scholarly journals Adaptive phenotypic plasticity in malaria parasites is not constrained by previous responses to environmental change

2019 ◽  
Vol 2019 (1) ◽  
pp. 190-198
Author(s):  
Philip L G Birget ◽  
Petra Schneider ◽  
Aidan J O’Donnell ◽  
Sarah E Reece
Keyword(s):  
Phenotypic Plasticity ◽  
Environmental Change ◽  
Life History Theory ◽  
Environmental Changes ◽  
Negative Consequences ◽  
Plastic Response ◽  
Malaria Parasites ◽  
Host Environment ◽  
Adaptive Phenotypic Plasticity ◽  
Plastic Responses

Abstract Background and objectives Phenotypic plasticity enables organisms to maximize fitness by matching trait values to different environments. Such adaptive phenotypic plasticity is exhibited by parasites, which experience frequent environmental changes during their life cycle, between individual hosts and also in within-host conditions experienced during infections. Life history theory predicts that the evolution of adaptive phenotypic plasticity is limited by costs and constraints, but tests of these concepts are scarce. Methodology Here, we induce phenotypic plasticity in malaria parasites to test whether mounting a plastic response to an environmental perturbation constrains subsequent plastic responses to further environmental change. Specifically, we perturb red blood cell resource availability to induce Plasmodium chabaudi to alter the trait values of several phenotypes underpinning within-host replication and between-host transmission. We then transfer parasites to unperturbed hosts to examine whether constraints govern the parasites’ ability to alter these phenotypes in response to their new in-host environment. Results Parasites alter trait values in response to the within-host environment they are exposed to. We do not detect negative consequences, for within-host replication or between-host transmission, of previously mounting a plastic response to a perturbed within-host environment. Conclusions and implications We suggest that malaria parasites are highly plastic and adapted to adjusting their phenotypes in response to the frequent changes in the within-host conditions they experience during infections. Our findings support the growing body of evidence that medical interventions, such as anti-parasite drugs, induce plastic responses that are adaptive and can facilitate the survival and potentially, drug resistance of parasites. Lay Summary Malaria parasites have evolved flexible strategies to cope with the changing conditions they experience during infections. We show that using such flexible strategies does not impact upon the parasites’ ability to grow (resulting in disease symptoms) or transmit (spreading the disease).

scholarly journals Avoiding extinction under nonlinear environmental change: models of evolutionary rescue with plasticity

2021 ◽  
Vol 17 (12) ◽  
Author(s):  
Philip B. Greenspoon ◽  
Hamish G. Spencer
Keyword(s):  
Phenotypic Plasticity ◽  
Environmental Change ◽  
Environmental Changes ◽  
Extinction Risk ◽  
Current Theory ◽  
Species At Risk ◽  
Adaptive Genetic Variation ◽  
Change Models ◽  
Numerous Species ◽  
Evolutionary Rescue

Rapid environmental changes are putting numerous species at risk of extinction. For migration-limited species, persistence depends on either phenotypic plasticity or evolutionary adaptation (evolutionary rescue). Current theory on evolutionary rescue typically assumes linear environmental change. Yet accelerating environmental change may pose a bigger threat. Here, we present a model of a species encountering an environment with accelerating or decelerating change, to which it can adapt through evolution or phenotypic plasticity (within-generational or transgenerational). We show that unless either form of plasticity is sufficiently strong or adaptive genetic variation is sufficiently plentiful, accelerating or decelerating environmental change increases extinction risk compared to linear environmental change for the same mean rate of environmental change.

scholarly journals Species’ range dynamics affect the evolution of spatial variation in plasticity under environmental change

2018 ◽  
Author(s):  
Max Schmid ◽  
Ramon Dallo ◽  
Frédéric Guillaume
Keyword(s):  
Phenotypic Plasticity ◽  
Environmental Change ◽  
Range Expansion ◽  
Evolutionary Dynamics ◽  
Environmental Changes ◽  
Species Range ◽  
Range Shifts ◽  
Environmental Tolerance ◽  
Spatial Differences ◽  
Range Dynamics

