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Effects of parental radiation exposure on developmental instability in grasshoppers
Abstract
Mutagenic and epigenetic effects of environmental stressors and their transgenerational consequences are of interest to evolutionary biologists because they can amplify natural genetic variation. We studied the effect of parental exposure to radioactive contamination on offspring development in lesser marsh grasshopper Chorthippus albomarginatus. We used a geometric morphometric approach to measure fluctuating asymmetry (FA), wing shape and wing size. We measured time to sexual maturity to check whether parental exposure to radiation influenced offspring developmental trajectory and tested effects of radiation on hatching success and parental fecundity. Wings were larger in early maturing individuals born to parents from high radiation sites compared to early maturing individuals from low radiation sites. As time to sexual maturity increased, wing size decreased but more sharply in individuals from high radiation sites. Radiation exposure did not significantly affect FA or shape in wings nor did it significantly affect hatching success and fecundity. Overall, parental radiation exposure can adversely affect offspring development and fitness depending on developmental trajectories although the cause of this effect remains unclear. We suggest more direct measures of fitness and the inclusion of replication in future studies to help further our understanding of the relationship between developmental instability, fitness and environmental stress.
... There has recently been increasing interest in protecting non-human species from the effects of ionizing radiation (Brèchignac and Doi, 2009;Beasley et al., 2012;Dallas et al., 2012;Bradshaw et al., 2014;Caffrey et al., 2014;Fuller et al., 2015;Boratyński et al., 2016;Fuller et al., 2017;Stark et al., 2017;Adam-Guillermin et al., 2018). However, only limited data are available on the effects of radionuclides on wildlife species or on ecosystems and methods for detecting such effects are not well developed. ...
... However, FA as a method has shown inconsistencies in previous studies. While several studies have supported a positive correlation between FA and environmental radioactivity (Møller, 1993a(Møller, , 1993bGileva and Nokhrin, 2001;Møller, 2002;Yavnyuk et al., 2009) or other environmental stresses (Parsons, 1990;Groenendijk et al., 1998;Bonada and Williams, 2002;Chang et al., 2007aChang et al., , 2007b, no increase of FA was observed in other studies in animals exposed to radioactive (Beasley et al., 2012;Fuller et al., 2017) or other contaminants (Postma et al., 1995;Leung and Forbes, 1997;Rabitsch, 1997;Dobrin and Corkum, 1999;Hogg et al., 2001). ...
... Furthermore, if the sampling in nature is done long after the contamination (Beasley et al., 2012;Fuller et al., 2017), the natural population may have adapted (genetically or epigenetically) to the pollution level and some effects may not be observable anymore. The approach used in this study avoids these problems. ...
There is increasing interest in effects of radionuclides on non-human species, but methods for studying such effects are not well developed. The aims of the current study were to investigate the effects of uranium mine-affected sediments on non-biting midge Chironomus riparius and to compare sensitivity of different endpoints. The midge larvae were exposed in controlled laboratory conditions to sediments from two ponds downstream from an abandoned uranium mine and a reference pond not receiving water from the mining site. Quartz sand was used as an additional control. Developmental effects were assessed by evaluating emergence of adult midges, body mass, and fluctuating asymmetry (FA) in the length of wing upper vein. FA has been suggested to be a sensitive indicator of developmental instability, but the results of previous studies are inconsistent. In the present study, no difference in FA was observed between the treatment groups, but time to emergence was significantly delayed in the contaminated sediments. The approach used in this study (laboratory experiments with sediments from a contaminated site) avoids confounding due to uncontrolled environmental variables and adaptation to long-term contamination, which may mask effects on natural populations. Using this approach, we found no effects on FA of wing length. Time to emergence, in contrast, was found to be a more sensitive endpoint.
... Wing measurements were estimated as previously described by Beasley et al (2012). Briefly, the forewings and hind wings were removed from the thorax, wet mounted on glass microscope slides with distilled water, and covered with a coverslip. ...
... A Procrustes ANOVA found the between-sides variation to far exceed the measurement error (F 72 p 12:09, r 2 p 0:97, P < 0:0001) and scanning technique (F 72 p 17:20, r 2 p 0:99, P < 0:0001). Measurement error due to mounting was very low for both the left wing (F 26 p 699:23, r 2 p 0:99, P < 0:0001) and the right wing (F 26 p 245:86, r 2 p 0:99, P < 0:0001), with repeatability in excess of 99.43% (Beasley et al. 2012). Furthermore, we confirmed the absence of directional asymmetry and antisymmetry (Beasley et al. 2012). ...
... Measurement error due to mounting was very low for both the left wing (F 26 p 699:23, r 2 p 0:99, P < 0:0001) and the right wing (F 26 p 245:86, r 2 p 0:99, P < 0:0001), with repeatability in excess of 99.43% (Beasley et al. 2012). Furthermore, we confirmed the absence of directional asymmetry and antisymmetry (Beasley et al. 2012). Mean landmark coordinates calculated by averaging the three measurements per landmark for each individual were used in the analysis ( fig. 2). ...
In Chernobyl, chronic exposure to radioactive contaminants has
a variety of deleterious effects on exposed organisms, including
genetic damage and mutation accumulation. However, the potential
for such effects to be transmitted to the next generation is
poorly understood.We captured lesser marsh grasshoppers (Chorthippus
albomarginatus) in the Chernobyl Exclusion Zone from
sites varying in levels of environmental radiation by more than
three orders of magnitude. We then raised their offspring in a
common garden experiment in order to assess the effects of
parental exposure to radiation on offspring development and
DNAdamage. Offspring that reached maturity at a younger age
had higher levels of DNA damage. Contrary to our hypothesis,
parental exposure to radioactive contamination did not affect
DNA damage in their offspring possibly because of intervening
adaptation or parental compensatory mechanisms. Our results
suggest a trade-off between developmental rate and resistance
toDNAdamage, whereby offspring developing at faster rates do
so at the cost of damaging their DNA. This result is consistent
with and extends findings in other species, suggesting that faster
growth rates cause increased oxidative damage and stress. We
propose that growth rates are subject to stabilizing selection
balancing the benefits of fast development and the competing
need of buffering its damaging effects to macromolecules and
tissues.
... Chernobyl (Beasley et al., 2012) and butterflies (Zizeeria maha) from the area around Fukushima Daiichi, Japan (Hiyama et al., 2012). This makes wing length an unreliable feature in keying. ...
... Danish grasshoppers had longer forewings, where the males from the Chernobyl population had longer bodies. Longer bodies and shorter wings in the Chernobyl population was also observed in a study from Beasley et al.. (2012). They examined the second generation of the grasshopper Ch. albomarginatus from Chernobyl and found that greater parental radiation increased maturation time of offspring (measured as mould to imago), which in turn decreased wing to body size. ...
... This suggests that the decreased wing to body size in the Chernobyl population, compared to the Danish, is a consequence of longer maturation time, which sequentially is due to radioactive exposure. Organisms exposed to a strong environmental pressure are likely to allocate metabolic energy towards protestants on the cost of slower maturation processes (Beasley et al., 2012). However, this could in principle also slow down growth (Asshoff and Hattenschwiler, 2005), which was not the case in this study, rather the Chernobyl population showed a trend to be larger. ...
