred pairs of male fledglings, which were subsequently exposed to the same tutor male during song learning. Inbreeding strongly affected syllable phonetics, but there were little or no effects on other song features. Nonetheless, females discriminated among inbred and outbred males, as they produced heavier clutches when mated with an outbred male. Our study highlights the importance of song phonetics, which has hitherto often been overlooked.

  • 30.
    de Boer, Raïssa A.
    et al.
    University of Antwerp, Belgium.
    Eens, Marcel
    Müller, Wendt
    Sex-specific effects of inbreeding on reproductive senescence2018Ingår i: Proceedings of the Royal Society of London. Biological Sciences, ISSN 0962-8452, E-ISSN 1471-2954, Vol. 285, nr 1879, artikel-id 20180231Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Inbreeding depression plays a significant role in evolutionary biology and ecology. However, we lack a clear understanding of the fitness consequences of inbreeding depression. Studies often focus on short-term effects of inbreeding in juvenile offspring, whereas inbreeding depression in adult traits and the interplay between inbreeding depression and age are rarely addressed. Inbreeding depression may increase with age and accelerate the decline in reproductive output in ageing individuals (reproductive senescence), which could be subject to sex-specific dynamics. We test this hypothesis with a longitudinal experimental study in a short-lived songbird. Adult inbred and outbred male and female canaries were paired in a 2 × 2 factorial design, and survival and annual reproductive performance were studied for 3 years. We found inbreeding depression in female egg-laying ability, male fertilization success and survival of both sexes. Annual reproductive success of both males and females declined when paired with an inbred partner independent of their own inbreeding status. This shows that inbreeding can have fitness costs in outbred individuals when they mate with an inbred individual. Further, inbred females showed faster reproductive senescence than outbred females, confirming that inbreeding depression and age can interact to affect fitness. By contrast, there was no evidence for an interaction between inbreeding depression and reproductive senescence in male fertilization success. Our findings highlight the importance of considering sex-specific effects and age to determine the full range of fitness consequences of inbreeding and demonstrate that inbreeding depression can accelerate reproductive senescence.

  • 31.
    de Boer, Raïssa Anna
    et al.
    University of Antwerp, Belgium.
    Costantini, David
    Casasole, Giulia
    AbdElgawad, Hamada
    Asard, Han
    Eens, Marcel
    Müller, Wendt
    Sex-specific effects of inbreeding and early life conditions on the adult oxidative balance2018Ingår i: Current Zoology, ISSN 1674-5507, Vol. 64, nr 5, s. 631-639Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Inbreeding negatively affects various life-history traits, with inbred individuals typically having lower fitness than outbred individuals (= inbreeding depression). Inbreeding depression is often emphasized under environmental stress, but the underlying mechanisms and potential long-lasting consequences of such inbreeding-environment interactions remain poorly understood. Here, we hypothesize that inbreeding-environment interactions that occur early in life have long-term physiological effects, in particular on the adult oxidative balance. We applied a unique experimental design to manipulate early life conditions of inbred and outbred songbirds (Serinus canaria) that allowed us to separate prenatal and postnatal components of early life conditions and their respective importance in inbreeding-environment interactions. We measured a wide variety of markers of oxidative status in adulthood, resulting in a comprehensive account for oxidative balance. Using a Bayesian approach with Markov chain Monte Carlo, we found clear sex-specific effects and we also found only in females small yet significant long-term effects of inbreeding-environment interactions on adult oxidative balance. Postnatal components of early life conditions were most persuasively reflected on adult oxidative balance, with inbred females that experienced disadvantageous postnatal conditions upregulating enzymatic antioxidants in adulthood. Our study provides some evidence that adult oxidative balance can reflect inbreeding-environment interactions early in life, but given the rather small effects that were limited to females, we conclude that oxidative stress might have a limited role as mechanism underlying inbreeding-environment interactions.

