| 1. |
- Hangartner, Sandra, et al.
(författare)
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Adaptive Divergence in Moor Frog (Rana Arvalis) Populations Along an Acidification Gradient : Inferences from QST-FST Correlations
- 2012
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Ingår i: Evolution. - : Wiley. - 0014-3820 .- 1558-5646. ; 66:3, s. 867-881
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Tidskriftsartikel (refereegranskat)abstract
- Microevolutionary responses to spatial variation in the environment seem ubiquitous, but the relative role of selection and neutral processes in driving phenotypic diversification remain often unknown. The moor frog (Rana arvalis) shows strong phenotypic divergence along an acidification gradient in Sweden. We here used correlations among population pairwise estimates of quantitative trait (PST or QST from common garden estimates of embryonic acid tolerance and larval life-history traits) and neutral genetic divergence (FST from neutral microsatellite markers), as well as environmental differences (pond pH, predator density, and latitude), to test whether this phenotypic divergence is more likely due to divergent selection or neutral processes. We found that trait divergence was more strongly correlated with environmental differences than the neutral marker divergence, suggesting that divergent natural selection has driven phenotypic divergence along the acidification gradient. Moreover, pairwise PSTs of embryonic acid tolerance and QSTs of metamorphic size were strongly correlated with breeding pond pH, whereas pairwise QSTs of larval period and growth rate were more strongly correlated with geographic distance/latitude and predator density, respectively. We suggest that incorporating measurements of environmental variation into QSTFST studies can improve our inferential power about the agents of natural selection in natural populations.
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| 2. |
- Hangartner, Sandra, et al.
(författare)
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Adaptive divergence of the moor frog (Rana arvalis) along an acidification gradient
- 2011
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Ingår i: BMC Evolutionary Biology. - : Springer Science and Business Media LLC. - 1471-2148. ; 11, s. 366-
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Tidskriftsartikel (refereegranskat)abstract
- Background: Environmental stress can result in strong ecological and evolutionary effects on natural populations, but to what extent it drives adaptive divergence of natural populations is little explored. We used common garden experiments to study adaptive divergence in embryonic and larval fitness traits (embryonic survival, larval growth, and age and size at metamorphosis) in eight moor frog, Rana arvalis, populations inhabiting an acidification gradient (breeding pond pH 4.0 to 7.5) in southwestern Sweden. Embryos were raised until hatching at three (pH 4.0, 4.3 and 7.5) and larvae until metamorphosis at two (pH 4.3 and 7.5) pH treatments. To get insight into the putative selective agents along this environmental gradient, we measured relevant abiotic and biotic environmental variables from each breeding pond, and used linear models to test for phenotype-environment correlations. Results: We found that acid origin populations had higher embryonic and larval acid tolerance (survival and larval period were less negatively affected by low pH), higher larval growth but slower larval development rates, and metamorphosed at a larger size. The phenotype-environment correlations revealed that divergence in embryonic acid tolerance and metamorphic size correlated most strongly with breeding pond pH, whereas divergence in larval period and larval growth correlated most strongly with latitude and predator density, respectively. Conclusion: Our results suggest that R. arvalis has diverged in response to pH mediated selection along this acidification gradient. However, as latitude and pH were closely spatially correlated in this study, further studies are needed to disentangle the specific agents of natural selection along acidification gradients. Our study highlights the need to consider the multiple interacting selective forces that drive adaptive divergence of natural populations along environmental stress gradients.
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| 3. |
- Jelena, Mausbach, et al.
(författare)
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Context dependent variation in corticosterone and phenotypic divergence of Rana arvalis populations along an acidification gradient
- 2022
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Ingår i: BMC Ecology and Evolution. - : Springer Nature. - 2730-7182. ; 22:1
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Tidskriftsartikel (refereegranskat)abstract
- Physiological processes, as immediate responses to the environment, are important mechanisms of phenotypic plasticity and can influence evolution at ecological time scales. In stressful environments, physiological stress responses of individuals are initiated and integrated via the release of hormones, such as corticosterone (CORT). In vertebrates, CORT influences energy metabolism and resource allocation to multiple fitness traits (e.g. growth and morphology) and can be an important mediator of rapid adaptation to environmental stress, such as acidification. The moor frog, Rana arvalis, shows adaptive divergence in larval life-histories and predator defense traits along an acidification gradient in Sweden. Here we take a first step to understanding the role of CORT in this adaptive divergence. We conducted a fully factorial laboratory experiment and reared tadpoles from three populations (one acidic, one neutral and one intermediate pH origin) in two pH treatments (Acid versus Neutral pH) from hatching to metamorphosis. We tested how the populations differ in tadpole CORT profiles and how CORT is associated with tadpole life-history and morphological traits.