The explosion of the Chernobyl nuclear power plant in 1986 was categorized as the most severe nuclear accident in history, resulting in some of the most radioactively contaminated habitats on Earth. The consequence was an increased mutation and mortality rate in biota, which caused major damage on the ecosystem level, observed as local extinction and community rearrangement. The area is still contaminated with chronic, low level radiation, but the hazardous effect from this is not apparent. Contrary, the biota is flourishing. This can be a result of immigration to the exclusion zone, which the ecosystem would not be sustained without. Alternatively, radiation which causes increased genetic diversity and environmental stress can have caused adaptation of biota to the elevated radioactivity. Whether the scenario is one or the other is important for the ecosystem dynamics, and useful to understand in wildlife management. This knowledge is relevant, especially in the light of the recent accident at the Fukushima Daiichi nuclear power plant in Japan.
The present study uses the oxidative DNA damage 8-OH-dG as a measure of adaptation in grasshoppers (Chorthippus spp.) from Chernobyl, in order to examine if organisms in the exclusion zone have adapted to the elevated radiation. The level of 8-OH-dG is detected by Enzyme-linked Immunosorbant Assay (ELISA) and compared to that of a Danish population which have not been exposed to chronic, low level radiation. Furthermore, DNA damage in Danish grasshoppers artificially irradiated with 178.8 mSV (1.9 mSv/h) is compared with that of the natural Danish and Chernobyl populations.
Grasshoppers from Chernobyl have significantly less DNA damage compared to the Danish population and to the artificially irradiated Danish grasshoppers, which suggests that chronic radiation in Chernobyl may has caused adaptation of grasshoppers to survive high radioactivity. More studies are needed in order to conclude how the adaptations have occurred and the mechanisms behind, but the result is likely a more efficient protective and/or repair mechanism to maintain DNA integrity. If grasshopper populations in Chernobyl have adapted to the elevated radioactivity, perhaps similar organisms have as well, indicating a recovering ecosystem. However, more studies on adaptation and recovery are needed, before writing off the consequences of this manmade catastrophe.
... Many studies on other insects suggested a reflection of body size in wing length (i.e. Dudley, 2000, Loh et al., 2008, Beasley et al., 2012, Bai et al., 2016. ...
This PhD project investigated the response of wing length (as a proxy of body size) of Odonata and Chironomidae, and wing shape of Odonata to temperature and latitude. Three complementary data sources were used: natural history collections, field data, and mesocosm experiments. While natural history collections are valuable resources of specimens collected over long historical time scales, field data provides a modern perspective and mesocosm experiments provide a window on the future, under a predicted climate warming scenario. This PhD project used 5,331 museum specimens of 14 British Odonata species representing different life cycle types to examine the potential drivers of body size and wing shape responses to latitude and temperature (Chapter II and V). To control for latitude a field survey was performed during the summer of 2018 at Edington, Somerset to compare modern wing length of three species with historical data based on museum specimens of the same species collected at the same locality (Chapter III).Furthermore, to investigate body size responses of chironomids under a future temperature scenario, 1,976 adult specimens of six chironomid species were collected from mesocosm experiments which comprised ponds at ambient temperature and ponds maintained at 4℃ higher than ambient (Chapter IV).
The results of Chapters II, III and IV showed that species and suborder (within Odonata) were significant factors affecting the magnitude of the temperature-size responses in Odonata and Chironomidae. Wing lengths of Zygoptera (Odonata) and Chironomidae are more sensitive to temperature and collection date than Anisoptera (Odonata). Zygoptera and Chironomidae tend to get smaller with increasingt emperature, likely due to higher temperatures disproportionately increasing developmental rate, resulting in smaller adults. Anisoptera showed no significant correlation with temperature, possibly due to selection for larger individuals in Anisoptera which are strongly territorial species. Adults of Zygoptera and Chironomidae emerging towards the end of the summer tend to be smaller than those emerging earlier in the season, likely due to larval development being time-constrainedlater in the season and as a result, larvae accelerate their developmental rate which comes at the cost of a smaller adult body size. The results of Chapter V indicated non-significant correlations between environment and wing shape in Anisoptera, while there were significant influences of latitude and mean seasonal temperature on wing shape in Zygoptera species, with broader and shorter wings found at lower latitudes with warmer temperatures. This finding corresponds well with a result of Chapter II which found shorter wing length with increasing temperature in all zygopteran species in the study. Overall, the results of this PhD project show that there are different factors influencing the temperature-size responses of insects, including phylogenetic relationships, sex, behaviour and life cycle types. Although this study found no universal temperature size responses in the focal taxa, Zygoptera and Chironomidae tend to have stronger negative body size responses to warming temperature and emergence date than Anisoptera. In addition, the study shows that wing shape variation in Zygoptera is more sensitive and adaptive to latitude and temperature than in Anisoptera.
... These anomalies may interrupt the developmental pathways (Møller 2002;Natarajan 2006). It also has an opposed effect on the development and health of the offspring (Beasley et al. 2012). Ingestion of Bacillus thuringiensis vegetative insecticidal protein (Vip3A) by susceptible insects such as the black cutworm (Agrotis ipsilon) and fall armyworm (Spodoptera frugiperda) causes gut paralysis at low concentrations and complete lyses of gut epithelium cells resulting in larval death at higher concentrations (Yu et al. 1997). ...
Purpose
Combining gamma irradiation and nanotechnology has become one of the most promising new approaches for area-wide (AW) pest management in recent years. The laboratory trials were conducted to determine the combining effects of BT-AgNPs and gamma irradiation for controlling P. gossypiella. Radio-sensitivity of male pupae at different doses of gamma radiation and the effectiveness of biosynthesized silver nanoparticles using Bacillus thuringiensis on larval instar were assayed. Additionally, the ultrastructure changes on the alimentary canal of 4th instar larvae were studied to evaluate the impact of the combined approach at a cellular level.
Materials and methods
Laboratory- rearing technique was used for rearing Pectinophora gossypiella. The irradiation process was achieved at Co⁶⁰ - Gamma Chamber (4000A). Alanine dosimeters were used for measuring the average absorbed dose and dose mapping. Preparation of Silver nanoparticles (AgNPs) using Bacillus thuringiensis (Bt) and their characterization has been investigated. The treated 4th instar larvae by gamma irradiation or ∕and BT-AgNPs were dissected under the stereo microscope. The alimentary canal was obtained anatomically and Transmission Electron Microscope) was used in examining the stained sections.
Results
Based on the non-hatching eggs produced by irradiated males’ pupae, the values of effective doses were calculated. The effective doses ranged from 16 to 291 Gy for the ED25 - ED75. The sterility index reached 74.1 % when irradiated with males by 291 Gy crossed with non-irradiated females and the adult emergence decreased to be 35.3%. The insecticidal potential of Bt-AgNPs on the 2nd and 4th larval instars was dose-dependent and its LC50 toxicity value was 0. 3 and 0. 4 mg /ml, respectively. The lethal concentration LC50 of the 2nd instar larvae increased the larval and pupal mortality to 55% and 44.4 %, respectively, and reduced the adult emergence to be 55.6%. The combining effects of Bt-AgNPs with 291 Gy induced 100% pupae mortality and there was no adult emergence in F1 generation. Such effects also severed the ultrastructure deformity of the midgut of the 4th instar larvae after the two-day post-treatment.