  • 32.
    de la Paz Celorio-Mancera, Maria
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Zoologiska institutionen, Avdelningen för populationsgenetik.
    Wheat, Christopher W.
    Stockholms universitet, Naturvetenskapliga fakulteten, Zoologiska institutionen, Avdelningen för populationsgenetik.
    Huss, Mikael
    Vezzi, Francesco
    Neethiraj, Ramprasad
    Stockholms universitet, Naturvetenskapliga fakulteten, Zoologiska institutionen, Avdelningen för populationsgenetik.
    Reimegård, Johan
    Nylin, Sören
    Stockholms universitet, Naturvetenskapliga fakulteten, Zoologiska institutionen, Avdelningen för zoologisk ekologi.
    Janz, Niklas
    Stockholms universitet, Naturvetenskapliga fakulteten, Zoologiska institutionen, Avdelningen för zoologisk ekologi.
    Evolutionary history of host use, rather than plant phylogeny, determines gene expression in a generalist butterfly2016Ingår i: BMC Evolutionary Biology, ISSN 1471-2148, E-ISSN 1471-2148, Vol. 16, artikel-id 59Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Background: Although most insect species are specialized on one or few groups of plants, there are phytophagous insects that seem to use virtually any kind of plant as food. Understanding the nature of this ability to feed on a wide repertoire of plants is crucial for the control of pest species and for the elucidation of the macroevolutionary mechanisms of speciation and diversification of insect herbivores. Here we studied Vanessa cardui, the species with the widest diet breadth among butterflies and a potential insect pest, by comparing tissue-specific transcriptomes from caterpillars that were reared on different host plants. We tested whether the similarities of gene-expression response reflect the evolutionary history of adaptation to these plants in the Vanessa and related genera, against the null hypothesis of transcriptional profiles reflecting plant phylogenetic relatedness. Result: Using both unsupervised and supervised methods of data analysis, we found that the tissue-specific patterns of caterpillar gene expression are better explained by the evolutionary history of adaptation of the insects to the plants than by plant phylogeny. Conclusion: Our findings suggest that V. cardui may use two sets of expressed genes to achieve polyphagy, one associated with the ancestral capability to consume Rosids and Asterids, and another allowing the caterpillar to incorporate a wide range of novel host-plants.

  • 33.
    Dinca, Vlad
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Zoologiska institutionen. Consejo Superior de Investigaciones Cientificas (CSIC) Pompeu Fabra University.
    Runquist, Marten
    Nilsson, Marten
    Vila, Roger
    Dispersal, fragmentation, and isolation shape the phylogeography of the European lineages of Polyommatus (Agrodiaetus) ripartii (Lepidoptera: Lycaenidae):  2013Ingår i: Biological Journal of the Linnean Society, ISSN 0024-4066, E-ISSN 1095-8312, Vol. 109, nr 4, s. 817-829Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Polyommatus ripartii is a biogeographically and taxonomically poorly understood species of butterfly with a scattered distribution in Europe. Recently, it has been shown that this species includes several European endemic and localized taxa (galloi, exuberans, agenjoi) that were previously considered species and even protected, a result that poses further questions about the processes that led to its current distribution. We analysed mitochondrial DNA and the morphology of P.ripartii specimens to study the phylogeography of European populations. Three genetically differentiated but apparently synmorphic lineages occur in Europe that could be considered evolutionarily significant units for conservation. Their strongly fragmented and counterintuitive distribution seems to be the result of multiple range expansions and contractions along Pleistocene climatic oscillations. Remarkably, based on the 79 specimens studied, these genetic lineages do not seem to extensively coexist in the distributional mosaic, a phenomenon most evident in the Iberian Peninsula. One of the important gaps in the European distribution of P.ripartii is reduced by the discovery of new Croatian populations, which also facilitate a better understanding of the biogeography of the species.

  • 34.
    Eckerström-Liedholm, Simon
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Zoologiska institutionen.
    Sowersby, Will
    Kotrschal, Alexander
    Näslund, Joacim
    Stockholms universitet, Naturvetenskapliga fakulteten, Zoologiska institutionen.
    Rowiński, Piotr
    Stockholms universitet, Naturvetenskapliga fakulteten, Zoologiska institutionen.
    Gonzalez-Voyer, Alejandro
    Stockholms universitet, Naturvetenskapliga fakulteten, Zoologiska institutionen.
    Rogell, Björn
    Stockholms universitet, Naturvetenskapliga fakulteten, Zoologiska institutionen.
    Fast life-histories are associated with larger brain size in killifishesManuskript (preprint) (Övrigt vetenskapligt)
    Abstract [en]

    Comparative studies suggest a negative relationship between pace of life-history, and relative energetic investment into brain size. However, since brain size typically evolves as a correlated response to selection on body size, any lag in brain size evolution will result in a shift in relative brain size (e.g. small body – large relative brain size).Coevolution between body size and life-history hence has the potential to drive secondary associations between relative brain size and life-history, when body size is correlated with life history. However, as far as we know, the relationship between relative brain size and life-history strategy has not been examined in systems that simultaneously present marked contrasts in life-history but no concordant shifts in body size. Using a common garden approach, we test the association between relative brain size and life-history in 21 species of killifish; a study system that fulfils the aforementioned requirements. Contrary to the prediction that brain size evolves through energetic trade-offs with life-history, we found that adults, but not juveniles, of fast-living species had larger relative brain sizes. Rather than an energetic link to life-history, our results suggest that fast- and slow-living species differ in terms of how cognitively demanding environments they inhabit are, or alternatively in the ontogenetic timing of somatic vs. neural growth.