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| 4. |
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| 5. |
- Lafuente, Elvira, et al.
(författare)
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Building on 150 Years of Knowledge : The Freshwater Isopod Asellus aquaticus as an Integrative Eco-Evolutionary Model System
- 2021
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Ingår i: Frontiers in Ecology and Evolution. - : Frontiers Media SA. - 2296-701X. ; 9
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Forskningsöversikt (refereegranskat)abstract
- Interactions between organisms and their environments are central to how biological diversity arises and how natural populations and ecosystems respond to environmental change. These interactions involve processes by which phenotypes are affected by or respond to external conditions (e.g., via phenotypic plasticity or natural selection) as well as processes by which organisms reciprocally interact with the environment (e.g., via eco-evolutionary feedbacks). Organism-environment interactions can be highly dynamic and operate on different hierarchical levels, from genes and phenotypes to populations, communities, and ecosystems. Therefore, the study of organism-environment interactions requires integrative approaches and model systems that are suitable for studies across different hierarchical levels. Here, we introduce the freshwater isopod Asellus aquaticus, a keystone species and an emerging invertebrate model system, as a prime candidate to address fundamental questions in ecology and evolution, and the interfaces therein. We review relevant fields of research that have used A. aquaticus and draft a set of specific scientific questions that can be answered using this species. Specifically, we propose that studies on A. aquaticus can help understanding (i) the influence of host-microbiome interactions on organismal and ecosystem function, (ii) the relevance of biotic interactions in ecosystem processes, and (iii) how ecological conditions and evolutionary forces facilitate phenotypic diversification.
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| 6. |
- Laugen, Ane T., et al.
(författare)
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Latitudinal countergradient variation in the common frog (Rana temporaria) developmental rates : evidence for local adaptation
- 2003
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Ingår i: Journal of Evolutionary Biology. - : Wiley. - 1010-061X .- 1420-9101. ; 16:5, s. 996-1005
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Tidskriftsartikel (refereegranskat)abstract
- Adaptive genetic differentiation along a climatic gradient as a response to natural selection is not necessarily expressed at phenotypic level if environmental effects on population mean phenotypes oppose the genotypic effects. This form of cryptic evolution--called countergradient variation--has seldom been explicitly demonstrated for terrestrial vertebrates. We investigated the patterns of phenotypic and genotypic differentiation in developmental rates of common frogs (Rana temporaria) along a ca. 1600 km latitudinal gradient across Scandinavia. Developmental rates in the field were not latitudinally ordered, but displayed large variation even among different ponds within a given latitudinal area. In contrast, development rates assessed in the laboratory increased strongly and linearly with increasing latitude, suggesting a genetic capacity for faster development in the northern than the southern larvae. Experiments further revealed that environmental effects (temperature and food) could easily override the genetic effects on developmental rates, providing a possible mechanistic explanation as to why the genetic differentiation was not seen in the samples collected from the wild. Our results suggest that the higher developmental rates of the northern larvae are likely to be related to selection stemming from seasonal time constrains, rather than from selection dictated by low ambient temperatures per se. All in all, the results provide a demonstration of environmental effects concealing substantial latitudinally ordered genetic differentiation understandable in terms of adaptation to clinal variation in time constrains.
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| 7. |
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| 8. |
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| 9. |
- Merilä, Juha, et al.
(författare)
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Local adaptation and genetics of acid-stress tolerance in the moor frog, Rana arvalis
- 2004
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Ingår i: Conservation Genetics. - 1566-0621 .- 1572-9737. ; 5:4, s. 513-527
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Tidskriftsartikel (refereegranskat)abstract
- As potential to adapt to environmental stress can be essential for population persistence, knowledge on the genetic architecture of local adaptation is important for conservation genetics. We investigated the relative importance of additive genetic, dominance and maternal effects contributions to acid stress tolerance in two moor frog (Rana arvalis) populations originating from low and neutral pH habitats. Experiments with crosses obtained from artificial matings revealed that embryos from the acid origin population were more tolerant to low pH than embryos from the neutral origin population in embryonic survival rates, but not in terms of developmental stability, developmental and growth rates. Strong maternal effect and small additive genetic contributions to variation were detected in all traits in both populations. In general, dominance contributions to variance in different traits were of similar magnitude to the additive genetic effects, but dominance effects outweighed the additive genetic and maternal effects contributions to early growth in both populations. Furthermore, the expression of additive genetic variance was independent of pH treatment, suggesting little additive genetic variation in acid stress tolerance. The results suggest that although local genetic adaptation to acid stress has taken place, the current variation in acid stress tolerance in acidified populations may owe largely to non-genetic effects. However, low but significant heritabilities ( h(2) approximate to 0.07 - 0.22) in all traits - including viability itself - under a wide range of pH conditions suggests that environmental stress created by low pH is unlikely to lower moor frog populations' ability to respond to selection in the traits studied. Nevertheless, acid conditions could lower populations' ability to respond to selection in the long run through reduction in effective population size.
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| 10. |
- Pahkala, Maarit, et al.
(författare)
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Lethal and Sublethal Effects of UV-B/pH Synergism on Common Frog Embryos
- 2002
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Ingår i: Conservation Biology. - : Wiley. - 0888-8892 .- 1523-1739. ; 16:4, s. 1063-1073
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Tidskriftsartikel (refereegranskat)abstract
- Although the negative effects of ultraviolet-B ( UV-B) radiation on the development of many amphibian species have been demonstrated, some speciessuch as the common frog ( Rana temporaria)seem to be tolerant of UV-B radiation. The amount of UV-B radiation received is likely to vary among populations of the same species, but little is known about geographic variation in UV-B tolerance. Similarly, although UV-B radiation can have synergistic effects with other stressors, no studies have focused on geographic variation of these effects on amphibians. We investigated the synergistic effects of UV-B radiation and low pH on hatchability and early development of R. temporaria embryos in a factorial laboratory experiment with animals originating from southern and northern Sweden. Newly fertilized eggs were exposed to three different UV-B treatments (no UV-B [control, 1.254 k/J/m 2[normal and 1.584 k/J/m 2[26 enhanced) and two pH treatments (4.5 [low and 7.6 [neutral). Ultraviolet-B radiation in combination with low pH lead to markedly (approximately 50) reduced survival rates and increased (approximately 30) frequency of developmental anomalies in the northern but not in the southern population. The UV-B- exposed embryos hatched at smaller size in the southern population, whereas low pH reduced hatchling size in both populations. In both populations and pH treatments, embryos in the normal UV-B treatment developed significantly faster than embryos in the enhanced or control UV-B treatments. No interaction between pH and UV-B on developmental rates or hatchling size was detected. The results demonstratecontrary to earlier beliefthat R. temporaria embryos are not insensitive to increased levels of UV-B radiation. The lethal effects of UV-B radiation may, however, become manifested only in combination with other stressors, such as low pH, and the effects of this synergism may differ among different populations of the same species.
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| 11. |
- Persson, M., et al.
(författare)
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Maternally determined adaptation to acidity in Rana arvalis : Are laboratory and field estimates of embryonic stress tolerance congruent?
- 2007
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Ingår i: Canadian Journal of Zoology. - 0008-4301 .- 1480-3283. ; 85:7, s. 832-838
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Tidskriftsartikel (refereegranskat)abstract
- Geographic variation indicating local adaptation, as well as its quantitative genetic basis, is commonly investigated in common garden experiments in the laboratory. However, the applicability of laboratory results to the complex conditions experienced by populations in the wild may be limited. Our previous laboratory experiments showed maternally determined local adaptation in embryonic acid-stress tolerance (viz. survival) of the moor frog, Rana arvalis Nilsson, 1842. Here we tested whether this laboratory finding holds even when embryos are exposed to acid stress in the wild. We conducted reciprocal crosses between an acid-origin population and a neutral-origin population of R. arvalis and transplanted the embryos to an acid site (pH ~4) in the field. Embryonic survival was much lower in the field experiment than in previous laboratory experiments, but, consistent with laboratory work, embryos from acid-origin females had threefold higher survival than embryos from neutral-origin females. These results suggest that laboratory tests can provide appropriate estimates of among population variation, as well as the quantitative genetic basis of acid-stress tolerance in amphibians.
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| 12. |
- Rowiński, Piotr K., 1982-
(författare)
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Evolutionary consequences of maternal effects and stress
- 2019
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Maternal effects occur when maternal environment or phenotype influence offspring phenotype, in addition to genetic contribution of the mother. As maternal effects often influence phenotypes that are under natural selection, they hence have evolutionary consequences. Further, the expression of both maternal effects and evolutionary potential has been argued to depend on environmental conditions, but the evidence of this dependency for the process of adaptation has been inconclusive. The main objective of this thesis was to investigate evolutionary consequences of maternal effects and stressful or variable environmental conditions.I started by performing a meta-analysis of quantitative genetic studies that investigated expression of additive genetic, maternal, and residual variance under both stressful and benign environmental conditions (Paper I). Data spanning over many animal taxa and stress types revealed that high levels of environmental stress correlated with increased expression of genetic and residual variances. However, against our predictions, maternal effects were relatively unaffected by stress.In Paper II and III, I explored the evolutionary divergences of traits previously shown to be under maternal control. Specifically, in Paper II, I performed a second meta-analysis, that investigated if parents of common frogs (Rana temporaria) influenced offspring development time to mediate the effects of time constraints, across a latitudinal cline. I found that reproductive delay in the parental generation correlated with decreased development time in tadpoles of northern R. temporaria populations, suggesting that parental effects may further decrease development time in populations from time-constrained environments.In Paper III, I used an annual killifish system, to explore if environmental unpredictability, measured by variation in precipitation during rainy season, correlated with maternally mediated variation in embryo development time (bet-hedging). Although I found significant among-species differences in variation in development time, there was no clear linear relationship between variation in development time and precipitation. The results suggest that either bet-hedging is not important for persistence in the unpredictable annual killifish habitats, or that other ecological factors, rather than precipitation unpredictability, influenced evolution of variation in development times.Lastly, I investigated if occurrence of placenta correlated with increased offspring brain size among poeciliid fish (Paper IV). In contrast to our prediction, I did not find any consistent differences in relative brain size between the fry of placental and non-placental species. It is possible that either the poeciliid placental structures do not have a sufficient capacity to transfer resources necessary for increased brain development, or that other factors, such as sexual selection, or differences in food abundance and competition, shaped brain evolution among poeciliids.In conclusion, the results of this thesis suggest that environmental stress may influence evolutionary potential by increasing genetic variation available for selection, that time-constrained habitats may be conducive to evolution of parental effects on offspring development times, and that maternal influence on offspring traits may be difficult to detect, as many ecological factors may potentially influence evolution of life-history and morphology traits.
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| 13. |
- Räsänen, Katja
(författare)
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Evolutionary implications of acidification: a frog’s eye view
- 2002
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Understanding the diversity of life is one of the main aims of evolutionary biology, and requires knowledge of the occurrence and causes of adaptive genetic differentiation among geographically distinct populations. Environmental stress caused by acidity may cause strong directional selection in natural populations, but is little explored from an evolutionary perspective. In this thesis, a series of laboratory experiments and field data was used to study evolutionary and ecological responses of amphibians to environmental acidity. Local adaptation to acid stress was studied in the moor frog (Rana arvalis).The results show that acid origin populations have higher acid stress tolerance during the embryonic stages than neutral origin populations, and that acid and neutral origin populations have diverged in embryonic and larval life-histories. The mechanisms underlying adaptive differentiation are partially mediated by maternal effects related to extra-embryonic membranes and egg size. Acid origin females invest in larger eggs and have a stronger egg size-fecundity trade-off than females from neutral areas, likely reflecting adaptive differentiation in maternal investment patterns. Potential carry-over effects of low pH, and the effects of UV-b/pH interaction were investigated in the common frog (R. temporaria). The results suggest that amphibian larvae are able to compensate for the negative effects of acidity experienced early in life, if conditions later turn beneficial. R. temporaria populations differed in their sensitivity to synergistic effects of low pH/UV-B, indicating variation in population responses to environmental stress.In conclusion, these results suggest rapid evolution in response to human induced environmental change, much of which may be mediated via adaptive maternal effects. Acidification may be a powerful selective force shaping life-history evolution.
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| 14. |
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| 15. |
- Räsänen, Katja, et al.
(författare)
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Geographic variation in maternal investment : Acidity affects egg size and fecundity in Rana arvalis
- 2008
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Ingår i: Ecology. - : Wiley. - 0012-9658 .- 1939-9170. ; 89:9, s. 2553-2562
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Tidskriftsartikel (refereegranskat)abstract
- Environmental-stress-mediated geographic variation in reproductive parameters has been little studied in natural vertebrate populations outside the context of climatic variation. Based on life-history theory, an increase in the degree of environmental stress experienced by a population should lead to (1) a shift in reproductive allocation from fecundity to offspring quality, (2) stronger trade-offs between reproductive parameters, and (3) changes in the relationship between female phenotype and maternal investment. To test these predictions, we investigated geographic variation in maternal investment of moor frogs (Rana arvalis) in relation to breeding site acidity (pH 4-8). We found that mean egg size increased and clutch size and total reproductive output (TRO) decreased with increasing acidity among 19 Swedish moor frog populations. Tests for variation and co-variation in maternal investment and female size and age in 233 females from a subset of four acid origin (AO) and four neutral origin (NO) populations revealed that clutch size and TRO increased with female size in both acid and neutral environments. However, in AO populations, egg size also increased with female size, and clutch size and TRO with female age, whereas in NO populations, egg size increased with female age. The strength of the egg-size-clutch-size trade-off tended to be stronger in AO than in NO females as expected if the former experience stronger environmental constraints. All in all, these results suggest that environmental acidfication selects for investment in larger eggs at a cost to fecundity, imposes negative effects on reproductive output, and alters the relationship between female phenotype and maternal investment.
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| 16. |
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| 17. |
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| 18. |
- Salo, Tiina, et al.
(författare)
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Resilience to heat waves in the aquatic snail Lymnaea stagnalis : Additive and interactive effects with micropollutants
- 2017
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Ingår i: Freshwater Biology. - : Wiley. - 0046-5070 .- 1365-2427. ; 62:11, s. 1831-1846
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Tidskriftsartikel (refereegranskat)abstract
- 1. Multiple anthropogenic changes, such as climate change and chemical pollution, threaten the persistence of natural populations. Yet, their potential additive and interactive effects on organismal performance and fitness are poorly understood, thus limiting our ability to predict the effects of the global change. 2. We conducted a laboratory experiment to study the singular and combined effects of experimental heat waves and micropollutants (i.e. low-concentration toxicants; henceforth micropollutants [MPs]) on the freshwater snail, Lymnaea stagnalis. To comprehensively understand physiological and ecological consequences of stress, we studied a broad range of traits from respiration rate to feeding performance and growth. We also determined traits contributing to fitness and immune responses, as these are key traits in determining both organismal fitness and interspecific (e.g. host-parasite) interactions. We tested whether a constant exposure to MPs affects the ability of snails to tolerate heat waves (8days of 23.5 degrees C), and subsequently to recover from them, and whether the effects are immediate or delayed. 3. We found strong immediate additive effects of both stressors on reproduction, while they synergistically increased respiration and antagonistically decreased food consumption. Moreover, these effects were transient. Although the heat wave increased metabolic rates, individuals did not increase their resource uptake. This caused an apparent imbalance in resource levelsa probable cause for the observed trade-off between immune function and reproductive traits (i.e. phenoloxidase-like activity decreased, while reproductive output increased). In addition, exposure to MPs led to a temporarily reduced reproductive output. 4. Our results indicate that even short-term heat waves and low concentrations of chemical pollution can have large, mainly additive impacts on organismal fitness (e.g. altering susceptibility to infections and reproductive output). This suggests that long-term effects of existing stressors and heat waves need to be considered when assessing the resilience of natural populations.
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| 19. |
- Salo, Tiina, et al.
(författare)
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Simultaneous exposure to a pulsed and a prolonged anthropogenic stressor can alter consumer multifunctionality
- 2018
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Ingår i: Oikos. - : Wiley. - 0030-1299 .- 1600-0706. ; 127:10, s. 1437-1448
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Tidskriftsartikel (refereegranskat)abstract
- Ecosystems face multiple anthropogenic threats globally, and the effects of these environmental stressors range from individual-level organismal responses to altered system functioning. Understanding the combined effects of stressors on process rates mediated by individuals in ecosystems would greatly improve our ability to predict organismal multifunctionality (e.g. multiple consumer-mediated functions). We conducted a laboratory experiment to test direct and indirect, as well as immediate and delayed effects of a heat wave (pulsed stress) and micropollutants (MPs) (prolonged stress) on individual consumers (the great pond snail Lymnaea stagnalis) and their multifunctionality (i.e. consumption of basal resources, growth, reproduction, nutrient excretion and organic-matter cycling). We found that stressful conditions increased the process rates of multiple functions mediated by individual consumers. Specifically, the artificial heat wave increased process rates in the majority of the quantified functions (either directly or indirectly), whereas exposure to MPs increased consumption of basal resources which led to increases in the release of nutrients and fine particulate organic matter. Moreover, snails exposed to a heat wave showed decreased reproduction and nutrient excretion after the heat-wave, indicating the potential for ecologically relevant delayed effects. Our study indicates that the immediate and delayed effects of stressors on individual organisms may directly and indirectly impact multiple ecosystem functions. In particular, delayed effects of environmental stress on individual consumers may cumulatively impede recovery due to decreased functioning following a perturbation. Reconciling these results with studies incorporating responses at higher levels of biological complexity will enhance our ability to forecast how individual responses upscale to ecosystem multifunctionality.
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| 20. |
- Scaramella, Nicholas, et al.
(författare)
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Short-term responses of Rana arvalis tadpoles to pH and predator stress : adaptive divergence in behavioural and physiological plasticity?
- 2022
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Ingår i: Journal of Comparative Physiology. B, Biochemical, Systemic, and Environmental Physiology. - : Springer Nature. - 0174-1578 .- 1432-136X. ; 192:5, s. 669-682
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Tidskriftsartikel (refereegranskat)abstract
- Environmental stress is a major driver of ecological and evolutionary processes in nature. To cope with stress, organisms can adjust through phenotypic plasticity and/or adapt through genetic change. Here, we compared short-term behavioural (activity) and physiological (corticosterone levels, CORT) responses of Rana arvalis tadpoles from two divergent populations (acid origin, AOP, versus neutral origin, NOP) to acid and predator stress. Tadpoles were initially reared in benign conditions at pH 7 and then exposed to a combination of two pH (acid versus neutral) and two predator cue (predator cue versus no predator cue) treatments. We assessed behavioural activity within the first 15 min, and tissue CORT within 8 and 24 h of stress exposure. Both AOP and NOP tadpoles reduced their activity in acidic pH, but the response to the predator cue differed between the populations: AOP tadpoles increased whereas NOP tadpoles decreased their activity. The AOP and NOP tadpoles differed also in their CORT responses, with AOP being more responsive (CORT levels of NOP tadpoles did not differ statistically across treatments). After 8 h exposure, AOP tadpoles had elevated CORT levels in the acid-predator cue treatment and after 24 h exposure they had elevated CORT levels in all three stress treatments (relative to the benign neutral-no-cue treatment). These results suggest that adaptation to environmental acidification in R. arvalis is mediated, in part, via behavioural and hormonal plasticity.
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| 21. |
- Shu, Longfei, et al.
(författare)
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Molecular phenotyping of maternally mediated parallel adaptive divergence within Rana arvalis and Rana temporaria
- 2016
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Ingår i: Molecular Ecology. - : Wiley. - 0962-1083 .- 1365-294X. ; 25:18, s. 4564-4579
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Tidskriftsartikel (refereegranskat)abstract
- When similar selection acts on the same traits in multiple species or populations, parallel evolution can result in similar phenotypic changes, yet the underlying molecular architecture of parallel phenotypic divergence can be variable. Maternal effects can influence evolution at ecological timescales and facilitate local adaptation, but their contribution to parallel adaptive divergence is unclear. In this study, we (i) tested for variation in embryonic acid tolerance in a common garden experiment and (ii) used molecular phenotyping of egg coats to investigate the molecular basis of maternally mediated parallel adaptive divergence in two amphibian species (Rana arvalis and Rana temporaria). Our results on three R. arvalis and two R. temporaria populations show that adaptive divergence in embryonic acid tolerance is mediated via maternally derived egg coats in both species. We find extensive polymorphism in egg jelly coat glycoproteins within both species and that acid-tolerant clutches have more negatively charged egg jelly - indicating that the glycosylation status of the jelly coat proteins is under divergent selection in acidified environments, likely due to its impact on jelly water balance. Overall, these data provide evidence for parallel mechanisms of adaptive divergence in two species. Our study highlights the importance of studying intraspecific molecular variation in egg coats and, specifically, their glycoproteins, to increase understanding of underlying forces maintaining variation in jelly coats.
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| 22. |
- Skulason, Skuli, et al.
(författare)
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A way forward with eco evo devo : an extended theory of resource polymorphism with postglacial fishes as model systems
- 2019
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Ingår i: Biological Reviews. - : John Wiley & Sons. - 1464-7931 .- 1469-185X. ; 94:5, s. 1786-1808
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Forskningsöversikt (refereegranskat)abstract
- A major goal of evolutionary science is to understand how biological diversity is generated and altered. Despite considerable advances, we still have limited insight into how phenotypic variation arises and is sorted by natural selection. Here we argue that an integrated view, which merges ecology, evolution and developmental biology (eco evo devo) on an equal footing, is needed to understand the multifaceted role of the environment in simultaneously determining the development of the phenotype and the nature of the selective environment, and how organisms in turn affect the environment through eco evo and eco devo feedbacks. To illustrate the usefulness of an integrated eco evo devo perspective, we connect it with the theory of resource polymorphism (i.e. the phenotypic and genetic diversification that occurs in response to variation in available resources). In so doing, we highlight fishes from recently glaciated freshwater systems as exceptionally well‐suited model systems for testing predictions of an eco evo devo framework in studies of diversification. Studies on these fishes show that intraspecific diversity can evolve rapidly, and that this process is jointly facilitated by (i) the availability of diverse environments promoting divergent natural selection; (ii) dynamic developmental processes sensitive to environmental and genetic signals; and (iii) eco evo and eco devo feedbacks influencing the selective and developmental environments of the phenotype. We highlight empirical examples and present a conceptual model for the generation of resource polymorphism – emphasizing eco evo devo, and identify current gaps in knowledge.
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| 23. |
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| 24. |
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| 25. |
- Teplitsky, Celine, et al.
(författare)
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Adaptive plasticity in stressful environments : Acidity constrains inducible defences in Rana arvalis
- 2007
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Ingår i: Evolutionary Ecology Research. - 1522-0613 .- 1937-3791. ; 9:3, s. 447-458
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Tidskriftsartikel (refereegranskat)abstract
- Questions: How do environmental stressors affect the expression of adaptive phenotypicplasticity? Is there inter-population variation in these effects? Hypothesis: Acid stress constrains the expression of inducible defences by decreasinginvestment in defences or by increasing the costs of investment. Organisms originating fromneutral environments suffer more from acid stress than organisms originating from acidenvironments. Organism: Tadpoles of Rana arvalis, originating from two different populations (acid andneutral). This species displays inducible defences in response to insect predators (here dragonflylarvae). Methods: A laboratory experiment with a factorial design crossing two factors: predatorpresence (present vs. absent) and acidity (neutral vs. acid). We tested the effects of experimentaltreatment on tadpole morphology as well as age and size at metamorphosis. Results: Tadpoles from the neutral origin population invested less in inducible defences (tailfin depth) in the acid than in the neutral treatment. In contrast, tadpoles from the acid originpopulation were able to respond equally well to predators in both pH treatments. pH-relatedcosts differed between populations: while tadpoles from the neutral origin population sufferedfrom acid stress in terms of reduced developmental rate, those from the acid origin populationseemed to suffer from neutral stress in terms of reduced size at metamorphosis.
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