Change search
Refine search result
1 - 49 of 49
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the Create feeds function.
  • 1.
    Ah-King, Malin
    et al.
    Stockholm University, Faculty of Humanities, Department of Ethnology, History of Religions and Gender Studies. Uppsala University, Sweden; University of California, USA.
    Gowaty, Patricia Adair
    A conceptual review of mate choice: stochastic demography, within-sex phenotypic plasticity, and individual flexibility2016In: Ecology and Evolution, ISSN 2045-7758, E-ISSN 2045-7758, Vol. 6, no 14, p. 4607-4642Article, review/survey (Refereed)
    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.

  • 2. Ardehed, Angelica
    et al.
    Johansson, Daniel
    Schagerström, Ellen
    Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences.
    Kautsky, Lena
    Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences.
    Johannesson, Kerstin
    Pereyra, Ricardo T.
    Complex spatial clonal structure in the macroalgae Fucus radicans with both sexual and asexual recruitment2015In: Ecology and Evolution, ISSN 2045-7758, E-ISSN 2045-7758, Vol. 5, no 19, p. 4233-4245Article in journal (Refereed)
    Abstract [en]

    In dioecious species with both sexual and asexual reproduction, the spatial distribution of individual clones affects the potential for sexual reproduction and local adaptation. The seaweed Fucus radicans, endemic to the Baltic Sea, has separate sexes, but new attached thalli may also form asexually. We mapped the spatial distribution of clones (multilocus genotypes, MLGs) over macrogeographic (>500km) and microgeographic (<100m) scales in the Baltic Sea to assess the relationship between clonal spatial structure, sexual recruitment, and the potential for natural selection. Sexual recruitment was predominant in some areas, while in others asexual recruitment dominated. Where clones of both sexes were locally intermingled, sexual recruitment was nevertheless low. In some highly clonal populations, the sex ratio was strongly skewed due to dominance of one or a few clones of the same sex. The two largest clones (one female and one male) were distributed over 100-550km of coast and accompanied by small and local MLGs formed by somatic mutations and differing by 1-2 mutations from the large clones. Rare sexual events, occasional long-distance migration, and somatic mutations contribute new genotypic variation potentially available to natural selection. However, dominance of a few very large (and presumably old) clones over extensive spatial and temporal scales suggested that either these have superior traits or natural selection has only been marginally involved in the structuring of genotypes.

  • 3. Astor, Tina
    et al.
    Strengbom, Joachim
    Berg, Matty P.
    Lenoir, Lisette
    Marteinsdottir, Bryndis
    Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences.
    Bengtsson, Jan
    Underdispersion and overdispersion of traits in terrestrial snail communities on islands2014In: Ecology and Evolution, ISSN 2045-7758, E-ISSN 2045-7758, Vol. 4, no 11, p. 2090-2102Article in journal (Refereed)
    Abstract [en]

    Understanding and disentangling different processes underlying the assembly and diversity of communities remains a key challenge in ecology. Species can assemble into communities either randomly or due to deterministic processes. Deterministic assembly leads to species being more similar (underdispersed) or more different (overdispersed) in certain traits than would be expected by chance. However, the relative importance of those processes is not well understood for many organisms, including terrestrial invertebrates. Based on knowledge of a broad range of species traits, we tested for the presence of trait underdispersion (indicating dispersal or environmental filtering) and trait overdispersion (indicating niche partitioning) and their relative importance in explaining land snail community composition on lake islands. The analysis of community assembly was performed using a functional diversity index (Rao's quadratic entropy) in combination with a null model approach. Regression analysis with the effect sizes of the assembly tests and environmental variables gave information on the strength of under- and overdispersion along environmental gradients. Additionally, we examined the link between community weighted mean trait values and environmental variables using a CWM-RDA. We found both trait underdispersion and trait overdispersion, but underdispersion (eight traits) was more frequently detected than overdispersion (two traits). Underdispersion was related to four environmental variables (tree cover, habitat diversity, productivity of ground vegetation, and location on an esker ridge). Our results show clear evidence for underdispersion in traits driven by environmental filtering, but no clear evidence for dispersal filtering. We did not find evidence for overdispersion of traits due to diet or body size, but overdispersion in shell shape may indicate niche differentiation between snail species driven by small-scale habitat heterogeneity. The use of species traits enabled us to identify key traits involved in snail community assembly and to detect the simultaneous occurrence of trait underdispersion and overdispersion.

  • 4.
    Audusseau, Helene
    et al.
    Stockholm University, Faculty of Science, Department of Zoology.
    Nylin, Sören
    Stockholm University, Faculty of Science, Department of Zoology.
    Janz, Niklas
    Stockholm University, Faculty of Science, Department of Zoology.
    Implications of a temperature increase for host plant range: predictions for a butterfly2013In: Ecology and Evolution, ISSN 2045-7758, E-ISSN 2045-7758, Vol. 3, no 9, p. 3021-3029Article in journal (Refereed)
    Abstract [en]

    Although changes in phenology and species associations are relatively well-documented responses to global warming, the potential interactions between these phenomena are less well understood. In this study, we investigate the interactions between temperature, phenology (in terms of seasonal timing of larval growth) and host plant use in the polyphagous butterfly Polygonia c-album. We found that the hierarchy of larval performance on three natural host plants was not modified by a temperature increase as such. However, larval performance on each host plant and temperature treatment was affected by rearing season. Even though larvae performed better at the higher temperature regardless of the time of the rearing, relative differences between host plants changed with the season. For larvae reared late in the season, performance was always better on the herbaceous plant than on the woody plants. In this species, it is likely that a prolonged warming will lead to a shift from univoltinism to bivoltinism. The demonstrated interaction between host plant suitability and season means that such a shift is likely to lead to a shift in selective regime, favoring specialization on the herbaceous host. Based on our result, we suggest that host range evolution in response to temperature increase would in this species be highly contingent on whether the population undergoes a predicted shift from one to two generations. We discuss the effect of global warming on species associations and the outcome of asynchrony in rates of phenological change.

  • 5. Barboza, Francisco R.
    et al.
    Kotta, Jonne
    Weinberger, Florian
    Jormalainen, Veijo
    Kraufvelin, Patrik
    Molis, Markus
    Schubert, Hendrik
    Pavia, Henrik
    Nylund, Göran M.
    Kautsky, Lena
    Stockholm University, Faculty of Science, Stockholm University Baltic Sea Centre.
    Schagerström, Ellen
    Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences.
    Rickert, Esther
    Saha, Mahasweta
    Fredriksen, Stein
    Martin, Georg
    Torn, Kaire
    Ruuskanen, Ari
    Wahl, Martin
    Geographic variation in fitness-related traits of the bladderwrack Fucus vesiculosus along the Baltic Sea-North Sea salinity gradient2019In: Ecology and Evolution, ISSN 2045-7758, E-ISSN 2045-7758, Vol. 9, no 16, p. 9225-9238Article in journal (Refereed)
    Abstract [en]

    In the course of the ongoing global intensification and diversification of human pressures, the study of variation patterns of biological traits along environmental gradients can provide relevant information on the performance of species under shifting conditions. The pronounced salinity gradient, co-occurrence of multiple stressors, and accelerated rates of change make the Baltic Sea and its transition to North Sea a suitable region for this type of study. Focusing on the bladderwrack Fucus vesiculosus, one of the main foundation species on hard-bottoms of the Baltic Sea, we analyzed the phenotypic variation among populations occurring along 2,000 km of coasts subjected to salinities from 4 to >30 and a variety of other stressors. Morphological and biochemical traits, including palatability for grazers, were recorded at 20 stations along the Baltic Sea and four stations in the North Sea. We evaluated in a common modeling framework the relative contribution of multiple environmental drivers to the observed trait patterns. Salinity was the main and, in some cases, the only environmental driver of the geographic trait variation in F. vesiculosus. The decrease in salinity from North Sea to Baltic Sea stations was accompanied by a decline in thallus size, photosynthetic pigments, and energy storage compounds, and affected the interaction of the alga with herbivores and epibiota. For some traits, drivers that vary locally such as wave exposure, light availability or nutrient enrichment were also important. The strong genetic population structure in this macroalgae might play a role in the generation and maintenance of phenotypic patterns across geographic scales. In light of our results, the desalination process projected for the Baltic Sea could have detrimental impacts on F. vesiculosus in areas close to its tolerance limit, affecting ecosystem functions such as habitat formation, primary production, and food supply.

  • 6. Birkhofer, Klaus
    et al.
    Bylund, Helena
    Dalin, Peter
    Ferlian, Olga
    Gagic, Vesna
    Hambäck, Peter A.
    Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences.
    Klapwijk, Maartje
    Mestre, Laia
    Roubinet, Eve
    Schroeder, Martin
    Stenberg, Johan A.
    Porcel, Mario
    Björkman, Christer
    Jonsson, Mattias
    Methods to identify the prey of invertebrate predators in terrestrial field studies2017In: Ecology and Evolution, ISSN 2045-7758, E-ISSN 2045-7758, Vol. 7, no 6, p. 1942-1953Article, review/survey (Refereed)
    Abstract [en]

    Predation is an interaction during which an organism kills and feeds on another organism. Past and current interest in studying predation in terrestrial habitats has yielded a number of methods to assess invertebrate predation events in terrestrial ecosystems. We provide a decision tree to select appropriate methods for individual studies. For each method, we then present a short introduction, key examples for applications, advantages and disadvantages, and an outlook to future refinements. Video and, to a lesser extent, live observations are recommended in studies that address behavioral aspects of predator-prey interactions or focus on per capita predation rates. Cage studies are only appropriate for small predator species, but often suffer from a bias via cage effects. The use of prey baits or analyses of prey remains are cheaper than other methods and have the potential to provide per capita predation estimates. These advantages often come at the cost of low taxonomic specificity. Molecular methods provide reliable estimates at a fine level of taxonomic resolution and are free of observer bias for predator species of any size. However, the current PCR-based methods lack the ability to estimate predation rates for individual predators and are more expensive than other methods. Molecular and stable isotope analyses are best suited to address systems that include a range of predator and prey species. Our review of methods strongly suggests that while in many cases individual methods are sufficient to study specific questions, combinations of methods hold a high potential to provide more holistic insights into predation events. This review presents an overview of methods to researchers that are new to the field or to particular aspects of predation ecology and provides recommendations toward the subset of suitable methods to identify the prey of invertebrate predators in terrestrial field research.

  • 7.
    Dalerum, Fredrik
    et al.
    Stockholm University, Faculty of Science, Department of Zoology. University of Oviedo, Spain; University of Pretoria, South Africa.
    Retief, Tarryn Anne
    Havemann, Carl Peter
    Chimimba, Christian T.
    van Rensburg, Berndt Janse
    The influence of distance to perennial surface water on ant communities in Mopane woodlands, northern Botswana2019In: Ecology and Evolution, ISSN 2045-7758, E-ISSN 2045-7758, Vol. 9, no 1, p. 154-165Article in journal (Refereed)
    Abstract [en]

    Studies of biodiversity along environmental gradients provide information on how ecological communities change in response to biotic and abiotic factors. For instance, distance to water is associated with several factors that shape the structure and the functioning of ecosystems at a range of spatial scales. We investigated the influence of distance to a perennial water source on ant communities in a semi-arid savanna in northern Botswana. Ant abundance, taxonomic richness, and both alpha and beta diversity were generally higher during the wet than the dry season. However, there were strong seasonal influences on the effects of distance to water, with more pronounced effects during the wet season. While both abundance and beta diversity declined with increasing distances to water during the wet season, there was a contrasting increase in alpha diversity. There was no major effect of distance to water on taxonomic richness during either season. Beta diversity was as high across as along gradients, and we found support for modular rather than nested community structures along gradients. Our study demonstrated that small-scale gradients in distance to water can influence several aspects of ant communities in semi-arid savannas. However, our results also point to strong effects of small-scale environmental variation, for instance associated with vegetation characteristics, soil properties, and plant community structure that are not directly linked to water access.

