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Rapid environmental change is forcing populations into environments where plasticity will no longer maintain fitness. When populations are exposed to novel environments, evolutionary theory predicts that genetic variation in fitness will increase and should be associated with genetic differences in plasticity. If true, then genetic variation in plasticity can increase adaptive potential in novel environments, and population persistence via evolutionary rescue is more likely. To test whether genetic variation in fitness increases in novel environments and is associated with plasticity, we transplanted 8149 clones of 314 genotypes of a Sicilian daisy (Senecio chrysanthemifolius) within and outside its native range, and quantified genetic variation in fitness, and plasticity in leaf traits and gene expression. Although mean fitness declined by 87% in the novel environment, genetic variance in fitness increased threefold and was correlated with plasticity in leaf traits. High fitness genotypes showed greater plasticity in gene expression, but lower plasticity in most leaf traits. Interestingly, genotypes with the highest fitness in the novel environment had the lowest fitness at the native site. These results suggest that standing genetic variation in plasticity could help populations to persist and adapt to novel environments, despite remaining hidden in native environments.

The active skeletal muscle and the maintenance of muscle mass are essential for good health, wellness and disease prevention and treatment. The muscle as an endocrine organ capable of synthesizing myokines, has been documented recently. These peptides are secreted as a response to muscular contractions induced by exercise, and can develop molecular communication with other tissues, improving cardiovascular, metabolic, and mental health. The endocrine function of a muscle continues to be in a constant investigation; however, knowledge up to date urge us to continue promoting physical activity. Additionally, the extended knowledge of myokins is useful to prescribe individualized physical exercise programs to each patient. El músculo esquelético activo y el mantenimiento de la masa muscular son esenciales para la salud, el bienestar, la prevención y el tratamiento de enfermedades. Recientemente se ha documentado que el músculo, como órgano endocrino, es capaz de sintetizar mioquinas. Estos péptidos son secretados en respuesta a las contracciones musculares inducidas por el ejercicio, y son capaces de crear comunicación molecular con otros tejidos, beneficiando así la salud cardiovascular, metabólica y mental. La función endocrina del músculo continúa en investigación constante, sin embargo, lo conocido hasta ahora nos insta a seguir promoviendo la actividad física. Adicionalmente a esto, extender el conocimiento sobre las mioquinas, es útil para poder prescribir el ejercicio físico de manera individualizada y a la medida de cada paciente.

Phenotypic plasticity enables plants to buffer against environmental stresses and match their phenotypes to local conditions. However, consistent conclusive evidence for adaptive plasticity has only been obtained for a few traits. More studies on a wider variety of plant functional traits and environmental factors are still needed to further understand the adaptive significance of plasticity. We grew 21 genotypes of the stoloniferous clonal plant Duchesnea indica under different light and nutrient conditions, and used selection gradient analyses to test the adaptive value (benefits) of morphological and physiological plasticity responding to variation in light and nutrient availability. Plants grown in shade exhibited lower values for fitness measures (fruit number, ramet number and biomass), shortened thinner internode length and decreased adult leaf chlorophyll content, but higher petiole length, specific leaf area and old leaf chlorophyll content, than plants grown without shade. Plants grown in the low nutrient condition had shorter petiole length, thicker and smaller leaf area, lower chlorophyll content, but higher fruit number and root:shoot ratio than plants grown under the high nutrient condition. Selection gradient analyses revealed that plasticity of petiole length and old leaf chlorophyll content in response to light variation was adaptive, and plasticity of old and adult leaf chlorophyll content in response to nutrient variation was adaptive. Therefore, the adaptive value of plasticity in different traits depends on the specific ecological context. Our findings contribute to understanding the adaptive significance of phenotypic plasticity of clonal plants in response to environmental variation.

Urban stressors represent strong selective gradients that can elicit evolutionary change, especially in non‐native species that may harbor substantial within‐population variability. To test whether urban stressors drive phenotypic differentiation and influence local adaptation, we compared stress responses of populations of a ubiquitous invader, reed canary grass (Phalaris arundinacea). Specifically, we quantified responses to salt, copper, and zinc additions by reed canary grass collected from four populations spanning an urbanization gradient (natural, rural, moderate urban, and intense urban). We measured ten phenotypic traits and trait plasticities, because reed canary grass is known to be highly plastic and because plasticity may enhance invasion success. We tested the following hypotheses: (a) Source populations vary systematically in their stress response, with the intense urban population least sensitive and the natural population most sensitive, and (b) plastic responses are adaptive under stressful conditions. We found clear trait variation among populations, with the greatest divergence in traits and trait plasticities between the natural and intense urban populations. The intense urban population showed stress tolerator characteristics for resource acquisition traits including leaf dry matter content and specific root length. Trait plasticity varied among populations for over half the traits measured, highlighting that plasticity differences were as common as trait differences. Plasticity in root mass ratio and specific root length were adaptive in some contexts, suggesting that natural selection by anthropogenic stressors may have contributed to root trait differences. Reed canary grass populations in highly urbanized wetlands may therefore be evolving enhanced tolerance to urban stressors, suggesting a mechanism by which invasive species may proliferate across urban wetland systems generally., We tested whether populations of a ubiquitous wetland invader, reed canary grass (Phalaris arundinacea), differed phenotypically across an urbanization gradient, suggesting evolutionary responses to common urban stressors. We found clear trait and trait plasticity variation among populations, suggesting reed canary grass may be evolving enhanced tolerance to anthropogenic stressors.

Understanding the fate of heterogenous herbicide resistant weed populations in response to management practices can help towards overcoming the resistance issues. We selected one pair of susceptible (S) and resistant (R) phenotypes (2B21-R vs 2B21-S and 2B37-R vs 2B37-S) separately from two glyphosate resistant heterogeneous populations (2B21 and 2B37) of Echinochloa colona and their fate and adaptive plasticity were evaluated after glyphosate application. Our study revealed the glyphosate concentration required to cause a 50% plant mortality (LD50) was 1187, 200, 3064, and 192 g a. e. ha−1 for the four phenotypes 2B21-R, 2B21-S, 2B37-R, and 2B37-S respectively. Both S phenotypes accumulated more biomass than the R phenotypes at the lower application rates (34 and 67.5 g a. e. ha−1) of glyphosate. However, the R phenotypes generally produced more biomass at rates of glyphosate higher than 100 g a. e. ha−1 throughout the growth period. Plants from the R phenotypes of 2B21 and 2B37 generated 32% and 38% fewer spikes plant−1 than their respective S counterparts in the absence of glyphosate respectively. The spike and seed numbers plant-1 significantly higher in R than S phenotypes at increased rates of glyphosate and these relationships were significant. Our research suggests that glyphosate-resistant E. colona plants will be less fit than susceptible plants (from the same population) in the absence of glyphosate. But in the presence of glyphosate, the R plants may eventually dominate in the field. The use of glyphosate is widespread in field, would favour the selection towards resistant individuals.

