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Generalist mice are key species for the long-term dynamics of fragmented forests due to their dual role as seed dispersers or predators of the dominant trees. Wood mice, Apodemus sylvaticus, usually act as a net predator in woodlots due to higher winter densities and earlier winter reproduction than in forests. Here we analyze the recruitment expectations of young mice born in woodlots in relation to food availability through an index of developmental stability that combined values of fluctuating asymmetry (FA) for six traits of the lower mandibles. FA was measured in young and adult mice caught at the end of the winter in control woodlots, food-supplemented woodlots and in a nearby large forest. Despite low sample sizes (n = 9 for young and n = 74 for adults), FA in young mice born in control woodlots were significantly higher than in those from food-supplemented woodlots and the forest and in all adults. Food limitation in woodlots was thus associated with increased developmental instability of young mice, but it had no effect on adults. Instability likely reduced the survival prospects of young mice through increased mortality, and this should be compensated by yearly recolonization of woodlots by adults from the agricultural matrix in autumn and winter. Future work analyzing mechanisms suggested here but using non-lethal methods will be important to clarify the impacts of FA on the population dynamics of wood mice., This paper is a contribution to the Spanish-funded projects RiskDisp (CGL2009-08430; 2010–2012) and VULGLO (CGL2010e22180-C03e03; 2011–2013); all them have ended long time ago.

The heterogeneity of grain quality can lead to limited predictability of qualitative and quantitative characteristics of the wheat yield, especially with an increase in the importance of drought and salinity caused by climate change. This study was undertaken with the aim of creating basic tools for phenotyping and assessing the sensitivity of genotypes to salt effects at the level of some wheat kernel attributes. The study considers 36 variants of the experiment, including four wheat cultivars—Zolotaya, Ulyanovskaya 105, Orenburgskaya 10, Orenburgskaya 23; three treatment variants—control (without salt) and two salts exposure (NaCl at a concentration of 1.1 g L−1 and Na2SO4 at a concentration of 0.4 g L−1); as well as three options for the arrangement of kernels in a simple spikelet—left, middle, and right. It has been established that the salt exposure had a positive effect on the percentage of kernel fulfilling in the cultivars Zolotaya, Ulyanovskaya 105, and Orenburgskaya 23 compared to control. The kernels of the Orenburgskaya 10 variety matured better in the experiment with Na2SO4 exposure, while the control variant and NaCl gave the same effect. When exposed to NaCl, significantly greater values of weight, transverse section area, and transverse section perimeter of the kernel were noted in the cv Zolotaya and Ulyanovskaya 105. Cv Orenburgskaya 10 responded positively to the use of Na2SO4. This salt caused an increase in the area, length, and width of the kernel. The fluctuating asymmetry of the left, middle, and right kernels in the spikelet was calculated. In the cv Orenburgskaya 23 the salts affected only the kernel perimeter among parameters examined. The indicators of the general (fluctuating) asymmetry were lower in the experiments with the use of salts, i.e., kernels were more symmetrical than in the control variant, both for the cultivar as a whole and when compared taking into account the kernel location in spikelet. However, this result was unexpected, since salt stress inhibited a number of morphological parameters: the number and average length of embryonic, adventitious, and nodal roots, flag leaf area, plant height, dry biomass accumulation, and plant productivity indicators. The study showed that low concentrations of salts can positively affect the fulfilling of kernels (the absence of a cavity inside the kernel) and the symmetry of the left and right sides of the kernel.

In this paper, we assess the environmental impact of urbanization in three freshwater biotopes, using the levels of fluctuating asymmetry (FA) in 10 meristic morphological traits in the Marsh Frog (Pelophylax ridibundus (Pallas, 1771)). Two of the studied biotopes are located in the boundaries of the city of Plovdiv (one in the central part, the other in a suburban residential area), and the third is located in the vicinity of the village of Orizare. Our working hypothesis is based on the assumption that urban and suburban sites are more severely affected by human activities than rural sites. However, according to our results, the population of P. ridibundus inhabiting Maritsa River in the central part of Plovdiv City, and that in the suburban zone, have found relatively good living conditions. Contrary to our expectations, the worst environmental conditions were observed in the rural zone, where anthropogenic stress related to intensive pastoral animal husbandry and crop farming was present. The absence of adult individuals in the rural site is also an indicator of unfavorable living conditions.

Habitat fragmentation influences leaf morphology, quantity and quality of plant resources to herbivores, which in turn affects the patterns of fluctuating asymmetry and herbivory in Quercus deserticola. Forest fragmentation has negative effects on biodiversity by modifying environmental conditions, ecological processes and biotic interactions. We analyzed the effects of forest fragment size and habitat type (forest edge × interior) on the amount of plant resources and their quality for herbivores, leaf morphology, fluctuating asymmetry (FA) and herbivory on Quercus deserticola at the Cuitzeo Basin in Mexico. Six forest fragments, where Q. deserticola occurs were classified as (i) small (≤ 10 ha); (ii) medium (≥ 25 ha); and (iii) large (≥ 65 ha). In each forest fragment, four parallel transects of 5 × 50 m were sampled, two located at the edge and two in the interior of the fragments. Chlorophyll content, leaf area, canopy cover and tree size were greater in small than in larger fragments. Leaves of individuals in small fragments and in forest edges were more elongated and wider than in large and in the interior of fragments. Our results also showed higher levels of FA and insect herbivory in the small fragments and forest edges. Insect herbivory was positively correlated with FA in small forest fragments, indicating that the mechanisms driving their interaction are scale-dependent and vary among habitat types according to fragment size. Our findings do not support the idea that the fluctuating asymmetry is a reliable biomarker to detect environmental stress in Q. deserticola in fragmented habitats, but FA may be a good biomarker of plant stress caused by the amount of herbivory damage.