  • 8.
    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.2016In: Ecology and Evolution, ISSN 2045-7758, E-ISSN 2045-7758, Vol. 6, no 21, p. 7921-7930Article in journal (Refereed)
    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.

  • 9.
    Ersmark, Erik
    et al.
    Stockholm University, Faculty of Science, Department of Zoology. Swedish Museum of Natural History, Sweden.
    Baryshnikov, Gennady
    Higham, Thomas
    Argant, Alain
    Castaños, Pedro
    Döppes, Doris
    Gasparik, Mihaly
    Germonpré, Mietje
    Lidén, Kerstin
    Stockholm University, Faculty of Humanities, Department of Archaeology and Classical Studies.
    Lipecki, Grzegorz
    Marciszak, Adrian
    Miller, Rebecca
    Moreno-García, Marta
    Pacher, Martina
    Robu, Marius
    Rodriguez-Varela, Ricardo
    Stockholm University, Faculty of Humanities, Department of Archaeology and Classical Studies.
    Rojo Guerra, Manuel
    Sabol, Martin
    Spassov, Nikolai
    Storå, Jan
    Stockholm University, Faculty of Humanities, Department of Archaeology and Classical Studies.
    Valdiosera, Christina
    Villaluenga, Aritza
    Stewart, John R.
    Dalén, Love
    Genetic turnovers and northern survival during the last glacial maximum in European brown bears2019In: Ecology and Evolution, ISSN 2045-7758, E-ISSN 2045-7758, Vol. 9, no 10, p. 5891-5905Article in journal (Refereed)
    Abstract [en]

    The current phylogeographic pattern of European brown bears (Ursus arctos) has commonly been explained by postglacial recolonization out of geographically distinct refugia in southern Europe, a pattern well in accordance with the expansion/contraction model. Studies of ancient DNA from brown bear remains have questioned this pattern, but have failed to explain the glacial distribution of mitochondrial brown bear clades and their subsequent expansion across the European continent. We here present 136 new mitochondrial sequences generated from 346 remains from Europe, ranging in age between the Late Pleistocene and historical times. The genetic data show a high Late Pleistocene diversity across the continent and challenge the strict confinement of bears to traditional southern refugia during the last glacial maximum (LGM). The mitochondrial data further suggest a genetic turnover just before this time, as well as a steep demographic decline starting in the mid-Holocene. Levels of stable nitrogen isotopes from the remains confirm a previously proposed shift toward increasing herbivory around the LGM in Europe. Overall, these results suggest that in addition to climate, anthropogenic impact and inter-specific competition may have had more important effects on the brown bear's ecology, demography, and genetic structure than previously thought.

  • 10. Flores, Olivier
    et al.
    Garnier, Eric
    Wright, Ian J.
    Reich, Peter B.
    Pierce, Simon
    Diaz, Sandra
    Pakeman, Robin J.
    Rusch, Graciela M.
    Bernard-Verdier, Maud
    Testi, Baptiste
    Bakker, Jan P.
    Bekker, Renee M.
    Cerabolini, Bruno E. L.
    Ceriani, Roberta M.
    Cornu, Guillaume
    Cruz, Pablo
    Delcamp, Matthieu
    Dolezal, Jiri
    Eriksson, Ove
    Stockholm University, Faculty of Science, Department of Botany.
    Fayolle, Adeline
    Freitas, Helena
    Golodets, Carly
    Gourlet-Fleury, Sylvie
    Hodgson, John G.
    Brusa, Guido
    Kleyer, Michael
    Kunzmann, Dieter
    Lavorel, Sandra
    Papanastasis, Vasilios P.
    Perez-Harguindeguy, Natalia
    Vendramini, Fernanda
    Weiher, Evan
    An evolutionary perspective on leaf economics: phylogenetics of leaf mass per area in vascular plants2014In: Ecology and Evolution, ISSN 2045-7758, E-ISSN 2045-7758, Vol. 4, no 14, p. 2799-2811Article in journal (Refereed)
    Abstract [en]

    In plant leaves, resource use follows a trade-off between rapid resource capture and conservative storage. This worldwide leaf economics spectrum consists of a suite of intercorrelated leaf traits, among which leaf mass per area, LMA, is one of the most fundamental as it indicates the cost of leaf construction and light-interception borne by plants. We conducted a broad-scale analysis of the evolutionary history of LMA across a large dataset of 5401 vascular plant species. The phylogenetic signal in LMA displayed low but significant conservatism, that is, leaf economics tended to be more similar among close relatives than expected by chance alone. Models of trait evolution indicated that LMA evolved under weak stabilizing selection. Moreover, results suggest that different optimal phenotypes evolved among large clades within which extremes tended to be selected against. Conservatism in LMA was strongly related to growth form, as were selection intensity and phenotypic evolutionary rates: woody plants showed higher conservatism in relation to stronger stabilizing selection and lower evolutionary rates compared to herbaceous taxa. The evolutionary history of LMA thus paints different evolutionary trajectories of vascular plant species across clades, revealing the coordination of leaf trait evolution with growth forms in response to varying selection regimes.

  • 11.
    Fors, Lisa
    et al.
    Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences.
    Mozuraitis, Raimondas
    Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences. Nature Research Centre, Lithuania.
    Blažytė‐Čereškienė, Laima
    Verschut, Thomas A.
    Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences.
    Hambäck, Peter A.
    Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences.
    Selection by parasitoid females among closely related hosts based on volatiles: Identifying relevant chemical cues2018In: Ecology and Evolution, ISSN 2045-7758, E-ISSN 2045-7758, Vol. 8, no 6, p. 3219-3228Article in journal (Refereed)
    Abstract [en]

    Parasitoid fitness is influenced by the ability to overcome host defense strategies and by the ability of parasitoid females to select high-quality host individuals. When females are unable to differentiate among hosts, their fitness will decrease with an increasing abundance of resistant hosts. To understand the effect of mixed host populations on female fitness, it is therefore necessary to investigate the ability of female parasitoids to select among hosts. Here, we used behavioral assays, headspace volatile collection, and electrophysiology to study the ability of Asecodes parviclava to use olfactory cues to select between a susceptible host (Galerucella calmariensis) and a resistant host (Galerucella pusilla) from a distance. Our studies show that parasitoid females have the capacity to distinguish the two hosts and that the selection behavior is acquired through experiences during earlier life stages. Further, we identified two volatiles (-terpinolene and [E]--ocimene) which amounts differ between the two plant-herbivore systems and that caused behavioral and electrophysiological responses. The consequence of this selection behavior is that females have the capacity to avoid laying eggs in G.pusilla, where the egg mortality is higher due to much stronger immune responses toward A.parviclava than in larvae of G.calmariensis.

  • 12. Garlovsky, Martin D.
    et al.
    Snook, Rhonda R.
    Stockholm University, Faculty of Science, Department of Zoology. University of Sheffield, UK.
    Persistent postmating, prezygotic reproductive isolation between populations2018In: Ecology and Evolution, ISSN 2045-7758, E-ISSN 2045-7758, Vol. 8, no 17, p. 9062-9073Article in journal (Refereed)
    Abstract [en]

    Studying reproductive barriers between populations of the same species is critical to understand how speciation may proceed. Growing evidence suggests postmating, prezygotic (PMPZ) reproductive barriers play an important role in the evolution of early taxonomic divergence. However, the contribution of PMPZ isolation to speciation is typically studied between species in which barriers that maintain isolation may not be those that contributed to reduced gene flow between populations. Moreover, in internally fertilizing animals, PMPZ isolation is related to male ejaculatefemale reproductive tract incompatibilities but few studies have examined how mating history of the sexes can affect the strength of PMPZ isolation and the extent to which PMPZ isolation is repeatable or restricted to particular interacting genotypes. We addressed these outstanding questions using multiple populations of Drosophila montana. We show a recurrent pattern of PMPZ isolation, with flies from one population exhibiting reproductive incompatibility in crosses with all three other populations, while those three populations were fully fertile with each other. Reproductive incompatibility is due to lack of fertilization and is asymmetrical, affecting female fitness more than males. There was no effect of male or female mating history on reproductive incompatibility, indicating that PMPZ isolation persists between populations. We found no evidence of variability in fertilization outcomes attributable to different femalexmale genotype interactions, and in combination with our other results, suggests that PMPZ isolation is not driven by idiosyncratic genotypexgenotype interactions. Our results show PMPZ isolation as a strong, consistent barrier to gene flow early during speciation and suggest several targets of selection known to affect ejaculate-female reproductive tract interactions within species that may cause this PMPZ isolation.

  • 13.
    George, Rushingisha
    et al.
    Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences. Tanzania Fisheries Research Institute (TAFIRI), Tanzania .
    Gullström, Martin
    Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences.
    Mangora, Mwita M.
    Mtolera, Matern S. P.
    Björk, Mats
    Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences.
    High midday temperature stress has stronger effects on biomass than on photosynthesis: A mesocosm experiment on four tropical seagrass species2018In: Ecology and Evolution, ISSN 2045-7758, E-ISSN 2045-7758, Vol. 8, no 9, p. 4508-4517Article in journal (Refereed)
    Abstract [en]

    The effect of repeated midday temperature stress on the photosynthetic performance and biomass production of seagrass was studied in a mesocosm setup with four common tropical species, including Thalassia hemprichii, Cymodocea serrulata, Enhalus acoroides, and Thalassodendron ciliatum. To mimic natural conditions during low tides, the plants were exposed to temperature spikes of different maximal temperatures, that is, ambient (29-33 degrees C), 34, 36, 40, and 45 degrees C, during three midday hours for seven consecutive days. At temperatures of up to 36 degrees C, all species could maintain full photosynthetic rates (measured as the electron transport rate, ETR) throughout the experiment without displaying any obvious photosynthetic stress responses (measured as declining maximal quantum yield, Fv/Fm). All species except T.ciliatum could also withstand 40 degrees C, and only at 45 degrees C did all species display significantly lower photosynthetic rates and declining Fv/Fm. Biomass estimation, however, revealed a different pattern, where significant losses of both above- and belowground seagrass biomass occurred in all species at both 40 and 45 degrees C (except for C.serrulata in the 40 degrees C treatment). Biomass losses were clearly higher in the shoots than in the belowground root-rhizome complex. The findings indicate that, although tropical seagrasses presently can cope with high midday temperature stress, a few degrees increase in maximum daily temperature could cause significant losses in seagrass biomass and productivity.

  • 14.
    Hambäck, Peter A.
    et al.
    Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences.
    Weingartner, Elisabeth
    Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences.
    Dalén, Love
    Wirta, Helena
    Roslin, Tomas
    Spatial subsidies in spider diets vary with shoreline structure: Complementary evidence from molecular diet analysis and stable isotopes2016In: Ecology and Evolution, ISSN 2045-7758, E-ISSN 2045-7758, Vol. 6, no 23, p. 8431-8439Article in journal (Refereed)
    Abstract [en]

    Inflow of matter and organisms may strongly affect the local density and diversity of organisms. This effect is particularly evident on shores where organisms with aquatic larval stages enter the terrestrial food web. The identities of such trophic links are not easily estimated as spiders, a dominant group of shoreline predator, have external digestion. We compared trophic links and the prey diversity of spiders on different shore types along the Baltic Sea: on open shores and on shores with a reed belt bordering the water. A priori, we hypothesized that the physical structure of the shoreline reduces the flow between ecosystem and the subsidies across the sea-land interface. To circumvent the lack of morphologically detectable remains of spider prey, we used a combination of stable isotope and molecular gut content analyses. The two tools used for diet analysis revealed complementary information on spider diets. The stable isotope analysis indicated that spiders on open shores had a marine signal of carbon isotopes, while spiders on reedy shores had a terrestrial signal. The molecular analysis revealed a diverse array of dipteran and lepidopteran prey, where spiders on open and reedy shores shared a similar diet with a comparable proportion of chironomids, the larvae of which live in the marine system. Comparing the methods suggests that differences in isotope composition of the two spider groups occurred because of differences in the chironomid diets: as larvae, chironomids of reedy shores likely fed on terrestrial detritus and acquired a terrestrial isotope signature, while chironomids of open shores utilized an algal diet and acquired a marine isotope signature. Our results illustrate how different methods of diet reconstruction may shed light on complementary aspects of nutrient transfer. Overall, they reveal that reed belts can reduce connectivity between habitats, but also function as a source of food for predators.