The mechanisms of adaptive resistance to genetic-based targeted therapies of solid malignancies have been the subject of intense research. These studies hold great promise for finding co-targetable hub/pathways which in turn would control the downstream non-genetic mechanisms of adaptive resistance. Many such mechanisms have been described in the paradigmatic BRAF-mutated melanoma model of adaptive response to BRAF inhibition. Currently, a major challenge for these mechanistic studies is to confirm in vivo, at the single-cell proteomic level, the existence of dependencies between the co-targeted hub/pathways and their downstream effectors. Moreover, the drug-induced in vivo modulation of these dependencies needs to be demonstrated. Here, we implement such single-cell-based in vivo expression dependency quantification using immunohistochemistry (IHC)-based analyses of sequential biopsies in two xenograft models. These mimic phase 2 and 3 trials in our own therapeutic strategy to prevent the adaptive response to BRAF inhibition. In this mechanistic model, the dependencies between the targeted Li2CO3-inducible hub HuR and the resistance effectors are more likely time-shifted and transient since the minority of HuRLow cells, which act as a reservoir of adaptive plasticity, switch to a HuRHigh state as they paradoxically proliferate under BRAF inhibition. Nevertheless, we show that a copula/kernel density estimator (KDE)-based quantification of mutual information (MI) efficiently captures, at the individual level, the dependencies between HuR and two relevant resistance markers pERK and EGFR, and outperforms classic expression correlation coefficients. Ultimately, the validation of MI as a predictive IHC-based metric of response to our therapeutic strategy will be carried in clinical trials., Comment: 9 pages, 5 figures Corrected typos

Parental care is predicted to evolve to mitigate harsh environments, thus adaptive plasticity of care may be an important response to our climate crisis. In biparental species, fitness costs may be reduced by resolving conflict and enhancing cooperation among partners. We investigated this prediction with the burying beetle, Nicrophorus orbicollis, by exposing them to contrasting benign and harsh thermal environments. Despite measurable fitness costs under the harsh environment, sexual conflict persisted in the form of sex‐specific social plasticity. That is, females provided equivalent care with or without males, whereas males with partners deserted earlier and reduced provisioning effort. The interaction of social condition and thermal environment did not explain variation in individual behavior, failing to support a temperature‐mediated shift from conflict to cooperation. Examining selection gradients and splines on cumulative care revealed a likely explanation for these patterns. Contrary to predictions, increased care did not enhance offspring performance under stress. Rather, different components of care were under different selection regimes, with optimization constrained due to lack of coordination between parents. We suggest that the potential for parenting to ameliorate the effects of our climate crisis may depend on the sex‐specific evolutionary drivers of parental care, and that this may be best reflected in components of care.

Phenotypic responses to a novel or extreme environment are initially plastic, only later to be followed by genetic change. Whether or not environmentally induced phenotypes are sufficiently recurrent and fit to leave a signature in adaptive evolution is debated. Here, we analyse multivariate data from 34 plant reciprocal transplant studies to test: (1) if plasticity is an adaptive source of bias that makes locally adapted populations resemble the environmentally induced phenotypes of ancestors; and (2) if plasticity, standing phenotypic variation and genetic divergence align during local adaptation. Phenotypic variation increased marginally in foreign environments but, as predicted, the direction of ancestral plasticity was generally well aligned with the phenotypic difference between locally adapted populations, making plasticity appear to ‘take the lead’ in adaptive evolution. Plastic responses were sometimes more extreme than the phenotypes of locally adapted plants, which can give the impression that plasticity and evolutionary adaptation oppose each other: however, environmentally induced and locally adapted phenotypes were rarely misaligned. Adaptive fine-tuning of phenotypes – genetic accommodation – did not fall along the main axis of standing phenotypic variation or the direction of plasticity, and local adaptation did not consistently modify the direction or magnitude of plasticity. These results suggest that plasticity is a persistent source of phenotypic bias that shapes how plant populations adapt to environmental change, even when plasticity does not constrain how populations respond to selection.

Reversible 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 and sexual selection can each promote adaptation in variable environments, but their combined influence on adaptive evolution is not well understood. We propose that sexual selection can facilitate adaptation in variable environments when individuals prefer mates that produce adaptively plastic offspring. We develop this hypothesis and review existing studies showing that diverse groups display both sexual selection and plasticity in nonsexual traits. Thus, plasticity could be a widespread but unappreciated benefit of mate choice. We describe methods and opportunities to test this hypothesis and describe how sexual selection might foster the evolution of phenotypic plasticity. Understanding this interplay between sexual selection and phenotypic plasticity might help predict which species will adapt to a rapidly changing world.

Emerging plans for travel to Mars and other deep space destinations make it critical for us to understand how spaceflight affects the human brain and behavior. Research over the past decade has demonstrated two co-occurring patterns of spaceflight effects on the brain and behavior: dysfunction and adaptive plasticity. Evidence indicates the spaceflight environment induces adverse effects on the brain, including intracranial fluid shifts, gray matter changes, and white matter declines. Past work also suggests that the spaceflight environment induces adaptive neural effects such as sensory reweighting and neural compensation. Here, we introduce a new conceptual framework to synthesize spaceflight effects on the brain, S paceflight P erturbation A daptation C oupled with D ysfunction (SPACeD). We review the literature implicating neurobehavioral dysfunction and adaptation in response to spaceflight and microgravity analogues, and we consider pre-, during-, and post-flight factors that may interact with these processes. We draw several instructive parallels with the aging literature which also suggests co-occurring neurobehavioral dysfunction and adaptive processes. We close with recommendations for future spaceflight research, including: 1) increased efforts to distinguish between dysfunctional versus adaptive effects by testing brain-behavioral correlations, and 2) greater focus on tracking recovery time courses.

