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  • 101.
    Lõhmus, Mare
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal Ecology.
    Sild, Elin
    Horak, Peeter
    Björklund, Mats
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal Ecology.
    Effects of chronic leptin administration on nitric oxide production and immune responsiveness of greenfinches2011In: Comparative Biochemistry and Physiology A, ISSN 1095-6433, E-ISSN 1531-4332, Vol. 158, no 4, p. 560-565Article in journal (Refereed)
    Abstract [en]

    Leptin and nitric oxide (NO) are both important messengers in intra- and intercellular communication systems in vertebrates. Several studies have demonstrated an involvement of both substances in the immune response. Here we tested the effects of chronic leptin and anti-leptin treatments on the NO production and phytohaemagglutinin- (PHA) induced cutaneous inflammatory response in a wild passerine, the greenfinch (Carduelis chloris). Plasma leptin levels of individual birds were consistent in time but could be still temporarily increased by administration of recombinant chicken leptin. Increase of plasma leptin was also induced by administration of anti-leptin, which can be most likely explained by increased endogenous leptin production due to disruption of signalling pathways. Contrary to previous findings in mammals, leptin administration reduced systemic NO production. Leptin increased cutaneous swelling response to PHA. This immune-enhancing effect was observable despite the similar plasma leptin levels of leptin-treated and control birds at the time of measurement of immune responses, i.e., 9 days after start of the treatments. This provides evidence for a delayed or long-term potentiation of the cells and cytokines involved. The effects of leptin administration on NO production and immune responsiveness were age-dependent, which indicates the complexity of underlying regulatory mechanisms.

  • 102.
    Maklakov, Alexei A.
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal Ecology.
    Cayetano, Luis
    Brooks, Robert C.
    Bonduriansky, Russell
    The roles of life-history selection and sexual selection in the adaptive evolution of mating behavior in a beetle2010In: Evolution, ISSN 0014-3820, E-ISSN 1558-5646, Vol. 64, no 5, p. 1273-1282Article in journal (Refereed)
    Abstract [en]

    Although there is continuing debate about whether sexual selection promotes or impedes adaptation to novel environments, the role of mating behavior in such adaptation remains largely unexplored We investigated the evolution of mating behavior (latency to mating, mating probability and duration) in replicate populations of seed beetles Callosobruchus maculatus subjected to selection on life-history ("Young" vs. "Old" reproduction) under contrasting regimes of sexual selection ("Monogamy" vs. "Polygamy"). Life-history selection is predicted to favor delayed mating in "Old" females, but sexual conflict under polygamy can potentially retard adaptive life-history evolution. We found that life-history selection yielded the predicted changes in mating behavior, but sexual selection regime had no net effect. In within-line crosses, populations selected for late reproduction showed equally reduced early-life mating probability regardless of mating system. In between-line crosses, however, the effect of life-history selection on early-life mating probability was stronger in polygamous lines than in monogamous ones. Thus, although mating system influenced male-female coevolution, removal of sexual selection did not affect the adaptive evolution of mating behavior Importantly, our study shows that the interaction between sexual selection and life-history selection can result in either increased or decreased reproductive divergence depending on the ecological context.

  • 103.
    Maklakov, Alexei A.
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal Ecology.
    Immler, Simone
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Evolutionary Biology.
    Gonzalez-Voyer, Alejandro
    Rönn, Johanna
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal ecology.
    Kolm, Niclas
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal Ecology.
    Brains and the city: big-brained passerine birds succeed in urban environments2011In: Biology Letters, ISSN 1744-9561, E-ISSN 1744-957X, Vol. 7, no 5, p. 730-732Article in journal (Refereed)
    Abstract [en]

    Urban regions are among the most human-altered environments on Earth and they are poised for rapid expansion following population growth and migration. Identifying the biological traits that determine which species are likely to succeed in urbanized habitats is important for predicting global trends in biodiversity. We provide the first evidence for the intuitive yet untested hypothesis that relative brain size is a key factor predisposing animals to successful establishment in cities. We apply phylogenetic mixed modelling in a Bayesian framework to show that passerine species that succeed in colonizing at least one of 12 European cities are more likely to belong to big-brained lineages than species avoiding these urban areas. These data support findings linking relative brain size with the ability to persist in novel and changing environments in vertebrate populations, and have important implications for our understanding of recent trends in biodiversity.

  • 104.
    Mats, Björklund
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal Ecology.
    Emma, Rova
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal Ecology.
    Assortative mating and the cost of inbreeding: A simulation approach2012In: Ecological Informatics, ISSN 1574-9541, E-ISSN 1878-0512, Vol. 9, p. 59-63Article in journal (Refereed)
    Abstract [en]

    Assortative mating is an important factor in the process of speciation. Models of speciation frequently deal with small founder populations often with mating preferences based on ecological traits or habitat preferences. Small populations, on the other hand might suffer from inbreeding. However, few studies have explored the combined effects of assortative mating and inbreeding in such populations. Can they speciate, or are they doomed to eventually go extinct? With this simulation we show that assortative mating based on similarities increases the possibility for change in a population, as long as the population does not suffer from inbreeding depression. Inbred populations seem not to be able to cope with strong assortative mating, as this is likely to elevate the level of inbreeding, increasing the risks of inbreeding depression and as a result decreasing population mean fitness. This in turn hinders the possibility of change, and instead might drive the population to extinction.

  • 105.
    Milbrink, Göran
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal Ecology.
    Vrede, Tobias
    Tranvik, Lars J.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Rydin, Emil
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Large-scale and long-term decrease in fish growth following the construction of hydroelectric reservoirs2011In: Canadian Journal of Fisheries and Aquatic Sciences, ISSN 0706-652X, E-ISSN 1205-7533, Vol. 68, no 12, p. 2167-2173Article in journal (Refereed)
    Abstract [en]

    Hydroelectric reservoirs retain large volumes of water and have a global impact on sea level, elemental cycles, and biodiversity. Using data from a total of 90 historical and recent surveys in nine regulated and eight unregulated alpine and subalpine lakes, we show an additional large effect of reservoirs, i.e., that impoundment causes drastically decreased fish growth and thereby great negative consequences for inland fisheries in Scandinavia. Following a long period (40-65 years) after impoundment, the length and mass of Arctic charr (Salvelinus alpinus) of the single age class 4+ years was, on average, 35% and 72% lower, respectively, in impounded versus natural lakes in northern Scandinavia. The effect was stronger at higher altitudes and can be mitigated by addition of inorganic nutrients. We suggest that the decreased fish growth is a consequence of lowered ecosystem productivity, oligotrophication, caused by impoundment, resulting in erosion and loss of the littoral ecosystem as well as delayed flooding and leakage of nutrients from the riparian zone until after the growing season.

  • 106.
    Mobley, Kenyon
    et al.
    Department of Ecology and Environmental Science, Umeå university.
    Kvarnemo, Charlotta
    Department of Zoology, Göteborg University.
    Ahnesjö, Ingrid
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal Ecology.
    Partridge, Charlyn
    Department of Biology, Texas A&M University, USA.
    Berglund, Anders
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal Ecology.
    Jones, Adam G.
    Department of Biology, Texas A&M University, USA.
    The effect of maternal body size on embryo survivorship in the broods of pregnant male pipefish2011In: Behavioral Ecology and Sociobiology, ISSN 0340-5443, E-ISSN 1432-0762, Vol. 65, no 6, p. 1169-1177Article in journal (Refereed)
    Abstract [en]

    The occurrence of male pregnancy in the family Syngnathidae (seahorses, pipefishes, and sea dragons) provides an exceptionally fertile system in which to investigate issues related to the evolution of parental care. Here, we take advantage of this unique reproductive system to study the influence of maternal body size on embryo survivorship in the brood pouches of pregnant males of the broad-nosed pipefish, Syngnathus typhle. Males were mated with either two large females, two small females, a large then a small female, or a small then a large female. Our results show that offspring survivorship depends on an interaction between female body size and the number of eggs transferred by the female. Eggs of larger females deposited in large numbers are more likely to result in viable offspring than eggs of smaller females laid in large numbers. However, when females deposited smaller numbers of eggs, the eggs from smaller females were more likely to produce viable offspring compared to those from larger females. We found no evidence that this result was based on mating order, the relative sizes of competing females, or egg characteristics such as dry weight of eggs. Additionally, male body size did not significantly influence the survivorship of offspring during brooding. Our results suggest that the factors underlying offspring survivorship in pipefish may be more complex than previously believed, with multiple factors interacting to determine the fitness of individual offspring within the broods of pregnant males.