  • 15. Hudson, Lawrence N.
    et al.
    Hylander, Kristoffer
    Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences.
    Samnegård, Ulrika
    Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences. Lund University, Sweden.
    The database of the PREDICTS (Projecting Responses of Ecological Diversity In Changing Terrestrial Systems) project2017In: Ecology and Evolution, ISSN 2045-7758, E-ISSN 2045-7758, Vol. 7, no 1, p. 145-188Article in journal (Refereed)
    Abstract [en]

    The PREDICTS project-Projecting Responses of Ecological Diversity In Changing Terrestrial Systems (www.predicts.org.uk)-has collated from published studies a large, reasonably representative database of comparable samples of biodiversity from multiple sites that differ in the nature or intensity of human impacts relating to land use. We have used this evidence base to develop global and regional statistical models of how local biodiversity responds to these measures. We describe and make freely available this 2016 release of the database, containing more than 3.2 million records sampled at over 26,000 locations and representing over 47,000 species. We outline how the database can help in answering a range of questions in ecology and conservation biology. To our knowledge, this is the largest and most geographically and taxonomically representative database of spatial comparisons of biodiversity that has been collated to date; it will be useful to researchers and international efforts wishing to model and understand the global status of biodiversity.

  • 16. Hudson, Lawrence N.
    et al.
    Newbold, Tim
    Contu, Sara
    Hill, Samantha L. L.
    Lysenko, Igor
    De Palma, Adriana
    Phillips, Helen R. P.
    Senior, Rebecca A.
    Bennett, Dominic J.
    Booth, Hollie
    Choimes, Argyrios
    Correia, David L. P.
    Day, Julie
    Echeverria-Londono, Susy
    Garon, Morgan
    Harrison, Michelle L. K.
    Ingram, Daniel J.
    Jung, Martin
    Kemp, Victoria
    Kirkpatrick, Lucinda
    Martin, Callum D.
    Pan, Yuan
    White, Hannah J.
    Aben, Job
    Abrahamczyk, Stefan
    Adum, Gilbert B.
    Aguilar-Barquero, Virginia
    Aizen, Marcelo A.
    Ancrenaz, Marc
    Arbelaez-Cortes, Enrique
    Armbrecht, Inge
    Azhar, Badrul
    Azpiroz, Adrian B.
    Baeten, Lander
    Baldi, Andras
    Banks, John E.
    Barlow, Jos
    Batary, Peter
    Bates, Adam J.
    Bayne, Erin M.
    Beja, Pedro
    Berg, Ake
    Berry, Nicholas J.
    Bicknell, Jake E.
    Bihn, Jochen H.
    Boehning-Gaese, Katrin
    Boekhout, Teun
    Boutin, Celine
    Bouyer, Jeremy
    Brearley, Francis Q.
    Brito, Isabel
    Brunet, Joerg
    Buczkowski, Grzegorz
    Buscardo, Erika
    Cabra-Garcia, Jimmy
    Calvino-Cancela, Maria
    Cameron, Sydney A.
    Cancello, Eliana M.
    Carrijo, Tiago F.
    Carvalho, Anelena L.
    Castro, Helena
    Castro-Luna, Alejandro A.
    Cerda, Rolando
    Cerezo, Alexis
    Chauvat, Matthieu
    Clarke, Frank M.
    Cleary, Daniel F. R.
    Connop, Stuart P.
    D'Aniello, Biagio
    da Silva, Pedro Giovani
    Darvill, Ben
    Dauber, Jens
    Dejean, Alain
    Diekoetter, Tim
    Dominguez-Haydar, Yamileth
    Dormann, Carsten F.
    Dumont, Bertrand
    Dures, Simon G.
    Dynesius, Mats
    Edenius, Lars
    Elek, Zoltan
    Entling, Martin H.
    Farwig, Nina
    Fayle, Tom M.
    Felicioli, Antonio
    Felton, Annika M.
    Ficetola, Gentile F.
    Filgueiras, Bruno K. C.
    Fonte, Steven J.
    Fraser, Lauchlan H.
    Fukuda, Daisuke
    Furlani, Dario
    Ganzhorn, Joerg U.
    Garden, Jenni G.
    Gheler-Costa, Carla
    Giordani, Paolo
    Giordano, Simonetta
    Gottschalk, Marco S.
    Goulson, Dave
    Gove, Aaron D.
    Grogan, James
    Hanley, Mick E.
    Hanson, Thor
    Hashim, Nor R.
    Hawes, Joseph E.
    Hebert, Christian
    Helden, Alvin J.
    Henden, John-Andre
    Hernandez, Lionel
    Herzog, Felix
    Higuera-Diaz, Diego
    Hilje, Branko
    Horgan, Finbarr G.
    Horvath, Roland
    Hylander, Kristoffer
    Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences.
    Isaacs-Cubides, Paola
    Ishitani, Masahiro
    Jacobs, Carmen T.
    Jaramillo, Victor J.
    Jauker, Birgit
    Jonsell, Mats
    Jung, Thomas S.
    Kapoor, Vena
    Kati, Vassiliki
    Katovai, Eric
    Kessler, Michael
    Knop, Eva
    Kolb, Annette
    Koroesi, Adam
    Lachat, Thibault
    Lantschner, Victoria
    Le Feon, Violette
    LeBuhn, Gretchen
    Legare, Jean-Philippe
    Letcher, Susan G.
    Littlewood, Nick A.
    Lopez-Quintero, Carlos A.
    Louhaichi, Mounir
    Loevei, Gabor L.
    Lucas-Borja, Manuel Esteban
    Luja, Victor H.
    Maeto, Kaoru
    Magura, Tibor
    Mallari, Neil Aldrin
    Marin-Spiotta, Erika
    Marshall, E. J. P.
    Martinez, Eliana
    Mayfield, Margaret M.
    Mikusinski, Grzegorz
    Milder, Jeffrey C.
    Miller, James R.
    Morales, Carolina L.
    Muchane, Mary N.
    Muchane, Muchai
    Naidoo, Robin
    Nakamura, Akihiro
    Naoe, Shoji
    Nates-Parra, Guiomar
    Navarrete Gutierrez, Dario A.
    Neuschulz, Eike L.
    Noreika, Norbertas
    Norfolk, Olivia
    Noriega, Jorge Ari
    Noeske, Nicole M.
    O'Dea, Niall
    Oduro, William
    Ofori-Boateng, Caleb
    Oke, Chris O.
    Osgathorpe, Lynne M.
    Paritsis, Juan
    Parra-H, Alejandro
    Pelegrin, Nicolas
    Peres, Carlos A.
    Persson, Anna S.
    Petanidou, Theodora
    Phalan, Ben
    Philips, T. Keith
    Poveda, Katja
    Power, Eileen F.
    Presley, Steven J.
    Proenca, Vania
    Quaranta, Marino
    Quintero, Carolina
    Redpath-Downing, Nicola A.
    Reid, J. Leighton
    Reis, Yana T.
    Ribeiro, Danilo B.
    Richardson, Barbara A.
    Richardson, Michael J.
    Robles, Carolina A.
    Roembke, Joerg
    Romero-Duque, Luz Piedad
    Rosselli, Loreta
    Rossiter, Stephen J.
    Roulston, T'ai H.
    Rousseau, Laurent
    Sadler, Jonathan P.
    Safian, Szabolcs
    Saldana-Vazquez, Romeo A.
    Samnegård, Ulrika
    Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences.
    Schueepp, Christof
    Schweiger, Oliver
    Sedlock, Jodi L.
    Shahabuddin, Ghazala
    Sheil, Douglas
    Silva, Fernando A. B.
    Slade, Eleanor M.
    Smith-Pardo, Allan H.
    Sodhi, Navjot S.
    Somarriba, Eduardo J.
    Sosa, Ramon A.
    Stout, Jane C.
    Struebig, Matthew J.
    Sung, Yik-Hei
    Threlfall, Caragh G.
    Tonietto, Rebecca
    Tothmeresz, Bela
    Tscharntke, Teja
    Turner, Edgar C.
    Tylianakis, Jason M.
    Vanbergen, Adam J.
    Vassilev, Kiril
    Verboven, Hans A. F.
    Vergara, Carlos H.
    Vergara, Pablo M.
    Verhulst, Jort
    Walker, Tony R.
    Wang, Yanping
    Watling, James I.
    Wells, Konstans
    Williams, Christopher D.
    Willig, Michael R.
    Woinarski, John C. Z.
    Wolf, Jan H. D.
    Woodcock, Ben A.
    Yu, Douglas W.
    Zaitsev, Andrey S.
    Collen, Ben
    Ewers, Rob M.
    Mace, Georgina M.
    Purves, Drew W.
    Scharlemann, Joern P. W.
    Purvis, Andy
    The PREDICTS database: a global database of how local terrestrial biodiversity responds to human impacts2014In: Ecology and Evolution, ISSN 2045-7758, E-ISSN 2045-7758, Vol. 4, no 24, p. 4701-4735Article in journal (Refereed)
    Abstract [en]

    Biodiversity continues to decline in the face of increasing anthropogenic pressures such as habitat destruction, exploitation, pollution and introduction of alien species. Existing global databases of species' threat status or population time series are dominated by charismatic species. The collation of datasets with broad taxonomic and biogeographic extents, and that support computation of a range of biodiversity indicators, is necessary to enable better understanding of historical declines and to project - and avert - future declines. We describe and assess a new database of more than 1.6 million samples from 78 countries representing over 28,000 species, collated from existing spatial comparisons of local-scale biodiversity exposed to different intensities and types of anthropogenic pressures, from terrestrial sites around the world. The database contains measurements taken in 208 (of 814) ecoregions, 13 (of 14) biomes, 25 (of 35) biodiversity hotspots and 16 (of 17) megadiverse countries. The database contains more than 1% of the total number of all species described, and more than 1% of the described species within many taxonomic groups - including flowering plants, gymnosperms, birds, mammals, reptiles, amphibians, beetles, lepidopterans and hymenopterans. The dataset, which is still being added to, is therefore already considerably larger and more representative than those used by previous quantitative models of biodiversity trends and responses. The database is being assembled as part of the PREDICTS project (Projecting Responses of Ecological Diversity In Changing Terrestrial Systems - ). We make site-level summary data available alongside this article. The full database will be publicly available in 2015.

  • 17.
    Hughes, Patrick William
    Max Planck Institute for Plant Breeding Research, Germany.
    Between semelparity and iteroparity: Empirical evidence for a continuum of modes of parity2017In: Ecology and Evolution, ISSN 2045-7758, E-ISSN 2045-7758, Vol. 7, no 20, p. 8232-8261Article in journal (Refereed)
    Abstract [en]

    The number of times an organism reproduces (i.e., its mode of parity) is a fundamental life‐history character, and evolutionary and ecological models that compare the relative fitnesses of different modes of parity are common in life‐history theory and theoretical biology. Despite the success of mathematical models designed to compare intrinsic rates of increase (i.e., density‐independent growth rates) between annual‐semelparous and perennial‐iteroparous reproductive schedules, there is widespread evidence that variation in reproductive allocation among semelparous and iteroparous organisms alike is continuous. This study reviews the ecological and molecular evidence for the continuity and plasticity of modes of parity—that is, the idea that annual‐semelparous and perennial‐iteroparous life histories are better understood as endpoints along a continuum of possible strategies. I conclude that parity should be understood as a continuum of different modes of parity, which differ by the degree to which they disperse or concentrate reproductive effort in time. I further argue that there are three main implications of this conclusion: (1) that seasonality should not be conflated with parity; (2) that mathematical models purporting to explain the general evolution of semelparous life histories from iteroparous ones (or vice versa) should not assume that organisms can only display either an annual‐semelparous life history or a perennial‐iteroparous one; and (3) that evolutionary ecologists should base explanations of how different life‐history strategies evolve on the physiological or molecular basis of traits underlying different modes of parity.

