scholarly journals Natural toxic impact and thyroid signaling interplay orchestrates riverine adaptive divergence of Dolly Varden.

2020 ◽  
Author(s):  
Evgeny V. Esin ◽  
Grigorii N. Markevich ◽  
Nikolay O. Melnik ◽  
Daria V. Kapitanova ◽  
Fedor N. Shkil
Keyword(s):  
Coniferous Forest ◽  
Common Garden ◽  
Adaptive Divergence ◽  
Dolly Varden ◽  
Evolutionary Diversification ◽  
Toxic Impact ◽  
Specific Morphology ◽  
Kamchatka River ◽  
Thyroid Axis ◽  
Forest Distribution

Abstract Background Adaptive radiation in fishes has been actively investigated over the last decades. Along with numerous well-studied cases of lotic radiation, some examples of riverine sympatric divergence have been recently discovered. In contrast to the lakes, the riverine conditions do not provide evident stability in the ecological gradients. Consequently, external factors triggering the radiation, as well as developmental mechanisms underpinning it, remain unclear. Herein, we present the comprehensive study of external and internal drivers of the riverine adaptive divergence of the salmonid fish Salvelinus malma. In the Kamchatka River, this species splits in the reproductively isolated morphs that drastically differ in ecology and morphology: the benthivorous Dolly Varden (DV) and the piscivorous Stone charr (SC). To understand why and how these morphs originated, we performed a series of field and experimental work, including common-garden rearing, comparative ontogenetic, physiological and endocrinological analyses, hormonal "engineering" of phenotypes.Results We revealed that the type of spawning ground acts as the main external factor driving the radiation of S. malma . In contrast to DV spawning in the leaf krummholz zone, SC reproduces in the zone of coniferous forest, which litter has a toxic impact on developing fishes. SC enhances resistance to the toxicants via metabolism acceleration provided by the elevated thyroid hormone content. These physiological changes lead to the multiple heterochronies resulting in a specific morphology and SC's expansion into a piscivorous niche.Conclusions S. malma represents a notable example of how the thyroid axis contributes to the generation of diverse phenotypic outcomes underlying the riverine sympatric divergence. Our findings, along with the paleoecology data concerning spruce forest distribution during the Pleistocene, provide an opportunity to reconstruct a scenario of S. malma divergence. Taken together, obtained results with the data of the role of thyroid hormones in the ontogeny and diversification of fishes contribute a resource to consider the thyroid axis as a prime director orchestrating the phenotypic plasticity promoting evolutionary diversification under the changing environmental conditions.

Natural toxic impact and thyroid signalling interplay orchestrates riverine adaptive divergence of salmonid fish

2021 ◽  
Author(s):  
Evgeny V. Esin ◽  
Grigorii N. Markevich ◽  
Nikolay O. Melnik ◽  
Daria V. Kapitanova ◽  
Fedor N. Shkil
Keyword(s):  
Salmonid Fish ◽  
Adaptive Divergence ◽  
Toxic Impact

scholarly journals Evolutionary inference from QST-FST comparisons: disentangling local adaptation from altitudinal gradient selection in snapdragon plants

2018 ◽  
Author(s):  
Sara Marin ◽  
Juliette Archambeau ◽  
Vincent Bonhomme ◽  
Mylène Lascoste ◽  
Benoit Pujol
Keyword(s):  
Local Adaptation ◽  
Natural Populations ◽  
Common Garden ◽  
Global Scale ◽  
Structured Populations ◽  
Adaptive Divergence ◽  
Adaptation To Climate Change ◽  
Phenotypic Differentiation ◽  
Multiple Populations ◽  
Environmental Demand

ABSTRACTPhenotypic differentiation among natural populations can be explained by natural selection or by neutral processes such as drift. There are many examples in the literature where comparing the effects of these processes on multiple populations has allowed the detection of local adaptation. However, these studies rarely identify the agents of selection. Whether population adaptive divergence is caused by local features of the environment, or by the environmental demand emerging at a more global scale, for example along altitudinal gradients, is a question that remains poorly investigated. Here, we measured neutral genetic (FST) and quantitative genetic (QST) differentiation among 13 populations of snapdragon plants (Antirrhinum majus) in a common garden experiment. We found low but significant genetic differentiation at putatively neutral markers, which supports the hypothesis of either ongoing pervasive homogenisation via gene flow between diverged populations or reproductive isolation between disconnected populations. Our results also support the hypothesis of local adaptation involving phenological, morphological, reproductive and functional traits. They also showed that phenotypic differentiation increased with altitude for traits reflecting the reproduction and the phenology of plants, thereby confirming the role of such traits in their adaptation to environmental differences associated with altitude. Our approach allowed us to identify candidate traits for the adaptation to climate change in snapdragon plants. Our findings imply that environmental conditions changing with altitude, such as the climatic envelope, influenced the adaptation of multiple populations of snapdragon plants on the top of their adaptation to local environmental features. They also have implications for the study of adaptive evolution in structured populations because they highlight the need to disentangle the adaptation of plant populations to climate envelopes and altitude from the confounding effects of selective pressures acting specifically at the local scale of a population.