AbstractWhile clines in environmental tolerance and phenotypic plasticity along a single species’ range are widespread and of special interest in the context of adaptation to environmental changes, we know little about their evolution. Recent empirical findings in ectotherms suggest that processes underlying dynamic species’ ranges can give rise to spatial differences in environmental tolerance and phenotypic plasticity within species. We used individual-based simulations to investigate how plasticity and tolerance evolve in the course of three scenarios of species’ range shifts and range expansions on environmental gradients. We found that regions of a species’ range which experienced a longer history or larger extent of environmental change generally exhibited increased plasticity or tolerance. Such regions may be at the trailing edge when a species is tracking its ecological niche in space (e.g., in a climate change scenario) or at the front edge when a species expands into a new habitat (e.g., in an expansion/invasion scenario). Elevated tolerance and plasticity in the distribution center was detected when asymmetric environmental change (e.g., polar amplification) led to a range expansion. Greater gene flow across the range had a dual effect on plasticity and tolerance clines, with an amplifying effect in niche expansion scenarios (allowing for faster colonization into novel environments), but with a dampening effect in range shift scenarios (favoring spatial translocation of adapted genotypes). However, tolerance and plasticity clines were transient and slowly flattened out after range dynamics because of genetic assimilation. In general, our approach allowed us to investigate the evolution of environmental tolerance and phenotypic plasticity under transient evolutionary dynamics in non-equilibrium situations, which contributes to a better understanding of observed patterns and of how species may respond to future environmental changes.Impact SummaryIn a variable and changing environment, the ability of a species to cope with a range of selection pressures and a multitude of environmental conditions is critical, both for its’ spatial distribution and its’ long-term persistence. Striking examples of spatial differences in environmental tolerance have been found within species, when single populations differed from each other in their environmental optimum and tolerance breadth, a characteristic that might strongly modify a species’ response to future environmental change. However, we still know little about the evolutionary processes causing these tolerance differences between populations, especially when the differences result from transient evolutionary dynamics in non-equilibrium situations. We demonstrate with individual-based simulations, how spatial differences in environmental tolerance and phenotypic plasticity evolved across a species’ range during three scenarios of range shifts and range expansion. Range dynamics were either driven by environmental change or by the expansion of the ecological niche. The outcome strongly differed between scenarios as tolerance and plasticity were maximized either at the leading edge, at the trailing edge, or in the middle of the species’ range. Spatial tolerance variation resulted from colonization chronologies and histories of environmental change that varied along the range. Subsequent to the range dynamics, the tolerance and plasticity clines slowly leveled out again as result of genetic assimilation such that the described responses are long-lasting, but in the end temporary. These findings help us better understand species’ evolutionary responses during range shifts and range expansion, especially when facing environmental change.

scholarly journals Epigenetic Control of Phenotypic Plasticity in the Filamentous Fungus Neurospora crassa

2016 ◽  
Vol 6 (12) ◽  
pp. 4009-4022 ◽  
Author(s):  
Ilkka Kronholm ◽  
Hanna Johannesson ◽  
Tarmo Ketola
Keyword(s):  
Gene Expression ◽  
Phenotypic Plasticity ◽  
Neurospora Crassa ◽  
Filamentous Fungus ◽  
Reaction Norm ◽  
Histone Deacetylation ◽  
Epigenetic Mechanisms ◽  
Plastic Response ◽  
H3k27 Methylation ◽  
Plastic Responses

Abstract Phenotypic plasticity is the ability of a genotype to produce different phenotypes under different environmental or developmental conditions. Phenotypic plasticity is a ubiquitous feature of living organisms, and is typically based on variable patterns of gene expression. However, the mechanisms by which gene expression is influenced and regulated during plastic responses are poorly understood in most organisms. While modifications to DNA and histone proteins have been implicated as likely candidates for generating and regulating phenotypic plasticity, specific details of each modification and its mode of operation have remained largely unknown. In this study, we investigated how epigenetic mechanisms affect phenotypic plasticity in the filamentous fungus Neurospora crassa. By measuring reaction norms of strains that are deficient in one of several key physiological processes, we show that epigenetic mechanisms play a role in homeostasis and phenotypic plasticity of the fungus across a range of controlled environments. In general, effects on plasticity are specific to an environment and mechanism, indicating that epigenetic regulation is context dependent and is not governed by general plasticity genes. Specifically, we found that, in Neurospora, histone methylation at H3K36 affected plastic response to high temperatures, H3K4 methylation affected plastic response to pH, but H3K27 methylation had no effect. Similarly, DNA methylation had only a small effect in response to sucrose. Histone deacetylation mainly decreased reaction norm elevation, as did genes involved in histone demethylation and acetylation. In contrast, the RNA interference pathway was involved in plastic responses to multiple environments.