Plastyczność układu nerwowo-mięśniowego to trwająca całe życie zdolność do reorganizacji struktury i funkcji pod wpływem doświadczenia. Obok plastyczności związanej z rozwojem organizmu, procesami uczenia się lub odnową funkcji po uszkodzeniach, wyróżnia się plastyczność adaptacyjną, która polega na dostosowaniu właściwości neuronów i/lub włókien mięśniowych do zmienionego poziomu aktywności ruchowej. Celem niniejszego artykułu było zebranie aktualnej wiedzy na temat zmian adaptacyjnych jednostek ruchowych w oparciu o wyniki kilku serii eksperymentów wykonanych na modelach zwierzęcych. Podobieństwo struktury i mechanizmów sterowania pracą mięśni u wszystkich ssaków uzasadniają wnioskowanie na temat podobnych procesów u człowieka. W pierwszych rozdziałach prezentujemy pojęcie jednostki ruchowej, składającej się z jednego motoneuronu i grupy włókien mięśniowych unerwianych przez ten motoneuron, przedstawiamy charakterystykę histologiczną, biochemiczną i elektrofizjologiczną trzech typów jednostek (S, FR i FF) o odmiennych cechach skurczu oraz omawiamy ich udział w różnych formach wysiłku fizycznego. W kolejnych rozdziałach prezentujemy wyniki projektów badawczych, przeprowadzonych w celu odpowiedzi na pytania, w jaki sposób odmienne rodzaje treningu fizycznego (prowadzonego w celu wzrostu wytrzymałości lub zwiększenia siły), przeciążenie mięśni, unieruchomienie kończyny lub ograniczenie ruchu wpływają na cechy skurczu włókien mięśniowych oraz właściwości elektrofizjologiczne motoneuronów różnych typów jednostek ruchowych. Omówione obserwacje doświadczalne dowodzą, że plastyczność jednostek ruchowych to procesy zachodzące równolegle w neuronach i włóknach mięśniowych. W zależności od rodzaju treningu i jego intensywności oraz od czasu trwania zwiększonej lub ograniczonej aktywności ruchowej mogą one polegać na transformacji włókien mięśniowych jednego typu w inny, modulacji podstawowych cech skurczu, zmian odporności na zmęczenie, zmian pobudliwości motoneuronów, lub częstotliwości generowanych przez nie impulsów nerwowych. Zwykle jednostki ruchowe szybkie (FF i FR) wykazują większą dynamikę procesów adaptacyjnych niż jednostki wolne (S).

Prenatal auditory sensitivity occurs across taxa, and is increasingly understood as playing a significant role in broad cognitive development. Yet, until recently, the possibility that prenatal sounds may provide information for embryos to finetune their phenotypes to current environments had not been considered. Emerging evidence in birds show that parental vocalisations and sibling embryonic cues can alter individual developmental trajectories post-hatch to cope with particular threats in the environment. Here, I highlight the relevance of such ‘Acoustic Developmental Programming’ for understanding sensitive periods and adaptive plasticity. In particular, I discuss the evidence towards the existence of sensitive periods for programming by sound and the evolutionary advantages of obtaining such prenatal acoustic information.

Phenotypic plasticity is an important mechanism for plant adaptation to variable environments, and plant responses to changing climates. However, plasticity in fitness or performance traits (i.e. fecundity, biomass, growth rate) is generally not adaptive since plasticity in these traits would require low fitness or poor performance in some environments. I assessed the use of plasticity in fitness and performance traits in recent plasticity studies, and in studies where I have recently acted as a reviewer or editor. I found that approximately one third of studies include plasticity in fitness and/or performance traits in their assessment of potentially adaptive responses to environmental variability. Misinterpreting plasticity may be due the simplicity and power of plasticity to investigate adaptation to heterogeneous environments, but no guidelines of how to interpret plasticity in fitness and performance traits. This review highlights the extent of the problem of misinterpreting plasticity, and as a guide to interpreting adaptive and maladaptive plastic responses in plants.

Understanding how tree species will respond to a future climate requires reliable and quantitative estimates of intra‐specific variation under current climate conditions. We studied three 10‐year‐old common garden experiments established across a rainfall and drought gradient planted with nearly 10,000 pedunculate oak (Quercus robur L.) trees from ten provenances with known family structure. We aimed at disentangling adaptive and plastic responses for growth (height and diameter at breast height) as well as for leaf and wood functional traits related to adaptation to dry environments. We used restricted maximum likelihood approaches to assess additive genetic variation expressed as narrow‐sense heritability (h2), quantitative trait differentiation among provenances (QST), and genotype‐by‐environment interactions (GxE). We found strong and significant patterns of local adaptation in growth in all three common gardens, suggesting that transfer of seed material should not exceed a climatic distance of approximately 1°C under current climatic conditions, while transfer along precipitation gradients seems to be less stringent. Moreover, heritability reached 0.64 for tree height and 0.67 for dbh at the dry margin of the testing spectrum, suggesting significant additive genetic variation of potential use for future selection and tree breeding. GxE interactions in growth were significant and explained less phenotypic variation than origin of seed source (4% versus 10%). Functional trait variation among provenances was partly related to drought regimes at provenances origins but had moderate explanatory power for growth. We conclude that directional selection, either naturally or through breeding, is the most likely and feasible outcome for pedunculate oak to adapt to warmer and drier climate conditions in the future.

Many theoretical models predict when genetic evolution and phenotypic plasticity allow adaptation to changing environmental conditions. These models generally assume stabilizing selection around some optimal phenotype. We however often ignore how optimal phenotypes change with the environment, which limit our understanding of the adaptive value of phenotypic plasticity. Here, we propose an approach based on our knowledge of the causal relationships between climate, adaptive traits, and fitness to further these questions. This approach relies on a sensitivity analysis of the process-based model Phenofit, which mathematically formalizes these causal relationships, to predict fitness landscapes and optimal budburst dates along elevation gradients in three major European tree species. Variation in the overall shape of the fitness landscape and resulting directional selection gradients were found to be mainly driven by temperature variation. The optimal budburst date was delayed with elevation, while the range of dates allowing high fitness narrowed and the maximal fitness at the optimum decreased. We also found that the plasticity of the budburst date should allow tracking the spatial variation in the optimal date, but with variable mismatch depending on the species, ranging from negligible mismatch in fir, moderate in beech, to large in oak. Phenotypic plasticity would therefore be more adaptive in fir and beech than in oak. In all species, we predicted stronger directional selection for earlier budburst date at higher elevation. The weak selection on budburst date in fir should result in the evolution of negligible genetic divergence, while beech and oak would evolve counter-gradient variation, where genetic and environmental effects are in opposite directions. Our study suggests that theoretical models should consider how whole fitness landscapes change with the environment. The approach introduced here has the potential to be developed for other traits and species to explore how populations will adapt to climate change.

Islands present significant technological and ecological challenges for long-term human settlement, with archaeological investigations of islands globally able to shed light on the adaptive plasticity of cultural groups to changing climatic regimes. The Massim islands of eastern New Guinea significantly reduced in size throughout the Holocene (⩽11.7 kya), providing a unique opportunity to investigate the long-term adaptive capabilities of humans to changing island ecosystems. Here, we report a 2500-2300 year cultural sequence on Nimowa Island in the Louisiade Archipelago of the Massim region which began with the arrival of a late Lapita population during initial beachfront development. Sediment analyses indicate earlier settlement on the island would not have been possible as the coastline was unstable until near-modern sea levels were reached. The island was abandoned from 1290 to 530 cal. BP during a period of unusually dry conditions (‘Medieval Climate Anomaly’) and probable freshwater shortages. Re-settlement coincided with wetter climatic conditions (‘Little Ice Age’), associated with the establishment of large villages, the earliest expression of local pottery traditions and the onset of large-scale regional exchange networks. Import of non-local obsidian reflects two pulses of interaction followed by periods of increased isolation. With the absence of high-quality lithic resources, shell, coral and bone were used as a locally available alternative for tool production. Increased cyclone frequency from ~500 cal. BP greatly increased beach volume in the island and coastal New Guinea, which facilitated the movement of populations onto smaller islands. A late prehistoric shift in settlement patterns had a profound impact on regional social dynamics.