  • 18. Jahnke, Marlene
    et al.
    Gullström, Martin
    Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences. University of Gothenburg, Sweden.
    Larsson, Josefine
    Asplund, Maria E.
    Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences. University of Gothenburg, Sweden.
    Mgeleka, Said
    Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences. Tanzania Fisheries Research Institute (TAFIRI), Tanzania.
    Silas, Mathew Ogalo
    Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences. Tanzania Fisheries Research Institute (TAFIRI), Tanzania.
    Hoamby, Arielle
    Mahafina, Jamal
    Mtwana Nordlund, Lina
    Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences. Uppsala University, Sweden.
    Population genetic structure and connectivity of the seagrass Thalassia hemprichii in the Western Indian Ocean is influenced by predominant ocean currents2019In: Ecology and Evolution, ISSN 2045-7758, E-ISSN 2045-7758, Vol. 9, no 16, p. 8953-8964Article in journal (Refereed)
    Abstract [en]

    This study is the first large-scale genetic population study of a widespread climax species of seagrass, Thalassia hemprichii, in the Western Indian Ocean (WIO). The aim was to understand genetic population structure and connectivity of T. hemprichii in relation to hydrodynamic features. We genotyped 205 individual seagrass shoots from 11 sites across the WIO, spanning over a distance of similar to 2,700 km, with twelve microsatellite markers. Seagrass shoots were sampled in Kenya, Tanzania (mainland and Zanzibar), Mozambique, and Madagascar: 4-26 degrees S and 33-48 degrees E. We assessed clonality and visualized genetic diversity and genetic population differentiation. We used Bayesian clustering approaches (TESS) to trace spatial ancestry of populations and used directional migration rates (DivMigrate) to identify sources of gene flow. We identified four genetically differentiated groups: (a) samples from the Zanzibar channel; (b) Mozambique; (c) Madagascar; and (d) the east coast of Zanzibar and Kenya. Significant pairwise population genetic differentiation was found among many sites. Isolation by distance was detected for the estimated magnitude of divergence (D-EST), but the three predominant ocean current systems (i.e., East African Coastal Current, North East Madagascar Current, and the South Equatorial Current) also determine genetic connectivity and genetic structure. Directional migration rates indicate that Madagascar acts as an important source population. Overall, clonality was moderate to high with large differences among sampling sites, indicating relatively low, but spatially variable sexual reproduction rates. The strongest genetic break was identified for three sites in the Zanzibar channel. Although isolation by distance is present, this study suggests that the three regionally predominant ocean current systems (i.e., East African Coastal Current, North East Madagascar Current, and the South Equatorial Current) rather than distance determine genetic connectivity and structure of T. hemprichii in the WIO. If the goal is to maintain genetic connectivity of T. hemprichii within the WIO, conservation planning and implementation of marine protection should be considered at the regional scale-across national borders.

  • 19. Kadin, Martina
    et al.
    Frederiksen, Morten
    Niiranen, Susa
    Stockholm University, Faculty of Science, Stockholm Resilience Centre.
    Converse, Sarah J.
    Linking demographic and food-web models to understand management trade-offs2019In: Ecology and Evolution, ISSN 2045-7758, E-ISSN 2045-7758, Vol. 9, no 15, p. 8587-8600Article in journal (Refereed)
    Abstract [en]

    Alternatives in ecosystem-based management often differ with respect to trade-offs between ecosystem values. Ecosystem or food-web models and demographic models are typically employed to evaluate alternatives, but the approaches are rarely integrated to uncover conflicts between values. We applied multistate models to a capture-recapture dataset on common guillemots Uria aalge breeding in the Baltic Sea to identify factors influencing survival. The estimated relationships were employed together with Ecopath-with-Ecosim food-web model simulations to project guillemot survival under six future scenarios incorporating climate change. The scenarios were based on management alternatives for eutrophication and cod fisheries, issues considered top priority for regional management, but without known direct effects on the guillemot population. Our demographic models identified prey quantity (abundance and biomass of sprat Sprattus sprattus) as the main factor influencing guillemot survival. Most scenarios resulted in projections of increased survival, in the near (2016-2040) and distant (2060-2085) future. However, in the scenario of reduced nutrient input and precautionary cod fishing, guillemot survival was projected to be lower in both future periods due to lower sprat stocks. Matrix population models suggested a substantial decline of the guillemot population in the near future, 24% per 10 years, and a smaller reduction, 1.1% per 10 years, in the distant future. To date, many stakeholders and Baltic Sea governments have supported reduced nutrient input and precautionary cod fishing and implementation is underway. Negative effects on nonfocal species have previously not been uncovered, but our results show that the scenario is likely to negatively impact the guillemot population. Linking model results allowed identifying trade-offs associated with management alternatives. This information is critical to thorough evaluation by decision-makers, but not easily obtained by food-web models or demographic models in isolation. Appropriate datasets are often available, making it feasible to apply a linked approach for better-informed decisions in ecosystem-based management.

  • 20.
    Kivelä, Sami M.
    et al.
    Stockholm University, Faculty of Science, Department of Zoology. University of Oulu, Finland.
    Välimäki, Panu
    Gotthard, Karl
    Stockholm University, Faculty of Science, Department of Zoology.
    Evolution of alternative insect life histories in stochastic seasonal environments2016In: Ecology and Evolution, ISSN 2045-7758, E-ISSN 2045-7758, Vol. 6, no 16, p. 5596-5613Article in journal (Refereed)
    Abstract [en]

    Deterministic seasonality can explain the evolution of alternative life history phenotypes (i.e., life history polyphenism) expressed in different generations emerging within the same year. However, the influence of stochastic variation on the expression of such life history polyphenisms in seasonal environments is insufficiently understood. Here, we use insects as a model and explore (1) the effects of stochastic variation in seasonality and (2) the life cycle on the degree of life history differentiation among the alternative developmental pathways of direct development and diapause (overwintering), and (3) the evolution of phenology. With numerical simulation, we determine the values of development (growth) time, growth rate, body size, reproductive effort, adult life span, and fecundity in both the overwintering and directly developing generations that maximize geometric mean fitness. The results suggest that natural selection favors the expression of alternative life histories in the alternative developmental pathways even when there is stochastic variation in seasonality, but that trait differentiation is affected by the developmental stage that overwinters. Increasing environmental unpredictability induced a switch to a bet-hedging type of life history strategy, which is consistent with general life history theory. Bet-hedging appeared in our study system as reduced expression of the direct development phenotype, with associated changes in life history phenotypes, because the fitness value of direct development is highly variable in uncertain environments. Our main result is that seasonality itself is a key factor promoting the evolution of seasonally polyphenic life histories but that environmental stochasticity may modulate the expression of life history phenotypes.

  • 21.
    Kodandaramaiah, Ullasa
    et al.
    Stockholm University, Faculty of Science, Department of Zoology. Indian Institute of Science Education & Research (IISER), India.
    Lindenfors, Patrik
    Stockholm University, Faculty of Science, Department of Zoology.
    Tullberg, Birgitta S.
    Stockholm University, Faculty of Science, Department of Zoology.
    Deflective and intimidating eyespots: a comparative study of eyespot size and position in Junonia butterflies2013In: Ecology and Evolution, ISSN 2045-7758, E-ISSN 2045-7758, Vol. 3, no 13, p. 4518-4524Article in journal (Refereed)
    Abstract [en]

    Eyespots are conspicuous circular features found on the wings of several lepidopteran insects. Two prominent hypotheses have been put forth explaining their function in an antipredatory role. The deflection hypothesis posits that eyespots enhance survival in direct physical encounters with predators by deflecting attacks away from vital parts of the body, whereas the intimidation hypothesis posits that eyespots are advantageous by scaring away a potential predator before an attack. In the light of these two hypotheses, we investigated the evolution of eyespot size and its interaction with position and number within a phylogenetic context in a group of butterflies belonging to the genus Junonia. We found that larger eyespots tend to be found individually, rather than in serial dispositions. Larger size and conspicuousness make intimidating eyespots more effective, and thus, we suggest that our results support an intimidation function in some species of Junonia with solitary eyespots. Our results also show that smaller eyespots in Junonia are located closer to the wing margin, thus supporting predictions of the deflection hypothesis. The interplay between size, position, and arrangement of eyespots in relation to antipredation and possibly sexual selection, promises to be an interesting field of research in the future. Similarly, further comparative work on the evolution of absolute eyespot size in natural populations of other butterfly groups is needed.

  • 22.
    Kodandaramaiah, Ullasa
    et al.
    Stockholm University, Faculty of Science, Department of Zoology. Indian Institute of Science Education & Research (IISER) - Thiruvananthapuram.
    Simonsen, Thomas J.
    Bromilow, Sean
    Wahlberg, Niklas
    Sperling, Felix
    Deceptive single-locus taxonomy and phylogeography: Wolbachia-associated divergence in mitochondrial DNA is not reflected in morphology and nuclear markers in a butterfly species2013In: Ecology and Evolution, ISSN 2045-7758, E-ISSN 2045-7758, Vol. 3, no 16, p. 5167-5176Article in journal (Refereed)
    Abstract [en]

    The satyrine butterfly Coenonympha tullia (Nymphalidae: Satyrinae) displays a deep split between two mitochondrial clades, one restricted to northern Alberta, Canada, and the other found throughout Alberta and across North America. We confirm this deep divide and test hypotheses explaining its phylogeographic structure. Neither genitalia morphology nor nuclear gene sequence supports cryptic species as an explanation, instead indicating differences between nuclear and mitochondrial genome histories. Sex-biased dispersal is unlikely to cause such mito-nuclear differences; however, selective sweeps by reproductive parasites could have led to this conflict. About half of the tested samples were infected by Wolbachia bacteria. Using multilocus strain typing for three Wolbachia genes, we show that the divergent mitochondrial clades are associated with two different Wolbachia strains, supporting the hypothesis that the mito-nuclear differences resulted from selection on the mitochondrial genome due to selective sweeps by Wolbachia strains.

  • 23.
    Kubrak, Olga I.
    et al.
    Stockholm University, Faculty of Science, Department of Zoology.
    Nylin, Sören
    Stockholm University, Faculty of Science, Department of Zoology.
    Flatt, Thomas
    Nässel, Dick R.
    Stockholm University, Faculty of Science, Department of Zoology.
    Leimar, Olof
    Stockholm University, Faculty of Science, Department of Zoology.
    Adaptation to fluctuating environments in a selection experiment with Drosophila melanogaster2017In: Ecology and Evolution, ISSN 2045-7758, E-ISSN 2045-7758, Vol. 7, no 11, p. 3796-3807Article in journal (Refereed)
    Abstract [en]

    A fundamental question in life-history evolution is how organisms cope with fluctuating environments, including variation between stressful and benign conditions. For short-lived organisms, environments commonly vary between generations. Using a novel experimental design, we exposed wild-derived Drosophila melanogaster to three different selection regimes: one where generations alternated between starvation and benign conditions, and starvation was always preceded by early exposure to cold; another where starvation and benign conditions alternated in the same way, but cold shock sometimes preceded starvation and sometimes benign conditions; and a third where conditions were always benign. Using six replicate populations per selection regime, we found that selected flies increased their starvation resistance, most strongly for the regime where cold and starvation were reliably combined, and this occurred without decreased fecundity or extended developmental time. The selected flies became stress resistant, displayed a pronounced increase in early life food intake and resource storage. In contrast to previous experiments selecting for increased starvation resistance in D. melanogaster, we did not find increased storage of lipids as the main response, but instead that, in particular for females, storage of carbohydrates was more pronounced. We argue that faster mobilization of carbohydrates is advantageous in fluctuating environments and conclude that the phenotype that evolved in our experiment corresponds to a compromise between the requirements of stressful and benign environments.