  • 107.
    Morrow, Edward H.
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal Ecology.
    Innocenti, Paolo
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal Ecology.
    Female postmating immune responses, immune system evolution and immunogenic males2012In: Biological Reviews, ISSN 1464-7931, E-ISSN 1469-185X, Vol. 87, no 3, p. 631-638Article, review/survey (Refereed)
    Abstract [en]

    Females in many taxa experience postmating activation of their immune system, independently of any genital trauma or pathogenic attack arising from male-female genital contact. This response has always been interpreted as a product of natural selection as it either prepares the female immune system for antigens arising from an implanted embryo (in the case of placental mammals), or is a pre-emptive strike against infection or injury acquired during mating. While the first hypothesis has empirical support, the second is not entirely satisfactory. Recently, studies that have experimentally dissected the postmating responses of Drosophila melanogaster females point to a different explanation: male reproductive peptides/proteins that have evolved in response to postmating male-male competition are directly responsible for activating particular elements of the female immune system. Thus, in a broad sense, males may be said to be immunogenic to females. Here, we discuss a possible direct role of sexual selection/sexual conflict in immune system evolution, in contrast to indirect trade-offs with other life-history traits, presenting the available evidence from a range of taxa and proposing ways in which the competing hypotheses could be tested. The major implication of this review is that immune system evolution is not only a product of natural selection but also that sexual selection and potentially sexual conflict enforces a direct selective pressure. This is a significant shift, and will compel researchers studying immune system evolution and ecological immunity to look beyond the forces generated by parasites and pathogens to those generated by the male ejaculate.

  • 108. Mucci, Nadia
    et al.
    Arrendal, Johanna
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal Ecology.
    Ansorge, Hermann
    Bailey, Michael
    Bodner, Michaela
    Delibes, Miguel
    Ferrando, Ainhoa
    Fournier, Pascal
    Fournier, Christine
    Godoy, Jose A.
    Hajkova, Petra
    Hauer, Silke
    Heggberget, Thrine Moen
    Heidecke, Dietrich
    Kirjavainen, Harri
    Krueger, Hans-Heinrich
    Kvaloy, Kirsti
    Lafontaine, Lionel
    Lanszki, Jozsef
    Lemarchand, Charles
    Liukko, Ulla-Maija
    Loeschcke, Volker
    Ludwig, Gilbert
    Madsen, Aksel Bo
    Mercier, Laurent
    Ozolins, Janis
    Paunovic, Momir
    Pertoldi, Cino
    Piriz, Ana
    Prigioni, Claudio
    Santos-Reis, Margarida
    Luis, Teresa Sales
    Stjernberg, Torsten
    Schmid, Hans
    Suchentrunk, Franz
    Teubner, Jens
    Tornberg, Risto
    Zinke, Olaf
    Randi, Ettore
    Genetic diversity and landscape genetic structure of otter (Lutra lutra) populations in Europe2010In: Conservation Genetics, ISSN 1566-0621, E-ISSN 1572-9737, Vol. 11, no 2, p. 583-599Article in journal (Refereed)
    Abstract [en]

    Eurasian otter populations strongly declined and partially disappeared due to global and local causes (habitat destruction, water pollution, human persecution) in parts of their continental range. Conservation strategies, based on reintroduction projects or restoration of dispersal corridors, should rely on sound knowledge of the historical or recent consequences of population genetic structuring. Here we present the results of a survey performed on 616 samples, collected from 19 European countries, genotyped at the mtDNA control-region and 11 autosomal microsatellites. The mtDNA variability was low (nucleotide diversity = 0.0014; average number of pairwise differences = 2.25), suggesting that extant otter mtDNA lineages originated recently. A star-shaped mtDNA network did not allow outlining any phylogeographic inference. Microsatellites were only moderately variable (H (o) = 0.50; H (e) = 0.58, on average across populations), the average allele number was low (observed A (o) = 4.9, range 2.5-6.8; effective A (e) = 2.8; range 1.6-3.7), suggesting small historical effective population size. Extant otters likely originated from the expansion of a single refugial population. Bayesian clustering and landscape genetic analyses however indicate that local populations are genetically differentiated, perhaps as consequence of post-glacial demographic fluctuations and recent isolation. These results delineate a framework that should be used for implementing conservation programs in Europe, particularly if they are based on the reintroduction of wild or captive-reproduced otters.

  • 109.
    Nenzén, Hedvig K.
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal Ecology.
    Araujo, M. B.
    Choice of threshold alters projections of species range shifts under climate change2011In: Ecological Modelling, ISSN 0304-3800, E-ISSN 1872-7026, Vol. 222, no 18, p. 3346-3354Article in journal (Refereed)
    Abstract [en]

    One of the least explored sources of algorithmic uncertainty in bioclimatic envelope models (BEM) is the selection of thresholds to transform modelled probabilities of occurrence (or indices of suitability) into binary predictions of species presence and absence. We investigate the impacts of such thresholds in the specific context of climate change. BEM for European tree species were fitted combining 9 climatic models and emissions scenarios, 7 modelling techniques, and 14 threshold-setting techniques. We quantified sources of uncertainty in projections of turnover, and found that the choice of the modelling technique explained most of the variability (39%), while threshold choice explained 25% of the variability in the results, and their interaction an additional 19%. Choice of future climates explained 9% of total variability among projections. Estimated species range shifts obtained by applying different thresholds and models were grouped by IUCN-based categories of threat. Thresholds had a large impact on the inferred risks of extinction, producing 1.7- to 9.9-fold differences in the proportions of species projected to become threatened by climate change. Results demonstrate that threshold selection has large - albeit often unappreciated - consequences for estimating species range shifts under climate change. 

  • 110.
    Nie, Xiang-Ping
    et al.
    Department of Ecology, Jian University, Guangzhou, China.
    Zie, Jenny
    Department of Systems Ecology, Stockholm University.
    Häubner, Norbert
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Ecological Botany.
    Tallmark, Bo
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal Ecology.
    Snoeijs, Pauli
    Department of Systems Ecology, Stokcholm University.
    Prey diversity and prey stomach contents affect astaxanthin levels in piscivorous fishIn: Limnology and Oceanography, ISSN 0024-3590, E-ISSN 1939-5590Article in journal (Refereed)
    Abstract [en]

    We analyzed astaxanthin concentrations and the composition of geometrical (E/Z) astaxanthin isomers in 631 tissue samples from the four chief fish species in the pelagic zone of the brackish Baltic Sea. Salmon and herring showed signs of astaxanthin deficiency, but cod and sprat did not. The isomers were distributed selectively in fish tissues, with highest proportions of all-E-astaxanthin in salmon gonads (71%) and lowest in herring gonads (19%). We discovered that the clupeids are no ideal prey for salmon and cod with respect to their high whole-body concentrations of astaxanthin Z-isomers, which have low bioavailability for salmon and cod. The salmon in the Baltic Sea is entirely dependent on herring and sprat for food intake while cod feeds on a more diverse diet, including crustaceans. This explains the normal low astaxanthin levels in the salmon in the Baltic Sea. Observed decreases in astaxanthin levels in the Baltic salmon during the last 50 years, which are related to a reproductional disturbance (M74 syndrome), can be explained by the here described poor quality of herring as astaxanthin source in combination with recorded changes in the feeding ecology of the Baltic salmon with less sprat and more herring in the diet today. Herring is inferior to sprat as astaxanthin source, especially in autumn when a salmon or cod obtains four times more bioavailable all-E-astaxanthin (by weight) from sprat than from herring. The Baltic herring is starving more than the sprat as a result of competition between the clupeids though fishing mortality and recruitment problems of the cod, their major predator during the last decades. Therefore, less crustacean astaxanthin (mainly all-E) is transferred directly to piscivorous fish from herring stomachs than from sprat stomachs.