In the last few decades, the frequency and importance of invasive species has been increasing mainly due to the disproportionate growth of world trade in animals and plants. Predator-prey interactions drive the evolution of many behavioral and morphological traits in aquatic animals. In aquatic environments, chemical cues reliably enable prey to assess and avoid predation risk. The presence of a predator affects prey populations either by direct predation by reducing its abundance and changing its behavior, or by modifying various parts of its life history. The effect induced by the risk of predation can have a stronger impact on populations than the direct effect of mortality. Non-native red-eared sliders (Trachemys scripta elegans) have the potential to disrupt aquatic ecosystems in Central Europe because of their superior competitive abilities and omnivorous diets. I investigated whether continuous predator-borne cues are tied to changes in the hatching time, developmental stage, and body size at hatching of common frog tadpoles (Rana temporaria). Whether the developmental rates, growth rates and sizes at metamorphosis would alter in the presence of a predator and examined the dynamics of the ontogeny of tadpoles under different time patterns of an alien predator presence. The presence of a predator affected all factors examined. I found that in the absence of the slider, the embryos hatched in 12 days, while hatching was accelerated by two days in slider treatment. At the same time, the embryos hatched smaller and at a lower stage of development with the slider than without it. The presence of turtles shortened the time at metamorphosis of tadpoles from 110?11.7 days to 93?13.0 days (mean ? S.D.). The froglets were significantly smaller (12.8?0.99mm) in the presence of the predator than in the control treatment (15.2?1.27mm). The growth rate trajectories were similar between the predator treatment and the control. Thus, predator-induced tadpole defences were evident in higher developmental rates and smaller sizes at metamorphosis without significant changes in growth. I also found out that the tadpoles had a longer larval period and were smaller in size at metamorphosis and lower in body mass when the predator was present in early development than when the tadpoles developed without a predator. The early presence of a predator conspicuously reduced the growth increments of the tadpoles at early development. After the removal of the predator, growth accelerated above the level measured under the conditions of both the late predator and no predator. However, these growth rates did not exceed the growth rates of equally sized tadpoles in the other treatments and therefore were not sufficient to compensate for the growth slowdown in the first part of development. The presence of a predator in late tadpole development influenced neither the time to metamorphosis nor size/body mass at metamorphosis. Results show rather rarely documented types of amphibian prey responses to caged predators. This study extends the range of predators studied, including the effect on different phases of development of potential amphibian prey.

Phenotypic plasticity is a widespread phenomenon across the tree of life, with far reaching consequences for ecological and evolutionary processes. In species facing strong sexual selection and marked variation in the socio-sexual context in which they reproduce, adaptive plasticity in reproductive behaviour is expected to evolve. In this thesis, we aimed to contribute to this area of evolutionary biology research using the model organism Drosophila melanogaster. The results of this thesis offer a twist to the steadily growing literature of ageing via sensory perception by showing that socio-sexual cues so far documented to accelerate ageing mostly bear fitness benefits in ecologically relevant scenarios. This suggests that plastic responses previously documented as maladaptive may in fact be by-products of widespread adaptive plasticity. First, we found that plastic responses induced by perception of female cues, previously reported to accelerate ageing, mostly yield lifetime fitness benefits by improving male reproductive success when competing against other males. Interestingly, these lifetime fitness benefits did not appear to be driven by clear short-term effects, but rather by an accumulation of benefits of small magnitude along the life of males. Using mathematical simulations parameterised with observed empirical data, we also show that variation in population mating rate across time and/or space can be a critical determinant for the evolution of male plastic responses to the presence of female cues, which suggests that such plasticity may have evolved in other iteroparous species with similar life-history patterns as Drosophila melanogaster. In addition, we show that, because fitness returns of plastic responses depend on male condition (so that high condition males mostly reap reproductive benefits whereas low condition males are more likely to suffer reproductive and actuarial costs), such plasticity can significantly strengthen sexual selection. Finally, we found that perception of dead conspecifics, also previously reported to accelerate ageing, actually triggers highly plastic responses that are rapidly induced and can be immediately reversed, and consist of females exposed to dead conspecifics repeatedly increasing their reproductive investment, both with respect to the quantity and quality of their offspring. We suggest that such modulation of reproductive investment represents an adaptive terminal investment strategy, whereby females shift their reproductive investment towards current reproduction as they perceive a threat to their survival. Taken together, these results suggest that Drosophila uses socio-sexual cues in order to display adaptive reproductive plasticity in response to demographic fluctuations that are common in the wild. The results from this thesis hopefully contribute towards a more comprehensive understanding of adaptive plastic responses in reproductive behaviour.

Objective: Our goal was to determine if pairing transcranial direct current stimulation (tDCS) with rehabilitation for two weeks could augment adaptive plasticity offered by these residual pathways to elicit longer-lasting improvements in motor function in incomplete spinal cord injury (iSCI). Design: Longitudinal, randomized, controlled, double-blinded cohort study. Setting: Cleveland Clinic Foundation, Cleveland, Ohio, USA. Participants: Eight male subjects with chronic incomplete motor tetraplegia. Interventions: Massed practice (MP) training with or without tDCS for 2 hrs, 5 times a week. Outcome Measures: We assessed neurophysiologic and functional outcomes before, after and three months following intervention. Neurophysiologic measures were collected with transcranial magnetic stimulation (TMS). TMS measures included excitability, representational volume, area and distribution of a weaker and stronger muscle motor map. Functional assessments included a manual muscle test (MMT), upper extremity motor score (UEMS), action research arm test (ARAT) and nine hole peg test (NHPT). Results: We observed that subjects receiving training paired with tDCS had more increased strength of weak proximal (15% vs 10%), wrist (22% vs 10%) and hand (39% vs. 16%) muscles immediately and three months after intervention compared to the sham group. Our observed changes in muscle strength were related to decreases in strong muscle map volume (r=0.851), reduced weak muscle excitability (r=0.808), a more focused weak muscle motor map (r=0.675) and movement of weak muscle motor map (r=0.935). Conclusion: Overall, our results encourage the establishment of larger clinical trials to confirm the potential benefit of pairing tDCS with training to improve the effectiveness of rehabilitation interventions for individuals with SCI. Trial Registration: NCT01539109