  • 24.
    Kurland, Sara
    et al.
    Stockholm University, Faculty of Science, Department of Zoology.
    Wheat, Christopher W.
    Stockholm University, Faculty of Science, Department of Zoology.
    Celorio Mancera, Maria de la Paz
    Stockholm University, Faculty of Science, Department of Zoology.
    Kutschera, Verena E.
    Stockholm University, Science for Life Laboratory (SciLifeLab). Stockholm University, Faculty of Science, Department of Biochemistry and Biophysics.
    Hill, Jason
    Stockholm University, Faculty of Science, Department of Zoology.
    Andersson, Anastasia
    Stockholm University, Faculty of Science, Department of Zoology.
    Rubin, Carl-Johan
    Andersson, Leif
    Ryman, Nils
    Stockholm University, Faculty of Science, Department of Zoology.
    Laikre, Linda
    Stockholm University, Faculty of Science, Department of Zoology.
    Exploring a Pool-seq-only approach for gaining population genomic insights in nonmodel species2019In: Ecology and Evolution, ISSN 2045-7758, E-ISSN 2045-7758, Vol. 9, p. 11448-11463Article in journal (Refereed)
    Abstract [en]

    Developing genomic insights is challenging in nonmodel species for which resources are often scarce and prohibitively costly. Here, we explore the potential of a recently established approach using Pool-seq data to generate a de novo genome assembly for mining exons, upon which Pool-seq data are used to estimate population divergence and diversity. We do this for two pairs of sympatric populations of brown trout (Salmo trutta): one naturally sympatric set of populations and another pair of populations introduced to a common environment. We validate our approach by comparing the results to those from markers previously used to describe the populations (allozymes and individual-based single nucleotide polymorphisms [SNPs]) and from mapping the Pool-seq data to a reference genome of the closely related Atlantic salmon (Salmo salar). We find that genomic differentiation (F-ST) between the two introduced populations exceeds that of the naturally sympatric populations (F-ST = 0.13 and 0.03 between the introduced and the naturally sympatric populations, respectively), in concordance with estimates from the previously used SNPs. The same level of population divergence is found for the two genome assemblies, but estimates of average nucleotide diversity differ (pi over bar approximate to 0.002 and pi over bar approximate to 0.001 when mapping to S. trutta and S. salar, respectively), although the relationships between population values are largely consistent. This discrepancy might be attributed to biases when mapping to a haploid condensed assembly made of highly fragmented read data compared to using a high-quality reference assembly from a divergent species. We conclude that the Pool-seq-only approach can be suitable for detecting and quantifying genome-wide population differentiation, and for comparing genomic diversity in populations of nonmodel species where reference genomes are lacking.

  • 25.
    König, Malin A. E.
    et al.
    Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences.
    Wiklund, Christer
    Stockholm University, Faculty of Science, Department of Zoology.
    Ehrlén, Johan
    Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences.
    Butterfly oviposition preference is not related to larval performance on a polyploid herb2016In: Ecology and Evolution, ISSN 2045-7758, E-ISSN 2045-7758, Vol. 6, no 9, p. 2781-2789Article in journal (Refereed)
    Abstract [en]

    The preference-performance hypothesis predicts that female insects maximize their fitness by utilizing host plants which are associated with high larval performance. Still, studies with several insect species have failed to find a positive correlation between oviposition preference and larval performance. In the present study, we experimentally investigated the relationship between oviposition preferences and larval performance in the butterfly Anthocharis cardamines. Preferences were assessed using both cage experiments and field data on the proportion of host plant individuals utilized in natural populations. Larval performance was experimentally investigated using larvae descending from 419 oviposition events by 21 females on plants from 51 populations of two ploidy types of the perennial herb Cardamine pratensis. Neither ploidy type nor population identity influenced egg survival or larval development, but increased plant inflorescence size resulted in a larger final larval size. There was no correlation between female oviposition preference and egg survival or larval development under controlled conditions. Moreover, variation in larval performance among populations under controlled conditions was not correlated with the proportion of host plants utilized in the field. Lastly, first instar larvae added to plants rejected for oviposition by butterfly females during the preference experiment performed equally well as larvae growing on plants chosen for oviposition. The lack of a correlation between larval performance and oviposition preference for A. cardamines under both experimental and natural settings suggests that female host choice does not maximize the fitness of the individual offspring.

  • 26.
    König, Malin A. E.
    et al.
    Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences.
    Wiklund, Christer
    Stockholm University, Faculty of Science, Department of Zoology.
    Ehrlén, Johan
    Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences.
    Timing of flowering and intensity of attack by a butterfly herbivore in a polyploid herb2015In: Ecology and Evolution, ISSN 2045-7758, E-ISSN 2045-7758, Vol. 5, no 9, p. 1863-1872Article in journal (Refereed)
    Abstract [en]

    Timing of plant development both determines the abiotic conditions that the plant experiences and strongly influences the intensity of interactions with other organisms. Plants and herbivores differ in their response to environmental cues, and spatial and temporal variation in environmental conditions might influence the synchrony between host plants and herbivores, and the intensity of their interactions. We investigated whether differences in first day of flowering among and within 21 populations of the polyploid herb Cardamine pratensis influenced the frequency of oviposition by the butterfly Anthocharis cardamines during four study years. The proportion of plants that became oviposited upon differed among populations, but these differences were not related to mean flowering phenology within the population in any of the four study years. Attack rates in the field were also not correlated with resistance to oviposition estimated under controlled conditions. Within populations, the frequency of butterfly attack was higher in early-flowering individuals in two of the four study years, while there was no significant relationship in the other 2years. Larger plants were more likely to become oviposited upon in all 4years. The effects of first flowering day and size on the frequency of butterfly attack did not differ among populations. The results suggest that differences in attack intensities among populations are driven mainly by differences in the environmental context of populations while mean differences in plant traits play a minor role. The fact that within populations timing of flowering influenced the frequency of herbivore attack only in some years and suggests that herbivore-mediated selection on plant phenology differs among years, possibly because plants and herbivores respond differently to environmental cues.

  • 27.
    Lindenfors, Patrik
    Stockholm University, Faculty of Science, Department of Zoology.
    The green beards of language2013In: Ecology and Evolution, ISSN 2045-7758, E-ISSN 2045-7758, Vol. 3, no 4, p. 1104-1112Article in journal (Refereed)
    Abstract [en]

    Language transfers information on at least three levels; (1) what is said, (2) how it is said (what language is used), and, (3) that it is said (that speaker and listener both possess the ability to use language). The use of language is a form of honest cooperation on two of these levels; not necessarily on what is said, which can be deceitful, but always on how it is said and that it is said. This means that the language encoding and decoding systems had to evolve simultaneously, through mutual fitness benefits. Theoretical problems surrounding the evolution of cooperation disappear if a recognition system is present enabling cooperating individuals to identify each other if they are equipped with green beards. Here, I outline how both the biological and cultural aspects of language are bestowed with such recognition systems. The biological capacities required for language signal their presence through speech and understanding. This signaling cannot be invaded by false green beards because the traits and the signal of their presence are one and the same. However, the real usefulness of language comes from its potential to convey an infinite number of meanings through the dynamic handling of symbols through language itself. But any specific language also signals its presence to others through usage and understanding. Thus, languages themselves cannot be invaded by false green beards because, again, the trait and the signal of its presence are one and the same. These twin green beards, in both the biological and cultural realms, are unique to language.

  • 28.
    Lindh, Magnus
    et al.
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Falster, Daniel S.
    Zhang, Lai
    Dieckmann, Ulf
    Brännström, Åke
    Latitudinal effects on crown shape evolution2018In: Ecology and Evolution, ISSN 2045-7758, E-ISSN 2045-7758, Vol. 8, no 16, p. 8149-8158Article in journal (Refereed)
    Abstract [en]

    Large variations in crown shape are observed across the globe, from plants with wide and deep crowns to those with leaves clustered at the top. While there have been advances in the large-scale monitoring of forests, little is known about factors driving variations in crown shape with environmental conditions. Previous theoretical research suggests a gradient in crown shape with latitude, due to the effects of sun angle. Yet, it remains unclear whether such changes are also predicted under competition. Using a size-structured forest-growth model that incorporates self-shading from plants and competitive shading from their neighbors, we investigate how changes in site productivity and sun angle shape crown evolution. We consider evolution in two traits describing the top-heaviness and width-to-height ratio of crowns, shaped by trade-offs reflecting the costs and benefits of alternative architectures. In top-heavy trees, most of the leaves are at the top half of the trunk. We show that, contrary to common belief, the angle of sun beams per se has only a weak influence on crown shapes, except at low site productivity. By contrast, reduced site productivity has a strong effect, with trees growing in less productive sites keeping their leaves closer to the ground. The crown width-to-height ratio is generally higher at a lower site productivity, but this trait is not strongly influenced by any environmental factor. This theoretical analysis brings into question established beliefs about the effects of latitude on crown shapes. By introducing geometry-related growth constraints caused by shading from both the surrounding forest and the tree on itself, and costs for constructing and maintaining a three-dimensional crown, our analysis suggests crown shapes may vary with latitude, mostly via effects on overall site productivity, and less because of the angle of the sun.

  • 29. Magnusson, Magnus
    et al.
    Bergsten, Arvid
    Stockholm University, Faculty of Science, Stockholm Resilience Centre.
    Ecke, Frauke
    Bodin, Örjan
    Stockholm University, Faculty of Science, Stockholm Resilience Centre.
    Bodin, Lennart
    Hörnfeldt, Birger
    Predicting grey-sided vole occurrence in northern Sweden at multiple spatial scales2013In: Ecology and Evolution, ISSN 2045-7758, E-ISSN 2045-7758, Vol. 3, no 13, p. 4365-4376Article in journal (Refereed)
    Abstract [en]

    Forestry is continually changing the habitats for many forest-dwelling species around the world. The grey-sided vole (Myodes rufocanus) has declined since the 1970s in forests of northern Sweden. Previous studies suggested that this might partly be caused by reduced focal forest patch size due to clear-cutting. Proximity and access to old pine forest and that microhabitats often contains stones have also been suggested previously but never been evaluated at multiple spatial scales. In a field study in 2010–2011 in northern Sweden, we investigated whether occurrence of grey-sided voles would be higher in (1) large focal patches of >60 years old forest, (2) in patches with high connectivity to sur- rounding patches, and (3) in patches in proximity to stone fields. We trapped animals in forest patches in two study areas (V€asterbotten and Norrbotten). At each trap station, we surveyed structural microhabitat characteristics. Land- scape-scale features were investigated using satellite-based forest data combined with geological maps. Unexpectedly, the vole was almost completely absent in Norrbotten. The trap sites in Norrbotten had a considerably lower amount of stone holes compared with sites with voles in V€asterbotten. We suggest this might help to explain the absence in Norrbotten. In V€asterbotten, the distance from forest patches with voles to stone fields was significantly shorter than from patches without voles. In addition, connectivity to surrounding patches and size of the focal forest patches was indeed related to the occurrence of grey-sided voles, with connectivity being the overall best predictor. Our results support previous findings on the importance of large forest patches, but also highlight the importance of connectivity for occurrence of grey-sided voles. The results further suggest that proximity to stone fields increase habitat quality of the forests for the vole and that the presence of stone fields enhances the voles’ ability to move between nearby forest patches through the matrix

  • 30. Marzal, Julia Carolina Segami
    et al.
    Rudh, Andreas
    Rogell, Björn
    Stockholm University, Faculty of Science, Department of Zoology.
    Ödeen, Anders
    Lovlie, Hanne
    Rosher, Charlotte
    Qvarnström, Anna
    Cryptic female Strawberry poison frogs experience elevated predation risk when associating with an aposematic partner2017In: Ecology and Evolution, ISSN 2045-7758, E-ISSN 2045-7758, Vol. 7, no 2, p. 744-750Article in journal (Refereed)
    Abstract [en]

    Population divergence in sexual signals may lead to speciation through prezygotic isolation. Sexual signals can change solely due to variation in the level of natural selection acting against conspicuousness. However, directional mate choice (i.e., favoring conspicuousness) across different environments may lead to gene flow between populations, thereby delaying or even preventing the evolution of reproductive barriers and speciation. In this study, we test whether natural selection through predation upon mate-choosing females can favor corresponding changes in mate preferences. Our study system, Oophaga pumilio, is an extremely color polymorphic neotropical frog with two distinctive antipredator strategies: aposematism and crypsis. The conspicuous coloration and calling behavior of aposematic males may attract both cryptic and aposematic females, but predation may select against cryptic females choosing aposematic males. We used an experimental approach where domestic fowl were encouraged to find digitized images of cryptic frogs at different distances from aposematic partners. We found that the estimated survival time of a cryptic frog was reduced when associating with an aposematic partner. Hence, predation may act as a direct selective force on female choice, favoring evolution of color assortative mating that, in turn, may strengthen the divergence in coloration that natural selection has generated.