Fluctuating asymmetries (FA) are small stress-induced random deviations from perfect symmetry that arise during the development of bilaterally symmetrical traits. One of the factors that can reduce developmental stability of the individuals and cause FA at a population level is the loss of genetic variation. Populations of founding colonists frequently have lower genetic variation than their ancestral populations that could be reflected in a higher level of FA. The European starling (Sturnus vulgaris) is native to Eurasia and was introduced successfully in the USA in 1890 and Argentina in 1983. In this study, we documented the genetic diversity and FA of starlings from England (ancestral population), USA (primary introduction) and Argentina (secondary introduction). We predicted the Argentinean starlings would have the highest level of FA and lowest genetic diversity of the three populations. We captured wild adult European starlings in England, USA, and Argentina, measured their mtDNA diversity and allowed them to molt under standardized conditions to evaluate their FA of primary feathers. For genetic analyses, we extracted DNA from blood samples of individuals from Argentina and USA and from feather samples from individuals from England and sequenced the mitochondrial control region. Starlings in Argentina showed the highest composite FA and exhibited the lowest haplotype and nucleotide diversity. The USA population showed a level of FA and genetic diversity similar to the native population. Therefore, the level of asymmetry and genetic diversity found among these populations was consistent with our predictions based on their invasion history.

Contrary to conventional agriculture, organic farming, where agrochemicals are entirely avoided, is considered more environmentally friendly. Numerous studies undertaken in agroecosystems have found that the intensification of agriculture has a negative impact on some small mammals species. In this study, we used two morphological indicators to evaluate the impact of agriculture intensification. Phenotypic variability and fluctuating asymmetry (FA- development instability proxy) have been widely used as morphological indicators of developmental stress. We implemented geometric morphometric methods to assess the influence of different agricultural farming systems on three rodent species. We hypothesize that conventional farming produces more stressful conditions than organic farming affecting species susceptible to agricultural intensification. We predicted that Akodon azarae, negatively affected by landscape simplification and more dependent on habitat quality, will show higher levels of phenotypic variation and greater FA in conventional farming. Whereas, Calomys musculinus and C. laucha, unaffected by agricultural intensification, will not show differences between farming systems. Akodon azarae exhibited higher phenotypic variability in conventional farms, while C. musculinus had no difference between farming systems. Contrarily, C. laucha exhibited higher values in conventional farms. Regarding FA, both Calomys species showed no differences between farming systems. Females of A. azarae tend to have higher FA values in conventional farming. Our results suggest that the effect of agricultural farming systems would vary according to the species, where the species most dependent on habitat quality would be more affected by intensive agriculture.

Evidence for selective disadvantages of large body size remains scarce in general. Previous studies of the yellow dung fly Scathophaga stercoraria have demonstrated strong positive sexual and fecundity selection on male and female size. Nevertheless, the body size of flies from a Swiss study population has declined by ~10% 1993–2009. Given substantial heritability of body size, this negative evolutionary response of an evidently positively selected trait suggests important selective factors being missed. An episodic epidemic outbreak of the fungus Entomophthora scatophagae permitted assessment of natural selection exerted by this fatal parasite. Fungal infection varied over the season from ~50% in the cooler and more humid spring and autumn to almost 0% in summer. The probability of dying from fungal infection increased with adult fly body size. Females never laid any eggs after infection, so there was no fungus effect on female fecundity beyond its impact on mortality. Large males showed their typical mating advantage in the field, but this positive sexual selection was nullified by fungal infection. Mean fluctuating asymmetry of paired appendages (legs, wings) did not affect the viability, fecundity or mating success of yellow dung flies in the field. This study documents rare parasite-mediated disadvantages of large-sized flies in the field. Reduced ability to combat parasites such as Entomophthora may be an immunity cost of large body size in dung flies, although the hypothesized trade-off between fluctuating asymmetry, a presumed indicator of developmental instability and environmental stress, and immunocompetence was not found here.

The expansion of urban environments and how animals may be affected by them are being increasingly investigated, leading to a surge in urban ecology studies. Many urban ecology studies involve a direct comparison between rural and urban populations, or the use of urban gradients along a continuum from rural to urban areas. The implicit, although not properly investigated, assumption in these rural vs urban comparisons is that the rural populations offer a control that represents a lack of the anthropogenic stressors affecting the urban populations. Here we used museum skulls from 14 rodent species to conduct two separate studies, measuring fluctuating asymmetry (FA) as a proxy of developmental stress to assess the effect of anthropogenic disturbance. First, we compared urban and rural specimens of Mus musculus (house mouse) to validate our methodological approach. Second, we compared rural specimens from 14 rodent species collected during the last two centuries across Austria. We hypothesised that FA in rural populations has not increased over the last two centuries, which would support the use of rural populations as a proper control in rural vs urban comparisons. We found higher morphological asymmetry in urban populations of Mus musculus compared to rural populations, which is consistent with similar studies in other species. However, we did not find any significant increase in FA over time in rural populations for any of the studied species. This offers some support to the common practice of using rural populations as a control in rural vs urban comparisons when assessing the effects of urbanisation.