In many species, males produce sounds to attract a female. In a chorus, males actively adjust their acoustic production depending on the presence and number of mating rivals. Plasticity in signal features might then be advantageous as males could tune their signalling activity to the contest intensity. However, the ability to exhibit plastic behaviour might be constrained and interindividual variation in plasticity can occur. In this field study, we examined the influence of body mass and social environment on the signal expression of male bushcrickets, Poecilimon veluchianus veluchianus. We tested whether differences in signal features of rivals of different body mass and number led to changes in the competition pressure perceived by focal males and, consequently, in their acoustic responses. We used the first principal component from a principal component analysis, reflecting verse duration, duty cycle and syllable number, as a measure of acoustic output. We found that the rivals' acoustic output depended only on their number, being higher for two rivals than one. However, the response of heavy focal males depended on the rivals' body mass. Contrary to what we expected, heavy males produced shorter verses with fewer syllables when competing against two heavy rivals than when competing against one or two light rivals or one heavy rival. Facing light competitors, heavy focal males responded more to two rivals than to one. In contrast, light focal males did not vary their signal features depending on competition conditions. These results indicate that body mass and social context drive interindividual variation in the capacity of P. v. veluchianus males to adjust their signal features to competition levels. We compare these findings with those previously obtained on congeneric species and discuss the outcomes' similarities and discrepancies. Lastly, we provide suggestions for future studies of socially induced plasticity in sexually selected acoustic signal features. (C) 2019 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved.

RESUMEN El músculo esquelético activo y el mantenimiento de la masa muscular son esenciales para la salud, el bienestar, la prevención y el tratamiento de enfermedades. Recientemente se ha documentado que el músculo, como órgano endocrino, es capaz de sintetizar mioquinas. Estos péptidos son secretados en respuesta a las contracciones musculares inducidas por el ejercicio, y son capaces de crear comunicación molecular con otros tejidos, beneficiando así la salud cardiovascular, metabólica y mental. La función endocrina del músculo continúa en investigación constante, sin embargo, lo conocido hasta ahora nos insta a seguir promoviendo la actividad física. Adicionalmente a esto, extender el conocimiento sobre las mioquinas, es útil para poder prescribir el ejercicio físico de manera individualizada y a la medida de cada paciente. ABSTRACT The active skeletal muscle and the maintenance of muscle mass are essential for good health, wellness and disease prevention and treatment. It has recently been documented that the muscle, as an endocrine organ, is capable of synthesizing myokines. These peptides are secreted in response to muscular contractions induced by exercise, and can develop molecular communication with other tissues, improving cardiovascular, metabolic, and mental health. The endocrine function of a muscle continues to be in a constant investigation; however, knowledge up to date urges us to continue promoting physical activity. Additionally, the extended knowledge of myokines is useful to prescribe individualized physical exercise programs to each patient.

The yeast Saccharomyces cerevisiae has a remarkable ability to adapt its lifestyle to fluctuating or hostile environmental conditions. This adaptation most often involves morphological changes such as pseudofilaments, biofilm formation, or cell aggregation in the form of flocs. A prerequisite for these phenotypic changes is the ability to self-adhere and to adhere to abiotic surfaces. This ability is conferred by specialized surface proteins called flocculins, which are encoded by the FLO genes family in this yeast species. This mini-review focuses on the flocculin encoded by FLO11, which differs significantly from other flocculins in domain sequence and mode of genetic and epigenetic regulation, giving it an impressive plasticity that enables yeast cells to swiftly adapt to hostile environments or into new ecological niches. Furthermore, the common features of Flo11p with those of adhesins from pathogenic yeasts make FLO11 a good model to study the molecular mechanism underlying cell adhesion and biofilm formation, which are part of the initial step leading to fungal infections.

The yeast Saccharomyces cerevisiae has a remarkable ability to adapt its lifestyle to fluctuating or hostile environmental conditions. This adaptation most often involves morphological changes such as pseudofilaments, biofilm formation, or cell aggregation in the form of flocs. A prerequisite for these phenotypic changes is the ability to self-adhere and to adhere to abiotic surfaces. This ability is conferred by specialized surface proteins called flocculins, which are encoded by the FLO genes family in this yeast species. This mini-review focuses on the flocculin encoded by FLO11, which differs significantly from other flocculins in domain sequence and mode of genetic and epigenetic regulation, giving it an impressive plasticity that enables yeast cells to swiftly adapt to hostile environments or into new ecological niches. Furthermore, the common features of Flo11p with those of adhesins from pathogenic yeasts make FLO11 a good model to study the molecular mechanism underlying cell adhesion and biofilm formation, which are part of the initial step leading to fungal infections.

Interactions with microbial symbionts have yielded great macroevolutionary innovations across the tree of life, like the origins of chloroplasts and the mitochondrial powerhouses of eukaryotic cells. There is also increasing evidence that host-associated microbiomes influence patterns of microevolutionary adaptation in plants and animals. Here we describe how microbes can facilitate adaptation in plants and how to test for and differentiate between the two main mechanisms by which microbes can produce adaptive responses in higher organisms: microbe-mediated local adaptation and microbe-mediated adaptive plasticity. Microbe-mediated local adaptation is when local plant genotypes have higher fitness than foreign genotypes because of a genotype-specific affiliation with locally beneficial microbes. Microbe-mediated adaptive plasticity occurs when local plant phenotypes, elicited by either the microbial community or the non-microbial environment, have higher fitness than foreign phenotypes as a result of interactions with locally beneficial microbes. These microbial effects on adaptation can be difficult to differentiate from traditional modes of adaptation but may be prevalent. Ignoring microbial effects may lead to erroneous conclusions about the traits and mechanisms underlying adaptation, hindering management decisions in conservation, restoration, and agriculture.

The cellular identity of pancreatic polypeptide (Ppy)-expressing γ-cells, one of the rarest pancreatic islet cell-type, remains elusive. Within islets, glucagon and somatostatin, released respectively from α- and δ-cells, modulate the secretion of insulin by β-cells. Dysregulation of insulin production raises blood glucose levels, leading to diabetes onset. Here, we present the genetic signature of human and mouse γ-cells. Using different approaches, we identified a set of genes and pathways defining their functional identity. We found that the γ-cell population is heterogeneous, with subsets of cells producing another hormone in addition to Ppy. These bihormonal cells share identity markers typical of the other islet cell-types. In mice, Ppy gene inactivation or conditional γ-cell ablation did not alter glycemia nor body weight. Interestingly, upon β-cell injury induction, γ-cells exhibited gene expression changes and some of them engaged insulin production, like α- and δ-cells. In conclusion, we provide a comprehensive characterization of γ-cells and highlight their plasticity and therapeutic potential.