  • 111. Nie, Xiang-Ping
    et al.
    Zie, Jenny
    Häubner, Norbert
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Plant Ecology and Evolution.
    Tallmark, Bo
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal Ecology.
    Snoeijs, Pauline
    Why Baltic herring and sprat are weak conduits for astaxanthin from zooplankton to piscivorous fish2011In: Limnology and Oceanography, ISSN 0024-3590, E-ISSN 1939-5590, Vol. 56, no 3, p. 1155-1167Article in journal (Refereed)
    Abstract [en]

    Atlantic salmon living in the brackish Baltic Sea have lower muscle pigmentation than populations elsewhere. The pigment in question is the antioxidant and vitamin A precursor astaxanthin, which is synthesized by crustaceans from algal carotenoids. Baltic salmon feed nearly exclusively on the clupeids sprat and herring. To evaluate astaxanthin availability to salmon we assessed astaxanthin levels and isomeric composition in their prey fish. We also analyzed astaxanthin dynamics in the dominant piscivorous fish in the Baltic Sea, the Atlantic cod. The geometrical E-(trans-) and Z-(cis-) isomers were distributed selectively in fish tissues, with highest E : Z ratios in salmon gonads (82 : 18) and lowest in herring gonads (24 : 76). Sprat and herring are not ideal prey with respect to their high whole-body concentrations of Z-isomers, which have low bioavailability for salmon and cod. These Z-isomers predominantly accumulate in the clupeid gonads. A crucial mechanism for the transport of astaxanthin from clupeids to piscivores is the direct transfer of crustacean astaxanthin (mainly all-E) from the clupeid stomachs. Low stomach astaxanthin content in clupeids decreases total astaxanthin transfer to higher trophic levels. In autumn, herring stomachs (including contents) had 12.5 times lower astaxanthin concentrations than sprat stomachs, and herring had 2.8 times less whole-body all-E-astaxanthin (by weight) than sprat. These results confirm recent reports of starvation in the Baltic herring, which may further decrease astaxanthin levels in the Baltic salmon. Cod did not have lower astaxanthin levels than their Atlantic counterpart, which may be attributed to their lower need for astaxanthin and higher food diversity.

  • 112.
    Nonaka, Yuki
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal Ecology. Uppsala University, Disciplinary Domain of Science and Technology, Biology, Biology Education Centre.
    Life-History Divergence and Relative Fitness of Nestling Ficedula Flycatcher Hybrids2012Independent thesis Advanced level (degree of Master (Two Years)), 30 credits / 45 HE creditsStudent thesis
    Abstract [en]

    The typical intermediate morphology of hybrids may result in their failure to utilize the same niches as their parents. However, the fitness consequences of the potentially intermediate life-history traits of hybrids have been given less scientific attention. In this study I aimed to investigate how life-history divergence in parental species affects the relative fitness of nestling hybrids resulting from crosses between collared (Ficedula albicollis) and pied flycatchers (F. hypoleuca). Previous studies showed that collared flycatcher nestlings beg more intensively and grow faster under good conditions, but are less robust against the seasonal decline in food availability compared to pied flycatcher nestlings. This life-history divergence between the species allows regional coexistence. To investigate whether the life-history divergence in flycatchers influences the relative fitness of nestling hybrids, I cross-fostered hybrid nestlings in aviaries into the nests of conspecific pairs and compared their performance. I found that the hybrids displayed intermediate growth rates between collared and pied flycatchers across the season. There might therefore be environmental conditions when hybrids perform better than purebred offspring with respect to growth and survival.

  • 113. Part, Tomas
    et al.
    Arlt, Debora
    Doligez, Blandine
    Low, Matthew
    Qvarnstrom, Anna
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal Ecology.
    Prospectors combine social and environmental information to improve habitat selection and breeding success in the subsequent year2011In: Journal of Animal Ecology, ISSN 0021-8790, E-ISSN 1365-2656, Vol. 80, no 6, p. 1227-1235Article in journal (Refereed)
    Abstract [en]

    1. Because habitats have profound effects on individual fitness, there is strong selection for improving the choice of breeding habitat. One possible mechanism is for individuals to use public information when prospecting future breeding sites; however, to our knowledge, no study has shown prospecting behaviour to be directly linked to subsequent choice of breeding site and future reproductive success.

    2. We collected long-term data on territory-specific prospecting behaviour and subsequent breeding in the short-lived northern wheatear (Oenanthe oenanthe). Non-breeders established prospecting territories (<2 ha) that overlapped the breeding territories of conspecifics. We tested whether: (i) prospectors used social and environmental cues that predicted territory-specific breeding success in the following year, and (ii) the prospecting territory was tightly linked to the subsequent breeding territory of the prospector, and whether this link would be weakened by intraspecific competition with original territory owners if they also survived.

    3. As expected, prospectors were attracted to a combination of site-specific cues that predicted future breeding success, i. e. short ground vegetation, a successfully breeding focal pair and successful close neighbours.

    4. Prospecting behaviour was directly linked to the choice of the following year's breeding territory: 79% of surviving prospectors established a breeding territory at their prospecting site in the following year, with their breeding success being higher than other individuals of the same age. As predicted, fidelity to the prospected site was strongly dependent on whether the original territory owner of the same sex had died or moved.

    5. Our findings suggest that the use of multiple cues reduces the negative impact of stochasticity on the reliability of social cues at small spatial scales (e. g. territories) and hence increases the probability of breeding success in the next year. Also, the use of conspecific attraction (i. e. the preference for breeding aggregations) is selectively advantageous because individuals are more likely to find a vacancy in an aggregation as compared to a solitary site. By extension, we hypothesize that species life-history traits may influence the spatial scale of prospecting behaviour and habitat selection strategies.

  • 114. Patrelle, Cecile
    et al.
    Hjernquist, Mårten B.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal Ecology.
    Laurila, Anssi
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Population and Conservation Biology. Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal ecology.
    Soderman, Fredrik
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Population and Conservation Biology. Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal ecology.
    Merila, Juha
    Sex differences in age structure, growth rate and body size of common frogs Rana temporaria in the subarctic2012In: Polar Biology, ISSN 0722-4060, E-ISSN 1432-2056, Vol. 35, no 10, p. 1505-1513Article in journal (Refereed)
    Abstract [en]

    The thermal environment and length of the activity season are important factors in shaping life-history trait variation in ectotherms. Many ectothermic vertebrates living at high latitudes or altitudes tend to be larger and older than their conspecifics living at lower latitudes or altitudes. However, detailed data on age, body size and growth variation-and how they may differ between males and females-are still scarce, especially from extreme high-latitude environments. We studied growth (body length increment), age and size structure of common frogs (Rana temporaria) in subarctic Finland (69A degrees 04'N) by applying skeletochronological methods to individually marked adults (n = 169) captured and recaptured between 1999 and 2003. We found that breeding males were on average younger (mean = 8.5 years) than females (11.9 years) and that males started reproducing earlier (a parts per thousand yen3-4 years of age) than females (> 4-5 years). The oldest encountered individual was an 18-year-old female, which to our knowledge is the oldest wild common frog ever reported. Females were on average larger (mean body length = 76.6 mm) than males (70.7 mm), and this appeared to be mainly due to their older age as compared to males. While body length increased and growth rate decreased with age in both sexes, growth rate declined significantly faster with age in males than in females. The latter finding provides a proximate explanation for the observation that even after accounting for age differences among sexes (females > males), females were longer than males.