  • 31. Mattila, Tiina M.
    et al.
    Laenen, Benjamin
    Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences. Stockholm University, Science for Life Laboratory (SciLifeLab).
    Horvath, Robert
    Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences. Stockholm University, Science for Life Laboratory (SciLifeLab).
    Hämälä, Tuomas
    Savolainen, Outi
    Slotte, Tanja
    Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences. Stockholm University, Science for Life Laboratory (SciLifeLab).
    Impact of demography on linked selection in two outcrossing Brassicaceae species2019In: Ecology and Evolution, ISSN 2045-7758, E-ISSN 2045-7758, Vol. 9, no 17, p. 9532-9545Article in journal (Refereed)
    Abstract [en]

    Genetic diversity is shaped by mutation, genetic drift, gene flow, recombination, and selection. The dynamics and interactions of these forces shape genetic diversity across different parts of the genome, between populations and species. Here, we have studied the effects of linked selection on nucleotide diversity in outcrossing populations of two Brassicaceae species, Arabidopsis lyrata and Capsella grandiflora, with contrasting demographic history. In agreement with previous estimates, we found evidence for a modest population size expansion thousands of generations ago, as well as efficient purifying selection in C. grandiflora. In contrast, the A. lyrata population exhibited evidence for very recent strong population size decline and weaker efficacy of purifying selection. Using multiple regression analyses with recombination rate and other genomic covariates as explanatory variables, we can explain 47% of the variance in neutral diversity in the C. grandiflora population, while in the A. lyrata population, only 11% of the variance was explained by the model. Recombination rate had a significant positive effect on neutral diversity in both species, suggesting that selection at linked sites has an effect on patterns of neutral variation. In line with this finding, we also found reduced neutral diversity in the vicinity of genes in the C. grandiflora population. However, in A. lyrata no such reduction in diversity was evident, a finding that is consistent with expectations of the impact of a recent bottleneck on patterns of neutral diversity near genes. This study thus empirically demonstrates how differences in demographic history modulate the impact of selection at linked sites in natural populations.

  • 32.
    Naud, Lucy
    et al.
    Stockholm University, Faculty of Science, Department of Zoology.
    Måsviken, Johannes
    Stockholm University, Faculty of Science, Department of Zoology.
    Freire, Susana
    Angerbjörn, Anders
    Stockholm University, Faculty of Science, Department of Zoology.
    Dalén, Love
    Stockholm University, Faculty of Science, Department of Zoology. Swedish Museum of Natural History, Sweden.
    Dalerum, Fredrik
    Stockholm University, Faculty of Science, Department of Zoology. Oviedo University, Spain; University of Pretoria, South Africa.
    Altitude effects on spatial components of vascular plant diversity in a subarctic mountain tundra2019In: Ecology and Evolution, ISSN 2045-7758, E-ISSN 2045-7758, Vol. 9, no 8, p. 4783-4795Article in journal (Refereed)
    Abstract [en]

    Environmental gradients are caused by gradual changes in abiotic factors, which affect species abundances and distributions, and are important for the spatial distribution of biodiversity. One prominent environmental gradient is the altitude gradient. Understanding ecological processes associated with altitude gradients may help us to understand the possible effects climate change could have on species communities. We quantified vegetation cover, species richness, species evenness, beta diversity, and spatial patterns of community structure of vascular plants along altitude gradients in a subarctic mountain tundra in northern Sweden. Vascular plant cover and plant species richness showed unimodal relationships with altitude. However, species evenness did not change with altitude, suggesting that no individual species became dominant when species richness declined. Beta diversity also showed a unimodal relationship with altitude, but only for an intermediate spatial scale of 1km. A lack of relationships with altitude for either patch or landscape scales suggests that any altitude effects on plant spatial heterogeneity occurred on scales larger than individual patches but were not effective across the whole landscape. We observed both nested and modular patterns of community structures, but only the modular patterns corresponded with altitude. Our observations point to biotic regulations of plant communities at high altitudes, but we found both scale dependencies and inconsistent magnitude of the effects of altitude on different diversity components. We urge for further studies evaluating how different factors influence plant communities in high altitude and high latitude environments, as well as studies identifying scale and context dependencies in any such influences.

  • 33.
    Olsen, Morten Tange
    et al.
    Stockholm University, Faculty of Science, Department of Genetics, Microbiology and Toxicology.
    Pampoulie, Christophe
    Danielsdottir, Anna K.
    Lidh, Emmelie
    Stockholm University, Faculty of Science, Department of Genetics, Microbiology and Toxicology.
    Berube, Martine
    Vikingsson, Gisli A.
    Palsbøll, Per J.
    Stockholm University, Faculty of Science, Department of Genetics, Microbiology and Toxicology.
    Fin whale MDH-1 and MPI allozyme variation is not reflected in the corresponding DNA sequences2014In: Ecology and Evolution, ISSN 2045-7758, E-ISSN 2045-7758, Vol. 4, no 10, p. 1787-1803Article in journal (Refereed)
    Abstract [en]

    The appeal of genetic inference methods to assess population genetic structure and guide management efforts is grounded in the correlation between the genetic similarity and gene flow among populations. Effects of such gene flow are typically genomewide; however, some loci may appear as outliers, displaying above or below average genetic divergence relative to the genomewide level. Above average population, genetic divergence may be due to divergent selection as a result of local adaptation. Consequently, substantial efforts have been directed toward such outlying loci in order to identify traits subject to local adaptation. Here, we report the results of an investigation into the molecular basis of the substantial degree of genetic divergence previously reported at allozyme loci among North Atlantic fin whale (Balaenoptera physalus) populations. We sequenced the exons encoding for the two most divergent allozyme loci (MDH-1 and MPI) and failed to detect any nonsynonymous substitutions. Following extensive error checking and analysis of additional bioinformatic and morphological data, we hypothesize that the observed allozyme polymorphisms may reflect phenotypic plasticity at the cellular level, perhaps as a response to nutritional stress. While such plasticity is intriguing in itself, and of fundamental evolutionary interest, our key finding is that the observed allozyme variation does not appear to be a result of genetic drift, migration, or selection on the MDH-1 and MPI exons themselves, stressing the importance of interpreting allozyme data with caution. As for North Atlantic fin whale population structure, our findings support the low levels of differentiation found in previous analyses of DNA nucleotide loci.

  • 34. Ord, Terry J.
    et al.
    Emblen, Jack
    Hagman, Mattias
    University of New South Wales Evolution and Ecology Research Centre and the School of Biological Kensington NSW, Australia.
    Shofner, Ryan
    Unruh, Sarah
    Manipulation of habitat isolation and area implicates deterministic factors and limited neutrality in community assembly2017In: Ecology and Evolution, ISSN 2045-7758, E-ISSN 2045-7758, Vol. 7, no 15, p. 5845-5860Article in journal (Refereed)
  • 35. Pfeifer, M.
    et al.
    Lefebvre, V.
    Gardner, Toby A.
    Stockholm University, Stockholm Environment Institute.
    Arroyo-Rodriguez, V.
    BIOFRAG – a new database for analyzing BIOdiversity responses to forest FRAGmentation2014In: Ecology and Evolution, ISSN 2045-7758, E-ISSN 2045-7758, Vol. 4, no 9, p. 1524-1537Article in journal (Refereed)
    Abstract [en]

    Habitat fragmentation studies have produced complex results that are challenging to synthesize. Inconsistencies among studies may result from variation in the choice of landscape metrics and response variables, which is often compounded by a lack of key statistical or methodological information. Collating primary datasets on biodiversity responses to fragmentation in a consistent and flexible database permits simple data retrieval for subsequent analyses. We present a relational database that links such field data to taxonomic nomenclature, spatial and temporal plot attributes, and environmental characteristics. Field assessments include measurements of the response(s) (e.g., presence, abundance, ground cover) of one or more species linked to plots in fragments within a partially forested landscape. The database currently holds 9830 unique species recorded in plots of 58 unique landscapes in six of eight realms: mammals 315, birds 1286, herptiles 460, insects 4521, spiders 204, other arthropods 85, gastropods 70, annelids 8, platyhelminthes 4, Onychophora 2, vascular plants 2112, nonvascular plants and lichens 320, and fungi 449. Three landscapes were sampled as long-term time series (>10 years). Seven hundred and eleven species are found in two or more landscapes. Consolidating the substantial amount of primary data available on biodiversity responses to fragmentation in the context of land-use change and natural disturbances is an essential part of understanding the effects of increasing anthropogenic pressures on land. The consistent format of this database facilitates testing of generalizations concerning biologic responses to fragmentation across diverse systems and taxa. It also allows the re-examination of existing datasets with alternative landscape metrics and robust statistical methods, for example, helping to address pseudo-replication problems. The database can thus help researchers in producing broad syntheses of the effects of land use. The database is dynamic and inclusive, and contributions from individual and large-scale data-collection efforts are welcome.

  • 36.
    Salo, Tiina
    et al.
    Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences. Åbo Akademi University, Finland; Eawag, Swiss Federal Institute of Aquatic Science and Technology, Switzerland; ETH Zürich, Switzerland.
    Kropf, Tabea
    Burdon, Francis J.
    Seppälä, Otto
    Diurnal variation around an optimum and near-critically high temperature does not alter the performance of an ectothermic aquatic grazer2019In: Ecology and Evolution, ISSN 2045-7758, E-ISSN 2045-7758, Vol. 9, no 20, p. 11695-11706Article in journal (Refereed)
    Abstract [en]

    The growing threat of global climate change has led to a profusion of studies examining the effects of warming on biota. Despite the potential importance of natural variability such as diurnal temperature fluctuations, most experimental studies on warming are conducted under stable temperatures. Here, we investigated whether the responses of an aquatic invertebrate grazer (Lymnaea stagnalis) to an increased average temperature differ when the thermal regime is either constant or fluctuates diurnally. Using thermal response curves for several life-history and immune defense traits, we first identified the optimum and near-critically high temperatures that Lymnaea potentially experience during summer heat waves. We then exposed individuals that originated from three different populations to these two temperatures under constant or fluctuating thermal conditions. After 7 days, we assessed growth, reproduction, and two immune parameters (phenoloxidase-like activity and antibacterial activity of hemolymph) from each individual. Exposure to the near-critically high temperature led to increased growth rates and decreased antibacterial activity of hemolymph compared to the optimum temperature, whilst temperature fluctuations had no effect on these traits. The results indicate that the temperature level per se, rather than the variability in temperature was the main driver altering trait responses in our study species. Forecasting responses in temperature-related responses remains challenging, due to system-specific properties that can include intraspecific variation. However, our study indicates that experiments examining the effects of warming using constant temperatures can give similar predictions as studies with fluctuating thermal dynamics, and may thus be useful indicators of responses in nature.