There are many theoretical models that attempt to accurately and consistently link kinematic and kinetic information to musculoskeletal pain and deformity of the foot. Biomechanical theory of the foot lacks a consensual model: clinicians are enticed to draw from numerous paradigms, each having different levels of supportive evidence and contrasting methods of evaluation, in order to engage in clinical deduction and treatment planning. Contriving to find a link between form and function lies at the heart of most of these competing theories and the physical nature of the discipline has prompted an engineering approach. Physics is of great importance in biology and helps us to model the forces that the foot has to deal with in order for it to work effectively. However, the tissues of the body have complex processes that are in place to protect them and they are variable between individuals. Research is uncovering why these differences exist and how these processes are governed. The emerging explanations for adaptability of foot structure and musculoskeletal homeostasis offer new insights into how clinical variation in outcomes and treatment effects might arise. These biological processes underlie how variation in the performance and use of common traits, even within apparently similar subgroups, make anatomical distinction less meaningful and are likely to undermine the justification of a “foot type.” Furthermore, mechanobiology introduces a probabilistic element to morphology based on genetic and epigenetic factors.

Synedrella nodiflora is an invasive species originated from tropical America and now has spread throughout Indonesia. We analysed the ability of Synedrella nodiflora from the level of HSP70 gene expression at different heat stress in urban tropical lowland landscape Universitas Indonesia. We used the qPCR to quantify the level of HSP70 gene expression and analysed using Pfaffl model. We found the level of HSP70 gene expression got higher related to elevated temperature from 29oC to 39oC with a range of fold from 123.1 to 1676.9. This ability reflects the adaptive plasticity of Synedrella nodiflora in the course of the invasion process.

Better understanding of the mechanistic basis of plant plasticity will enhance efforts to breed crops resilient to predicted climate change. However, complexity in plasticity's conceptualisation and measurement may hinder fruitful crossover of concepts between disciplines that would enable such advances. We argue active adaptive plasticity is particularly important in shaping the fitness of wild plants, representing the first line of a plant's defence to environmental change. Here, we define how this concept may be applied to crop breeding, suggest appropriate approaches to measure it in crops, and propose a refocussing on active adaptive plasticity to enhance crop resilience. We also discuss how the same concept may have wider utility, such as in ex situ plant conservation and reintroductions., Trends in Plant Science, 27 (7), ISSN:1360-1385, ISSN:1878-4372

In many species, males can rapidly adjust their ejaculate performance in response to changing levels of sperm competition, an ability that is probably mediated by seminal fluid adaptive plasticity. In the black goby, Gobius niger , territorial males attach viscous ejaculate trails to the nest roof, from which sperm are slowly released into the water during the long-lasting spawning events. Sneaker males release their sperm in the vicinity of the nest, and territorial males try to keep them at a distance by patrolling their territory. We show here that territorial males' ejaculate trails released a higher proportion of their sperm in the presence of a single sneaker, but this proportion decreased when there were three sneakers, an effect that is most likely mediated by a change in the seminal fluid composition. Field observations showed that when multiple sneaking attempts occurred, territorial males spent more time outside the nest, suggesting that ejaculation rate and territory defence are traded-off. Altogether, these results suggest that the adjustment of sperm release from the ejaculate may be strategic, guaranteeing a more continuous concentration of the territorial male's sperm in the nest, although at a lower level, when he is engaged in prolonged territory defence outside the nest.

Climate warming is predicted to shift species’ ranges as previously uninhabitable environments just beyond the leading range edges become suitable habitat and trailing range edges become increasingly unsuitable. Understanding which aspects of the environment and species traits mediate these range shifts is critical for understanding species’ possible redistributions under global change, yet we have a limited understanding of the ecological and evolutionary responses underlying population spread or extinction at species’ range edges. Within plant populations, shifts in flowering phenology have been one of the strongest and most consistent responses to climate change, and are likely to play an important role in mediating population dynamics within and beyond species’ ranges. However, the role of phenological shifts, and particularly phenological plasticity, in species’ range shifts remains relatively unstudied. Here, we synthesize literature on phenology, plasticity, and adaptation to suggest ways in which phenological responses to climate may vary across species’ ranges and review the empirical evidence for and against these hypotheses. We then outline how phenological plasticity could facilitate or hinder persistence and potential consequences of phenological plasticity in range expansions, including phenological cues, shifts in correlated traits, altered species interactions, and effects on gene flow. Finally, we suggest future avenues for research, such as characterizing reaction norms for phenology across a species’ range and in beyond-the-range transplant experiments. Given the prevalence and magnitude of phenological shifts, future work should carefully dissect its costs and benefits for population persistence, and incorporate phenological plasticity into models predicting species’ persistence and geographic range shifts under climate change.

Phenotypic plasticity is a potentially definitive solution to environment heterogeneity, driving biologists to understand why it is not ubiquitous in nature. While costs and constraints may limit the success of plasticity, we are still far from a complete theory of when these limitations actually proscribe adaptive plasticity. Here I use a simple model of plasticity incorporating developmental noise to explore the competitive and evolutionary relationships of specialist and generalist genotypes spreading across a heterogeneous landscape. Results show that plasticity can arise in the context of specialism, preadapting genotypes to later evolve toward plastic generalism. Developmental noise helps a mutant with imperfect plasticity successfully compete against its ancestor, providing an evolutionary path by which subsequent mutations can refine plasticity toward its optimum. These results address how the complex selection pressures across a heterogeneous environment can help evolution find paths around constraints arising from developmental mechanisms.

Theoretical research has outlined how selection may shape both genetic variation and the expression of phenotypic plasticity in multivariate trait space. Specifically, research regarding the evolution of patterns of additive genetic variances and covariances (summarized in matrix form as G) and complementary research into how selection may shape adaptive plasticity lead to the general prediction that G, plasticity, and selection surfaces are all expected to align with each other. However, less well discussed is how this prediction might be assessed and how the modeled theoretical processes are expected to manifest in actual populations. Here, we discuss the theoretical foundations of the overarching prediction of alignment, what alignment mathematically means, how researchers might test for alignment and important caveats to this testing. The most important caveat concerns the fact that, for plasticity, the prediction of alignment only applies to cases where plasticity is adaptive, whereas organisms express considerable plasticity that may be neutral or even maladaptive. We detail the ramifications of these alternative expressions of plasticity vis-à-vis predictions of alignment. Finally, we briefly highlight some important interpretations of deviations from the prediction of alignment and what alignment might mean for populations experiencing environmental and selective changes.

This work was supported by the University of Exeter through an Exeter Graduate Fellow studentship.