  • 115.
    Pitala, Natalia
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal Ecology.
    Siitari, Heli
    Gustafsson, Lars
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal Ecology.
    Brommer, Jon E.
    Costs and Benefits of Experimentally Induced Changes in the Allocation of Growth versus Immune Function under Differential Exposure to Ectoparasites2010In: PLoS ONE, ISSN 1932-6203, Vol. 5, no 5, p. e10814-Article in journal (Refereed)
    Abstract [en]

    Background: Ecological immunology has focused on the costs of investment in immunocompetence. However, understanding optimal resource allocation to immune defence requires also identification of its benefits, which are likely to occur only when parasites are abundant. Methodology: We manipulated the abundance of parasitic hen fleas in blue tit (Cyanistes caeruleus) nests, and supplemented their hosts, the nestlings, with methionine (a sulphur amino acid enhancing cell-mediated immunity) during day 3-6. We found a significant interaction between these two experimental factors on the development of immune defences and growth rates. Only in parasitized nests did methionine supplementation boost immune (PHA) response, and did nestling with experimentally increased immunocompetence show a relatively faster growth rate than control nestlings between days 6-9. Hence, the allocation of resources into immune defence and its growth-benefits are apparent only in presence of parasites. The main cost of methionine-induced increased allocation to the immune system was an increase in mortality, independently of ectoparasites. Nestlings in all treatments compensated initial growth reduction and all reached equal body size at day 16 (just prior to fledging), indicating a lack of long-term benefits. In addition, methionine treatment tended (P = 0.09) to lower circulating plasma immunoglobulin levels, possibly indicating a trade-off between the cell-mediated and humoral components of the immune system. Conclusions: We found no strong benefits of an increased investment in immunocompetence in a parasite-rich environment. Any deviation from the growth trajectory (due to changes in allocation induced by methionine) is largely detrimental for survival. Hence, while costs are apparent identifying the benefits of investment in immunocompetence during ontogeny is challenging.

  • 116.
    Podevin, Murielle
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal Ecology. Uppsala University, Disciplinary Domain of Science and Technology, Biology, Biology Education Centre.
    Sperm morphology and reproductive isolation in Ficedula flycatchers2011Independent thesis Advanced level (degree of Master (Two Years)), 30 credits / 45 HE creditsStudent thesis
    Abstract [en]

    Speciation lies at the heart of evolution and the study of reproductive barriers allows a better understanding of the different steps leading to the complete isolation of two species. Pre-mating (behavior tactics, habitat or food divergence, phenotypic divergence and assortative mating) and post-mating, post-zygotic isolation barriers (selection against unfit hybrids) are well studied in numerous species, but little is known about what is happening between insemination and fertilization (post-mating, pre-zygotic isolation barriers). In this study, we chose the well-studied population of pied and collared flycatchers (Ficedula hypoleuca and F. albicollis) of the hybrid zone of Öland, Sweden, to investigate possible patterns of gamete divergence between these two closely related species. We compared sperm morphology between the two species and their hybrids, analyzing traits that are thought to play an important role in the fertilization success of the males. We did not detect any divergence in sperm morphology between the two species, but we report an extreme reduction of sperm production in hybrid males, as well as spermatogenesis dysfunctions and particularly high rates of extra-pair young in the nests of hybrid males.

  • 117.
    Qvarnström, Anna
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal Ecology.
    Rice, Amber M.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal Ecology.
    Ellegren, Hans
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Evolutionary Biology.
    Speciation in Ficedula flycatchers2010In: Philosophical Transactions of the Royal Society of London. Biological Sciences, ISSN 0962-8436, E-ISSN 1471-2970, Vol. 365, no 1547, p. 1841-1852Article, review/survey (Refereed)
    Abstract [en]

    Speciation in animals often requires that population divergence goes through three major evolutionary stages, i.e. ecological divergence, development of sexual isolation and the build-up of genetic incompatibility. There is theoretical consensus regarding favourable conditions required for speciation to reach its final and irreversible stage, but empirical tests remain rare. Here, we review recent research on processes of speciation, based on studies in hybrid zones between collared (Ficedula albicollis) and pied flycatchers (Ficedula hypoleuca). A major advantage of this study system is that questions concerning all three major sources of reproductive isolation and their interconnections can be addressed. We conclude that (i) ecological divergence is caused by divergence in life-history traits, (ii) females prefer mates of their own species based on differences in both plumage and song characteristics, (iii) male plumage characteristics have diverged but their song has converged in sympatry, (iv) there is genetic incompatibility in accordance with Haldane's rule, and (v) the Z-chromosome appears to be a hotspot for genes involved in sexual isolation and genetic incompatibility. We discuss how identification of the genes underlying the three major sources of reproductive isolation can be used to draw conclusions about links between the processes driving their evolution.

  • 118.
    Qvarnström, Anna
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal Ecology.
    Vallin, Niclas
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal Ecology.
    Rudh, Andreas
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal Ecology.
    The role of male contest competition over mates in speciation2012In: Current Zoology, ISSN 1674-5507, Vol. 58, no 3, p. 493-509Article in journal (Refereed)
    Abstract [en]

    Research on the role of sexual selection in the speciation process largely focuses on the diversifying role of mate choice. In particular, much attention has been drawn to the fact that population divergence in mate choice and in the male traits subject to choice directly can lead to assortative mating. However, male contest competition over mates also constitutes an important mechanism of sexual selection. We review recent empirical studies and argue that sexual selection through male contest competition can affect speciation in ways other than mate choice. For example, biases in aggression towards similar competitors can lead to disruptive and negative frequency-dependent selection on the traits used in contest competition in a similar way as competition for other types of limited resources. Moreover, male contest abilities often trade-off against other abilities such as parasite resistance, protection against predators and general stress tolerance. Populations experiencing different ecological conditions should therefore quickly diverge non-randomly in a number of traits including male contest abilities. In resource based breeding systems, a feedback loop between competitive ability and habitat use may lead to further population divergence. We discuss how population divergence in traits used in male contest competition can lead to the build up of reproductive isolation through a number of different pathways. Our main conclusion is that the role of male contest competition in speciation remains largely scientifically unexplored.

  • 119. Radwan, Jacek
    et al.
    Zagalska-Neubauer, Magdalena
    Cichon, Mariusz
    Sendecka, Joanna
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Population and Conservation Biology.
    Kulma, Katarzyna
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal Ecology.
    Gustafsson, Lars
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal Ecology.
    Babik, Wieslaw
    MHC diversity, malaria and lifetime reproductive success in collared flycatchers2012In: Molecular Ecology, ISSN 0962-1083, E-ISSN 1365-294X, Vol. 21, no 10, p. 2469-2479Article in journal (Refereed)
    Abstract [en]

    Major histocompatibility complex (MHC) genes encode proteins involved in the recognition of parasite-derived antigens. Their extreme polymorphism is presumed to be driven by co-evolution with parasites. Hostparasite co-evolution was also hypothesized to optimize within-individual MHC diversity at the intermediate level. Here, we use unique data on lifetime reproductive success (LRS) of female collared flycatchers to test whether LRS is associated with within-individual MHC class II diversity. We also examined the association between MHC and infection with avian malaria. Using 454 sequencing, we found that individual flycatchers carry between 3 and 23 functional MHC class II B alleles. Predictions of the optimality hypothesis were not confirmed by our data as the prevalence of blood parasites decreased with functional MHC diversity. Furthermore, we did not find evidence for an association between MHC diversity and LRS.