  • 37. Southern, Helen M.
    et al.
    Berger, Mitchell A.
    Young, Philippe G.
    Snook, Rhonda R.
    Stockholm University, Faculty of Science, Department of Zoology. University of Sheffield, UK.
    Sperm morphology and the evolution of intracellular sperm-egg interactions2018In: Ecology and Evolution, ISSN 2045-7758, E-ISSN 2045-7758, Vol. 8, no 10, p. 5047-5058Article in journal (Refereed)
    Abstract [en]

    Sperm morphology is incredibly diverse, even among closely related species, yet the coevolution between males and females of fertilization recognition systems is necessary for successful karyogamy (male and female pronuclear fusion). In most species, the entire sperm enters the egg during fertilization so sperm morphological diversity may impact the intracellular sperm-egg interactions necessary for karyogamy. We quantified morphological variation of sperm inside eggs prior to and following karyogamy in several species of Drosophila to understand whether evolution of sperm morphology could influence intracellular sperm-egg interactions (ISEIs). We measured seven parameters that describe ISEIs among species to determine whether these parameters varied both within a species across development and across species at the same developmental stage. We used heterospecific crosses to test the relative role of male origin, female origin, and interaction between the male and female in determining ISEIs. We found that sperm shape changed within a species as development proceeded and, at particular development stages, species varied in some ISEIs. Parental origin had an effect on some ISEIs, with a general trend for a stronger female effect. Overall, our findings identify conserved and variable ISEIs among species and demonstrate the potential to contribute understanding to gamete evolution and development.

  • 38.
    Staveley, Thomas A. B.
    et al.
    Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences. AquaBiota Water Research, Sweden.
    Jacoby, David M. P.
    Perry, Diana
    Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences. University of Agricultural Sciences, Sweden.
    van der Meijs, Felix
    Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences.
    Lagenfelt, Ingvar
    Cremle, Mikael
    Gullstrom, Martin
    Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences. University of Gothenburg, Sweden.
    Sea surface temperature dictates movement and habitat connectivity of Atlantic cod in a coastal fjord system2019In: Ecology and Evolution, ISSN 2045-7758, E-ISSN 2045-7758Article in journal (Refereed)
    Abstract [en]

    While movements of organisms have been studied across a myriad of environments, information is often lacking regarding spatio-seasonal patterning in complex temperate coastal systems. Highly mobile fish form an integral part of marine food webs providing linkages within and among habitats, between patches of habitats, and at different life stages. We investigated how movement, activity, and connectivity patterns of Atlantic cod (Gadus morhua) are influenced by dynamic environmental conditions. Movement patterns of 39 juvenile and subadult Atlantic cod were assessed in two coastal sites in the Swedish Skagerrak for 5 months. We used passive acoustic telemetry and network analysis to assess seasonal and spatial movement patterns of cod and their relationships to different environmental factors, using statistical correlations, analysis of recurrent spatial motifs, and generalized linear mixed models. Temperature, in combination with physical barriers, precludes significant connectivity (complex motifs) within the system. Sea surface temperature had a strong influence on connectivity (node strength, degree, and motif frequency), where changes from warmer summer waters to colder winter waters significantly reduced movement activity of fish. As the seasons changed, movement of fish gradually decreased from large-scale (km) linkages in the summer to more localized movement patterns in the winter (limited to 100s m). Certain localized areas, however, were identified as important for connectivity throughout the whole study period, likely due to these multiple-habitat areas fulfilling functions required for foraging and shelter. This study provides new knowledge regarding inshore movement dynamics of juvenile and subadult Atlantic cod that use complex, coastal fjord systems. The findings show that connectivity, seasonal patterns in particular, should be carefully considered when selecting conservation areas to promote marine stewardship.

  • 39.
    Stålhandske, Sandra
    et al.
    Stockholm University, Faculty of Science, Department of Zoology.
    Lehmann, Philipp
    Stockholm University, Faculty of Science, Department of Zoology.
    Pruisscher, Peter
    Stockholm University, Faculty of Science, Department of Zoology.
    Leimar, Olof
    Stockholm University, Faculty of Science, Department of Zoology.
    Effect of winter cold duration on spring phenology of the orange tip butterfly, Anthocharis cardamines 2015In: Ecology and Evolution, ISSN 2045-7758, E-ISSN 2045-7758, Vol. 5, no 23, p. 5509-5520Article in journal (Refereed)
    Abstract [en]

    The effect of spring temperature on spring phenology is well understood in a wide range of taxa. However, studies on how winter conditions may affect spring phenology are underrepresented. Previous work on Anthocharis cardamines (orange tip butterfly) has shown population-specific reaction norms of spring development in relation to spring temperature and a speeding up of post-winter development with longer winter durations. In this experiment, we examined the effects of a greater and ecologically relevant range of winter durations on post-winter pupal development of A. cardamines of two populations from the United Kingdom and two from Sweden. By analyzing pupal weight loss and metabolic rate, we were able to separate the overall post-winter pupal development into diapause duration and post-diapause development. We found differences in the duration of cold needed to break diapause among populations, with the southern UK population requiring a shorter duration than the other populations. We also found that the overall post-winter pupal development time, following removal from winter cold, was negatively related to cold duration, through a combined effect of cold duration on diapause duration and on post-diapause development time. Longer cold durations also lead to higher population synchrony in hatching. For current winter durations in the field, the A. cardamines population of southern UK could have a reduced development rate and lower synchrony in emergence because of short winters. With future climate change, this might become an issue also for other populations. Differences in winter conditions in the field among these four populations are large enough to have driven local adaptation of characteristics controlling spring phenology in response to winter duration. The observed phenology of these populations depends on a combination of winter and spring temperatures; thus, both must be taken into account for accurate predictions of phenology.

  • 40.
    Stålstedt, Jeanette
    et al.
    Swedish Museum of Natural History, Sweden.
    Bergsten, Johannes
    Swedish Museum of Natural History, Sweden.
    Ronquist, Fredrik
    Swedish Museum of Natural History, Sweden.
    “Forms” of water mites (Acari: Hydrachnidia): intraspecificvariation or valid species?2013In: Ecology and Evolution, ISSN 2045-7758, E-ISSN 2045-7758, Vol. 3, no 10, p. 3415-3435Article in journal (Refereed)
    Abstract [en]

    In many groups of organisms, especially in the older literature, it has been common practice to recognize sympatrically occurring phenotypic variants of a species as “forms”. However, what these forms really represent often remains unclear, especially in poorly studied groups. With new algorithms for DNA-based species delimitation, the status of forms can be explicitly tested with molecular data. In this study, we test a number of what is now recognized as valid species of water mites (Hydrachnidia), but have in the past been treated as forms sympatrically occurring with their nominate species. We also test a form without prior taxonomical status, using DNA and morphometrics. The barcoding fragment of COI, nuclear 28S and quantitative analyses of morphological data were used to test whether these taxa merit species status, as suggested by several taxonomists. Our results confirm valid species. Genetic distances between the form and nominate species (Piona dispersa and Piona variabilis, COI 11%), as well as likelihood ratio tests under the general mixed-Yule coalescent model, supported that these are separately evolving lineages as defined by the unified species concept. In addition, they can be diagnosed with morphological characters. The study also reveals that some taxa genetically represent more than one species. We propose that P. dispersa are recognized as valid taxa at the species level. Unionicola minor (which may consist of several species), Piona stjordalensis, P. imminuta s. lat., and P. rotundoides are confirmed as species using this model. The results also imply that future studies of other water mite species complexes are likely to reveal many more genetically and morphologically distinct species.

  • 41. Tsuboi, Masahito
    et al.
    Shoji, Jun
    Sogabe, Atsushi
    Ahnesjö, Ingrid
    Kolm, Niclas
    Stockholm University, Faculty of Science, Department of Zoology.
    Within species support for the expensive tissue hypothesis: a negative association between brain size and visceral fat storage in females of the Pacific seaweed pipefish2016In: Ecology and Evolution, ISSN 2045-7758, E-ISSN 2045-7758, Vol. 6, no 3, p. 647-655Article in journal (Refereed)
    Abstract [en]

    The brain is one of the most energetically expensive organs in the vertebrate body. Consequently, the high cost of brain development and maintenance is predicted to constrain adaptive brain size evolution (the expensive tissue hypothesis, ETH). Here, we test the ETH in a teleost fish with predominant female mating competition (reversed sex roles) and male pregnancy, the pacific seaweed pipefish Syngnathus schlegeli. The relative size of the brain and other energetically expensive organs (kidney, liver, heart, gut, visceral fat, and ovary/testis) was compared among three groups: pregnant males, nonpregnant males and egg producing females. Brood size in pregnant males was unrelated to brain size or the size of any other organ, whereas positive relationships were found between ovary size, kidney size, and liver size in females. Moreover, we found that the size of energetically expensive organs (brain, heart, gut, kidney, and liver) as well as the amount of visceral fat did not differ between pregnant and nonpregnant males. However, we found marked differences in relative size of the expensive organs between sexes. Females had larger liver and kidney than males, whereas males stored more visceral fat than females. Furthermore, in females we found a negative correlation between brain size and the amount of visceral fat, whereas in males, a positive trend between brain size and both liver and heart size was found. These results suggest that, while the majority of variation in the size of various expensive organs in this species likely reflects that individuals in good condition can afford to allocate resources to several organs, the cost of the expensive brain was visible in the visceral fat content of females, possibly due to the high costs associated with female egg production.

  • 42. Vehmaa, Anu
    et al.
    Hogfors, Hedvig
    Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences.
    Gorokhova, Elena
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Brutemark, Andreas
    Holmborn, Towe
    Engström-Öst, Jonna
    Projected marine climate change: effects on copepod oxidative status and reproduction2013In: Ecology and Evolution, ISSN 2045-7758, E-ISSN 2045-7758, Vol. 3, no 13, p. 4548-4557Article in journal (Refereed)
    Abstract [en]

    Zooplankton are an important link between primary producers and fish. Therefore, it is crucial to address their responses when predicting effects of climate change on pelagic ecosystems. For realistic community-level predictions, several biotic and abiotic climate-related variables should be examined in combination. We studied the combined effects of ocean acidification and global warming predicted for year 2100 with toxic cyanobacteria on the calanoid copepod, Acartia bifilosa. Acidification together with higher temperature reduced copepod antioxidant capacity. Higher temperature also decreased egg viability, nauplii development, and oxidative status. Exposure to cyanobacteria and its toxin had a negative effect on egg production but, a positive effect on oxidative status and egg viability, giving no net effects on viable egg production. Additionally, nauplii development was enhanced by the presence of cyanobacteria, which partially alleviated the otherwise negative effects of increased temperature and decreased pH on the copepod recruitment. The interactive effects of temperature, acidification, and cyanobacteria on copepods highlight the importance of testing combined effects of climate-related factors when predicting biological responses.