Loss of developmental stability can lead to deviations from bilateral symmetry (i.e. Fluctuating Asymmetry ‐ FA), and is thought to be caused by environmental and genetic factors associated with habitat loss and stress. Therefore, levels of FA might be a valuable tool to monitor wild populations if FA serves as an indicator of exposure to stress due to impacts of habitat loss and fragmentation. In studies examining FA and habitat fragmentation, FA levels are often explained by loss of genetic variation, though few studies have addressed FA’s use as indicator of environmental impact. Here, we investigated whether habitat loss, genetic variation, and/or inbreeding affect the developmental instability in Brazilian Atlantic forest populations of a Neotropical water rat (Nectomys squamipes). We sampled individuals from eight sites within Atlantic forest remnants with different amounts of available forest habitat and assessed FA levels with geometric morphometric techniques using adult mandibles. We used observed heterozygosity (Ho) and inbreeding coefficient (Fis), from seven microsatellite markers, as a proxy of genetic variation at individual and population levels. Populations were not significantly different for shape or size FA levels. Furthermore, interindividual variation in both shape and size FA levels and interpopulational differences in size FA levels were best explained by chance. However, habitat amount was negatively associated with both interpopulational variance and average shape FA levels. This association was stronger in populations living in areas with, We used geometric morphometric data to asses whether fluctuating asymmetry (FA) on mandibles of Neotropical water rats (Nectomys squamipes) from eight sites within Brazilian Atlantic forest remnants would be related to habitat amount, genetic diversity, and/or inbreeding on individual and populational level. FA might be a valuable tool to monitor wild populations, as it might serve as an indicator of exposure to stress due to impacts of habitat loss and fragmentation. We used observed heterozygosity and inbreeding coefficient from seven microsatellite markers, as a proxy of genetic variation. We found that habitat availability rather than genetic or biological factors was negatively associated with both inter‐populational variance and average shape FA levels, which are higher in populations living in areas with

Fluctuating asymmetry (FA), defined as the random difference between two sides of a bilaterally symmetrical character, is often used to monitor biological populations in altered habitats. We aimed to compare the values of FA for wing and tarsi of three bird species (Antilophia galeata, Myiothlypis flaveola and Basileuterus culicivorus) in areas with different environmental stresses and to analyze their potential use as biomonitors. The birds were captured between March 2010 and March 2011, in seven forest fragments. In areas of high environmental stress, FA was higher for the wings of A. galeata and M. flaveola and the tarsi of B. culicivorus. FA depends on the functional importance of the character for each species. Thus, this study demonstrated that FA in wings and tarsi is a useful tool to assess the quality of the Brazilian Savanna (Cerrado) forest habitat.

We measured gill slit fluctuating asymmetry (FA), a measure of developmental noise, in adults of three invertebrate deuterostomes with different feeding modes: the cephalochordate Branchiostoma floridae (an obligate filter feeder), the enteropneusts Protoglossus graveolens (a facultative filter feeder/deposit feeder) and Saccoglossus bromophenolosus (a deposit feeder). FA was substantially and significantly low in B. floridae and P. graveolens and high in S. bromophenolosus. Our results suggest that the gills of species that have experienced a relaxation of the filter feeding trait exhibit elevated FA. We found that the timing of development of the secondary collagenous gill bars, compared to the primary gill bars, was highly variable in P. graveolens but not the other two species, demonstrating an independence of gill FA from gill bar heterochrony. We also discovered the occasional ectopic expression of a second set of paired gills posterior to the first set of gills in the enteropneusts and that these were more common in S. bromophenolosus. Moreover, our finding that gill slits in enteropneusts exhibit bilateral symmetry suggests that the left‐sidedness of larval cephalochordate gills, and the directional asymmetry of Cambrian stylophoran echinoderm fossil gills, evolved independently from a bilaterally symmetrical ancestor., We measured gill slit fluctuating asymmetry (FA) and developmental stability, in three species of invertebrate deuterostomes with different feeding modes: the cephalochordate Branchiostoma floridae (an obligate filter feeder), and the enteropneusts Protoglossus graveolens (a facultative filter feeder/deposit feeder) and Saccoglossus bromophenolosus (a deposit feeder). Our results suggest that the gills of species that have experienced a relaxation of the filter feeding trait exhibit elevated FA and developmental noise.

Genetic and environmental disturbances are expected to increase developmental instability, which may result in higher fluctuating asymmetry (FA), i.e. small random deviations from symmetry. Plant leaves often do not show this pattern, possibly due to high phenotypic plasticity of leaf shape and low adaptive significance of leaf symmetry. In contrast, symmetry in many animal traits but also in flower shape is considered to be under selection, and FA in such traits may better reflect developmental instability. Using geometric morphometrics, I analysed the symmetry of flowers of inbred and outbred Mimulus guttatus (Phrymaceae) plants grown under five stress treatments with and without grass competition. Flower FA was not increased by abiotic stress, but by inbreeding and competition. As inbreeding and competition affected different principal components of flower FA, different mechanisms may be involved in their effects on FA. FA decreased with individual biomass particularly in selfed offspring, which suggests that inbreeding increased FA particularly when growth was limited by environmental or genetic constraints. Increased flower FA of inbred offspring may explain increased flower handling time and reduced pollinator preference for inbred plants in other M. guttatus studies, and could thus have important consequences for plant demography and plant–pollinator interactions.