  • 120. Robinson, Matthew R.
    et al.
    van Doorn, G. Sander
    Gustafsson, Lars
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal Ecology.
    Qvarnström, Anna
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal Ecology.
    Environment-dependent selection on mate choice in a natural population of birds2012In: Ecology Letters, ISSN 1461-023X, E-ISSN 1461-0248, Vol. 15, no 6, p. 611-618Article in journal (Refereed)
    Abstract [en]

    Female mate choice acts as an important evolutionary force, yet the influence of the environment on both its expression and the selective pressures acting upon it remains unknown. We found consistent heritable differences between females in their choice of mate based on ornament size during a 25-year study of a population of collared flycatchers. However, the fitness consequences of mate choice were dependent on environmental conditions experienced whilst breeding. Females breeding with highly ornamented males experienced high relative fitness during dry summer conditions, but low relative fitness during wetter years. Our results imply that sexual selection within a population can be highly variable and dependent upon the prevailing weather conditions experienced by individuals.

  • 121.
    Rogell, Björn
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal Ecology. Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Population and Conservation Biology.
    Dannewitz, Johan
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Population and Conservation Biology.
    Palm, Stefan
    Petersson, Erik
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal Ecology.
    Dahl, Jonas
    Prestegaard, Tore
    Jarvi, Torbjorn
    Laurila, Anssi
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Population and Conservation Biology.
    Strong divergence in trait means but not in plasticity across hatchery and wild populations of sea-run brown trout Salmo trutta2012In: Molecular Ecology, ISSN 0962-1083, E-ISSN 1365-294X, Vol. 21, no 12, p. 2963-2976Article in journal (Refereed)
    Abstract [en]

    There is ample evidence that organisms adapt to their native environment when gene flow is restricted. However, evolution of plastic responses across discrete environments is less well examined. We studied divergence in means and plasticity across wild and hatchery populations of sea-run brown trout (Salmo trutta) in a common garden experiment with two rearing environments (hatchery and a nearly natural experimental stream). Since natural and hatchery environments differ, this arrangement provides an experiment in contemporary adaptation across the two environments. A QST - FST approach was used to investigate local adaptation in survival and growth over the first summer. We found evidence for divergent selection in survival in 1 year and in body length in both years and rearing environments. In general, the hatchery populations had higher survival and larger body size in both environments. QST in body size did not differ between the rearing environments, and constitutive divergence in the means was in all cases stronger than divergence in the plastic responses. These results suggest that in this system, constitutive changes in mean trait values are more important for local adaptation than increased plasticity. In addition, ex situ rearing conditions induce changes in trait means that are adaptive in the hatchery, but potentially harmful in the wild, suggesting that hatchery rearing is likely to be a suboptimal management strategy for trout populations facing selection in the stream environment.

  • 122.
    Rosenqvist, Gunilla
    et al.
    Gotland University, School of Culture, Energy and Environment.
    Berglund, Anders
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal Ecology.
    Sexual signals and mating patterns in Syngnathidae2011In: Journal of Fish Biology, ISSN 0022-1112, E-ISSN 1095-8649, Vol. 78, no 6, p. 1647-1661Article in journal (Refereed)
    Abstract [en]

    Male pregnancy in the family Syngnathidae (pipefishes, seahorses and seadragons) predisposes males to limit female reproductive success and sexual selection may then operate more strongly on females and female sexual signals may evolve (“sex role reversal”).  A bewildering array of female signals have evolved in Syngnathids, e.g. skin folds, large body size, colouration, markings on the body and elaborate courtship.These female sexual signals do not seem quantitatively or qualitatively different from those that evolve in males in species with conventional sex roles where males provide females or offspring with direct benefits. In several syngnathid species also males evolve ornaments, females are choosy in addition to being competitive, and males compete as well as chose partners. Thus, sex roles form a continuum, spanning from conventional to reversed within this group of fishes. Cases are here presented suggesting that stronger sexual selection on females may be most extreme in species showing classical polyandry (one male mates with several females, such as many species where males brood their eggs on the trunk), intermediate in polygynandrous species (males and females both mate multiply, as in many species where males brood their eggs on the tail), and least extreme, even exhibiting conventional sex roles, in monogamous species (one male mates solely with one female, as in many seahorses and tropical pipefish). At the same time caution is needed before unanimously establishing this pattern: first, the connection between mating patterns, strength of sexual selection, sex roles and ornament expression is far from simple and straight-forward, and second, knowledge of the actual morphology, ecology and behavior of most syngnathid species is scanty: basically only a few Nerophis, Syngnathus and Hippocampus species have been studied in any detail. It is known, however, that this group of fish exhibits a remarkable variation in sex roles and ornamentation, making them an ideal group for the study of mating patterns, sexual selection and sexually selected signals.   

     

  • 123.
    Rova, Emma
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal Ecology.
    Björklund, Mats
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal Ecology.
    Can preference for oviposition sites initiate reproductive isolation in Callosobruchus maculatus?2011In: PLoS ONE, ISSN 1932-6203, Vol. 6, no 1, p. e14628-Article in journal (Refereed)
    Abstract [en]

    Theory has identified a variety of evolutionary processes that may lead to speciation. Our study includes selection experiments using different host plants and test key predictions concerning models of speciation based on host plant choice, such as the evolution of host use (preference and performance) and assortative mating. This study shows that after only ten generations of selection on different resources/hosts in allopatry, strains of the seed beetle Callosobruchus maculatus develop new resource preferences and show resource-dependent assortative mating when given the possibility to choose mates and resources during secondary contact. The resulting reduced gene flow between the different strains remained for two generations after contact before being overrun by disassortative mating. We show that reduced gene flow can evolve in a population due to a link between host preference and assortative mating, although this result was not found in all lines. However, consistent with models of speciation, assortative mating alone is not sufficient to maintain reproductive isolation when individuals disperse freely between hosts. We conclude that the evolution of reproductive isolation in this system cannot proceed without selection against hybrids. Other possible factors facilitating the evolution of isolation would be longer periods of allopatry, the build up of local adaptation or reduced migration upon secondary contact.

  • 124.
    Rova, Emma
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal Ecology.
    Björklund, Mats
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal Ecology.
    Competitive environments induce shifts in host fidelity2010In: Journal of Evolutionary Biology, ISSN 1010-061X, E-ISSN 1420-9101, Vol. 23, no 8, p. 1657-1663Article in journal (Refereed)
    Abstract [en]

    Recent models support the idea of sympatric speciation as a result of the joint effects of disruptive selection and assortative mating. We present experimental data, testing models of speciation through frequency-dependent selection. We show that under high competition on a mixture of resources/hosts, strains of the Seed beetle, Callosobruchus maculatus, change their host fidelity and evolve a more generalistic behaviour in resource utilisation among females. The change in host fidelity did not result in disruptive selection and was not followed by assortative mating. This means that only one out of three fundamental prerequisites for sympatric speciation evolved as a result of the frequency-dependent selection. We conclude that for this process to work, a shift to a novel food resource as a result of selection must also lead to a loss of preference for the original source such that individuals are only able to use either one of the two.