scholarly journals Adaptive divergence in shell morphology in an ongoing gastropod radiation from Lake Malawi

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Bert Van Bocxlaer ◽  
Claudia M. Ortiz-Sepulveda ◽  
Pieter R. Gurdebeke ◽  
Xavier Vekemans
Keyword(s):  
Common Garden ◽  
Shell Morphology ◽  
Model Systems ◽  
Shell Shape ◽  
Adaptive Divergence ◽  
Nominal Species ◽  
Shape Variation ◽  
In The Wild ◽  
Evolutionary Radiations ◽  
Contrasting Habitats

Abstract Background Ecological speciation is a prominent mechanism of diversification but in many evolutionary radiations, particularly in invertebrates, it remains unclear whether supposedly critical ecological traits drove or facilitated diversification. As a result, we lack accurate knowledge on the drivers of diversification for most evolutionary radiations along the tree of life. Freshwater mollusks present an enigmatic example: Putatively adaptive radiations are being described in various families, typically from long-lived lakes, whereas other taxa represent celebrated model systems in the study of ecophenotypic plasticity. Here we examine determinants of shell-shape variation in three nominal species of an ongoing ampullariid radiation in the Malawi Basin (Lanistes nyassanus, L. solidus and Lanistes sp. (ovum-like)) with a common garden experiment and semi-landmark morphometrics. Results We found significant differences in survival and fecundity among these species in contrasting habitats. Morphological differences observed in the wild persisted in our experiments for L. nyassanus versus L. solidus and L. sp. (ovum-like), but differences between L. solidus and L. sp. (ovum-like) disappeared and re-emerged in the F1 and F2 generations, respectively. These results indicate that plasticity occurred, but that it is not solely responsible for the observed differences. Our experiments provide the first unambiguous evidence for genetic divergence in shell morphology in an ongoing freshwater gastropod radiation in association with marked fitness differences among species under controlled habitat conditions. Conclusions Our results indicate that differences in shell morphology among Lanistes species occupying different habitats have an adaptive value. These results also facilitate an accurate reinterpretation of morphological variation in fossil Lanistes radiations, and thus macroevolutionary dynamics. Finally, our work testifies that the shells of freshwater gastropods may retain signatures of adaptation at low taxonomic levels, beyond representing an evolutionary novelty responsible for much of the diversity and disparity in mollusks altogether.

Combined phylogenetic analysis of ribosomal ITS1 sequences and new chromosome data supports three subgroups of Dolly Varden char (Salvelinus malma)

1999 ◽  
Vol 56 (8) ◽  
pp. 1504-1511 ◽  
Author(s):  
Ruth B Phillips ◽  
Linda I Gudex ◽  
Kathleen M Westrich ◽  
Alfred DeCicco
Keyword(s):  
Phylogenetic Analysis ◽  
Dna Sequences ◽  
Lake Trout ◽  
Salvelinus Alpinus ◽  
Dolly Varden ◽  
Salvelinus Malma ◽  
Dolly Varden Char ◽  
The North ◽  
Rdna Sequences ◽  
Kamchatka River

A phylogenetic analysis of the subspecies of Salvelinus malma (Dolly Varden char) was done using DNA sequences from the first internal transcribed spacer (ITS1) of the ribosomal DNA (rDNA). Sequences were obtained from the northern S. malma malma from the Noatak River, Alaska, and the Kamchatka River, Russia; from the southern North American form S. malma lordi from the Fox River, Kenai peninsula, and Auke Bay near Juneau, Alaska; and from the southern Asian form S. malma krascheninnikovi from Belaya River in Sakhalin Island, Russia. These sequences were combined with others from Salvelinus alpinus (Arctic char) from several locations in the North Pacific and Europe and analyzed using maximum parsimony and neighbor joining algorithms with Salvelinus namaycush (lake trout) as an outgroup. The resulting trees had two well-supported groups: S. m. malma and S. m. krascheninnikovi in one group and S. m. lordi and various populations of S. alpinus in the other. Salvelinus m. malma and S. m. krascheninnikovi were sister taxa, and S. m. lordi was most closely related to S. alpinus from Northwest Territories (S. a. erythrinus). New chromosome data from S. m. malma from northwestern Alaska supported the three named subspecies because S. m. malma from both Alaska and Russia have 2n = 78 compared with 2n = 82 for the two southern forms and the location of the nuclear organizer regions (NORs) was different in each of the three subspecies.