Conclusions
The combining effects are recommended as an effective IPM program to control P. gossypiella by releasing sterile males (derived from pupae irradiated with 291 Gy) crossing with the normal females in the field, and reducing the fertility of the population to 31.2%. Subsequently, the resulted larvae treated with LC50 of Bt-AgNPs prevented the adult emergence and stopped the life cycle of P. gossypiella.
... Additionally, studies on body size in insects (Clapham & Karr, 2012) and Odonata (Worthen & Jones, 2006) suggest a strong correlation between body dimensions and wing length. Many studies on other insects suggested a reflection of body size in wing length (Dudley, 2000;Loh et al., 2008;Beasley et al., 2012;Bai et al., 2016). Furthermore, wing length remains constant in museum specimens, whereas other insect body parts, including the thorax and abdomen, shrink over time (Krogmann & Holstein, 2010;Gilbert, 2011). ...
1. Body size is highly correlated with physiological traits, fitness, and trophic interactions. These traits are subject to change if there are widespread reductions of body size with warming temperatures, which is suggested as one of the “universal” ecological responses to climate change. However, general patterns of body size response to temperature in insects have not yet emerged.
2. To address this knowledge gap, we paired the wing length (as a proxy for body size) of 5,331 museum specimens of 14 species of British Odonata with historical temperature data. Three sets of analyses were performed 1) a regression analysis to test for a relationship between wing length and mean seasonal temperature within species and subsequent comparisons across species and suborders, 2) an investigation of whether the body size of species has an effect on sensitivity to warming temperature and, 3) a linear-mixed effects model to investigate factors that potentially affect temperature-size response.
3. The regression analysis indicated that wing length is negatively correlated with mean seasonal temperatures for Zygoptera, while, Anisoptera showed no significant correlation with temperature.
4. There is a significant decline in wing length of all Zygoptera (but not Anisoptera) with collection date, suggesting that individuals emerging later in the season are smaller.
5. Life-cycle type was not important for predicting wing length-temperature responses, whereas sex, species and suborder were indicated as important factors affecting the magnitude of temperature-size responses in Odonata.
6.Overall, wing lengths of Zygoptera are more sensitive to temperature and collection date than Anisoptera.<br/
... Additionally, radiation exposure did not significantly affect FA or shape in wings of the marsh grasshopper (Chorthippus albomarginatus) nor did it significantly affect hatching success and fecundity in the ChEZ up to dose rate of 50 μGy h −1 (Beasley et al., 2012). There was no correlation of aquatic isopod (Asellus aquaticus) FA with radiation doses (up to 18 μGy h −1 ), suggesting that differences in asymmetry were not attributed to radionuclide contamination (Fuller et al., 2017). ...
The assessment of the fluctuating asymmetry based on measurement of the parameters of left and right parts of silver birch (Betula pendula (L.) Roth.) leaves and relative sizes of pairs of Scots pine (Pinus sylvestris L.) needles from the Chernobyl Exclusion Zone (ChEZ) was carried out. Twelve samples of both birch leaves and pairs of needles were collected from 10 trees at 5 sites in the Chernobyl Exclusion Zone and also at one control site located outside the ChEZ. Values of gamma dose rate in the air varied between the sites from 0.1 to 40 μGy h-1. Activity concentrations of 90Sr and 137Cs in the birch leaves varied over the range of 0.9÷2460 kBq kg-1 and 0.1÷339 kBq·kg-1 (DW), respectively. In addition to the above, in the Scots pine needles, these ranges were 0.7 ÷1970 kBq kg-1f for 90Sr and 0.1÷78 kBq kg-1 (DW) for 137Cs. From the values of the radionuclides activity concentrations in the plants, the internal dose rate is estimated to be in the range of 0.1 ÷ 274 μGy h-1. The main sources of the internal dose rate were radiation of 90Sr and 90Y. Indices of fluctuating asymmetry of silver birch leaves and Scots pine needles varied over the range of 0.048 ± 0.007 ÷ 0.060 ± 0.009 and 0.014 ± 0.002 ÷ 0.018 ± 0.002, respectively, and did not statistically differ for all experimental sites. The indices also did not depend on the external or internal dose rate of ionizing radiation for plants. The above findings seem to be consistent with other research effort in terms of understanding the response of organisms to chronic pollutant exposure and the long-term effects of large scale nuclear accidents.
... Moreover, radiation-induced abnormalities may affect the fertility and mating ability of the studied insects and could lead to genomic instability in mitotically dividing cells and interfere with the function of tissues and organs (Moskalev 2007). This transgenerational genomic instability leads to destabilization in the developmental pathways (Møller 2002) and consequently, could adversely affect offspring development and fitness (Beasley et al. 2012). Such abnormalities seem to be irreversible and could be inherited (Bloem et al. 1999;Carpenter et al. 2009). ...
Ultrastructure alterations in spermiogenesis of the ground beetle, Blaps sulcata (Coleoptera: Tenebrionidae) were studied in normal adult males and in two male groups irradiated by gamma rays of 3 and 16 μSv/h dose rate. Ultrastructure examination of irradiated sperms revealed many alterations both in the head and in the flagellum regions of mature sperm. Alterations of the head region included nuclei with uncondensed chromatin materials and irregular nuclear envelope. Abnormal flagella contained malformed mitochondrial derivatives and damaged axonemes in addition to the absence of accessory bodies. Bi- and multi-flagellate sperms (with two, three, and four axonemes) were the most common alterations. Sperm cells with residual bodies were also obtained. Agglutinated sperms and sperms with enlarged and/or vacuolated cytoplasm were common. Sperm abnormalities were more pronounced in males irradiated by 16 μSv/h dose rate than those irradiated by 3 μSv/h. Spermiogenesis alterations induced by irradiation of B. sulcata may be used as a monitoring model for predicting the effects of environmental radioactivity.
... Body size (wing size) changes significantly along environmental gradients. The larger body size of T. annulata with bigger wing size, so wing size could be used as a proxy for body size in this study, in line with other similar studies of insects 46,47 , and the variation in the body size of T. annulata is reflected in changes in wing size. Variability in body size is one of the most striking traits of most insects and strong relationships exist between body size and a variety of environmental factors associated with insects. ...
... Body size (wing size) changes significantly along environmental gradients. The larger body size of T. annulata with bigger wing size, so wing size could be used as a proxy for body size in this study, in line with other similar studies of insects 46,47 , and the variation in the body size of T. annulata is reflected in changes in wing size. Variability in body size is one of the most striking traits of most insects and strong relationships exist between body size and a variety of environmental factors associated with insects. ...