The article presents materials about the rearing of Siberian sturgeon from the Lena population (Acipenser Baerii Brandt) in the conditions of the northern regions. It is noted that, despite the difficult climatic conditions of the European North, the biological and reproductive features of the Siberian sturgeon make it possible to effectively grow sturgeon to marketable sizes, as well as to obtain high quality sexual products and stocking material. The use of Siberian sturgeon in the aquaculture of the North is quite relevant, as it has a high adaptive plasticity, can be grow in a wide temperature range, characterized by good product performance (fast growth, low feed costs, high survival). When creating optimal conditions in fish farms, this species shows considerable potential and shows high grow efficiency. Analysis of fish breeding, biological and economic indicators of growing Siberian sturgeon showed that it has high values of survival (over 95%) and growth rate when using different methods of rearing. Also analyzed the costs of growing marketable fish in cages, established natural reservoirs and in closed recirculating systems (CRS). With using these methods, the cost structure is different, but both technologies allow obtaining products with a high payback level. The reproductive indices of the Siberian sturgeon ripened in the conditions of the North were estimated and it was noted that the females have very high values of working fertility, gametosomatic indices and the mass of eggs. This testifies to the high quality of Siberian sturgeon producers which grown and kept in the natural water bodies of the Northern regions. The comprehensive evaluation of the Siberian sturgeon growing has shown a high efficiency of this object using in the aquaculture of the European North.

The brain changes in response to sensory signals it is exposed to. It has been shown that long term potentiation-like neuroplasticity can be experimentally induced via visual paired-associative stimulation (V-PAS). V-PAS combines afferent visual stimuli with a transcranial magnetic stimulation pulse to induce plasticity. Preparation of a reaching movement to generate activity in superior parietal occipital cortex (SPOC) was used in this study as an additional afferent contributor to modulate the resultant plasticity. We hypothesized that V-PAS with a reaching movement would induce greater cortical excitability than V-PAS alone and would exhibit facilitated SPOC to M1 projections. All four experiments enrolled groups of 10 participants to complete variations of V-PAS in a repeated measures design. SPOC to M1 projections facilitated motor cortex excitability following V-PAS regardless of intervention received. We did not observe evidence indicating extra afferent information provided an additive effect to participants. Investigation of PMd to M1 projections confirmed disinhibition and suggested interneuronal populations within M1 may be mechanistically involved. Future research should look to rule out the existence of an upper limit for effective afference during V-PAS and investigate the average influence of V-PAS on cortical excitability in the larger population.

Phenotypic plasticity, or an organism’s capacity to change its phenotype in response to environmental variation, is a pervasive—perhaps even ubiquitous—feature of the biological world. Accordingly, plasticity research suggests serious implications for biological theory, including evolutionary theory. The theoretical implications of plasticity have growing support from empirical literature documenting the range, extent, and adaptiveness of plasticity. However, the empirical evidence for particular instances of plasticity has still not been adequately scrutinized by biologists or philosophers. After reviewing some important conceptual and theoretical background information, this paper synthesizes some past discussions of the methodology of plasticity studies and provides some novel methodological guidance for plasticity researchers. My conclusion is that not all plasticity studies should carry the same weight: there are patterns we can identify in the features of such studies that should contribute to (or detract from) their credibility. In particular, I argue that some types of organisms and some types of plastic phenotypes are more conducive to the empirical study of plasticity than others.

The Southwestern North America megadrought is an extreme climate event. Artemisia tridentata (big sagebrush) is the dominant, keystone species of sagebrush-steppe ecosystems in arid and semi-arid habitats of western North America. I conducted a genotype-by-environment (GxE) experiment on two putative genotypes (drought-tolerant, G1 and drought-sensitive, G2) and two cytotypes, diploid (2x) and tetraploid (4x), to determine the phenotypic responses of big sagebrush seedlings to drought. For three chlorophyll fluorescence parameters, my results indicate a complex set of factors influence sagebrush responses to drought, including canalization, adaptive phenotypic plasticity, cryptic genetic diversity, and GxE interactions. Variation in leaf temperature profiles of sagebrush seedlings is exclusively driven by treatment effects, suggesting that variation for this trait is determined by non-adaptive phenotypic plasticity. I did not detect significant treatment effects for root to shoot (R:S) length ratios for 2x and 4x families exposed to drought, although I did detect significant differences among G1 and G2 genotypes of both cytotypes. Tetraploid seedlings significantly outperformed 2x seedlings for R:S length ratios across all three watering treatments. My results indicate that sagebrush populations differ in their capacity to respond to megadrought; thus, proper sourcing of seeds for restoration efforts should account for the genotypes and cytotypes of populations.

Intense solar radiation in desert ecosystems drives adaptation in cacti. Several Mojave Desert members of the cactus genus Cylindropuntia may exhibit morphological adaptations to reduce the impact of solar irradiation, such as light-blocking spines and the ability to point their new growth parallel to the sun’s rays. To detect adaptive morphologies in three Cylindropuntia species, we measured the orientation, spine density, and pigmentation of the new growth on the southwest and northeast sides of the plant. Additionally, we took morphometric measurements such as segment size to better understand how cacti allocate their resources and growth to cope with the sun. We found that two species of Cylindropuntia (C. echinocarpa and C. acanthocarpa) cacti do grow in line with the sun’s rays. We found no relationship between spine coverage and side of plant across all three species. For C. ramosissima, which bore the least number of spines on each of its segments, the results of damaging UV rays were frequently apparent in the form of stem-flattening somatic meristem mutations, despite their apparent investment in other pigment-based forms of defense. Two Cylindropuntia species display adaptive orientation but likely do not use spine density to avoid solar radiation. These results suggest that segment orientation is a more plastic trait than spine coverage in Cylindropuntia., CEC Research Volume 5, Issue 2

Interactions with microbial symbionts have yielded great macroevolutionary innovations across the tree of life, like the origins of chloroplasts and the mitochondrial powerhouses of eukaryotic cells. There is also increasing evidence that host-associated microbiomes influence patterns of microevolutionary adaptation in plants and animals. Here we describe how microbes can facilitate adaptation in plants and how to test for and differentiate between the two main mechanisms by which microbes can produce adaptive responses in higher organisms: microbe-mediated local adaptation and microbe-mediated adaptive plasticity. Microbe-mediated local adaptation is when local plant genotypes have higher fitness than foreign genotypes because of a genotype-specific affiliation with locally important microbes. Microbe-mediated adaptive plasticity occurs when local plant phenotypes have higher fitness than foreign phenotypes as a result of interactions with locally important microbes. These microbial effects on adaptation can be difficult to differentiate from traditional modes of adaptation but may be prevalent. Ignoring microbial effects may lead to erroneous conclusions about the traits and mechanisms underlying adaptation, hindering management decisions in conservation, restoration, and agriculture.