scholarly journals Multivariate distributions of behavioural, morphological, and ontogenetic traits in hybrids bring new insights into the divergence of sympatric Arctic charr morphs

2020 ◽  
Author(s):  
Quentin J.B. Horta-Lacueva ◽  
Sigurður S. Snorrason ◽  
Michael B. Morrissey ◽  
Camille A. Leblanc ◽  
Kalina H. Kapralova
Keyword(s):  
Salvelinus Alpinus ◽  
Arctic Charr ◽  
Common Garden ◽  
Covariance Structures ◽  
Adaptive Divergence ◽  
Phenotypic Traits ◽  
Phenotypic Variance ◽  
Multivariate Distributions ◽  
Phenotypic Novelty ◽  
Trait Covariance

AbstractStudying the development of fitness related traits in hybrids from populations diverging in sympatry is a fundamental approach to understand the processes of speciation. However, such traits are often affected by covariance structures that complicate the comprehension of these processes, especially because the interactive relationships between traits of different nature (e.g. morphology, behaviour, life-history) remain largely unknown in this context. In a common garden setup, we conducted an extensive examination of phenotypic traits suspected to be involved in the divergence of two recently evolved morphs of Arctic charr (Salvelinus alpinus), and investigated the consequences of potential patterns of trait covariance on the phenotype of their hybrids. We observed differences among morphs in overall phenotypic variance and in trait correlations. Phenotypic contrainsts also tended to be reduced in the hybrids, which corroborates the narrative of hybridization facilitating adaptive divergence by relaxing trait covariance. However, the hybrids were associated with reduced phenotypic variance at different scales (i.e. at the scale of the entire P matrix and in different parts of the multivariate space), and we identified stronger correlations between several ontogenetic and morphological traits in the hybrids than in both morphs. These findings suggest a limited potential for hybridization to generate phenotypic novelty, and emphasise the need for multivariate approaches conciliating ontogenetic, morphological and behavioural processes to study the processes of adaptive divergence and speciation.

scholarly journals The dynamic ontogenetic patterns of adaptive divergence and sexual dimorphism in Arctic charr

2021 ◽  
Author(s):  
Marina De la Cámara ◽  
Lieke Ponsioen ◽  
Quentin J.B. Horta-Lacueva ◽  
Kalina H Kapralova
Keyword(s):  
Sexual Dimorphism ◽  
Sexual Maturation ◽  
Salvelinus Alpinus ◽  
Arctic Charr ◽  
Common Garden ◽  
Open Water ◽  
Adaptive Divergence ◽  
Shape Variation ◽  
Ontogenetic Trajectories ◽  
Main Driver

ABSTRACTArctic charr (Salvelinus alpinus) in lake Thingvallavatn (Iceland) is one of the most iconic examples of post-glacial adaptive divergence, resulting in four ecomorphs that diverge along the ecological benthic-limnetic axis (bottom lake versus open water feeders), and are distinct both phenotypically and genotypically. Here, we used geometric morphometrics tools on a common garden setup to determine the factors responsible for genetically based shape variation during the post-embryonic ontogeny of two morphs that represent the benthic-limnetic axis: the small benthic (SB) and the planktivorous (PL). This experiment uses pure crosses and F1 reciprocal hybrids between the two morphs, and includes the onset of sexual maturation, offering an excellent opportunity to explore the genetic component of adaptive divergence and the role of sexual dimorphism in this scenario. We found that growth is the main driver of shape variation across time and provided evidence of a genetically-controlled ontogenetic shift that gives rise to the limnetic morph. Additionally, our results indicate that the onset of sexual maturation triggers differences both in sex ontogenetic trajectories and in static shape variation at different time points, likely dissipating the canalisation for traits traditionally associated with benthic-limnetic adaptations.

scholarly journals Fine-scale local adaptation in an invasive freshwater fish has evolved in contemporary time

2013 ◽  
Vol 280 (1751) ◽  
pp. 20122327 ◽  
Author(s):  
Peter A. H. Westley ◽  
Eric J. Ward ◽  
Ian A. Fleming
Keyword(s):  
Freshwater Fish ◽  
Local Adaptation ◽  
Relative Survival ◽  
Common Garden ◽  
Population Level ◽  
Adaptive Divergence ◽  
Fine Scale ◽  
Ecological Selection ◽  
Reciprocal Transplants ◽  
Common Garden Experiments