  • 35.
    Eckerström-Liedholm, Simon
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Zoologiska institutionen.
    Sowersby, Will
    Stockholms universitet, Naturvetenskapliga fakulteten, Zoologiska institutionen.
    Morozov, Sergey
    van der Bijl, Wouter
    Rowiński, Piotr
    Stockholms universitet, Naturvetenskapliga fakulteten, Zoologiska institutionen.
    Gonzalez-Voyer, Alejandro
    Stockholms universitet, Naturvetenskapliga fakulteten, Zoologiska institutionen.
    Rogell, Björn
    Stockholms universitet, Naturvetenskapliga fakulteten, Zoologiska institutionen.
    Macroevolutionary evidence suggests trait-dependent coevolution between behaviour and life-historyManuskript (preprint) (Övrigt vetenskapligt)
    Abstract [en]

    Species with fast life-histories prioritize current over future reproduction, which ought to require greater energetic resources, but also results in a shorter time-period to realize their reproductive potential, compared to slow life-histories, which prioritize future reproduction. Hence, behaviours that increase access to both resources and mating opportunities, at a cost of increased mortality risk, are thought to coevolve with the pace of life-history. However, whether this prediction holds across species, is yet to be tested under standardized conditions. Here, we test how potentially risky behaviours, which facilitate access to resources and mating opportunities (i.e. activity, boldness and aggression), along with metabolic rate, correlates with the pace of life-history across 20 species of killifish, which present a remarkable divergence in the pace of their life-histories. We found a positive correlation between the pace of life-history and aggression, but not with any other behavioural traits or metabolic rate. Aggression is often expressed in the context of mating, while the other behaviours we measured might be more relevant for access to energetic resources. Our results therefore suggest that the trade-off between current and future reproduction plays a more prominent role in shaping mating behaviour, while behaviours related to acquisition of energetic resources may be more affected by ecological factors.

  • 36.
    Eliasson, Clara
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och botanik.
    Hur pollineras kottepalmer?2013Självständigt arbete på grundnivå (kandidatexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
  • 37.
    Emma, Lind
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Zoologiska institutionen. Södertörns högskola.
    Ohlin, Helena
    Mälardalens högskola.
    Grahn, Mats
    Södertörns högskola.
    Fine scale genetic structure in Thresspine sticklback (Gasterosteus aculeatus) along Sweden's coastManuskript (preprint) (Övrigt vetenskapligt)
    Abstract [en]

    There are three basic types of population structures in marine environments; populations that are distinct, with a continuous change and without any differentiation. In each type the population units are characterized by groups of individuals with panmixia within groups and site fidelity to a limited geographic area. Earlier studies of the population genetic structure on sticklebacks in the Baltic Sea have shown none or only little structure. We have sampled 8 sites (253 individuals) along Sweden’s coast to estimate the genetic structure, using five microsatellites and 173 Amplified Fragment Length Polymorphism (AFLP) markers and detected a fine scale genetic structure (AFLP FST= 25%, microsatellites FST = 2.7%). With AFLPs the observed variation followed isolation by distance model (but not with microsatellites). Even sites separated by only 2 km of water are significantly separated. Both Bayesian clustering analysis and Capscale separated populations and identified populations from Gulf of Bothnia (4 psu) and from the west coast (20 psu) as genetically distinctly different from Baltic populations (about 7-8 psu).  In conclusion, gene flow is limited between sampled sites, and since no geographic barriers can be distinguished the population structure is likely caused by the sticklebacks’ behavior. Hence, we have probably sampled either stationary populations of marine sticklebacks, or homing sticklebacks. In this study AFLP and microsatellites did not give congruent results; with AFLPs we got high separation, and genetic variation followed isolation by distance model and supported the continuous change type of population structure.