The stability of development (in terms of the fluctuating asymmetry of leaf measurements) was studied in populations of the silver birch Betula pendula from different parts of the range under varying degrees of anthropogenic impact (under the influence of industrial facilities in the territory of Khakassia and the Belgorod region and in the urbanized environment in Yoshkar-Ola, Yakutsk, and Moscow). The data obtained show an increase in the degree of disturbance of the developmental stability as adverse effects increase, from a conditionally normal state to a critical one. In habitats with a similar degree of deviation of conditions, a similar reaction of plants is observed, despite the considerable spatial remoteness and various kinds of impact.

Determination of the factors influencing the population structure and adaptive tolerance to environmental pressures of the synanthropic hoverfly Eristalis arbustorum is of essential importance in understanding how pollinator populations could respond to climate change or ecosystem management. We addressed the issue of connectivity among conspecific populations sampled in Bosnia and Herzegovina. Twenty environmental factors, mitochondrial DNA sequences of the cytochrome c oxidase subunit I gene (COI mtDNA), allele frequencies at allozyme loci and wing traits (size and shape) were compared for characterization of population structure and environmental niches. Additionally, patterns of within-individual asymmetry (fluctuating asymmetry; FA) in wing size and shape within and among conspecific populations were studied. In line with the overall similarity of the environmental factors extracted for our study sites, the results of COI mtDNA diversity and STRUCTURE allozyme data provide evidence for shallow differentiation among conspecific populations. In contrast, geo-referenced Bayesian clustering methods (BAPS and GENELAND) and population-based approaches (pairwise F-ST values and AMOVA) indicate that the dispersal potential of E. arbustorum may be limited across the study area. Along with a significant FA in wing size and shape, a consistent level of FA regardless of urban/rural sampling origin is an indication of the great potential of E. arbustorum for local adaptation, because increased FA levels can be considered to be a way of expression of phenotypic variation and, hence, may contribute to adaptive responses in populations facing changing environments. Thus, by using a combined genetic-morphological approach, we significantly contributed to the understanding of the fine-scale genetic structure of the synanthropic generalist pollinator E. arbustorum.

We present a novel analysis of fluctuating asymmetry (FA) for butterfly wings at the community-level, along an altitudinal gradient. FA is an important biomonitoring tool that detects deviations of perfect symmetry in bilateral characters, assuming that genetic and/or environmental factors can be a source of stress. This study evaluated the effects of increased altitude on the symmetry of butterfly wings, testing the hypothesis that FA should increase with increased elevation in a tropical mountain. Butterflies were sampled along an altitudinal gradient of 800 to 1.400 m and forewings were detached, scanned and evaluated for symmetry. Length, width and area of the right and left forewings were measured as surrogates for FA and then combined into an index taking into account the variability of wing sizes of the whole butterfly community. We observed true patterns of FA in the length, width and area of the wings, and wing FA area increased with increased altitude. This study pioneered the analysis of FA for a community of butterflies and FA was efficient to detect developmental instability indicated by imperfections in butterfly wings.

Understanding how environmental variation influences even cryptic traits is important to clarify the roles of selection and developmental constraints in past evolutionary divergence and to predict future adaptation under environmental change. Female yellow dung flies (Scathophaga stercoraria) typically have three sperm storage compartments (3S), but occasionally four (4S). More spermathecae are thought to be a female adaptation facilitating sperm sorting after mating, but the phenotype is very rare in nature. We manipulated the flies' developmental environment by food restriction, pesticides, and hot temperatures to investigate the nature and extent of developmental plasticity of this trait, and whether spermatheca expression correlates with measures of performance and developmental stability, as would be expected if 4S expression is a developmental aberration. The spermathecal polymorphism of yellow dung fly females is heritable, but also highly developmentally plastic, varying strongly with rearing conditions. 4S expression is tightly linked to growth rate, and weakly positively correlated with fluctuating asymmetry of wings and legs, suggesting that the production of a fourth spermatheca could be a nonadaptive developmental aberration. However, spermathecal plasticity is opposite in the closely related and ecologically similar Scathophaga suilla, demonstrating that overexpression of spermathecae under developmental stress is not universal. At the same time, we found overall mortality costs as well as benefits of 4S pheno- and genotypes (also affecting male siblings), suggesting that a life history trade-off may potentially moderate 4S expression. We conclude that the release of cryptic genetic variation in spermatheca number in the face of strong environmental variation may expose hidden traits (here reproductive morphology) to natural selection (here under climate warming or food augmentation). Once exposed, hidden traits can potentially undergo rapid genetic assimilation, even in cases when trait changes are first triggered by random errors that destabilize developmental processes.