Adaptive evolutionary change in only a few generations can increase the ability of non-native invasive species to spread, and yet adaptive divergence is rarely assessed in recently established populations. In this study, we experimentally test for evidence of fine-scale local adaptation in juvenile survival and growth among three populations of an invasive freshwater fish with reciprocal transplants and common-garden experiments. Despite intrinsic differences in habitat quality, in two of three populations we detected evidence of increased survival in ‘home’ versus ‘away’ environments with a Bayesian occupancy model fitted to mark–recapture data. We found support for the ‘local’ versus ‘foreign’ criterion of local adaptation as 14 of 15 pairwise comparisons of performance were consistent with local adaptation ( p < 0.001). Patterns in growth were less clear, though we detected evidence of location- and population-level effects. Although the agents of divergent ecological selection are not known in this system, our results combine to indicate that adaptive divergence—reflected by higher relative survival of local individuals—can occur in a small number of generations and only a few kilometres apart on the landscape.

scholarly journals Adaptive Divergence of Meiotic Recombination Rate in Ecological Speciation

2020 ◽  
Vol 12 (10) ◽  
pp. 1869-1881
Author(s):  
Swatantra Neupane ◽  
Sen Xu
Keyword(s):  
Meiotic Recombination ◽  
Recombination Rate ◽  
Natural Populations ◽  
Daphnia Pulex ◽  
Common Garden ◽  
Population Level ◽  
Directional Selection ◽  
Neutral Evolution ◽  
Adaptive Divergence ◽  
Rate Variation

Abstract Theories predict that directional selection during adaptation to a novel habitat results in elevated meiotic recombination rate. Yet the lack of population-level recombination rate data leaves this hypothesis untested in natural populations. Here, we examine the population-level recombination rate variation in two incipient ecological species, the microcrustacean Daphnia pulex (an ephemeral-pond species) and Daphnia pulicaria (a permanent-lake species). The divergence of D. pulicaria from D. pulex involved habitat shifts from pond to lake habitats as well as strong local adaptation due to directional selection. Using a novel single-sperm genotyping approach, we estimated the male-specific recombination rate of two linkage groups in multiple populations of each species in common garden experiments and identified a significantly elevated recombination rate in D. pulicaria. Most importantly, population genetic analyses show that the divergence in recombination rate between these two species is most likely due to divergent selection in distinct ecological habitats rather than neutral evolution.

scholarly journals Heritable plant phenotypes track light and herbivory levels at fine spatial scales

2017 ◽  
Author(s):  
P.T. Humphrey ◽  
A.D. Gloss ◽  
J. Frazier ◽  
A. C. Nelson–Dittrich ◽  
S. Faries ◽  
...  
Keyword(s):  
Spatial Scales ◽  
Common Garden ◽  
Flowering Phenology ◽  
Adaptive Divergence ◽  
Shade Avoidance ◽  
Native Plant ◽  
Fine Grained ◽  
Habitat Mosaic ◽  
Resistance To Herbivory ◽  
Common Gardens

ABSTRACTThe biotic and the abiotic environment play a major role in shaping plant phenotypes and their geographic distributions. However, little is known about the extent to which plant phenotypes match local patterns of herbivory across fine-grained habitat mosaics, despite the strong effect of herbivory on plant fitness. Through a reciprocal transplant-common garden experiment with clonally propagated rhizomes, we tested for local phenotypic differentiation in bittercress (Brassicaceae: Cardamine cordifolia) plants collected across an ecotonal habitat mosaic. We found that bittercress in sunny meadows (high herbivory) and shaded understories (low herbivory) have diverged in heritable growth and herbivore resistance phenotypes. The expression of these differences was habitat dependent, mirroring patterns of adaptive divergence in phenotypic plasticity between plant populations in meadow and understory habitats at broader geographic scales, and showed no evidence for a constraint imposed by growth–defense tradeoffs. Most notably, plants derived from shade habitats exhibited a weaker shade-induced elongation response (i.e., shade avoidance syndrome, SAS) and reduced resistance to herbivory, relative to plants derived from sun habitats, when both were grown in shade common gardens. Greenhouse experiments revealed that divergent SAS phenotypes in shade conditions were expressed in offspring grown from seed as well. Finally, we observed partially non-overlapping flowering phenology between habitat-types in the field, which may be at least one factor that helps to reinforce habitat-specific phenotypic divergence. Altogether, our study illuminates how a native plant may cope with overlapping biotic and abiotic stressors across a fine-grained habitat mosaic.

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