  • 125.
    Rova, Emma
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal Ecology.
    Björklund, Mats
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal Ecology.
    The influence of migration on the maintenance of assortative mating2012In: Animal Behaviour, ISSN 0003-3472, E-ISSN 1095-8282, Vol. 83, no 1, p. 11-15Article in journal (Refereed)
    Abstract [en]

    Rapid speciation has been shown to be plausible without the need for extreme founder events, complete geographical isolation, the existence of distinct adaptive peaks or selection for local adaptation. However, standard theory predicts that extremely low migration rates are enough to hinder divergence between populations, and thus speciation. In this study we asked how low migration rates need to be for divergence to occur and hence for speciation to be possible. We experimentally transferred individual seed beetles, Callosobruchus maculatus, between populations in the laboratory, thus mimicking different rates of migration, and used deviations from Hardy-Weinberg equilibrium as an indicator of assortative mating. We found that assortative mating was upheld for several generations in populations experiencing immigration rates of up to 8% or 13-15 immigrants per generation, despite the lack of adaptive divergence and trade-offs between the exchanging populations. However, after some generations of extensive gene flow and in the absence of selection against hybrids, the system of assortative mating faltered. Based on our results, we conclude that selection is likely to be an important factor in speciation in the face of gene flow and that without it divergence will simply come to a halt.

  • 126. Rowe, Locke
    et al.
    Arnqvist, Göran
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal Ecology.
    Sexual selection and the evolution of genital shape and complexity in water striders2012In: Evolution, ISSN 0014-3820, E-ISSN 1558-5646, Vol. 66, no 1, p. 40-54Article in journal (Refereed)
    Abstract [en]

    Animal genitalia show two striking but incompletely understood evolutionary trends: a great evolutionary divergence in the shape of genitalic structures, and characteristic structural complexity. Both features are thought to result from sexual selection, but explicit comparative tests are hampered by the fact that it is difficult to quantify both morphological complexity and divergence in shape. We undertake a comparative study of multiple nongenitalic and male genital traits in a clade of 15 water strider species to quantify complexity and shape divergence. We show that genital structures are more complex and their shape more divergent among species than nongenital traits. Further, intromittent genital traits are more complex and have evolved more divergently than nonintromittent genital traits. More importantly, shape and complexity of nonintromittent genital traits show correlated evolution with indices of premating sexual selection and intromittent genital traits with postmating sexual selection, suggesting that the evolution of different components of genital morphology are shaped independently by distinct forms of sexual selection. Our quantitative results provide direct comparative support for the hypothesis that sexual selection is associated with morphological complexity in genitalic traits and highlight the importance of quantifying morphological shape and complexity, rather than size in studies of genital evolution.

  • 127.
    Rubene, Diana
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal Ecology.
    Håstad, Olle
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Evolution and Developmental Biology.
    Tauson, Ragnar
    Wall, Helena
    Ödeen, Anders
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal Ecology.
    The presence of UV wavelengths improves the temporal resolution of the avian visual system2010In: Journal of Experimental Biology, ISSN 0022-0949, E-ISSN 1477-9145, Vol. 213, no 19, p. 3357-3363Article in journal (Refereed)
    Abstract [en]

    The ability to perceive rapid movement is an essential adaptation in birds, which are involved in rapid flight, pursuing prey and escaping predators. Nevertheless, the temporal resolution of the avian visual systems has been less well explored than spectral sensitivity. There are indications that birds are superior to humans in their ability to detect movement, as suggested by higher critical flicker frequencies (CFFs). It has also been implied, but not properly tested, that properties of CFF, as a function of light intensity, are affected by the spectral composition of light. This study measured CFF in the chicken, Gallus gallus L., using four different light stimuli - white, full-spectrum (white with addition of UV), yellow (590 nm) and UV (400 nm) - and four light intensity levels, adjusted to relative cone sensitivity. The results showed significantly higher CFF values for full-spectrum compared with white light, as well as a steeper rate of increase with intensity. The presence of UV wavelengths, previously demonstrated to affect mate choice and foraging, appears to be important also for detection of rapid movement. The yellow and UV light stimuli yielded rather similar CFFs, indicating no special role for the double cone in flicker detection.

  • 128.
    Rudh, Andreas
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal Ecology.
    Aposematism, Crypsis and Population Differentiation in the Strawberry Poison Frog2012Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

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

    List of papers
    1. Non-gradual variation in colour morphs of the strawberry poison frog Dendrobates pumilio: genetic and geographical isolation suggest a role for selection in maintaining polymorphism
    Open this publication in new window or tab >>Non-gradual variation in colour morphs of the strawberry poison frog Dendrobates pumilio: genetic and geographical isolation suggest a role for selection in maintaining polymorphism
    2007 (English)In: Molecular Ecology, ISSN 0962-1083, E-ISSN 1365-294X, Vol. 16, no 20, p. 4284-4294Article in journal (Refereed) Published
    Abstract [en]

    The relative roles that geographical isolation and selection play in driving population divergence remain one of the central questions in evolutionary biology. We approached this question by investigating genetic and morphological variation among populations of the strawberry poison frog, Dendrobates pumilio, in the Bocas del Toro archipelago, Panama. We found significant population genetic structure and isolation by distance based on amplified fragment length polymorphism markers. Snout vent length (SVL), coloration and the extent and size of dorsal black spots showed large variation among the studied populations. Differences in SVL correlated with genetic distance, whereas black spot patterns and other coloration parameters did not. Indeed, the latter characters were observed to be dramatically different between contiguous populations located on the same island. These results imply that neutral divergence among populations may account for the genetic patterns based on amplified fragment length polymorphism markers and SVL. However, selective pressures need to be invoked in order to explain the extraordinary variation in spot size and coverage, and coloration. We discuss the possibility that the observed variation in colour morphs is a consequence of a combination of local variation in both natural selection on an aposematic signal towards visual predators and sexual selection generated by colour morph-specific mate preferences.

    Keywords
    genetic diversity, morphological variation, neutral divergence, Poison dart frogs, selection, speciation
    National Category
    Biological Sciences
    Identifiers
    urn:nbn:se:uu:diva-14742 (URN)10.1111/j.1365-294X.2007.03479.x (DOI)000249829700007 ()
    Available from: 2008-01-31 Created: 2008-01-31 Last updated: 2017-12-11Bibliographically approved
    2. Loss of conspicuous colouration has co-evolved with decreasing body size in populations of a poison dart frog
    Open this publication in new window or tab >>Loss of conspicuous colouration has co-evolved with decreasing body size in populations of a poison dart frog
    (English)Manuscript (preprint) (Other academic)
    National Category
    Zoology Evolutionary Biology
    Research subject
    Biology with specialization in Animal Ecology
    Identifiers
    urn:nbn:se:uu:diva-179390 (URN)
    Available from: 2012-08-14 Created: 2012-08-14 Last updated: 2012-09-07
    3. Pattern coarseness affects detectability of dull but not of conspicuously coloured poison frogs by an avian predator - implications for evolutionary transitions between aposematism and crypsis
    Open this publication in new window or tab >>Pattern coarseness affects detectability of dull but not of conspicuously coloured poison frogs by an avian predator - implications for evolutionary transitions between aposematism and crypsis
    Show others...
    (English)Manuscript (preprint) (Other academic)
    National Category
    Zoology Evolutionary Biology Behavioral Sciences Biology
    Research subject
    Biology with specialization in Animal Ecology
    Identifiers
    urn:nbn:se:uu:diva-179391 (URN)
    Available from: 2012-08-14 Created: 2012-08-14 Last updated: 2012-09-07
    4. Rapid population divergence linked with co-variation between coloration and sexual display in strawberry poison frogs
    Open this publication in new window or tab >>Rapid population divergence linked with co-variation between coloration and sexual display in strawberry poison frogs
    2011 (English)In: Evolution, ISSN 0014-3820, E-ISSN 1558-5646, Vol. 65, no 5, p. 1271-1282Article in journal (Refereed) Published
    Abstract [en]