Birds face many human-induced environmental challenges that we associate with population declines. Because of this, we need more ways to monitor populations before they become endangered. Several authors have proposed that fluctuating asymmetry, or nondirectional deviation from bilateral symmetry, could be used as an indicator of population declines. Fluctuating asymmetry is linked to developmental instability and stress associated with environmental challenges such as habitat loss in populations of birds and other animals. Two key premises of the argument for linking fluctuating asymmetry and population declines are that (1) fluctuating asymmetry changes over time, and (2) change over time results in overall population- or species-level differences in fluctuating asymmetry. I evaluated these premises by measuring tarsus and hallux lengths of museum specimens primarily from 1875–1950 in a pair of closely related species with different population statuses—the White-breasted Nuthatch (Sitta carolinensis) and the Brown-headed Nuthatch (S. pusilla). Since Brown-headed Nuthatch populations are decreasing whereas White-breasted Nuthatch populations are increasing, I predicted that Brown-headed Nuthatches would have increasing fluctuating asymmetry over time whereas White-breasted Nuthatches would have no change or decreasing fluctuating asymmetry over time, and this would result in Brown-headed Nuthatches having more overall fluctuating asymmetry in both morphological traits than White-breasted Nuthatches. The percent asymmetry of tarsi and halluces for Brown-headed Nuthatches were at least 1.5× higher than the corresponding values for White-breasted Nuthatches, which supported the second premise. However, since I also found that there was a great deal of interindividual variation and no change in fluctuating asymmetry over time in either species, it is still unclear whether fluctuating asymmetry could be used to help monitor populations for evidence of decline before they reach endangered status. Future studies should more broadly and deeply explore the associations between avian population declines and fluctuating asymmetry.

Within-plant variation in seed size may merely reflect developmental instability, or it may be adaptive in facilitating diversifying bet-hedging, that is, production of phenotypically diverse offspring when future environments are unpredictable. To test the latter hypothesis, we analyzed patterns of variation in seed size in 11 populations of the perennial vine Dalechampia scandens grown in a common greenhouse environment. We tested whether population differences in the mean and variation of seed size covaried with environmental predictability at two different timescales. We also tested whether within-plant variation in seed size was correlated with independent measures of floral developmental instability and increased under stressful conditions. Populations differed genetically in the amount of seed-size variation occurring among plants, among infructescences within plants, and among seeds within infructescences. Within-individual variation was not detectably correlated with measures of developmental instability and did not increase under stress, but it increased weakly with short-term environmental unpredictability of precipitation at the source-population site. These results support the hypothesis that greater variation in seed size is adaptive when environmental predictability is low.

Phenotypic plasticity and developmental instability in leaf traits are common in oak species but the role of environmental factors is not well understood. To decipher possible correlations between different leaf traits and effects of the position of leaves within the tree canopy, we quantified the plasticity of three leaf traits of 30 trees of Quercus alba L., Quercus palustris Muench and Quercus velutina Lam. We hypothesized that trees could modify the shape of their leaves for better adaptation to the variable microclimate within the canopy. Our results demonstrated that the south and north outer leaves were significantly smaller, more lobed and denser than those situated in the inner canopy. The order of leaves on the branch accounted for the plasticity of leaf traits in Q. alba only. Plasticity of lobing in Q. alba and Q. velutina depended on the height of the trees. We detected fluctuating asymmetry (FA) in all three species, but the source of variation depended on branch position in Q. velutina only. FA was more pronounced in north‐facing leaves. Plasticity of the leaf traits ranged from small to medium. Plasticity of leaf area and leaf mass per area (LMA) depended on the branch position. However, the plasticity of lobation was not affected by the location of a branch within the tree canopy. Quercus alba and Q. palustris had similar plastic responses but the plasticity of Q. velutina was significantly smaller. We concluded that individual plants detect and cope with environmental stress through vegetative organ modification.

Fluctuating asymmetry (FA), a widely used measure of developmental instability in plants and animals, which describes random differences in size and/or shape between the two sides of a bilateral character. We used FA as a tool to detect stress in three mangrove species (Avicennia germinans, Laguncularia racemosa, Rhizophora mangle), growing in both disturbed and conserved habitats in the Atlantic coast of Mexico. In this region, disturbed habitats are the result of deforestation, livestock, tourism and agriculture activities. Twenty plants of each species were sampled in each of four sites (two disturbed and two conserved) and levels of FA, proportion of individuals with herbivory, proportion of leaves with damage, and leaf area removed by herbivores were evaluated. In disturbed habitats, regardless of plant species, more plants were attacked by insects, more leaves were damaged, and more leaf area was removed by herbivores, indicating higher overall damage to plants. We detected that FA levels varied significantly amongst mangrove species, they were higher in disturbed compared to conserved habitats, indicating the importance of FA as a monitoring tool of mangrove stress. A positive relationship between FA and herbivory levels also indicates that herbivores might be a source of stress.