  • 38.
    Enquist, Magnus
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Zoologiska institutionen. Stockholms universitet, Humanistiska fakulteten, Centrum för evolutionär kulturforskning.
    Ghirlanda, Stefano
    Stockholms universitet, Humanistiska fakulteten, Centrum för evolutionär kulturforskning.
    Jarrick, Arne
    Stockholms universitet, Humanistiska fakulteten, Historiska institutionen. Stockholms universitet, Humanistiska fakulteten, Centrum för evolutionär kulturforskning.
    Wachtmeister, C-A
    Stockholms universitet, Humanistiska fakulteten, Centrum för evolutionär kulturforskning.
    Why does human culture increase exponentially?2008Ingår i: Theoretical Population Biology, ISSN 0040-5809, E-ISSN 1096-0325, Vol. 74, nr 1, s. 46-55Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Historical records show that culture can increase exponentially in time, e.g., in number of poems, musical works, scientific discoveries. We model how human capacities for creativity and cultural transmission may make such an increase possible, suggesting that: (1) creativity played a major role at the origin of human culture and for its accumulation throughout history, because cultural transmission cannot, on its own, generate exponentially increasing amounts of culture; (2) exponential increase in amount of culture can only occur if creativity is positively influenced by culture. The evolution of cultural transmission is often considered the main genetic bottleneck for the origin of culture, because natural selection cannot favor cultural transmission without any culture to transmit. Our models suggest that an increase in individual creativity may have been the first step toward human culture, because in a population of creative individuals there may be enough non-genetic information to favor the evolution of cultural transmission.

  • 39.
    Ersmark, Erik
    Stockholms universitet, Naturvetenskapliga fakulteten, Zoologiska institutionen. Swedish Museum of Natural History (NRM).
    Large carnivore population turnover and ecological change during the Late Quaternary2016Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    The cave lion (Panthera spelaea), the grey wolf (Canis lupus) and the brown bear (Ursus arctos) all shared an intercontinental distribution across the northern hemisphere during most of the Late Quaternary, and experienced repeated events of climate change. The cave lion went extinct at the end of the Pleistocene and although the wolf and the bear have survived until present day, recent human persecution has caused demographic bottlenecks and local extinctions. In this thesis, mitochondrial and nuclear DNA was analyzed from ancient and modern samples in order to study spatiotemporal changes in genetic diversity in the three species. Mitochondrial sequences analyzed from 48 radiocarbon dated cave lion remains revealed two haplogroups, of which the more genetically diverse seemingly disappeared around 41,000 years BP. Serial coalescent simulations on the data supported a population bottleneck in Beringia between roughly 47-18,000 years BP. Its long duration prevents a specific causal factor to be singled out, but the early onset and overlapping declines of other large mammals in the region suggests that major environmental changes greatly impacted the fauna of Beringia during this time. Using a similar genetic marker, a set of 126 modern wolves and two Siberian wolf remains of Late Pleistocene age were analyzed. The sequences yielded from the latter samples pertained to a basal haplogroup, which contained all Late Pleistocene wolves from previous studies. As data from both modern and ancient wolves were combined, a pattern of decreasing genetic diversity was identified around the Pleistocene-Holocene transition. This decrease was further tested by serial coalescent simulations, which supported a bottleneck in northern North America around this time. Further analyses were applied to one of the ancient wolf remains from Siberia, producing a draft genome sequence and a complete mitochondrial genome. Given the radiocarbon date of the Siberian wolf, a slower mutation rate could be inferred, which pushed back the split between the lineages leading to modern wolves and dogs to at least 27,000 years BP. The Siberian wolf was positioned close to the split but basal to these lineages. A global comparison with modern dogs indicated a closer genetic affiliation between the Siberian wolf and some arctic breeds. For the brown bear, phylogeographic changes in Europe were studied over the last 50,000 years, using radiocarbon dating and mitochondrial sequences. When concatenated and compared with published data, the mtDNA revealed a turnover event just before the LGM, while the dating confirmed a presence of brown bears at relatively high latitudes during this period. Marked shifts in population size were also inferred. Furthermore, data of stable isotope levels confirmed a dietary shift to increasing herbivory around the LGM. Finally, a recent anthropogenic bottleneck among Scandinavian brown bears was studied. While no change in genetic structure could be detected, mitochondrial and microsatellite markers showed a decline in genetic diversity, especially pronounced in the southern subpopulation. ABC simulations supported a bottleneck taking place across all of Scandinavia. Taken together, this thesis have identified and elucidated several impacts on genetic diversity in the past populations of large carnivores. The use of different genetic markers has enabled comparisons with published data, but also revealed their comparatively different benefits and limitations. Overall, the presented studies compose a synthesis of past population dynamics in large carnivores, uniquely revealed by ancient DNA.