scholarly journals Beyond buying time: the role of plasticity in phenotypic adaptation to rapid environmental change

2019 ◽  
Vol 374 (1768) ◽  
pp. 20180174 ◽  
Author(s):  
Rebecca J. Fox ◽  
Jennifer M. Donelson ◽  
Celia Schunter ◽  
Timothy Ravasi ◽  
Juan D. Gaitán-Espitia
Keyword(s):  
Phenotypic Plasticity ◽  
Environmental Change ◽  
Environmental Conditions ◽  
Theme Issue ◽  
The Future ◽  
Selection For ◽  
The Individual ◽  
Plastic Responses ◽  
Rapid Environmental Change

How populations and species respond to modified environmental conditions is critical to their persistence both now and into the future, particularly given the increasing pace of environmental change. The process of adaptation to novel environmental conditions can occur via two mechanisms: (1) the expression of phenotypic plasticity (the ability of one genotype to express varying phenotypes when exposed to different environmental conditions), and (2) evolution via selection for particular phenotypes, resulting in the modification of genetic variation in the population. Plasticity, because it acts at the level of the individual, is often hailed as a rapid-response mechanism that will enable organisms to adapt and survive in our rapidly changing world. But plasticity can also retard adaptation by shifting the distribution of phenotypes in the population, shielding it from natural selection. In addition to which, not all plastic responses are adaptive—now well-documented in cases of ecological traps. In this theme issue, we aim to present a considered view of plasticity and the role it could play in facilitating or hindering adaption to environmental change. This introduction provides a re-examination of our current understanding of the role of phenotypic plasticity in adaptation and sets the theme issue's contributions in their broader context. Four key themes emerge: the need to measure plasticity across both space and time; the importance of the past in predicting the future; the importance of the link between plasticity and sexual selection; and the need to understand more about the nature of selection on plasticity itself. We conclude by advocating the need for cross-disciplinary collaborations to settle the question of whether plasticity will promote or retard species' rates of adaptation to ever-more stressful environmental conditions. This article is part of the theme issue ‘The role of plasticity in phenotypic adaptation to rapid environmental change’.

scholarly journals Plasticity and flexibility in the anti-predator responses of treefrog tadpoles

2021 ◽  
Vol 75 (10) ◽  
Author(s):  
Castellano Sergio ◽  
Racca Luca ◽  
Friard Olivier
Keyword(s):  
Life History ◽  
Body Size ◽  
Natural Selection ◽  
Phenotypic Plasticity ◽  
Plastic Response ◽  
Heritable Variation ◽  
Size At Metamorphosis ◽  
Adaptive Phenotypic Plasticity ◽  
Similar Body ◽  
And Behavior

Abstract Tadpoles can respond to perceived predation risk by adjusting their life history, morphology, and behavior in an adaptive way. Adaptive phenotypic plasticity can evolve by natural selection only if there is variation in reaction norms and if this variation is, at least in part, heritable. To provide insights into the evolution of adaptive phenotypic plasticity, we analyzed the environmental and parental components of variation in predator-induced life history (age and size at metamorphosis), morphology (tail depth), and behavior of Italian treefrog tadpoles (Hyla intermedia). Using an incomplete factorial design, we raised tadpoles either with or without caged predators (dragonfly larvae, gen. Aeshna) and, successively, we tested them in experimental arenas either with or without caged predators. Results provided strong evidence for an environmental effect on all three sets of characters. Tadpoles raised with caged predators (dragonfly larvae, gen. Aeshna) metamorphosed earlier (but at a similar body size) and developed deeper tails than their fullsib siblings raised without predators. In the experimental arenas, all tadpoles, independent of their experience, flexibly changed their activity and position, depending on whether the cage was empty or contained the predator. Tadpoles of the two experimental groups, however, showed different responses: those raised with predators were always less active than their predator-naive siblings and differences slightly increased in the presence of predators. Besides this strong environmental component of phenotypic variation, results provided evidence also for parental and parental-by-environment effects, which were strong on life-history, but weak on morphology and behavior. Interestingly, additive parental effects were explained mainly by dams. This supports the hypothesis that phenotypic plasticity might mainly depend on maternal effects and that it might be the expression of condition-dependent mechanisms. Significance statement Animals, by plastically adjusting their phenotypes to the local environments, can often sensibly improve their chances of survival, suggesting the hypothesis that phenotypic plasticity evolved by natural selection. We test this hypothesis in the Italian treefrog tadpoles, by investigating the heritable variation in the plastic response to predators (dragonfly larvae). Using an incomplete factorial common-garden experiment, we showed that tadpoles raised with predators metamorphosed earlier (but at similar body size), developed deeper tails, and were less active than their siblings raised without predators. The plastic response varied among families, but variation showed a stronger maternal than paternal component. This suggests that plasticity might largely depend on epigenetic factors and be the expression of condition-dependent mechanisms.