A quantitative analysis of wing variation in grasshoppers can help us to understand how environmental heterogeneity affects the phenotypic patterns of insects. In this study, geometric morphometric methods were used to measure the differences in wing shape and size of Trilophidia annulata among 39 geographical populations in China, and a regression analysis was applied to identify the major environmental factors contributing to the observed morphological variations. The results showed that the size of the forewing and hindwing were significantly different among populations; the shape of the forewing among populations can be divided into geographical groups, however hindwing shape are geographical overlapped, and populations cannot be divided into geographical groups. Environmental PCA and thin-plate spline analysis suggested that smaller individuals with shorter and blunter-tip forewings were mainly distributed in the lower latitudes and mountainous areas, where they have higher temperatures and more precipitation. Correspondingly, the larger-bodied grasshoppers, those that have longer forewings with a longer radial sector, are distributed in contrary circumstances. We conclude that the size variations in body, forewing and hindwing of T. annulata apparently follow the Bergmann clines. The importance of climatic variables in influencing morphological variation among populations, forewing shape of T. annulata varies along an environmental gradient.
... Body size (wing size) changes significantly along environmental gradients. The larger body size of T. annulata with bigger wing size, so wing size could be used as a proxy for body size in this study, in line with other similar studies of insects 46,47 , and the variation in the body size of T. annulata is reflected in changes in wing size. Variability in body size is one of the most striking traits of most insects and strong relationships exist between body size and a variety of environmental factors associated with insects. ...
... Body size (wing size) changes significantly along environmental gradients. The larger body size of T. annulata with bigger wing size, so wing size could be used as a proxy for body size in this study, in line with other similar studies of insects 46,47 , and the variation in the body size of T. annulata is reflected in changes in wing size. Variability in body size is one of the most striking traits of most insects and strong relationships exist between body size and a variety of environmental factors associated with insects. ...
A quantitative analysis of wing variation in grasshoppers can help us to understand how environmental
heterogeneity affects the phenotypic patterns of insects. In this study, geometric morphometric
methods were used to measure the differences in wing shape and size of Trilophidia annulata among
39 geographical populations in China, and a regression analysis was applied to identify the major
environmental factors contributing to the observed morphological variations. The results showed that
the size of the forewing and hindwing were significantly different among populations; the shape of the
forewing among populations can be divided into geographical groups, however hindwing shape are
geographical overlapped, and populations cannot be divided into geographical groups. Environmental
PCA and thin-plate spline analysis suggested that smaller individuals with shorter and blunter-tip
forewings were mainly distributed in the lower latitudes and mountainous areas, where they have
higher temperatures and more precipitation. Correspondingly, the larger-bodied grasshoppers, those
that have longer forewings with a longer radial sector, are distributed in contrary circumstances. We
conclude that the size variations in body, forewing and hindwing of T. annulata apparently follow the
Bergmann clines. The importance of climatic variables in influencing morphological variation among
populations, forewing shape of T. annulata varies along an environmental gradient.
... The Fukushima Nuclear Power Plant (NPP) accident is the second largest nuclear accident next to the Chernobyl accident in the history of mankind. Epidemiological and physiological studies on humans following the Chernobyl accident that assessed infant leukemia [1][2][3][4][5][6], infant mortality [7,8], blood cell counts [9], and thyroid cancer [10,11], and ecological studies on wild organisms, including plants, insects, birds and small mammals [12][13][14][15][16][17][18][19][20][21], have accumulated evidence that indicates a number of biological impacts of the accident. In these studies, ingestional risks and transgenerational effects are discussed. ...
One important public concern in Japan is the potential health effects on animals and humans that live in the Tohoku-Kanto districts associated with the ingestion of foods contaminated with artificial radionuclides from the collapsed Fukushima Dai-ichi Nuclear Power Plant. Additionally, transgenerational or heritable effects of radiation exposure are also important public concerns because these effects could cause long-term changes in animal and human populations. Here, we concisely review our findings and implications related to the ingestional and transgenerational effects of radiation exposure on the pale grass blue butterfly, Zizeeria maha, which coexists with humans. The butterfly larval ingestion of contaminated leaves found in areas of human habitation, even at low doses, resulted in morphological abnormalities and death for some individuals, whereas other individuals were not affected, at least morphologically. This variable sensitivity serves as a basis for the adaptive evolution of radiation resistance. The distribution of abnormality and mortality rates from low to high doses fits well with a Weibull function model or a power function model. The offspring generated by morphologically normal individuals that consumed contaminated leaves exhibited high mortality rates when fed contaminated leaves; importantly, low mortality rates were restored when they were fed non-contaminated leaves. Our field monitoring over 3 years (2011-2013) indicated that abnormality and mortality rates peaked primarily in the fall of 2011 and decreased afterwards to normal levels. These findings indicate high impacts of early exposure and transgenerationally accumulated radiation effects over a specific period; however, the population regained normality relatively quickly after ∼15 generations within 3 years.
... Adaptation to radiation stress has been reported in the literature. For example, transgenerational developmental responses to radiation have been documented in grasshoppers in Chernobyl [20], and possible adaptation to oxidative stress in birds as a consequence of the Chernobyl accident has been reported recently [21]. In regions with high natural radiation levels, radiation resistance has been observed in Drosophila [22] and other organisms [23]. ...
Long-term monitoring of the biological impacts of the radioactive pollution caused by the Fukushima nuclear accident in March 2011 is required to understand what has occurred in organisms living in the polluted areas. Here, we investigated spatial and temporal changes of the abnormality rate (AR) in both field-caught adult populations and laboratory-reared offspring populations of the pale grass blue butterfly, Zizeeria maha, which has generation time of approximately one month. We monitored 7 localities (Fukushima, Motomiya, Hirono, Iwaki, Takahagi, Mito, and Tsukuba) every spring and fall over 3 years (2011-2013).
The adult ARs of these localities quickly increased and peaked in the fall of 2011, which was not observed in non-contaminated localities. In the offspring generation, the total ARs, which include deaths at the larval, prepupal, and pupal stages and morphological abnormalities at the adult stage, peaked either in the fall of 2011 or in the spring of 2012, with much higher levels than those of the parent field populations, suggesting that high incidence of deaths and abnormalities might have occurred in the field populations. Importantly, the elevated ARs of the field and offspring populations settled back to a normal level by the fall of 2012 and by the spring of 2013, respectively. Similar results were obtained not only in the spatiotemporal dynamics of the number of individuals caught per minute but also in the temporal dynamics of the correlation coefficient between the adult abnormality rate and the ground radiation dose or the distance from the Power Plant.
These results demonstrated an occurrence and an accumulation of adverse physiological and genetic effects in early generations, followed by their decrease and leveling off at a normal level, providing the most comprehensive record of biological dynamics after a nuclear accident available today. This study also indicates the importance of considering generation time and adaptive evolution in evaluating the biological impacts of artificial pollution in wild organisms.
... There is currently very little empirical information on these possible mechanisms. For example, Beasley et al. (2012) showed for grasshoppers Chorthippus albomarginatus from Chernobyl in a common garden experiment that parental radiation exposure had little measurable effect on developmental instability in morphology, fecundity or survival. More studies of this sort are required for a better understanding of the underlying mechanisms responsible for differences in abundance of invertebrates related to differences in background radiation. ...
... Such a study could potentially expand into multi-generational responses of FA to a stressor, and insect models would be ideal (e.g. Beasley et al., 2012). This is particularly important for contaminants such as oil spills, radiological and metal pollutants that are expected to persist in the environment for long periods of time. ...