  • 40.
    Ersmark, Erik
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Zoologiska institutionen. Swedish Museum of Natural History, Sweden.
    Baryshnikov, Gennady
    Higham, Tom
    Argant, Alain
    Döppes, Doris
    Germonpré, Mietje
    Lidén, Kerstin
    Stockholms universitet, Humanistiska fakulteten, Institutionen för arkeologi och antikens kultur, Arkeologiska forskningslaboratoriet.
    Lipecki, Grzegorz
    Marciszak, Adrian
    Pacher, Martina
    Storå, Jan
    Stockholms universitet, Humanistiska fakulteten, Institutionen för arkeologi och antikens kultur, Osteoarkeologiska forskningslaboratoriet.
    Sabol, Martin
    Valdiosera, Christina
    Villaluenga, Aritza
    Stewart, John
    Dalén, Love
    Stockholms universitet, Naturvetenskapliga fakulteten, Zoologiska institutionen.
    Genetic revolutions and northern survival during the last glacial maximum in European brown bearsManuskript (preprint) (Övrigt vetenskapligt)
  • 41.
    Ersmark, Erik
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Zoologiska institutionen. Swedish Museum of Natural History, Sweden.
    Klütsch, Cornelya
    Chan, Yvonne
    Dalén, Love
    Stockholms universitet, Naturvetenskapliga fakulteten, Zoologiska institutionen.
    Sinding-Larsen, Mikkel
    Gilbert, Thomas
    Arvestad, Lars
    Stockholms universitet, Naturvetenskapliga fakulteten, Numerisk analys och datalogi (NADA).
    Fain, Steven R.
    Illarionova, Natalia
    Oskarsson, Mattias
    Uhlén, Mathias
    Zhang, Ya-Ping
    Savolainen, Peter
    From the past to the present: Wolf phylogeography and demographic history based on the mitochondrial control regionManuskript (preprint) (Övrigt vetenskapligt)
  • 42.
    Ersmark, Erik
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Zoologiska institutionen. Swedish Museum of Natural History, Sweden.
    Orlando, Ludovic
    Sandoval-Castellanos, Edson
    Stockholms universitet, Naturvetenskapliga fakulteten, Zoologiska institutionen. Swedish Museum of Natural History, Sweden.
    Barnes, Ian
    Barnett, Ross
    Stuart, Anthony
    Lister, Adrian
    Dalén, Love
    Swedish Museum of Natural History, Sweden.
    Population demography and genetic diversity in the Pleistocene cave lion2015Ingår i: Open Quaternary, ISSN 2055-298X, Vol. 1, nr 1, artikel-id 4Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    With a range that covered most of northern Eurasia and parts of North America, the cave lion (Panthera spelaea) was one of the most widespread carnivores of the Late Pleistocene. Earlier ancient DNA analyses have shown that it is distinct from modern lions, and have suggested a demographic decline in Beringia during marine isotope stage 3 (MIS 3). Here, we further investigate the Late Pleistocene population dynamics in more detail by combining a powerful algorithm that couples MCMC with coalescent simulations under an approximate Bayesian computation framework. We use an ancient DNA dataset of previously published (n = 34) and new radiocarbon dated specimens (n = 14). Phylogenetic and network analyses based on the mitochondrial control region and the ATP8 gene identified two major haplogroups, one of which appears to vanish around 41,000 cal a BP. The approximate Bayesian computation analysis suggested a decline in effective population size (Ne) in Beringia of at least a 2-fold magnitude that began approximately 47,000 cal a BP, followed by an increase in Ne, most likely around 18,000 cal a BP. The cave lion went through a demographic bottleneck during MIS 3, which may have lasted for several tens of thousands of years, and only recovered shortly before the species' extinction. Several other large mammal species display similar declines in genetic diversity in Beringia during MIS 3, suggesting that major environmental changes might have affected megafaunal populations during this time period.

  • 43.
    Fogarty, Laurel
    et al.
    University of St Andrews, Centre for Social Learning and Cognitive Evolution, School of Biology.
    Strimling, Pontus
    Stockholms universitet, Humanistiska fakulteten, Centrum för evolutionär kulturforskning.
    Laland, Kevin Neville
    University of St Andrews, Centre for Social Learning and Cognitive Evolution, School of Biology.
    THE EVOLUTION OF TEACHING2011Ingår i: Evolution, ISSN 0014-3820, E-ISSN 1558-5646, Vol. 65, nr 10, s. 2760-2770Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Teaching, alongside imitation, is widely thought to underlie the success of humanity by allowing high-fidelity transmission of information, skills, and technology between individuals, facilitating both cumulative knowledge gain and normative culture. Yet, it remains a mystery why teaching should be widespread in human societies but extremely rare in other animals. We explore the evolution of teaching using simple genetic models in which a single tutor transmits adaptive information to a related pupil at a cost. Teaching is expected to evolve where its costs are outweighed by the inclusive fitness benefits that result from the tutor's relatives being more likely to acquire the valuable information. We find that teaching is not favored where the pupil can easily acquire the information on its own, or through copying others, or for difficult to learn traits, where teachers typically do not possess the information to pass on to relatives. This leads to a narrow range of traits for which teaching would be efficacious, which helps to explain the rarity of teaching in nature, its unusual distribution, and its highly specific nature. Further models that allow for cumulative cultural knowledge gain suggest that teaching evolved in humans because cumulative culture renders otherwise difficult-to-acquire valuable information available to teach.