Sandy beaches are the most frequented coastal environments in the world, and they consequently suffer different types of impacts due to the rapid urban occupation and demographic growth in coastal regions, which generate stressful conditions for the resident species and reduce the environmental quality of the beaches for resident species. Crustaceans can be used as reliable bioindicators of human stress, and the amphipod Atlantorchestoidea brasiliensis and the decapod Emerita brasiliensis are highlighted. One tool for evaluating the environmental quality and the instability of individual development is fluctuating asymmetry (FA), which measures small, random deviations from a perfect bilateral symmetry. To evaluate the environmental quality of the beaches, some indices have been developed in recent years; among the most used are the conservation, recreation and urbanization indices, which offer easy-to-use metric for decision makers. This study aimed to quantify and compare the levels of FA in the populations of A. brasiliensis and E. brasiliensis on 14 beaches in Rio de Janeiro State with different levels of urbanization and conservation. For each species, two individual indices and two composite indices of asymmetry were calculated and tested in four bilateral traits. The urbanization, recreation and conservation indices were used to assess environmental quality of the sandy beaches. The results of the present study indicate a complex spatial distribution of FA in relation to the indices of the environmental quality of the beaches. The beaches that obtained the highest values in the conservation index obtained the lowest values of FA for both species. The beaches located in the Metropolitan region, specifically in the city of Rio de Janeiro, generally presented the highest levels of FA for both species. These species are susceptible to different forms of impacts due to their distinct characteristics in feeding behavior, development mode and beach zone occurrence. A. brasiliensis is more susceptible to direct impacts on the beach, such as recreational activities, while E. brasiliensis is more sensitive to impacts on water (contamination and physicochemical changes). Our results indicate that fluctuating asymmetry can be used as a good tool to evaluate impacts on sandy beaches, but additional studies should be conducted to improve the understanding of the spatial distribution of FA on sandy beaches.

Fluctuating asymmetry (FA), defined as the random deviations from symmetry in morphological traits, has repeatedly been suggested as a handy indicator of genetic and environmental stress experienced by organisms during their development. However, the value of FA for applied ecological and environmental research is now questioned by a growing number of studies that have found no increases in FA under stress. We used geometric morphometrics to test the hypothesis that FA measures based on naturally defined landmarks are better suited for detection of deviations from leaf symmetry than are traditional measures of FA. We compared two sets of mountain birch (Betula pubescens ssp. czerepanovii) leaves, obtained from trees growing in industrially polluted natural populations and from experimentally stressed seedlings, by examining three measures of FA: 1) a traditional distance-based measure calculated from the width of the left and right halves of a leaf at the middle of the lamina (FAwidth), 2) a distance-based measure reflecting differences in vein length calculated from three landmarks (FAveins), and 3) a multivariate FA measure describing asymmetry in leaf shape based on five landmarks (FAshape). These three FA measures were poorly (albeit positively) correlated with each other. The two distance-based measures reflected different parts of the multivariate measure FAshape, which had the highest sensitivity for detection of deviations from leaf symmetry. FAshape was also the only FA measure that weakly confirmed the expected increase in FA under experimental stress, and particularly under stress caused by application of heavy metals. However, very high levels of within-individual variation in asymmetry remain to be explained, and even FAshape did not show the expected effects of industrial pollution on leaf symmetry. We conclude that FA in birch leaves cannot be regarded as a reliable indicator of environmental stress, even when quantified using modern methods.

The American lobster supports the most economically valuable fishery in the Gulf of Maine and Atlantic Canada. Across much of its range, ocean temperatures have increased at rates faster than almost anywhere in the world. Studies of warming effects on larvae have largely focused on survival and development, but rarely have examined sub-lethal effects that could influence settlement and subsequent recruitment to the fishery. We explored how warming influences rate of development, survival, stress, and developmental stability of larval lobsters reared under four nominal temperatures: 14, 16, 18, and 22 °C. Our study is the first to evaluate the use of fluctuating asymmetry as a biomarker for developmental instability in larval American lobster. We also recorded total hemocyte counts in postlarvae as an indicator of stress, a novel technique for work in larval lobster. Development proceeded significantly faster as temperature increased, and cumulative survival was significantly positively correlated with temperature. However, postlarvae reared under temperature extremes exhibited elevated hemocyte counts and had significantly lower levels of variance in midline asymmetry compared to intermediate temperature groups. Together, this suggests that warmer temperatures may facilitate faster growth at the expense of increased physiological stress and a loss of genetic diversity, potentially affecting the species’ ability to adapt to changing environmental conditions. Fluctuating asymmetry could prove to be a useful bioindicator for population resilience.

The way urbanization shapes the intraspecific variation of pollinator functional traits is little understood. However, this topic is relevant for investigating ecosystem services and pollinator health. Here, we studied how urbanization affects the functional traits of workers in two bumblebee species (Bombus terrestris and B. pascuorum) sampled in 37 sites along a gradient of urbanization in North Italy (an area of 1800 km2 including the metropolitan context of Milan and other surrounding capital districts). Namely, we investigated the role played by land-use composition, configuration, temperature, flower resource abundance, and air pollutants on the variation of traits related to flight performance (i.e., body size, wing shape and size fluctuating asymmetry). These traits are relevant because they are commonly used as indicators of stress during insect development. The functional traits of the two bumblebees responded idiosyncratically to urbanization. Urban temperatures were associated with smaller wing sizes in B. pascuorum and with more accentuated fluctuating asymmetry of wing size in B. terrestris. Moreover, flower abundance correlated with bigger wings in B. terrestris and with less asymmetric wing sizes in B. pascuorum. Other traits did not vary significantly and other urban variables played minor effects. These patterns highlight that environmental stressors linked to urbanization negatively impact traits related to flight performance and development stability of these species with possible consequences on the pollination service they provide.Overall, this study found species-specific variation patterns in syntopic taxa, expanding our understanding about the effects of anthropic disturbance in shaping relevant functional traits of pollinator model species.