    The likelihood of speciation is assumed to increase when sexually selected traits diverge together with ecologically important traits. According to sexual selection theory, the evolution of exaggerated display behavior is driven by increased mating success, but limited by natural selection, for example, through predation. However, the evolution of aposematic coloration (i.e., an ecologically important trait) could relieve the evolution of exaggerated display behavior from the bound of predation, resulting in joint divergence in aposematic coloration and sexual display behavior between populations. We tested this idea by examining conspicuousness, using color contrasts between individuals and their native backgrounds, and sexual display of 118 males from genetically diverged populations of the Strawberry poison frog, Dendrobates pumilio. Our results show that the level of conspicuousness of the population predicts the sexual display behavior of males. Males from conspicuous populations used more exposed calling sites. We argue that changes in aposematic coloration may rapidly cause not only postmating isolation due to poorly adapted hybrids, but also premating isolation through shifts in mating behaviors.

    Keywords
    Aposematism, natural selection, Oophaga pumilio, population differentiation, sexual selection, speciation
    National Category
    Biological Sciences
    Identifiers
    urn:nbn:se:uu:diva-153586 (URN)10.1111/j.1558-5646.2010.01210.x (DOI)000289893000005 ()21166789 (PubMedID)
    Available from: 2011-05-16 Created: 2011-05-16 Last updated: 2017-12-11Bibliographically approved
    5. Does aggression and explorative behaviour decrease with lost warning colouration?
    Open this publication in new window or tab >>Does aggression and explorative behaviour decrease with lost warning colouration?
    2013 (English)In: Biological Journal of the Linnean Society, ISSN 0024-4066, E-ISSN 1095-8312, Vol. 108, no 1, p. 116-126Article in journal (Refereed) Published
    Abstract [en]

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

    Keywords
    Anura, Amphibia, aposematism, co-evolution, evolutionary innovation, Oophaga pumilio, population divergence
    National Category
    Zoology Evolutionary Biology
    Research subject
    Biology with specialization in Animal Ecology
    Identifiers
    urn:nbn:se:uu:diva-179389 (URN)10.1111/j.1095-8312.2012.02006.x (DOI)000312543100011 ()
    Available from: 2012-08-14 Created: 2012-08-14 Last updated: 2017-12-07Bibliographically approved
  • 129.
    Rudh, Andreas
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal Ecology.
    Loss of conspicuous colouration has co-evolved with decreasing body size in populations of a poison dart frogManuscript (preprint) (Other academic)
  • 130.
    Rudh, Andreas
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal Ecology.
    Edström, Torkel
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal Ecology.
    Ödeen, Anders
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal Ecology.
    Løvlie, Hanne
    IFM, Biology, Linköping University.
    Tullberg, Birgitta
    Department of Zoology. Stockholm University.
    Qvarnström, Anna
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal Ecology.
    Pattern coarseness affects detectability of dull but not of conspicuously coloured poison frogs by an avian predator - implications for evolutionary transitions between aposematism and crypsisManuscript (preprint) (Other academic)
  • 131.
    Rudh, Andreas
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal Ecology.
    Rogell, Björn
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Population and Conservation Biology. Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal ecology.
    Håstad, Olle
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology.
    Qvarnström, Anna
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal Ecology.
    Rapid population divergence linked with co-variation between coloration and sexual display in strawberry poison frogs2011In: Evolution, ISSN 0014-3820, E-ISSN 1558-5646, Vol. 65, no 5, p. 1271-1282Article in journal (Refereed)
    Abstract [en]

    The likelihood of speciation is assumed to increase when sexually selected traits diverge together with ecologically important traits. According to sexual selection theory, the evolution of exaggerated display behavior is driven by increased mating success, but limited by natural selection, for example, through predation. However, the evolution of aposematic coloration (i.e., an ecologically important trait) could relieve the evolution of exaggerated display behavior from the bound of predation, resulting in joint divergence in aposematic coloration and sexual display behavior between populations. We tested this idea by examining conspicuousness, using color contrasts between individuals and their native backgrounds, and sexual display of 118 males from genetically diverged populations of the Strawberry poison frog, Dendrobates pumilio. Our results show that the level of conspicuousness of the population predicts the sexual display behavior of males. Males from conspicuous populations used more exposed calling sites. We argue that changes in aposematic coloration may rapidly cause not only postmating isolation due to poorly adapted hybrids, but also premating isolation through shifts in mating behaviors.

  • 132. Ruuskanen, Suvi
    et al.
    Doligez, Blandine
    Gustafsson, Lars
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal Ecology.
    Laaksonen, Toni
    Long-term effects of yolk androgens on phenotype and parental feeding behavior in a wild passerine2012In: Behavioral Ecology and Sociobiology, ISSN 0340-5443, E-ISSN 1432-0762, Vol. 66, no 9, p. 1201-1211Article in journal (Refereed)
    Abstract [en]

    Early growth conditions, such as exposure to maternally derived androgens in bird eggs, have been shown to shape offspring in ways that may have important long-term consequences for phenotype and behavior. Using an experimental approach, we studied the long-term effects of yolk androgens on several phenotypic traits and parental behavior in adult and female collared flycatchers (Ficedula albicollis). We elevated yolk androgen levels and monitored the experimental recruits the following breeding seasons. Androgen treatment had a sex-dependent effect on adult body condition, yolk androgen-treated males being heavier than control males when controlling for size, a result which may be caused potentially by selective mortality, physiological differences, or different life-history strategies. Androgen treatment did not however affect the expression of sexually selected plumage ornaments (forehead and wing patch size), UV coloration, or parental feeding rate in either sex. Our results suggest that yolk androgens are unlikely to affect sexual selection via plumage characteristics or contribute to breeding success via altered parental care. Yolk androgens do not seem to act as a means for female collared flycatchers to enhance the attractiveness of their sons. The lower return rate previously observed for androgen-treated male offspring compared to controls may therefore not be due to lower mating or breeding success, but may rather reflect lower survival or higher dispersal propensity of yolk androgen-treated males.

  • 133. Ruuskanen, Suvi
    et al.
    Siitari, Heli
    Eeva, Tapio
    Belskii, Eugen
    Jarvinen, Antero
    Kerimov, Anvar
    Krams, Indrikis
    Moreno, Juan
    Morosinotto, Chiara
    Maend, Raivo
    Moestl, Erich
    Orell, Markku
    Qvarnström, Anna
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal Ecology.
    Salminen, Juha-Pekka
    Slater, Fred
    Tilgar, Vallo
    Visser, Marcel E.
    Winkel, Wolfgang
    Zang, Herwig
    Laaksonen, Toni
    Geographical Variation in Egg Mass and Egg Content in a Passerine Bird2011In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 6, no 11, p. e25360-Article in journal (Refereed)
    Abstract [en]

    Reproductive, phenotypic and life-history traits in many animal and plant taxa show geographic variation, indicating spatial variation in selection regimes. Maternal deposition to avian eggs, such as hormones, antibodies and antioxidants, critically affect development of the offspring, with long-lasting effects on the phenotype and fitness. Little is however known about large-scale geographical patterns of variation in maternal deposition to eggs. We studied geographical variation in egg components of a passerine bird, the pied flycatcher (Ficedula hypoleuca), by collecting samples from 16 populations and measuring egg and yolk mass, albumen lysozyme activity, yolk immunoglobulins, yolk androgens and yolk total carotenoids. We found significant variation among populations in most egg components, but ca. 90% of the variation was among individuals within populations. Population however explained 40% of the variation in carotenoid levels. In contrast to our hypothesis, we found geographical trends only in carotenoids, but not in any of the other egg components. Our results thus suggest high within-population variation and leave little scope for local adaptation and genetic differentiation in deposition of different egg components. The role of these maternally-derived resources in evolutionary change should be further investigated.