scholarly journals Individual reversible plasticity as a genotype-level bet-hedging strategy

2020 ◽  
Author(s):  
T.R. Haaland ◽  
J. Wright ◽  
I.I. Ratikainen
Keyword(s):  
Phenotypic Plasticity ◽  
Environmental Change ◽  
Environmental Conditions ◽  
Life History Theory ◽  
Reaction Norm ◽  
Phenotypic Traits ◽  
Bet Hedging ◽  
Hedging Strategy ◽  
Individual Level ◽  
Environmental Fluctuations

AbstractReversible plasticity in phenotypic traits allows organisms to cope with environmental variation within lifetimes, but costs of plasticity may limit just how well the phenotype matches the environmental optimum. An additional adaptive advantage of plasticity might be to reduce fitness variance, or bet-hedging to maximize geometric (rather than simply arithmetic) mean fitness. Here we model the evolution of reaction norm slopes, with increasing costs as the slope or degree of plasticity increases. We find that greater investment in plasticity (i.e. steeper reaction norm slopes) is favoured in scenarios promoting bet-hedging as a response to multiplicative fitness accumulation (i.e. coarser environmental grains and fewer time steps prior to reproduction), because plasticity lowers fitness variance across environmental conditions. In contrast, in scenarios with finer environmental grain and many time steps prior to reproduction, bet-hedging plays less of a role and individual-level optimization favours evolution of shallower reaction norm slopes. We discuss contrasting predictions from this partitioning of the different adaptive causes of plasticity into short-term individual benefits versus long-term genotypic (bet-hedging) benefits under different costs of plasticity scenarios, thereby enhancing our understanding of the evolution of optimum levels of plasticity in examples from thermal physiology to advances in avian lay dates.Impact summaryPhenotypic plasticity is a key mechanism by which organisms cope with environmental change. Plasticity relies on the existence of some reliable environmental cue that allows organisms to infer current or future conditions, and adjust their traits in response to better match the environment. In contrast, when environmental fluctuations are unpredictable, bet-hedging favours lineages that persist by lowering their fitness variance, either among or within individuals. Plasticity and bet-hedging are therefore often considered to be alternative modes of adaptation to environmental change. However, we here make the point that plasticity also has the capacity to change an organism’s variance in fitness across different environmental conditions, and could thus itself be part of – and not an alternative to – a bet-hedging strategy. We show that bet-hedging at the genotype level affects the optimal degree of plasticity that individuals use to track environmental fluctuations, because despite a reduction in expected fitness at the individual level, costly investment in the ability to be plastic also lowers variance in fitness. We also discuss alternative predictions that arise from scenarios with different types of costs of plasticity. Evolutionary bet-hedging and phenotypic plasticity are both topics experiencing a renewed surge of interest as researchers seek to better integrate different adaptations to ongoing rapid environmental change in a range of areas of literature within ecology and evolution, including behavioural ecology, evolutionary physiology and life-history theory. We believe that demonstrating an important novel link between these two mechanisms is of interest to research in many different fields, and opens new avenues for understanding organismal adaptation to environmental change.