The rapid and selective responses to changes in habitat structure and climate have made butterflies valuable environmental indicators. In this study, we asked whether the decline in butterfly populations near the copper-nickel smelter in Monchegorsk in northwestern Russia is accompanied by phenotypic stress responses to toxic pollutants, expressed as a decrease in body size and an increase in fluctuating asymmetry. We measured the concentrations of nickel and copper, forewing length, and fluctuating asymmetry in two elements of wing patterns in Boloria euphrosyne, Plebejus idas, and Agriades optilete collected 1–65 km from Monchegorsk. Body metal concentrations increased toward the smelter, confirming the local origin of the collected butterflies. The wings of butterflies from the most polluted sites were 5–8% shorter than those in unpolluted localities, suggesting adverse effects of pollution on butterfly fitness due to larval feeding on contaminated plants. However, fluctuating asymmetry averaged across two hindwing spots did not change systematically with pollution, thereby questioning the use of fluctuating asymmetry as an indicator of habitat quality in butterfly conservation projects.

Background Developmental instability in archaeological samples can be detected through analysis of skeletal and dental remains. During life, disruptions to biological internal homeostasis that occur during growth and development redirect bodily resources to returning to homeostasis and away from normal processes such as symmetrical development. Because dental enamel does not remodel in life, any deviations from normal development are left behind. Even subtle disturbances to developmental trajectory may be detected in asymmetrical development of traits, specifically a random variation in sides termed fluctuating asymmetry. Human dental fluctuating asymmetry studies are common, but here we investigate the permanent dentition of a non-human primate Papio anubis, for potential fluctuating asymmetry relative to sex, weaning, and reproductive maturity. The sample stems from an outlier population that lives in the wettest and most humid habitat of any studied baboon group. Methods The skulls of adult baboons were collected after their natural death in Gashaka Gumti National Park, Nigeria. The permanent dentition of antimeric teeth (paired) were measured for maximum length and breadth using standard methods. The metrics were analyzed to assess the presence of fluctuating asymmetry in adult permanent mandibular and maxillary dentition. Measurement error and other forms of asymmetry (antisymmetry, directional asymmetry) were considered and dental measures expressing true fluctuating asymmetry were used to address three research questions. Results Males exhibit greater fluctuating asymmetry than females, suggesting that males experience greater overall instability during the developmental period. While weaning is not more stressful than other life history stages for males and females (using the first molar fluctuating asymmetry index as a proxy compared to other teeth), it is more stressful for females than males. The onset of reproduction is also not more stressful than other life history stages for males and females (using the third molar fluctuating asymmetry index as a proxy compared to other teeth), but it is more stressful for males than females. We explore possible explanations for these findings in the discussion.

In our study we used the data set on morphimetric traits in beetles species. It has been constantly replenishing for 20 years by the samples, received from different regions of Russia and abroad. In this case we have selected data on nine species for which the left and right sides had been measured and fluctuating asymmetry (FA) could be estimated. The samples were from 6 provinces of Russia and Belarus, which ranged in 3 degrees in latitude and 57 degrees in longitude and included more than 150 plots in different types of biotopes. FA was assessed according to the standard method in 5265 specimen in one dimensional trait and one - meristic. ANOVA showed that biotope, species and their interaction affected FA in both traits, that is different species reacted differently to biotope type. In uncommon biotopes (according to accepted in carabidology classification) FA was increased. In forest species the negative relationship between FA in dimensional and meristic traits in the range in biotopes was revealed. In those species only FA values were higher in males than in females. In generalist species FA varieв similarly in both sexes and in both traits being the highest in open biotopes. In eudomonant of arable lands biotopes – Poecilus cupreus – the highest values of FA were recorded in the meadows, being about equal in all types of crops.

Experimental, latitudinal, and historical approaches have been used to explore and/or predict the effects of global change on biota, and each approach has its own advantages and disadvantages. The weaknesses of these individual approaches can, potentially, be avoided by applying them simultaneously, but this is rarely done in global change research. Here, we explored the temporal and spatial variations in the leaf size and fluctuating asymmetry (FA) of mountain birch (Betula pubescens var. pumila) in the Murmansk region of Russia, with the aim of verifying the predictions derived from the responses of these traits to experimental manipulations of abiotic drivers of global change. The examination of herbarium specimens revealed that leaf length increased during the 20th century, whereas the FA in the number of leaf teeth decreased, presumably reflecting an increase in the carbon and nitrogen availability to plants in that century. Along a northward latitudinal gradient, leaf length decreased whereas FA increased, presumably due to the poleward decreases in air temperature. The study site, collection year, and latitude explained a larger part of the leaf length variation in mountain birch relative to the variation in FA. Leaf length is likely a better indicator than FA in studies addressing global environmental change impacts on plant performance.