  • 43.
    Verschut, Thomas A.
    et al.
    Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences.
    Blažytė-Čereškienė, Laima
    Apšegaitė, Violeta
    Mozūraitis, Raimondas
    Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences. Institute of Ecology, Nature Research Centre, Lithuania.
    Hambäck, Peter A.
    Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences.
    Natal origin affects host preference and larval performance relationships in a tritrophic system2017In: Ecology and Evolution, ISSN 2045-7758, E-ISSN 2045-7758, Vol. 7, p. 2079-2090Article in journal (Refereed)
    Abstract [en]

    Many insects face the challenge to select oviposition sites in heterogeneous environments where biotic and abiotic factors can change over time. One way to deal with this complexity is to use sensory experiences made during developmental stages to locate similar habitats or hosts in which larval development can be maximized. While various studies have investigated oviposition preference and larval performance relationships in insects, they have largely overlooked that sensory experiences made during the larval stage can affect such relationships. We addressed this issue by determining the role of natal experience on oviposition preference and larval performance relationships in a tritrophic system consisting of Galerucella sagittariae, feeding on the two host plants Potentilla palustris and Lysimachia thyrsiflora, and its larval parasitoid Asecodes lucens. We firstly determined whether differences in host-derived olfactory information could lead to divergent host selection, and secondly, whether host preference could result in higher larval performance based on the natal origin of the insects. Our results showed that the natal origin and the quality of the current host are both important aspects in oviposition preference and larval performance relationships. While we found a positive relationship between preference and performance of natal Lysimachia beetles, natal Potentilla larvae showed no such relationship and developed better on L. thyrsiflora. Additionally, the host selection by the parasitoid was mainly affected by the natal origin, while its performance was higher on Lysimachia larvae. With this study we showed that the relationship between oviposition preference and larval performance depends on the interplay between the natal origin of the female and the quality of the current host. However, without incorporating the full tritrophic context of these interactions, their implication in insect fitness and potential adaptation cannot be fully understood.

  • 44.
    Verschut, Thomas A.
    et al.
    Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences.
    Inouye, Brian D.
    Hambäck, Peter A.
    Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences.
    Sensory deficiencies affect resource selection and associational effects at two spatial scales2018In: Ecology and Evolution, ISSN 2045-7758, E-ISSN 2045-7758, Vol. 8, no 21, p. 10569-10577Article in journal (Refereed)
    Abstract [en]

    Many insect species have limited sensory abilities and may not be able to perceive the quality of different resource types while approaching patchily distributed resources. These restrictions may lead to differences in selection rates between separate patches and between different resource types within a patch, which may have consequences for associational effects between resources. In this study, we used an oviposition assay containing different frequencies of apple and banana substrates divided over two patches to compare resource selection rates of wild-type Drosophila melanogaster at the between- and within-patch scales. Next, we compared the wild-type behavior with that of the olfactory-deficient strain Orco(2) and the gustatory-deficient strain Poxn(Delta M22-B5) and found comparable responses to patch heterogeneity and similarly strong selection rates for apple at both scales for the wild-type and olfactory-deficient flies. Their oviposition behavior translated into associational susceptibility for apple and associational resistance for banana. The gustatory-deficient flies, on the other hand, no longer had a strong selection rate for apple, strongly differed in between- and within-patch selection rates from the wild-type flies, and caused no associational effects between the resources. Our study suggests that differences in sensory capabilities can affect resource selection at different search behavior scales in different ways and in turn underlie associational effects between resources at different spatial scales.

  • 45. Wang, Houshuai
    et al.
    Holloway, Jeremy D.
    Janz, Niklas
    Stockholm University, Faculty of Science, Department of Zoology.
    Braga, Mariana P.
    Stockholm University, Faculty of Science, Department of Zoology.
    Wahlberg, Niklas
    Wang, Min
    Nylin, Sören
    Stockholm University, Faculty of Science, Department of Zoology.
    Polyphagy and diversification in tussock moths: Support for the oscillation hypothesis from extreme generalists2017In: Ecology and Evolution, ISSN 2045-7758, E-ISSN 2045-7758, Vol. 7, no 19, p. 7975-7986Article in journal (Refereed)
    Abstract [en]

    Theory on plasticity driving speciation, as applied to insect-plant interactions (the oscillation hypothesis), predicts more species in clades with higher diversity of host use, all else being equal. Previous support comes mainly from specialized herbivores such as butterflies, and plasticity theory suggests that there may be an upper host range limit where host diversity no longer promotes diversification. The tussock moths (Erebidae: Lymantriinae) are known for extreme levels of polyphagy. We demonstrate that this system is also very different from butterflies in terms of phylogenetic signal for polyphagy and for use of specific host orders. Yet we found support for the generality of the oscillation hypothesis, in that clades with higher diversity of host use were found to contain more species. These clades also consistently contained the most polyphagous single species. Comparing host use in Lymantriinae with related taxa shows that the taxon indeed stands out in terms of the frequency of polyphagous species. Comparative evidence suggests that this is most probably due to its nonfeeding adults, with polyphagy being part of a resulting life history syndrome. Our results indicate that even high levels of plasticity can drive diversification, at least when the levels oscillate over time.

  • 46. Winsa, Marie
    et al.
    Öckinger, Erik
    Bommarco, Riccardo
    Lindborg, Regina
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Roberts, Stuart P. M.
    Wärnsberg, Johanna
    Bartomeus, Ignasi
    Sustained functional composition of pollinators in restored pastures despite slow functional restoration of plants2017In: Ecology and Evolution, ISSN 2045-7758, E-ISSN 2045-7758, Vol. 7, no 11, p. 3836-3846Article in journal (Refereed)
    Abstract [en]

    Habitat restoration is a key measure to counteract negative impacts on biodiversity from habitat loss and fragmentation. To assess success in restoring not only biodiversity, but also functionality of communities, we should take into account the re-assembly of species trait composition across taxa. Attaining such functional restoration would depend on the landscape context, vegetation structure, and time since restoration. We assessed how trait composition of plant and pollinator (bee and hoverfly) communities differ between abandoned, restored (formerly abandoned) or continuously grazed (intact) semi-natural pastures. In restored pastures, we also explored trait composition in relation to landscape context, vegetation structure, and pasture management history. Abandoned pastures differed from intact and restored pastures in trait composition of plant communities, and as expected, had lower abundances of species with traits associated with grazing adaptations. Further, plant trait composition in restored pastures became increasingly similar to that in intact pastures with increasing time since restoration. On the contrary, the trait composition of pollinator communities in both abandoned and restored pastures remained similar to intact pastures. The trait composition for both bees and hoverflies was influenced by flower abundance and, for bees, by connectivity to other intact grasslands in the landscape. The divergent responses across organism groups appeared to be mainly related to the limited dispersal ability and long individual life span in plants, the high mobility of pollinators, and the dependency of semi-natural habitat for bees. Our results, encompassing restoration effects on trait composition for multiple taxa along a gradient in both time (time since restoration) and space (connectivity), reveal how interacting communities of plants and pollinators are shaped by different trait-environmental relationships. Complete functional restoration of pastures needs for more detailed assessments of both plants dispersal in time and of resources available within pollinator dispersal range.

  • 47. Wirta, Helena K.
    et al.
    Vesterinen, Eero J.
    Hambäck, Peter A.
    Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences.
    Weingartner, Elisabeth
    Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences.
    Rasmussen, Claus
    Reneerkens, Jeroen
    Schmidt, Niels M.
    Gilg, Olivier
    Roslin, Tomas
    Exposing the structure of an Arctic food web2015In: Ecology and Evolution, ISSN 2045-7758, E-ISSN 2045-7758, Vol. 5, no 17, p. 3842-3856Article in journal (Refereed)
    Abstract [en]

    How food webs are structured has major implications for their stability and dynamics. While poorly studied to date, arctic food webs are commonly assumed to be simple in structure, with few links per species. If this is the case, then different parts of the web may be weakly connected to each other, with populations and species united by only a low number of links. We provide the first highly resolved description of trophic link structure for a large part of a high-arctic food web. For this purpose, we apply a combination of recent techniques to describing the links between three predator guilds (insectivorous birds, spiders, and lepidopteran parasitoids) and their two dominant prey orders (Diptera and Lepidoptera). The resultant web shows a dense link structure and no compartmentalization or modularity across the three predator guilds. Thus, both individual predators and predator guilds tap heavily into the prey community of each other, offering versatile scope for indirect interactions across different parts of the web. The current description of a first but single arctic web may serve as a benchmark toward which to gauge future webs resolved by similar techniques. Targeting an unusual breadth of predator guilds, and relying on techniques with a high resolution, it suggests that species in this web are closely connected. Thus, our findings call for similar explorations of link structure across multiple guilds in both arctic and other webs. From an applied perspective, our description of an arctic web suggests new avenues for understanding how arctic food webs are built and function and of how they respond to current climate change. It suggests that to comprehend the community-level consequences of rapid arctic warming, we should turn from analyses of populations, population pairs, and isolated predator-prey interactions to considering the full set of interacting species.

  • 48. Zanatta, Florian
    et al.
    Vanderpoorten, Alain
    Hedenäs, Lars
    Johansson, Victor
    Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences. Swedish University of Agricultural Sciences, Sweden.
    Patiño, Jairo
    Lönnell, Niklas
    Hylander, Kristoffer
    Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences.
    Under which humidity conditions are moss spores released? A comparison between species with perfect and specialized peristomes2018In: Ecology and Evolution, ISSN 2045-7758, E-ISSN 2045-7758, Vol. 8, no 23, p. 11484-11491Article in journal (Refereed)
    Abstract [en]

    Dispersal is a fundamental biological process that can be divided into three phases: release, transportation, and deposition. Determining the mechanisms of diaspore release is of prime importance to understand under which climatic conditions and at which frequency diaspores are released and transported. In mosses, wherein spore dispersal takes place through the hygroscopic movements of the peristome, the factors enhancing spore release has received little attention. Here, we determine the levels of relative humidity (RH) at which peristome movements are induced, contrasting the response of species with perfect (fully developed) and specialized (reduced) peristomes. All nine investigated species with perfect peristomes displayed a xerochastic behavior, initiating a closing movement from around 50%–65% RH upon increasing humidity and an opening movement from around 90% RH upon drying. Five of the seven species with specialized peristomes exhibited a hygrochastic behavior, initiating an opening movement under increasing RH (from about 80%) and a closing movement upon drying (from about 90%). These differences between species with hygrochastic and xerochastic peristomes suggest that spore dispersal does not randomly occur regardless of the prevailing climate conditions, which can impact their dispersal distances. In species with xerochastic peristomes, the release of spores under decreasing RH can be interpreted as an adaptive mechanism to disperse spores under optimal conditions for long‐distance wind dispersal. In species with hygrochastic peristomes, conversely, the release of spores under wet conditions, which decreases their wind long‐distance dispersal capacities, might be seen as a safe‐site strategy, forcing spores to land in appropriate (micro‐) habitats where their survival is favored. Significant variations were observed in the RH thresholds triggering peristome movements among species, especially in those with hygrochastic peristomes, raising the question of what mechanisms are responsible for such differences.

  • 49. Zeng, Yu
    et al.
    Lou, Shang Ling
    Liao, Wen Bo
    Jehle, Robert
    Kotrschal, Alexander
    Stockholm University, Faculty of Science, Department of Zoology.
    Sexual selection impacts brain anatomy in frogs and toads2016In: Ecology and Evolution, ISSN 2045-7758, E-ISSN 2045-7758, Vol. 6, no 19, p. 7070-7079Article in journal (Refereed)
    Abstract [en]

    Natural selection is a major force in the evolution of vertebrate brain size, but the role of sexual selection in brain size evolution remains enigmatic. At least two opposing schools of thought predict a relationship between sexual selection and brain size. Sexual selection should facilitate the evolution of larger brains because better cognitive abilities may aid the competition for mates. However, it may also restrict brain size evolution due to energetic trade-offs between brain tissue and sexually selected traits. Here, we examined the patterns of selection on brain size and brain anatomy in male anurans (frogs and toads), a group where the strength of sexual selection differs markedly among species, using a phylogenetically controlled generalized least-squared (PGLS) regression analyses. The analysis revealed that in 43 Chinese anuran species, neither mating system, nor type of courtship, or testes mass was significantly associated with relative brain size. While none of those factors related to the relative size of olfactory nerves, optic tecta, telencephalon, and cerebellum, the olfactory bulbs were relatively larger in monogamous species and those using calls during courtship. Our findings support the mosaic model of brain evolution and suggest that while the investigated aspects of sexual selection do not seem to play a prominent role in the evolution of brain size of anurans, they do impact their brain anatomy.

1 - 49 of 49
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf