| 1. |
- De Lisle, Stephen P., et al.
(författare)
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Phenotypic plasticity is aligned with phenological adaptation on both micro- and macroevolutionary timescales
- 2022
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Ingår i: Ecology Letters. - : John Wiley & Sons. - 1461-023X .- 1461-0248. ; 25:4, s. 790-801
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Tidskriftsartikel (refereegranskat)abstract
- In seasonally variable environments, phenotypic plasticity in phenology may be critical for adaptation to fluctuating environmental conditions. Using an 18-generation longitudinal dataset from natural damselfly populations, we show that phenology has strongly advanced. Individual fitness data suggest this is likely an adaptive response towards a temperature-dependent optimum. A laboratory experiment revealed that developmental plasticity qualitatively matches the temperature dependence of selection, partially explaining observed advance in phenology. Expanding our analysis to the macroevolutionary level, we use a database of over 1-million occurrence records and spatiotemporally matched temperature data from 49 Swedish Odonate species to infer macroevolutionary dynamics of phenology. Phenological plasticity was more closely aligned with adaptation for species that have recently colonised northern latitudes, but with higher phenological mismatch at lower latitudes. Our results show that phenological plasticity plays a key role in microevolutionary dynamics within a single species, and such plasticity may have facilitated post-Pleistocene range expansion in this insect clade.
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| 2. |
- Wellenreuther, Maren, et al.
(författare)
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Climatic niche divergence or conservatism? Environmental niches and range limits in ecologically similar damselflies
- 2012
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Ingår i: Ecology. - : Wiley. - 0012-9658 .- 1939-9170. ; 93:6, s. 1353-1366
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Tidskriftsartikel (refereegranskat)abstract
- The factors that determine species' range limits are of central interest to biologists. One particularly interesting group comprises odonates (dragonflies and damselflies), which show large differences in secondary sexual traits and respond quickly to climatic factors, but often have minor interspecific niche differences, challenging models of niche-based species coexistence. We quantified the environmental niches at two geographic scales to understand the ecological causes of northern range limits and the coexistence of two congeneric damselflies (Calopteryx splendens and C. virgo). Using environmental niche modeling, we quantified niche divergence first across the whole geographic range in Fennoscandia, and second only in the sympatric part of this range. We found evidence for interspecific divergence along the environmental axes of temperature and precipitation across the northern range in Fennoscandia, suggesting that adaptation to colder and wetter climate might have allowed C. virgo to expand farther north than C. splendens. However, in the sympatric zone in southern Fennoscandia we found only negligible and nonsignificant niche differences. Minor niche differences in sympatry lead to frequent encounters and intense interspecific sexual interactions at the local scale of populations. Nevertheless, niche differences across Fennoscandia suggest that species differences in physiological tolerances limit range expansions northward, and that current and future climate could have large effects on the distributional ranges of these and ecologically similar insects.
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| 3. |
- Abbott, Jessica, et al.
(författare)
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Morph-specific variation in intersexual genetic correlations in an intra-specific mimicry system
- 2010
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Ingår i: Evolutionary Ecology Research. - : Evolutionary Ecology. - 1522-0613 .- 1937-3791. ; 12:1, s. 105-118
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Tidskriftsartikel (refereegranskat)abstract
- Background: Positive intersexual genetic correlations are typically viewed as constraining the evolution of sexual dimorphism, when traits are subject to sexually antagonistic selection. Our study species, the damselfly Ischnura elegans, has a female-limited colour polymorphism with three female colour morphs (males are monomorphic), one of which is considered to be a male mimic. Questions: Are there morph-specific differences in the magnitude of intersexual genetic correlations in I. elegans? Specifically, do male-mimic (Androchrome) females have higher intersexual genetic correlations for morphological traits than non-mimic (Infuscans) females'? Methods: We collected copulating pairs in the field and raised offspring from these pairs in the laboratory. We measured five morphological traits in both parent and offspring generations and investigated their heritabilities and genetic correlations. Results: We found a negative overall relationship between the degree of sexual dimorphism for a trait and its intersexual genetic correlation. But the magnitude and direction of intersexual genetic correlations depended on the female morph. As expected, male mimic (Androchrome) females had higher intersexual genetic correlations. In addition, the genetic correlations between the morphs were in all cases significantly lower than unity. Male mimic (Androchrome) females had higher mother son covariances than the non-mimic (Infuscans) morph, and this difference is the proximate explanation for the difference in intersexual genetic correlations between the morphs.
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| 4. |
- Abbott, Jessica, et al.
(författare)
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Ontogeny of sexual dimorphism and phenotypic integration in heritable morphs
- 2008
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Ingår i: Evolutionary Ecology. - : Springer Science and Business Media LLC. - 1573-8477 .- 0269-7653. ; 22:1, s. 103-121
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Tidskriftsartikel (refereegranskat)abstract
- In this study we investigated the developmental basis of adult phenotypes in a non-model organism, a polymorphic damselfly (Ischnura elegans) with three female colour morphs. This polymorphic species presents an ideal opportunity to study intraspecific variation in growth trajectories, morphological variation in size and shape during the course of ontogeny, and to relate these juvenile differences to the phenotypic differences of the discrete adult phenotypes; the two sexes and the three female morphs. We raised larvae of different families in individual enclosures in the laboratory, and traced morphological changes during the course of ontogeny. We used principal components analysis to examine the effects of Sex, Maternal morph, and Own morph on body size and body shape. We also investigated the larval fitness consequences of variation in size and shape by relating these factors to emergence success. Females grew faster than males and were larger as adults, and there was sexual dimorphism in body shape in both larval and adult stages. There were also significant effects of both maternal morph and own morph on growth rate and body shape in the larval stage. There were significant differences in body shape, but not body size, between the adult female morphs, indicating phenotypic integration between colour, melanin patterning, and body shape. Individuals that emerged successfully grew faster and had different body shape in the larval stage, indicating internal (non-ecological) selection on larval morphology. Overall, morphological differences between individuals at the larval stage carried over to the adult stage. Thus, selection in the larval stage can potentially result in correlated responses in adult phenotypes and vice versa.
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| 5. |
- Abbott, Jessica, et al.
(författare)
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Phenotypic and genetic variation in emergence and development time of a trimorphic damselfly
- 2005
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Ingår i: Journal of Evolutionary Biology. - : Wiley. - 1010-061X .- 1420-9101. ; 18:6, s. 1464-1470
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Tidskriftsartikel (refereegranskat)abstract
- Although colour polymorphisms in adult organisms of many taxa are often adaptive in the context of sexual selection or predation, genetic correlations between colour and other phenotypic traits expressed early in ontogeny could also play an important role in polymorphic systems. We studied phenotypic and genetic variation in development time among female colour morphs in the polymorphic damselfly Ischnura elegans in the field and by raising larvae in a common laboratory environment. In the field, the three different female morphs emerged at different times. Among laboratory-raised families, we found evidence of a significant correlation between maternal morph and larval development time in both sexes. This suggests that the phenotypic correlation between morph and emergence time in the field has a parallel in a genetic correlation between maternal colour and offspring development time. Maternal colour morph frequencies could thus potentially change as correlated responses to selection on larval emergence dates. The similar genetic correlation in male offspring suggests that sex-limitation in this system is incomplete, which may lead to an ontogenetic sexual conflict between selection for early male emergence (protandry) and emergence times associated with maternal morph.
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| 6. |
- Blow, Rachel, et al.
(författare)
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A molecular phylogeny of forktail damselflies (genus Ischnura) reveals a dynamic macroevolutionary history of female colour polymorphisms
- 2021
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Ingår i: Molecular Phylogenetics and Evolution. - : Elsevier BV. - 1055-7903 .- 1095-9513. ; 160
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Tidskriftsartikel (refereegranskat)abstract
- Colour polymorphisms are popular study systems among biologists interested in evolutionary dynamics, genomics, sexual selection and sexual conflict. In many damselfly groups, such as in the globally distributed genus Ischnura (forktails), sex-limited female colour polymorphisms occur in multiple species. Female-polymorphic species contain two or three female morphs, one of which phenotypically matches the male (androchrome or male mimic) and the other(s) which are phenotypically distinct from the male (heterochrome). These female colour polymorphisms are thought to be maintained by frequency-dependent sexual conflict, but their macroevolutionary histories are unknown, due to the lack of a robust molecular phylogeny. Here, we present the first time-calibrated phylogeny of Ischnura, using a multispecies coalescent approach (StarBEAST2) and incorporating both molecular and fossil data for 41 extant species (55% of the genus). We estimate the age of Ischnura to be between 13.8 and 23.4 millions of years, i.e. Miocene. We infer the ancestral state of this genus as female monomorphism with heterochrome females, with multiple gains and losses of female polymorphisms, evidence of trans-species female polymorphisms and a significant positive relationship between female polymorphism incidence and current geographic range size. Our study provides a robust phylogenetic framework for future research on the dynamic macroevolutionary history of this clade with its extraordinary diversity of sex-limited female polymorphisms.
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| 7. |
- Eroukhmanoff, Fabrice, et al.
(författare)
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Patterns of Phenotypic Divergence in Wing Covariance Structure of Calopterygid Damselflies
- 2009
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Ingår i: Evolutionary Biology. - : Springer Science and Business Media LLC. - 0071-3260 .- 1934-2845. ; 36:2, s. 214-224
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Forskningsöversikt (refereegranskat)abstract
- Comparing species differences in covariance patterns of traits subject to divergent selection pressures can increase our understanding to the mechanisms of phenotypic divergence. Different species of calopterygid damselflies have diverged in the melanized wing patch of males. This trait serves multiple ecological functions and has behavioral consequences in terms of sexual selection, interspecific interactions, reproductive isolation. We compared the phenotypic variance-covariance matrices (P) of wing traits among nine populations of four European species of calopterygid damselflies. We found modest divergence in covariance structure among populations of the same species, but strong divergence between species. Interestingly, the orientation of the first eigenvector of P (P (max) ) differed more between closely related species than between distantly related species, although this pattern was absent when overall covariance structures were compared. We also found that distantly related species but geographically closer had converged towards a similar covariance structure. Finally, divergence in covariance structure was correlated with divergence in wing patch length, but not with other wing traits. This last finding suggests that divergent selection on wing patch length might have affected the stability of P. These results indicate that P might not only reflect ancestral developmental pathways but might also be influenced by current ecology.
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| 8. |
- Eroukhmanoff, Fabrice, et al.
(författare)
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Rapid adaptive divergence between ecotypes of an aquatic isopod inferred from F-ST-Q(ST) analysis
- 2009
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Ingår i: Molecular Ecology. - Oxford, United Kingdom : Wiley-Blackwell. - 0962-1083 .- 1365-294X. ; 18:23, s. 4912-4923
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Tidskriftsartikel (refereegranskat)abstract
- Divergent natural selection is often thought to be the principal factor driving phenotypic differentiation between populations. We studied two ecotypes of the aquatic isopod Asellus aquaticus which have diverged in parallel in several Swedish lakes. In these lakes, isopods from reed belts along the shores colonized new stonewort stands in the centre of the lakes and rapid phenotypic changes in size and pigmentation followed after colonization. We investigated if selection was likely to be responsible for these observed phenotypic changes using indirect inferences of selection (F-ST-Q(ST) analysis). Average Q(ST) for seven quantitative traits were higher than the average F-ST between ecotypes for putatively neutral markers (AFLPs). This suggests that divergent natural selection has played an important role during this rapid diversification. In contrast, the average Q(ST) between the different reed ecotype populations was not significantly different from the mean F-ST. Genetic drift could therefore not be excluded as an explanation for the minor differences between allopatric populations inhabiting the same source habitat. We complemented this traditional F-ST-Q(ST) approach by comparing the F-ST distributions across all loci (n = 67-71) with the Q(ST) for each of the seven traits. This analysis revealed that pigmentation traits had diverged to a greater extent and at higher evolutionary rates than size-related morphological traits. In conclusion, this extended and detailed type of F-ST-Q(ST) analysis provides a powerful method to infer adaptive phenotypic divergence between populations. However, indirect inferences about the operation of divergent selection should be analyzed on a per-trait basis and complemented with detailed ecological information.
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| 9. |
- Hansson, Lars-Anders, et al.
(författare)
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High zooplankton diversity in the extreme environments of the McMurdo Dry Valley lakes, Antarctica
- 2012
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Ingår i: Antarctic Science. - 1365-2079 .- 0954-1020. ; 24:2, s. 131-138
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Tidskriftsartikel (refereegranskat)abstract
- The McMurdo Dry Valley lakes of Antarctica constitute some of the harshest and most isolated freshwater environments on Earth which might be expected to limit the biogeographical expansion of many organisms. Despite this, we found that the biodiversity of rotifer zooplankton is the highest ever recorded on the Antarctic mainland. We identified in total nine rotifer taxa, of which six are new to the Antarctic continent, in Lake Hoare, and also the first sub- adult crustacean copepod belonging to the genus Boeckella. A possible explanation for the high biodiversity is that many of the recorded species have arrived in the region in relatively recent times and then established invasive populations, suggesting that their distribution pattern was previously limited only by biogeographical borders. Interestingly, we show that the cosmopolitan rotifer taxa identified are relatively abundant, suggesting that they have established viable populations. Hence, our study suggests that the biogeographical maps have to be redrawn for several species.
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| 10. |
- Lord, Hans, 1953, et al.
(författare)
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Sexual dimorphism in Bosmina: The role of morphology, drag, and swimming
- 2006
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Ingår i: Ecology. - : Wiley. - 0012-9658. ; 87:3, s. 788-795
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Tidskriftsartikel (refereegranskat)abstract
- Some Bosmina water flea species develop morphological antipredatory defenses, such as long antennules and a high carapace, but in Bosmina (Eubosmina) coregoni gibbera these traits are larger and more variable in females than in males. Here we propose that this sexual dimorphism derives from differential costs of hydrodynamic drag and selection for mobility in males. We tested this hypothesis by estimating drag of several Bosmina morphologies by using scale models sinking in glycerin of different concentrations and viscosities. Body forms included males, Sexual and asexual females of B. c. gibbera, and males and asexual females of Bosmina (Eubosmina) longispina, a taxon with less variable body shape. For a given body length or body volume, male models had lower drag than models of sexual and asexual females, Suggesting that males call swim 14-28% faster with the same energy consumption. Consistent with this conclusion, video recordings showed that males of B. c. gibbera advanced 55-73% farther than females in each swimming stroke. We Conclude that hydrodynamic drag may have significant implications for swimming and evolution of sexual dimorphism in water fleas, and we suggest that males lack the defensive Structures of females of B. c. gibbera (e.g.. high carapaces) because Competition over mates favors low drag.
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