  • 44.
    Forsman, Anders
    et al.
    Department of Biology and Environmental Science, University of Kalmar.
    Hagman, Mattias
    School of Biological Sciences A08, University of Sydney, NSW 2006, Australia.
    Calling is an honest indicator of paternal genetic quality in male poison frogs2006Ingår i: Evolution, ISSN 0014-3820, E-ISSN 1558-5646, Vol. 60, nr 10, s. 2148-2157Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Several competing hypotheses have been put forward to explain why females of many species mate preferentially with males possessing the most conspicuous signals (e.g., ornaments, displays, or songs). We performed a laboratory experiment using two species of poison frogs, Dendrobates leucomelas and Epipedobates tricolor, to test the hypothesis that male calling performance is an honest indicator of parental quality. Our analyses are based on data from behavioral observations of mating activities of captive-reared individuals (and their offspring) that were housed in terraria for four consecutive breeding seasons. Male mating success increased with male calling rate and chirp duration in both species, suggesting that females preferred males with more elaborate calls. Because calling performance improved with age in D. leucomelas, female poison frogs that prefer males with more elaborate calls in the wild may end up mating with older males that have already proven their ability to survive. Females that mated with good callers obtained higher quality offspring. Eggs fertilized by males with high calling rates and long chirp durations had higher hatching success and produced tadpoles that were more likely to metamorphose into surviving frogs. As a consequence, females that mated with males with high calling performance obtained more surviving offspring per egg, compared to females that mated with poor callers. Collectively, our findings comply with the notion that female poison frogs prefer to mate with good callers because calling performance is a reliable predictor of offspring quality. The possible influence of maternal allocation and reasons for the strong effect size compared to previous studies are discussed.

  • 45.
    Hagman, Mattias
    et al.
    Department of Biology and Environmental Sciences, Kalmar University.
    Forsman, Anders
    Department of Biology and Environmental Sciences, Kalmar University.
    Correlated evolution of conspicuous colouration and body size in the poison frog family Dendrobatidae2003Ingår i: Evolution, ISSN 0014-3820, E-ISSN 1558-5646, Vol. 57, nr 12, s. 2904-2910Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Conspicuous coloration is often used in combination with chemical defenses to deter predators from attacking. Experimental studies have shown that the avoidance inducing effect of conspicuous prey coloration increases with increasing size of pattern elements and with increasing body size. Here we use a comparative approach to test the prediction from these findings, namely that conspicuous coloration will evolve in tandem with body size. In our analysis, we use a previously published mitochondrial DNA-based phylogeny and comparative analysis of independent contrasts to examine if evolutionary shifts in color pattern have been associated with evolutionary changes in body size in aposematic poison frogs (Anura: Dendrobatidae). Information on body size (snout to vent length) and coloration were obtained from the literature. Two different measures of conspicuousness were used, one based on rankings by human observers and the other based on computer analysis of digitized photographs. The results from comparative analyses using either measure of coloration indicated that avoidance inducing coloration and body size have evolved in concert in poison frogs. Results from reconstruction of character change further indicate that the correlated evolution of size and coloration has involved changes in both directions within each of the different clades of the phylogenetic tree. This finding is consistent with the hypothesis that selection imposed by visually guided predators has promoted the evolution of larger body size in species with conspicuous coloration, or enhanced evolution of conspicuous coloration in larger species.

  • 46.
    Hambäck, Peter A.
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och botanik.
    Weingartner, Elisabet
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och botanik.
    Ericson, Lars
    Fors, Lisa
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och botanik.
    Cassel-Lundhagen, Anna
    Stenberg, Johan A.
    Bergsten, Johannes
    Bayesian species delimitation reveals generalist and specialist parasitic wasps on Galerucella beetles (Chrysomelidae): sorting by herbivore or plant host2013Ingår i: BMC Evolutionary Biology, ISSN 1471-2148, E-ISSN 1471-2148, Vol. 13, artikel-id 92Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Background: To understand the ecological and evolutionary consequences of species interactions in food webs necessitates that interactions are properly identified. Genetic analyses suggest that many supposedly generalist parasitoid species should rather be defined as multiple species with a more narrow diet, reducing the probability that such species may mediate indirect interactions such as apparent competition among hosts. Recent studies showed that the parasitoid Asecodes lucens mediate apparent competition between two hosts, Galerucella tenella and G. calmariensis, affecting both interaction strengths and evolutionary feedbacks. The same parasitoid was also recorded from other species in the genus Galerucella, suggesting that similar indirect effects may also occur for other species pairs. Methods: To explore the possibility of such interactions, we sequenced mitochondrial and nuclear genetic markers to resolve the phylogeny of both host and parasitoid and to test the number of parasitoid species involved. We thus collected 139 Galerucella larvae from 8 host plant species and sequenced 31 adult beetle and 108 parasitoid individuals. Results: The analysis of the Galerucella data, that also included sequences from previous studies, verified the five species previously documented as reciprocally monophyletic, but the Bayesian species delimitation for A. lucens suggested 3-4 cryptic taxa with a more specialised host use than previously suggested. The gene data analyzed under the multispecies coalescent model allowed us to reconstruct the species tree phylogeny for both host and parasitoid and we found a fully congruent coevolutionary pattern suggesting that parasitoid speciation followed upon host speciation. Conclusion: Using multilocus sequence data in a Bayesian species delimitation analysis we propose that hymenopteran parasitoids of the genus Asecodes that infest Galerucella larvae constitute at least three species with narrow diet breath. The evolution of parasitoid Asecodes and host Galerucella show a fully congruent coevolutionary pattern. This finding strengthens the hypothesis that the parasitoid in host search uses cues of the host rather than more general cues of both host and plant.

  • 47. Haydock, Hannah
    et al.
    Clarke, Leon
    Craig-Atkins, Elizabeth
    Howcroft, Rachel
    Stockholms universitet, Humanistiska fakulteten, Institutionen för arkeologi och antikens kultur, Arkeologiska forskningslaboratoriet.
    Buckberry, Jo
    Weaning at Anglo-Saxon raunds: Implications for changing breastfeeding practice in britain over two millennia2013Ingår i: American Journal of Physical Anthropology, ISSN 0002-9483, E-ISSN 1096-8644, Vol. 151, nr 4, s. 604-612Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This study investigated stable-isotope ratio evidence of weaning for the late Anglo-Saxon population of Raunds Furnells, Northamptonshire, UK. delta N-15 and delta C-13 values in rib collagen were obtained for individuals of different ages to assess the weaning age of infants within the population. A peak in delta N-15 values at about 2-year-old, followed by a decline in delta N-15 values until age three, indicates a change in diet at that age. This change in nitrogen isotope ratios corresponds with the mortality profile from the site, as well as with archaeological and documentary evidence on attitudes towards juveniles in the Anglo-Saxon period. The pattern of delta C-13 values was less clear. Comparison of the predicted age of weaning to published data from sites dating from the Iron Age to the 19th century in Britain reveals a pattern of changing weaning practices over time, with increasingly earlier commencement and shorter periods of complementary feeding in more recent periods. Such a change has implications for the interpretation of socioeconomic changes during this period of British history, since earlier weaning is associated with decreased birth spacing, and could thus have contributed to population growth.

  • 48.
    Henriksson, Oskar
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Zoologiska institutionen, Avdelningen för zoologisk ekologi. Södertörns högskola.
    Grahn, Mats
    Södertörns högskola.
    Contrasting population genetic structure of Siganus sutor between mainland coastal and oceanic island populationsManuskript (preprint) (Övrigt vetenskapligt)
    Abstract [en]

    Studies on genetic connectivity are important for the management of fisheries. In this study we used AFLP to investigate population structure of the endemic Spinefoot shoemaker, Siganus sutor, from 6 countries, Kenya, Tanzania, Comoros, Seychelles and Mauritius in the Western Indian Ocean. We collected 506 samples from 20 fish landing sites, 171 variable loci were used in the statistical analysis. Global FST was significant and showed a pattern of isolation by distance, mostly influenced by remote oceanic islands. In a previous study we have described the temporal variation of Siganus sutor to be about 1/5 of the global variation, and by applying a 1/5 of the global variation cut of value for the pair-wise comparisons we were able to account some of the pair- wise genetic variation as temporal fluctuations. A STRUCTURE analysis was also preformed that corroborates the pair-wise FST comparisons. Overall these results show that S. sutor is genetically diverse and subdivided throughout the region, but also that the current management regime might not be optimal. 