  • 134.
    Rybinski, Jakub
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal Ecology. Uppsala University, Disciplinary Domain of Science and Technology, Biology, Biology Education Centre.
    Should I stay or should I go?: Breeding dispersal decisions in a young avian hybrid zone2012Independent thesis Advanced level (degree of Master (Two Years)), 30 credits / 45 HE creditsStudent thesis
  • 135.
    Rönn, Johanna Liljestrand
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal ecology.
    Katvala, Mari
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics.
    Arnqvist, Göran
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal Ecology.
    Correlated evolution between male and female primary reproductive characters in seed beetles2011In: Functional Ecology, ISSN 0269-8463, E-ISSN 1365-2435, Vol. 25, no 3, p. 634-640Article in journal (Refereed)
    Abstract [en]

     Because males and females of internally inseminating species interact directly during mating, adaptations in one sex in primary reproductive traits may trigger an evolutionary response in the other sex. Divergent postcopulatory sexual selection is considered the main driving force behind the evolution of many male and female reproductive traits, generating unique morphologies and physiologies that can contribute to reproductive isolation and, ultimately, speciation. 2. The focus of most previous studies of the evolution of primary reproductive characters has been male reproductive traits and ejaculate or sperm characteristics. However, in order to more fully understand the evolution of primary reproductive characters it is crucial that we also include female traits. 3. In insects, both the size and the composition of the ejaculate have been shown to influence female reproduction in numerous ways by affecting female remating behaviour, female fecundity and female life span. Here, we employ a phylogenetic comparative approach to assess correlated evolution between primary reproductive characters in males and those in females in a group of seed beetles (Chrysomelidae: Bruchinae). We further explore correlated evolution between ejaculate size and female fitness in these insects. 4. Our analyses revealed positive correlated evolution between three internal female reproductive traits and ejaculate weight as well as correlated evolution between ejaculate weight and female fitness. We discuss the causal factors behind this correlated evolution and suggest that the evolution of larger ejaculates, primarily by postcopulatory sexual selection, causes selection for larger primary sexual traits in females to allow females to more rapidly process ejaculates. This may then feedback on postcopulatory selection in males, reinforcing selection for larger ejaculates. 5. Our results show that the primary reproductive traits of males and females show correlated evolution and suggest that intersexual co-evolution may affect the evolution of female fitness.

  • 136. Sagebakken, Gry
    et al.
    Ahnesjö, Ingrid
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal Ecology.
    Goncalves, Ines Braga
    Kvarnemo, Charlotta
    Multiply mated males show higher embryo survival in a paternally caring fish2011In: Behavioral Ecology, ISSN 1045-2249, E-ISSN 1465-7279, Vol. 22, no 3, p. 625-629Article in journal (Refereed)
    Abstract [en]

    We explored the effects of multiple mates on male reproductive success in a species with male parental care in which an increase in the number of female mating partners does not increase the number of eggs received. The broad-nosed pipefish (Syngnathus typhle) has a polygynandrous mating system. In this species, the male cares for embryos in a specially developed brood pouch. During brooding, some embryos fail to develop. We experimentally mated males with either one or two females while keeping brood size similar. We found that broods of singly mated males showed significantly lower embryo survival than those of doubly mated males. Furthermore, larger broods showed relatively lower levels of embryo survivorship independent of number of mates. We conclude that embryo survival is affected by postcopulatory processes that appear to result in higher fitness of multiply mated males. We discuss our results in the light of parental care, sibling competition, genetic benefits, and kin selection. Key words: brood reduction, paternal care, polygyny, postcopulatory sexual selection, progeny diversity, Syngnathidae.

  • 137. Salehialavi, Yassaman
    et al.
    Fritzsche, Karoline
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal Ecology.
    Arnqvist, Göran
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal Ecology.
    The cost of mating and mutual mate choice in 2 role-reversed honey locust beetles2011In: Behavioral Ecology, ISSN 1045-2249, E-ISSN 1465-7279, Vol. 22, no 5, p. 1104-1113Article in journal (Refereed)
    Abstract [en]

    Situations where both males and females simultaneously exercise mate choice may be much more common than previously believed. Yet, experimental studies of mutual mate choice are rare as is information on the types of female traits that are favored by male mate choice. We first assessed the cost of mating to males under different feeding regimes in 2 honey locust beetles (Bruchidae, Megabruchidius spp.) where females actively search for and court males. Further, in a series of mate choice trials, we manipulated female mating status and male food provisioning to assess how male and female characteristics affected the outcome of male-female interactions. Mating carried substantial costs to males, but these costs were independent of food availability. Males generally showed a preference for large females but also for females that delivered a more vigorous courtship display. Moreover, males preferred virgin females in one species but nonvirgin females in the other species, and we provide data suggesting that this choice is adaptive. Female choice was restricted to a lower rate of female mate rejection of larger males in one of the species. Our results reveal a striking interspecific variation in mutual mate choice, even between these closely related species, and show that sexual selection in females can act on much the same types of traits that are commonly considered sexually selected in males, such as size-related traits and courtship vigor. This suggests that a preference for condition-dependent traits may be a commonality that is shared between mate choice by both sexes.

  • 138. Schaerer, Lukas
    et al.
    Rowe, Locke
    Arnqvist, Göran
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal Ecology.
    Anisogamy, chance and the evolution of sex roles2012In: Trends in Ecology & Evolution, ISSN 0169-5347, E-ISSN 1872-8383, Vol. 27, no 5, p. 260-264Article in journal (Refereed)
    Abstract [en]

    Recently, several authors have challenged the view that anisogamy, the defining feature of the sexes, is an important determinant of the evolution of sex roles. Sex roles are instead suggested to result from chance, or from non-heritable differences in life histories of females and males. Here, we take issue with these ideas. We note that random processes alone cannot cause consistent differences between the sexes, and that those differences between the sexes in life histories that affect the sex roles are themselves the result of sex-specific selection that can ultimately be traced back to anisogamy. To understand sex roles, one should ask how environmental variation and female male coevolution cause variation in sex-specific selection in the light of anisogamy.

  • 139. Sogabe, A.
    et al.
    Ahnesjö, Ingrid
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal Ecology.
    The ovarian structure and mode of egg production in two polygamous pipefishes: a link to mating pattern2011In: Journal of Fish Biology, ISSN 0022-1112, E-ISSN 1095-8649, Vol. 78, no 6, p. 1833-1846Article in journal (Refereed)
    Abstract [en]

    In this study, the ovarian structure and mode of egg production were examined in two pipefishes, the broad-nosed pipefish Syngnathus typhle and the straight-nosed pipefish Nerophis ophidion, which show different types of polygamous mating patterns. Syngnathus typhle showed an ovary with one germinal ridge and asynchronous egg production, corresponding to previous findings in other polygamous Syngnathus pipefishes. In contrast, the ovary of N. ophidion had two germinal ridges and eggs were produced synchronously in groups, similar to what has been observed in monogamous syngnathids. The egg production of N. ophidion, however, is clearly distinguished from that of monogamous syngnathids by the additional egg production after an ovulation. It is suggested that the differences in female mating strategies result from the difference in egg production process and that this is related to the difference in mating pattern between these two polygamous species.

  • 140.