Transportation to long distances and handling of colonies can affect development and survival conditions of bees. Our study investigated the stress intensity of individuals of Melipona scutellaris Latreille, 1811, due to transportation of colonies to long distances, within the natural range of the species. We used 746 bee workers. The right and left forewings were removed and measured using 15 landmarks in vein insertions. Individuals were divided into four groups: (1) workers collected at the origin site, (2) workers emerged at the place of destination in pupal stage during transportation, (3) workers emerged at the destination site in the 3rd instar of larval stage during transportation, and (4) workers collected after three months of colony establishment at the destination site. The Procrustes ANOVA showed significant results as well as the presence of Fluctuating Asymmetry (FA) in all treatments for the shape of wings (P

Environmental pollution is currently identified as one of the major drivers of rapid decline of insect populations, and this finding has revitalized interest in insect responses to pollution. We tested the hypothesis that the pollution-induced decline of insect populations can be predicted from phenotypic stress responses expressed as morphological differences between populations inhabiting polluted and unpolluted sites. We explored populations of the brassy tortrix Eulia ministrana in subarctic forests along an environmental disturbance gradient created by long-lasting severe impacts of aerial emissions of the copper-nickel smelter in Monchegorsk, northwestern Russia. We used pheromone traps to measure the population densities of this leafrolling moth and to collect specimens for assessment of three morphological stress indices: size, forewing melanization, and fluctuating asymmetry in wing venation. Wing length of E. ministrana increased by 10%, and neither forewing melanization nor fluctuating asymmetry changed from the unpolluted forest to the heavily polluted industrial barren. However, the population density of E. ministrana decreased 5 to 10 fold in the same pollution gradient. Thus, none of the studied potential morphological stress indicators signaled vulnerability of E. ministrana to environmental pollution and/or to pollution-induced environmental disturbance. We conclude that insect populations can decline without any visible signs of stress. The use of morphological proxies of insect fitness to predict the consequences of human impact on insect populations is therefore risky until causal relationships between these proxies and insect abundance are deciphered.

Fluctuating asymmetry (FA) is hypothesized to be a useful predictor of population canalization, especially for organisms at risk from environmental change.Identification of traits that meet statistical criteria as FA measures remains a challenge.Here, a laboratory experiment subjected immature butterflies (Vanessa cardui) to diet and temperature conditions of varying stress levels. Variation in dietary macronutrient ratio (protein: carbohydrate) and rearing temperature (optimal: 25°C; elevated: 32°C) was introduced as stressors. Temperature and nutrition are key variables influencing ectotherm growth and fitness and so are likely to be important stressors that influence FA.Individuals subjected to stressful conditions were predicted to show elevated FA of three wing size traits, as well as increased mortality and decreased adult body size.Trait FA did not vary across treatments. Instead, treatment levels impacted viability: The combined incidence of pupal death and expression of significant wing malformations increased in treatment levels designated as stressful. Variation in adult dry mass also reflected predicted stress levels. Results suggest that individuals predicted to display increased FA either died or displayed gross developmental aberrations.This experiment illustrates important constraints on the investigation of FA, including selection of appropriate traits and identification of appropriate levels of stressors to avoid elevated mortality. The latter concern brings into question the utility of FA as an indicator of stress in vulnerable, natural populations, where stress levels cannot be controlled, and mortality and fitness effects are often not quantifiable., While the topic of fluctuating asymmetry (FA) has received wide attention for its potential applicability to understanding stressors in populations, very few studies have examined this possibility rigorously both from an experimental perspective and an analytical one. This manuscript reports on a study that does both. In this study, FA was measured in the wings of a model butterfly.

The results of determining the fluctuating asymmetry (FA) index of Betula pubescens leaves as well as the state of birches in general, as an aboriginal species in the Murmansk region to assess the pollution of urban ecosystems of the Kola North (Murmansk, Apatity, Olenegorsk, Polyarnye Zori, Kandalaksha) in the zone of influence of railway transport have been presented in the article. It has been shown that the most weakened birches grow in Kandalaksha and Olenegorsk, while in Kandalaksha area, there are more than 10% of dead trees. It has been revealed that the highest FA index which characterizes the critical state of plants and the high level of environmental pollution is observed in Olenegorsk. The increased level of FA has also been in Kandalaksha and Polyarnye Zori. The comparative analysis of the state of plants and FA index showed existence of functional interrelation only in Kandalaksha and Olenegorsk when with a significant proportion of weakened trees the indicator of FA is the highest. Due to the fact that the increase in the level of FA is influenced by stress factors caused not only by pollution, the method of assessing the quality of the environment by the fluctuating asymmetry should be used in complex with other studies.

Body size is commonly associated with biological features such as reproductive capacity, competition, and resource acquisition. Many studies have tried to understand how these isolated factors can affect the body pattern of individuals. However, little is known about how interactions among species in multitrophic communities determine the body shape of individuals exploiting the same resource. Here, we evaluate the effect of fruit infestation, parasitism rate, and seed biomass on size, allometric and asymmetric patterns of morphological structures of insects that exploit the same resource. To test it, we measured 750 individuals associated with the plant Senegalia tenuifolia (Fabaceae), previously collected over three consecutive years. Negative allometry was maintained for all species, suggesting that with increasing body size the body structure did not grow proportionally. Despite this, some variations in allometric slopes suggest that interactions in a multitrophic food web can shape the development of these species. Also, we observed a higher confidence interval at higher categories of infestation and parasitism rate, suggesting a great variability in the allometric scaling. We did not observe fluctuating asymmetry for any category or species, but we found some changes in morphological structures, depending on the variables tested. These findings show that both allometry and morphological trait measurements are the most indicated in studies focused on interactions and morphometry. Finally, we show that, except for the fluctuating asymmetry, each species and morphological structure respond differently to interactions, even if the individuals play the same functional role within the food web.