Phenotypic plasticity

2018 ◽  
Author(s):  
Karen D. Williams ◽  
Marla B. Sokolowski
Keyword(s):  
Gene Expression ◽  
Phenotypic Plasticity ◽  
Environmental Change ◽  
Behavioral Plasticity ◽  
Behavioral Flexibility ◽  
Insect Behavior ◽  
Behavioral Variability ◽  
Gene By Environment Interactions ◽  
Affect Gene Expression

Why is there so much variation in insect behavior? This chapter will address the sources of behavioral variability, with a particular focus on phenotypic plasticity. Variation in social, nutritional, and seasonal environmental contexts during development and adulthood can give rise to phenotypic plasticity. To delve into mechanism underlying behavioral flexibility in insects, examples of polyphenisms, a type of phenotypic plasticity, will be discussed. Selected examples reveal that environmental change can affect gene expression, which in turn can affect behavioral plasticity. These changes in gene expression together with gene-by-environment interactions are discussed to illuminate our understanding of insect behavioral plasticity.

scholarly journals Temporal changes in reproductive success and optimal breeding decisions in a long-distance migratory bird

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Cynthia Reséndiz-Infante ◽  
Gilles Gauthier
Keyword(s):  
Reproductive Success ◽  
Clutch Size ◽  
Environmental Changes ◽  
Migratory Bird ◽  
Laying Date ◽  
Negative Consequences ◽  
Breeding Phenology ◽  
Additional Time ◽  
Long Distance ◽  
Seasonal Decline

AbstractMany avian migrants have not adjusted breeding phenology to climate warming resulting in negative consequences for their offspring. We studied seasonal changes in reproductive success of the greater snow goose (Anser caerulescens atlantica), a long-distance migrant. As the climate warms and plant phenology advances, the mismatch between the timing of gosling hatch and peak nutritive quality of plants will increase. We predicted that optimal laying date yielding highest reproductive success occurred earlier over time and that the seasonal decline in reproductive success increased. Over 25 years, reproductive success of early breeders increased by 42%, producing a steeper seasonal decline in reproductive success. The difference between the laying date producing highest reproductive success and the median laying date of the population increased, which suggests an increase in the selection pressure for that trait. Observed clutch size was lower than clutch size yielding the highest reproductive success for most laying dates. However, at the individual level, clutch size could still be optimal if the additional time required to acquire nutrients to lay extra eggs is compensated by a reduction in reproductive success due to a delayed laying date. Nonetheless, breeding phenology may not respond sufficiently to meet future environmental changes induced by warming temperatures.

Pleistocene–Holocene environmental change in the Canary Archipelago as inferred from the stable isotope composition of land snail shells

2011 ◽  
Vol 75 (3) ◽  
pp. 658-669 ◽  
Author(s):  
Yurena Yanes ◽  
Crayton J. Yapp ◽  
Miguel Ibáñez ◽  
María R. Alonso ◽  
Julio De-la-Nuez ◽  
...  
Keyword(s):  
Environmental Change ◽  
Canary Islands ◽  
Environmental Changes ◽  
Isotope Composition ◽  
Moving Average ◽  
Land Snail ◽  
Balance Model ◽  
Low Latitude ◽  
The Times

AbstractThe isotopic composition of land snail shells was analyzed to investigate environmental changes in the eastern Canary Islands (28–29°N) over the last ~ 50 ka. Shell δ13C values range from −8.9‰ to 3.8‰. At various times during the glacial interval (~ 15 to ~ 50 ka), moving average shell δ13C values were 3‰ higher than today, suggesting a larger proportion of C4 plants at those periods. Shell δ18O values range from −1.9‰ to 4.5‰, with moving average δ18O values exhibiting a noisy but long-term increase from 0.1‰ at ~ 50 ka to 1.6–1.8‰ during the LGM (~ 15–22 ka). Subsequently, the moving average δ18O values range from 0.0‰ at ~ 12 ka to 0.9‰ at present. Calculations using a published snail flux balance model for δ18O, constrained by regional temperatures and ocean δ18O values, suggest that relative humidity at the times of snail activity fluctuated but exhibited a long-term decline over the last ~ 50 ka, eventually resulting in the current semiarid conditions of the eastern Canary Islands (consistent with the aridification process in the nearby Sahara). Thus, low-latitude oceanic island land snail shells may be isotopic archives of glacial to interglacial and tropical/subtropical environmental change.

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