Biological evolution exhibits an extraordinary capability to adapt organisms to their environments. The explanation for this often takes for granted that random genetic variation produces at least some beneficial phenotypic variation for natural selection to act on. Such genetic evolvability could itself be a product of evolution, but it is widely acknowledged that the immediate selective gains of evolvability are small on short timescales. So how do biological systems come to exhibit such extraordinary capacity to evolve? One suggestion is that adaptive phenotypic plasticity makes genetic evolution find adaptations faster. However, the need to explain the origin of adaptive plasticity puts genetic evolution back in the driving seat, and genetic evolvability remains unexplained. To better understand the interaction between plasticity and genetic evolvability, we simulate the evolution of phenotypes produced by gene-regulation network-based models of development. First, we show that the phenotypic variation resulting from genetic and environmental change are highly concordant. This is because phenotypic variation, regardless of its cause, occurs within the relatively specific space of possibilities allowed by development. Second, we show that selection for genetic evolvability results in the evolution of adaptive plasticity andvice versa. This linkage is essentially symmetric but, unlike genetic evolvability, the selective gains of plasticity are often substantial on short, including within-lifetime, timescales. Accordingly, we show that selection for phenotypic plasticity is, in general, the most efficient and results in the rapid evolution of high genetic evolvability. Thus, without overlooking the fact that adaptive plasticity is itself a product of genetic evolution, this shows how plasticity can influence adaptive evolution and helps explain the genetic evolvability observed in biological systems.

The extracranial and intracranial circulations are richly interconnected at numerous locations, a functional connectivity which underlies their impressive capacity for adaptive plasticity in the setting of vasoocclusive disease. While evolutionarily beneficial, these connections can also result in inadvertent communication with the intracranial circulation during embolization of extracranial vessels, potentially resulting in stroke or cranial nerve palsy. While these anastomoses are always present to a certain extent, flow through them occurs under predictable circumstances, and thus embolization of the extracranial vasculature can be performed safely when knowledge of functional anatomy is combined with adherence to basic principles. Herein, we will review the anatomy of known extracranial–intracranial anastomoses and strategies for avoidance of unwanted intracranial embolization. We will also review the vascular supply to cranial nerves most at risk during common neurointerventional procedures, as well as blood supply to mucosal structures.

Following an injury to the central nervous system (CNS), spontaneous plasticity is observed throughout the neuraxis and affects multiple key circuits. Much of this spontaneous plasticity can elicit beneficial and deleterious functional outcomes, depending on the context of plasticity and circuit affected. Injury-induced activation of the neuroimmune system has been proposed to be a major factor in driving this plasticity, as neuroimmune and inflammatory factors have been shown to influence cellular, synaptic, structural, and anatomical plasticity. Here, we will review the mechanisms through which the neuroimmune system mediates plasticity after CNS injury. Understanding the role of specific neuroimmune factors in driving adaptive and maladaptive plasticity may offer valuable therapeutic insight into how to promote adaptive plasticity and/or diminish maladaptive plasticity, respectively.

Background In species with complex life cycles, size at metamorphosis is a key life-history trait which reflects the complex interactions between costs and benefits of life in the aquatic and terrestrial environments. Whereas the effects of a deteriorating larval habitat (e.g. pond desiccation) on triggering an early metamorphosis have been extensively investigated in amphibians, the consequences of the resulting reduced size at metamorphosis on fitness in the post-metamorphic terrestrial stage remain poorly understood. We tested the hypothesis that a smaller size at metamorphosis negatively affects performance and survival in the ensuing terrestrial stage. Using as model a tropical amphibian (Ceratophrys stolzmanni) showing a large phenotypic plasticity in metamorphosing traits, we evaluated the effects of size at metamorphosis on fitness-related trophic and locomotor performance traits, as well as on growth and survival rates. Results Our results support the hypothesis that a larger size at metamorphosis is correlated with better survival and performance. The survival rate of large metamorphosing individuals was 95%, compared to 60% for those completing metamorphosis at a small size. Locomotor performance and gape size were positively correlated with body size, larger animals being more mobile and capable to ingest larger prey. However, smaller individuals achieved higher growth rates, thus reducing the size gap. Conclusions Overall, size at metamorphosis affected profoundly the chances of survival in the short term, but smaller surviving individuals partly compensated their initial disadvantages by increasing growth rates.

Males of many species evolved the capability of adjusting their ejaculate phenotype in response to social cues to match the expected mating conditions. When females store sperm for a prolonged time, the expected fitness return of plastic adjustments of ejaculate phenotype may depend on the interval between mating and fertilization. Although prolonged female sperm storage (FSS) increases the opportunity for sperm competition, as a consequence of the longer temporal overlap of ejaculates from several males, it may also create variable selective forces on ejaculate phenotype, for example by exposing trade-offs between sperm velocity and sperm survival. We evaluated the relationship between the plasticity of ejaculate quality and FSS in the guppy, Poecilia reticulata, a polyandrous live-bearing fish in which females store sperm for several months and where stored sperm contribute significantly to a male's lifelong reproductive success. In this species, males respond to the perception of future mating opportunities by increasing the quantity (number) and quality (swimming velocity) of ready-to-use sperm (an anticipatory response called 'sperm priming'). Here we investigated (a) the effect of sperm priming on in vitro sperm viability at stripping and its temporal decline (as an estimate of sperm survival), and (b) the in vivo competitive fertilization success in relation to female sperm storage using artificial insemination. As expected, sperm-primed males produced more numerous and faster sperm, but with a reduced in vitro sperm viability at stripping and after 4 hr, compared with their counterparts. Artificial insemination revealed that the small (nonsignificant) advantage of primed sperm when fertilization immediately follows insemination is reversed when eggs are fertilized by female-stored sperm, weeks after insemination. By suggesting a plastic trade-off between sperm velocity and viability, these results demonstrate that prolonged female sperm storage generates divergent selection pressures on ejaculate phenotype.

Phenotypic responses to a novel or extreme environment are initially plastic, only later to be followed by genetic change. Whether or not environmentally induced phenotypes are sufficiently recurrent and fit to leave a signature in adaptive evolution is debated. Here, we analyze multivariate data from 34 plant reciprocal transplant studies to test: (1) if plasticity is an adaptive source of developmental bias that makes locally adapted populations resemble the environmentally induced phenotypes of ancestors; and (2) if plasticity, standing phenotypic variation and genetic divergence align during local adaptation. Phenotypic variation increased marginally in foreign environments but, as predicted, the direction of ancestral plasticity was generally well aligned with the phenotypic difference between locally adapted populations, making plasticity appear to "take the lead" in adaptive evolution. Plastic responses were sometimes more extreme than the phenotypes of locally adapted plants, which can give the impression that plasticity and evolutionary adaptation oppose each other; however, environmentally induced and locally adapted phenotypes were rarely misaligned. Adaptive fine-tuning of phenotypes—genetic accommodation—did not fall along the main axis of standing phenotypic variation or the direction of plasticity, and local adaptation did not consistently modify the direction or magnitude of plasticity. These results suggest that plasticity is a persistent source of developmental bias that shapes how plant populations adapt to environmental change, even when plasticity does not constrain how populations respond to selection.