  • 49.
    Henriksson, Oskar
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Zoologiska institutionen, Avdelningen för zoologisk ekologi. Södertörns högskola.
    Mwandya, Augustine
    Gullström, Martin
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och botanik.
    Thorberg, Marika
    Grahn, Mats
    AFLP assisted DNA-Barcoding of mullets (Mugilidae) used in East African aquaculture2012Ingår i: Western Indian Ocean journal of marine science, ISSN 0856-860X, Vol. 11, nr 1, s. 41-54Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    There is a growing demand for wild caught juvenile fish to supply the market for aquaculture. However, little is known about the genetic effects of juvenile collection from wild populations. There are a number of imminent threats to both aquaculture systems and wild fish populations. Juvenile collection from a single population can for example reduce population’s evolutionary potential as well as the disease resistance within an aquaculture pond. In this study, we investigated the local genetic structure of juvenile mullets collected from five sites around Bagamoyo (Tanzanian mainland) and Zanzibar Island, East Africa. Fish were caught in low tide using a seine net. The fish were morphologically identified, and then genetically identified using direct sequencing of the CO1 gene with cross referencing with the Barcode of Life Database (BOLD) systems.  Molecular variance analyses were used to infer genetic subdivision based on geographic sampling site as well as inferring population structure through the Bayesian assignment test implemented in STRUCTURE 2.3. Our results showed that samples morphologically identified as Mugil cephalus where in fact Valamugil buchanani and we also found evidence of an introgression genome event, where the gene flow from one species may have affected the general gene pool. The Bayesian analysis revealed a clear genetic population structure among the sampled fish; the main difference was the presence of a unique mainland cluster. Our findings may have important implications for management and conservation of mullet fishes in the region and elsewhere.

  • 50.
    Hill, Jason
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Zoologiska institutionen, Avdelningen för populationsgenetik. Uppsala University, Sweden.
    Rastas, Pasi
    Hornett, Emily A.
    Neethiraj, Ramprasad
    Stockholms universitet, Naturvetenskapliga fakulteten, Zoologiska institutionen, Avdelningen för populationsgenetik.
    Clark, Nathan
    Morehouse, Nathan
    de la Paz Celorio-Mancera, Maria
    Stockholms universitet, Naturvetenskapliga fakulteten, Zoologiska institutionen, Avdelningen för populationsgenetik.
    Carnicer Cols, Jofre
    Dircksen, Heinrich
    Stockholms universitet, Naturvetenskapliga fakulteten, Zoologiska institutionen, Avdelningen för funktionell zoomorfologi.
    Meslin, Camille
    Keehnen, Naomi
    Stockholms universitet, Naturvetenskapliga fakulteten, Zoologiska institutionen, Avdelningen för populationsgenetik.
    Pruisscher, Peter
    Stockholms universitet, Naturvetenskapliga fakulteten, Zoologiska institutionen, Avdelningen för populationsgenetik.
    Sikkink, Kristin
    Vives, Maria
    Vogel, Heiko
    Wiklund, Christer
    Stockholms universitet, Naturvetenskapliga fakulteten, Zoologiska institutionen, Avdelningen för populationsgenetik.
    Woronik, Alyssa
    Stockholms universitet, Naturvetenskapliga fakulteten, Zoologiska institutionen, Avdelningen för populationsgenetik. New York University, USA.
    Boggs, Carol L.
    Nylin, Sören
    Stockholms universitet, Naturvetenskapliga fakulteten, Zoologiska institutionen, Avdelningen för populationsgenetik.
    Wheat, Christopher W.
    Stockholms universitet, Naturvetenskapliga fakulteten, Zoologiska institutionen, Avdelningen för populationsgenetik.
    Unprecedented reorganization of holocentric chromosomes provides insights into the enigma of lepidopteran chromosome evolution2019Ingår i: Science Advances, E-ISSN 2375-2548, Vol. 5, nr 6, artikel-id eaau3648Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Chromosome evolution presents an enigma in the mega-diverse Lepidoptera. Most species exhibit constrained chromosome evolution with nearly identical haploid chromosome counts and chromosome-level gene collinearity among species more than 140 million years divergent. However, a few species possess radically inflated chromosomal counts due to extensive fission and fusion events. To address this enigma of constraint in the face of an exceptional ability to change, we investigated an unprecedented reorganization of the standard lepidopteran chromosome structure in the green-veined white butterfly (Pieris napi). We find that gene content in P. napi has been extensively rearranged in large collinear blocks, which until now have been masked by a haploid chromosome number close to the lepidopteran average. We observe that ancient chromosome ends have been maintained and collinear blocks are enriched for functionally related genes suggesting both a mechanism and a possible role for selection in determining the boundaries of these genome-wide rearrangements.

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