Random and subtle deviations from bilateral symmetry (fluctuating asymmetry) have long been of interest to biologists who wish to study the susceptibility of organisms to changes in environmental quality. However, the reliability of FA as a biomarker has come under question due to inconsistent results in the literature. We conducted a meta-analysis of published literature to test the hypothesis that FA is a reliable biomarker of environmental stress in insects and identify possible sources of variation amongst studies. We expected studies to detect larger, positive magnitudes of effect on FA in lab populations due to the lack of confounding effects from other environmental factors compared to wild populations.
Additionally, we predicted that studies that used geometric morphometric approaches to FA in shape and size would be more sensitive to changes in environmental quality compared to linear and meristic measures and thus show larger effects on FA. We also expected anthropogenic stressors to generate significantly larger effects on FA compared to naturally occurring stressors due to the organisms’ inability to buffer developmental pathways against a novel stressor. Finally, we predicted comparatively larger magnitudes
of effect in studies that verified the environmental factor acting on the organism was a stressor by detecting negative effects on fitness-related traits. Overall, we found that FA is a sensitive biomarker of environmental stress. Environmental stressors explained 36% of the variation of effect on FA across studies. Studies that demonstrated a negative effect of the stressor on fitness-related traits showed significantly larger, positive magnitudes of effect on FA compared to studies that did not detect an effect from the environmental stressor. Additionally, studies conducted under laboratory conditions detected
significantly larger, effects on FA compared to field-based studies. The kind of trait measured and the novelty of the stressor did not significantly account for differences amongst studies. Thus, the use of FA as a biomarker of environmental stress is a legitimate tool particularly when studies verify the biological relevance of stressors for the study organism.
Purpose:
Task Group 121 - Effects of ionizing radiation exposure in offspring and next generations - is a task group under the Committee 1 of the International Commission on Radiological Protection (ICRP), approved by the Main Commission on 18th November 2021. The main goals of Task Group 121 are to (1) review and update the scientific literature of relevance to radiation-related effects in the offspring of parent(s) exposed to ionizing radiation in both human and non-human biota; (2) to assess preconceptional and intrauterine effects of radiation exposure and related morbidity and mortality; and, (3) to provide advice about the level of evidence and how to consider these preconceptional and postconceptional effects in the system of radiological protection for humans and non-human biota.
Methods:
The Task Group is reviewing relevant literature since Publication 90 'Biological effects after prenatal irradiation (embryo and fetus)' (2003) and will include radiation-related effects on future generations in humans, animals, and plants. This review will be conducted to account for the health effects on offspring and subsequent generations in the current system of radiological protection. Radiation detriment calculation will also be reviewed. Finally, preliminary recommendations will be made to update the integration of health effects in offspring and next generations in the system of radiological protection.
Results:
A Workshop, jointly organized by ICRP Task Group 121 and European Radiation Protection Research Platforms MELODI and ALLIANCE was held in Budapest, Hungary, from 31st May to 2nd June 2022. Participants discussed four important topics: (1) hereditary and epigenetic effects due to exposure of the germ cell line (preconceptional exposure), (2) effects arising from exposure of the embryo and fetus (intrauterine exposure), (3) transgenerational effects on biota, and (4) its potential impact on the system of radiological protection.
Conclusions:
Based on the discussions and presentations during the breakout sessions, newer publications, and gaps on the current scientific literature were identified. For instance, there are some ongoing systematic reviews and radiation epidemiology reviews of intrauterine effects. There are newer methods of Monte Carlo simulation for fetal dosimetry, and advances in radiation genetics, epigenetics, and radiobiology studies. While the current impact of hereditary effects on the global detriment was reported as small, the questions surrounding the effects of radiation exposure on offspring and the next generation are crucial, recurring, and with a major focus on exposed populations. This article summarizes the workshop discussions, presentations, and conclusions of each topic and introduces the special issue of the International Journal of Radiation Biology resulting from the discussions of the meeting.
Environmental disasters and growth of nuclear power contribute to increasing levels of radiation pollution in the biosphere. Major impacts concern development, fertility, and survivorship in diverse species. Subtle impacts are less appreciated even though they may have profound effects on individuals and populations. Here, we examined radiation impacts on male crickets, Acheta domesticus (L.) (Orthoptera: Gryllidae), specific to wing development. Alterations in global wing morphology are detectable, but this is a flightless species. However, mating success of males is highly dependent on specialized courtship songs generated by structures associated with the opposing forewings. Such signals identify males as both conspecific and ‘attractive/fit’ mates. Highly specialized structures found on male forewings include the chord, harp, mirror, plectrum, and file. These work in concert to generate the species‐specific male courtship song. Even slight alterations in wing morphology can alter these signals, and variation may also vary acoustic signals among populations. Here, we analyze the impacts of early‐life radiation exposure (0–10 Gy) on male forewing shape and size using morphometric analysis. A canonical variate analysis (CVA) illustrated that wing shape was significantly altered in a dose‐dependent basis: 10 Gy (P<0.0001), 7 Gy (P<0.0001), and 2 Gy (P = 0.0001). Principal component (PC) analysis as well as the CVA indicated that most variation in wing structure was associated with the mirror, one of the two main resonating regions on the forewing. Analysis of centroid size found significant reductions with 7 and 10 Gy radiation exposures. Significant radiation‐induced increases in fluctuating asymmetry were also detected, with fluctuating asymmetry values increasing with dose. Due to the known specialized nature of song‐producing structures and its association with both courtship songs and mating, it is likely that the alterations observed in shape and size will have larger impacts on male reproductive success. We are currently quantifying this and analyzing recordings of song structure to detect and characterize specific alterations by radiation. This article analyzes the impact of early‐life radiation on wings of male crickets Acheta domesticus (Orthoptera: Gryllidae). Using morphometric analysis on song‐producing regions we determined radiation‐induced alterations to both the size and shape of song regions. As male crickets, like many other insect species, use specialized acoustic signaling to identify themselves as both male and conspecific, any alterations to wing size and structure could have catastrophic impacts on male reproductive success.
Purpose: On April 26, 1986 reactor 4 at the Chernobyl power plant underwent a catastrophic failure leading to core explosions and open-air fires. On March 11, 2011, a combination of earthquake and tsunami led to a similar disaster at the Fukushima Daiichi power plant. In both cases radioactive isotopes were released and contaminated the air, soil and water in a substantial area around the power plants. Humans were evacuated from the immediate regions but the wildlife stayed and continued to be affected by the ongoing high radiation exposure initially and later decayed amounts of fallout dusts with time. In this review, we will examine the significant effects of the increased radiation on vegetation, insects, fish, birds and mammals.
Conclusions: The initial intense radiation in these areas has gradually begun to decrease but still remains high. Adaptation to radiation is evident and the ecosystems have dynamically changed from the periods immediately after the accidents to the present day. Understanding the molecular mechanisms that allow the adaptation and recovery of wildlife to chronic radiation challenges would aid in future attempts at ecosystem remediation in the wake of such incidents.
In this study, UV–visible light spectrophotometry was used for the first time to examine the migration behaviours of cationic and nonionic imidazoline corrosion inhibitors in concrete. Imidazoline can react with bromocresol purple resulting in a reduction in absorbance, which can be used to calculate quantitatively imidazoline concentration. The results showed that the migration rate of nonionic imidazoline was faster than that of cationic imidazoline with or without the presence of an electric field, possibly because of the better water solubility of nonionic imidazoline. The electric field could significantly accelerate the migration rate of the cationic and nonionic imidazoline. However, the penetration performance of nonionic imidazoline was much improved compared with that of cationic imidazoline in concrete. From X‐ray photoelectron spectroscopy analysis, the N element could be detected on steel, verifying the migration behaviour of the nonionic imidazoline. This nonionic imidazoline could markedly retard steel corrosion according to potentiodynamic polarization.
This study was conducted to examine the effect of gamma radiation on biological specimens. Thus, our concept is to clarify that exposure to accumulated dose of 0.2 Gy gamma rays (0.66 rad/Sec. dose rate) from Cs137 source induces cellular perturbations in the midgut epithelium of the F1 progeny of Blaps polycresta, therefore affecting nutrition and growth. Beetles were reared in laboratory conditions and the newly emerged adults were irradiated with the aforementioned dose. Histological and ultrastructure anomalies of midgut cells (digestive and regenerative cells) were observed by 72 h after radiation exposure to ensure that the cells will not return to control state. Retardation in the development of the F1 progeny was also noticed and beetles died through two weeks. In the light of these observations, biological tissue act as an indicator to the continuous exposure to environmental radiation.
This chapter attempts to place the genetics of neurodevelopmental disorders (NDDs) in an evolutionary perspective. It offers a brief review of developmental instability (DI) theory, emphasizing its deep roots in evolutionary biology. The recent revolution in genetic technology has led to the first wave of studies offering direct assessments of mutation load. The chapter focuses mostly on a specific type of mutation copy number variations (CNVs). Three very different approaches have provided support for the hypothesis that mutation load in general, that is, individually specific patterns of mutations distributed across the genome, impacts important human phenotypes, ranging from diverse health issues to intelligence to risk of NDD. The chapter discusses two critical issues that emerge as especially important for studies attempting direct measurements of mutations in our DNA. It further analyzes the reasons why CNVs may be especially important to psychiatric disorders.
Numerous organisms have shown an ability to survive and reproduce under low-dose ionizing radiation arising from natural background radiation or from nuclear accidents. In a literature review, we found a total of 17 supposed cases of adaptation, mostly based on common garden experiments with organisms only deriving from typically two or three sampling locations. We only found one experimental study showing evidence of improved resistance to radiation. Finally, we examined studies for the presence of hormesis (i.e., superior fitness at low levels of radiation compared with controls and high levels of radiation), but found no evidence to support its existence. We conclude that rigorous experiments based on extensive sampling from multiple sites are required.
Studies of the responses of birds and other organisms to the nuclear accidents at Chernobyl and Fukushima. Jpn J Ornithol 64: 71–76. (2015)
Recently, the adaptive significance of maternal effects has been increasingly recognized. No longer are maternal effects relegated as simple `troublesome sources of environmental resemblance' that confound our ability to estimate accurately the genetic basis of traits of interest. Rather, it has become evident that many maternal effects have been shaped by the action of natural selection to act as a mechanism for adaptive phenotypic response to environmental heterogeneity. Consequently, maternal experience is translated into variation in offspring fitness.
The effect of photoperiod on nymphal development in the cricket Modicogryllus siamensis was studied. In constant long-days with 16 hr light at 25°C, nymphs matured within 40 days undergoing 7 moults, while in constant short-days with 12 hr light, 12∼23 weeks and 11 or more moults were necessary for nymphal development. When nymphs were transferred from long to short day conditions in the 2nd instar, both the number of nymphal instars and the nymphal duration increased. However, only the nymphal duration increased when transferred to short day conditions in the 3rd instar or later. When the reciprocal transfer was made, the accelerating effect of long-days was less pronounced. The earlier the transfer was made, the fewer the nymphal instars and the shorter the nymphal duration. The decelerating effect of short-days or accelerating effect of long-days on nymphal development varied depending on instar. These results suggest that the photoperiod differentially controls the number of nymphal instars and the duration of each instar, and that the stage most important for the photoperiodic response is the 2nd instar.
Females of three tropical satyrine butterflies in the genus Mycalesis lay variable-sized eggs. The species also differ substantially in their mean egg weights with M. perseus laying smaller eggs than M. terminus and M. sirius. The adaptive significance of the egg size variation was examined in relation to three offspring fitness components: larval survival, larval developmental time and pupal weight, to establish if larvae derived from heavier eggs were in any way better than those derived from lighter eggs when reared on different hostplant qualities varying in leaf toughness and nitrogen content. When the three species were reared on the tougher nitrogen-poor host quality (Panicum-intermediate category) larvae from heavier eggs had significantly better chance of surviving and reaching adulthood than those from lighter eggs. However, when larvae were reared on the softer nitrogen-rich host quality (Panicum-soft category) the advantage to heavier eggs diminished in M. terminus and M. sirius, but not in M. perseus. Egg weight was also positively correlated with subsequent pupal weight in M. perseus for both male and female larvae reared on Panicum-soft, and with larval development rate in M. sirius (both sexes) when reared on Themeda - a hostplant known to be of poor quality for M. sirius. The positive correlation between egg size and offspring fitness suggests that under field conditions larvae from larger eggs may do better than those from smaller eggs when conditions are unfavourable, for example, adverse climate or poor host quality. Moreover, a strong positive correlation between egg size and the width of the head capsule of newly emerged first instar larvae suggests that larvae from larger eggs have bigger mandibles and therefore potentially able to chew and survive better on tougher foliage. Potential selective pressures likely to influence egg size in these satyrines and other butterflies are discussed.
The Chernobyl accident of 1986 released vast quantities of radioactive materials and significantly contaminated about 200,000 square kilometers of land. The Chernobyl Forum Report, an initiative of the International Atomic Energy Agency, suggested that the effects of radiation on wildlife were negligible relative to the impacts of human habitation, but this position was based on the very limited data available prior to this 2006 report. The wildlife of this region has been the subject of extensive study since 2005; since then, research has found that many birds, insects, spiders, and mammals show significant declines as a probable consequence of exposure to radionuclides. The best-studied group, birds, shows a 50 percent decrease in species richness and a 66 percent drop in abundance in the most contaminated areas compared to areas with normal background radiation in the same neighborhood. In addition, mutation rates and developmental abnormalities are dramatically higher, and survival rates and fertility are lower, in regions of moderate to high contamination. These findings challenge reports in the popular media and the conclusions of the Chernobyl Forum Report and are of relevance today, given recent interest in returning contaminated lands to agriculture use and the renaissance of the global nuclear power industry.
The explosion at the Chernobyl nuclear power plant on 26 April 1986 released vast amounts of radioactive material over an area of 200,000km2 in eastern and central Europe, affecting all living organisms. The biological impacts including the conservation consequences of this event are still poorly known even 25years after the disaster. Here we assess the effects of this environmental disaster for conservation by focusing on two connected questions addressing the short-term ecological and the long-term evolutionary consequences: First, we pose the question of whether rare species are more impacted by radiation than common species? Second, what are the conservation consequences of elevated mutation rates due to the mutagenic effects of radionuclides from Chernobyl? Furthermore, we assess the extent to which ecological and evolutionary aspects interact. We censused breeding birds across 731 census points in Ukraine and Belarus during 3years to assess the relationship between abundance of different species and radiation. Most bird species avoided contaminated sites and individuals were concentrated in relatively uncontaminated sites. While common species were recorded at a wide range of radiation levels, rare species were restricted to the least contaminated sites and to sites with a high biodiversity. Thus, rare species were disproportionately impacted by the accident. Mutation rates of plants and animals have increased by up to a factor 20 due to release of radionuclides from Chernobyl. Given that each slightly deleterious mutation is expected to result in a selective genetic death, and that an average fruitfly under normal conditions may carry as many as 80 mutations, the number of mutations in animals and plants around Chernobyl and hence the number of selective deaths is bound to be much higher. There is empirical evidence for highly elevated mortality rates and dramatically increased rates of reproductive failure in contaminated areas, consistent with the expected high frequency of selective deaths due to mutations. The average slightly deleterious mutation is present for 33–167 generations in Drosophila, so if these estimates are qualitatively similar in other organisms, we can expect that mutants will disperse outside contaminated areas resulting in the spread of mutations well beyond the reach of contamination with radionuclides. Therefore, it should be possible to document the gradual spread of mutations from Chernobyl. We consider that the Chernobyl disaster and other nuclear releases may have significant consequences for population size and population viability of many species due to the large number of selective deaths. These effects remain to be investigated. Finally, comparative analyses of birds revealed that species with high mitochondrial DNA substitution rates had short dispersal distances, suggesting that mutations will spread relatively short distances when they are common, but will spread longer distances in species when they are rare.
Geographic clines in body size have been described for many species, but relatively few investigations have tested hypotheses for the ontogenetic mechanisms maintaining geographic clines. We formalize and test the predictions for the role of ontogenetic mechanisms (e.g., hatching timing and size, juvenile developmental time, juvenile growth rate) in maintaining a longitudinal cline in adult body size of lubber grasshoppers [Romalea microptera (Beauvois)]. To obtain hatching timing and size, we collected eggs from wild females from several populations along the longitudinal gradient in 2 yr (2006 and 2007) and measured hatchling size and hatch date. To obtain juvenile developmental time and growth rates, we surveyed populations along the longitudinal gradient during 2 yr (2006 and 2007) and estimated developmental time and growth rates. We found the developmental time (hatching to fourth instar) and female growth rates increase from west to east along the cline. Patterns of hatching timing and hatching size were not consistent with the size cline. The size cline becomes evident in the third instar and is magnified in the fourth and fifth instars. Our data suggest that the size cline arises from some combination of clinal variation in developmental time and female growth rates; prolonged development and greater growth rates lead to larger mean size. Equally important, we found no evidence that differences in hatching time or size are ontogenetic causes of this cline. Our hypotheses for ontogenetic mechanisms producing an adult size cline should serve as a template for ecologists seeking to understand the ontogenetic basis of spatial variation in phenotypes.
The purpose of the International Database on Insect Disinfestation and Sterilization (IDIDAS: http://www-ididas.iaea.org/ididas/) website is to collect and share information about radiation doses for disinfestation and reproductive sterilization of arthropods and to perform a comparative analysis and quality assurance check on existing data. IDIDAS was developed based on a literature review and analysis of >2,750 references, published during the past five decades. In total, 309 species of arthropods, mostly of economic importance, from 196 genera, 84 families, 9 insect orders, and 2 arachnid orders, have been subjected to irradiation studies for purposes of (1) research, such as sperm precedence determination and parasitoid-host interaction studies, (2) disinfestation for quarantine or phytosanitary purposes or (3) different pest control applications, including the sterile insect technique (SIT) and biological control programs. Sensitivity to radiation among families, and in particular orders, varies sometimes over two orders of magnitude, with Arctiidae and Pyralidae (Lepidoptera) being the most radioresistant, requiring the highest sterilizing doses (100–300 Gy), and Acrididae (Orthoptera) and Blaberidae (Dictyoptera) the lowest (<5 Gy). Within Diptera, Coleoptera and Hemiptera radiation doses vary widely among families and range from 20 to 200 Gy. Soft Acari species belonging to Ixodidae are more sensitive than hard species of Argasidae and Tetranychidae mites. In general, most insect, mite, and tick families require a sterilizing dose of <200 Gy. Analysis of data shows that, with few exceptions, generic doses of radiation apply to species within the same genus, and thus, there is generally no need to develop radiation biology data for all species. Although the objective of this database is to present the optimum dose for research, disinfestation, or sterilization at the species level, there is some inconsistency in the recorded doses resulting from variation in many factors affecting sensitivity to radiation. Thus, this review highlights the need for further efforts to standardize experimental dosimetry and irradiation procedures for arthropods and provides a suitable platform for guiding future research in this area.
El fenómeno genético único responsable para la esterilidad heredada en estado F1 de los lepidópteros y otros artrópodos provee una ventaja para el uso de la esterilidad heredada en un programa de técnica de insecto estéril (TIE). Las hembras de lepidópteros generalmente pueden ser completamente esterilizadas con una dosis de radiación que solamente esteriliza parcialmente los machos de la misma especie. Cuando estos machos esterilizados parcialmente se aparean con hembras fértiles, muchos de los efectos delectivos inducidos por la radiación son heredados por la generación F1. A la dosis de radiación apropiada, la eclosión de los huevos de las hembras apareadas con machos irradiados es reducida y las progenies que resultan son altamente estériles y predominantemente del sexo macho. Las dosis mas bajas de radiación usada para inducir la esterilidad de F1 aumentan la calidad y la competividad de los insectos liberados. Sin embargo, durante el programa de TIE es posible que las trampas usadas para monitorear poblaciones de polillas salvajes y la tasa de sobre liberación (machos liberados marcados versus los machos salvajes no marcados) pueden capturar machos estériles de F1 no marcados que no pueden ser distinguidos de machos salvajes fértiles. En este estudio nosotros desarrollamos una técnica citológica usando cepas de orcein y Giemsa, lo cual distingue la progenie F1 de los adultos machos irradiados y machos fértiles. Nuestras observaciones sobre especies de 6 plagas en 5 families del orden Lepidóptero indican que los machos F1 (estériles) que provienen de machos irradiados pueden ser distinguidos de los que provienen de machos fértiles por un grupo de núcleos en bultos de esperma eupirene. El grupo de núcleos en los machos fértiles presentaron un arreglo de esperma regular y organizado y fue homogéneamente teñido, mientras que en los machos de F1 el grupo de los núcleos de esperma fue desorganizado, irregular y teñido de una manera dispareja.
Fear lives among Everest’s mighty ice-fluted faces and howls across its razor-sharp crags. Gnawing at reason and enslaving minds, it has killed many and defeated countless others. But in 1953, Edmund Hillary and Tenzing Norgay stared into its dark eye and did not waver. On May 29, they pushed spent bodies and aching lungs past the achievable to pursue the impossible. At a terminal altitude of 29,028 feet, they stood triumphant atop the highest peak in the world. With nimble words and a straightforward style, New Zealand mountaineering legend Hillary recollects the bravery and frustration, the agony and glory that marked his Everest odyssey. From the 1951 expedition that led to the discovery of the Southern Route, through the grueling Himalayan training of 1952, and on to the successful 1953 expedition led by Colonel John Hunt, Hillary conveys in precise language the mountain’s unforgiving conditions. In explicit detail he recalls an Everest where chaotic icefalls force costly detours, unstable snow ledges promise to avalanche at the slightest misstep, and brutal weather shifts from pulse-stopping cold to fiendish heat in mere minutes. In defiance of these torturous conditions, Hillary remains enthusiastic and never hesitates in his quest for the summit. Despite the enormity of his and Norgay’s achievement, he regards himself, Norgay, and the other members of his expedition as hardworking men, not heroes. And while he never would have reached the top without practiced skill and technical competence, his thrilling memoir speaks first to his admiration of the human drive to explore, to understand, to risk, and to conquer.
In this study, I examine the effects of natural and experimentally induced variation in life cycle timing on offspring fitness in Arphia sulphurea and Chortophaga viridifasciata, to understand the selective pressures shaping phenology in these two species of nymph-overwintering grasshoppers. Because these species lack embryonic diapause, hatching varies over a two month range under natural conditions. I used a cold treatment to delay hatching of some egg pods and extend the natural range of hatching dates. Due to the shorter time for growth and poorer growing conditions late in the fall, late-hatching nymphs of both species grew to a smaller size before winter and suffered higher overwinter mortality, compared to early nymphs. In addition, late nymphs that did survive the winter became reproductive later in the following year's breeding season. Size- dependent mortality of offspring during the winter is a strong selective pressure favoring early reproduction in these species. Female adult life history traits appear responsive to the seasonal declines in offspring fitness, in that late-maturing females began reproducing sooner after adult maturation and reproduced at a more rapid rate, even at the expense of having shorter adult longevity and producing fewer total egg pods. Experimental manipulations were crucial in understanding the fitness consequences of intrapopulation variation in the timing of specific life-cycle events for these species.
Although fluctuating asymmetry has become popular as a measure of developmental instability, few studies have examined its developmental basis. We propose an approach to investigate the role of development for morphological asymmetry by means of morphometric methods. Our approach combines geometric morphometrics with the two-way ANOVA customary for conventional analyses of fluctuating asymmetry and can discover localized features of shape variation by examining the patterns of covariance among landmarks. This approach extends the notion of form used in studies of fluctuating asymmetry from collections of distances between morphological landmarks to an explicitly geometric concept of shape characterized by the configuration of landmarks. We demonstrate this approach with a study of asymmetry in the wings of tsetse flies (Glossina palpalis gambiensis). The analysis revealed significant fluctuating and directional asymmetry for shape as well as ample shape variation among individuals and between the offspring of young and old females. The morphological landmarks differed markedly in their degree of variability but multivariate patterns of landmark covariation identified by principal component analysis were generally similar between fluctuating asymmetry (within-individual variability) and variation among individuals. Therefore there is no evidence that special developmental processes control fluctuating asymmetry. We relate some of the morphometric patterns to processes known to be involved in the development of fly wings.
In this paper, we consider the-principal migration pathways of radionuclides from the Chernobyl-accident in and through nearby terrestrial landscapes. Specifically, we study terrestrial ecosystems and the geological environment, taking into account the influence of critical (anomalous) landscapes on these processes. We show that migration activity of radionuclides is maximal in these landscapes. We determined that the following factors (in diminishing order) affect the migration of radionuclides: the geological environment, vegetation, superficial drainage, and wind resuspension. Downward radionuclide migration paths play the main role in the multilayer system of water-bearing horizon contamination. According to balance estimates, about 2,600 Ci of Cs-137 and Sr-90 have come into the geological environment and deposited radionuclides. This estimate is 5-25 times the amount carried out from the 30 km Chernobyl Exclusion Zone by water via the Prypyat River.
Release and dispersion of radioactive material from the Chernobyl accident and the radiological consequences are described. Protective measures taken are outlined. International assessments of this accident are summarized and placed in perspective with radiation exposure from other sources, in particular, natural background radiation, weapons testing, medical uses of ionizing radiation, and nuclear power production.
Effects of ultraviolet and infra-red light have been investigated on the life cycle of the most destructive pest of stored pulses - Callosobruchus chinensis Linn. The beetles were treated with different durations of exposure to UV and IR light and the effects were evaluated on the basis of various parameters pertaining to oviposition, adult emergence and extent of damage caused to the host pulse. UV light has been found to inflict an inhibitory effect on the oviposition and emergence of pulse beetle. The damage caused to the host pulse was also reduced after the administration of UV. Whereas, IR treatment imposed tonic effects on the oviposition and emergence of beetles and level of infestation was found to be significantly enhanced.
This chapter presents a review that aims to bring together what is known of the physiology of ecdysis with what is known of the behavior of ecdysing insects and shows how one is integrated with the other. Ecdysial behavior is probably largely programmed within the CNS, but once initiated the details of its performance may be more or less influenced by sensory feedback according to the species, and which part of the behavior is being considered. The exceptional stereotypy of the abdominal movements involved in the preeclosion and eclosion behavior of H. cecropia and the confinement of eclosion to a narrow, temporal “gate” by a circadian clock in the brain are key factors that led to the discovery of the role of the eclosion hormone in initiating eclosion behavior. The chapter provides evidence that silkmoth eclosion behavior is initiated directly by eclosion hormone. H. cecropia and A. pernyi emerge from the pupal cuticle only at a particular time of day, during relatively narrow gates determined by a circadian clock. If the pharate adults are removed from their pupal cases during the few hours before the normal eclosion gate, then they continue to show predominantly pupal behavior. In the case of A .pernyi, this is particularly striking, the peeled moth showing very little spontaneous motor activity at all. However, at the time of the normal eclosion gate, the moths go through a pantomime emergence, despite having been free of the pupal case for several hours.
Variable growth and development were imposed on the pitcher-plant mosquito. Wyeomyia smithii, to test whether the initiation of metamorphosis was determined early in larval life or remained flexible throughout development. Like anurans, larval W. smithii are specialized for a suspension-feeding way of life and they metamorphose into dispersing, reproductive adults. We therefore used models originally formulated in an amphibian context to examine the effects of modified larval growth on the triggering of metamorphosis and then used our results to reexamine metamorphosis in amphibians. Response to enhanced and decreased food regimens showed that larval growth during the first two (of four) instars affected both the time to and mass at metamorphosis. The major effects of developmental inertia are prominent for about one to two instars and then abate, but do not necessarily disappear, with each succeeding instar. Despite evidence for developmental inertia in W. smithii, experiments transferring larvae from high food to starvation show that the physiological commitment to undergo metamorphosis does not take place until the last (fourth) instar and that nonzero growth during the last instar is required to trigger metamorphosis. All amphibian models for the initiation of metamorphosis involve the effects of rates: developmental rate and past or present growth rates. In W. smithii, there is no primacy of developmental rate and low growth rate does not stimulate metamorphosis of larvae having attained the minimum mass required for metamorphosis. An insect-derived model involving the effects of size-specific growth increments is more consistent than any amphibian model with our results in W. smithii. Testing the reciprocal ability of the insect model to predict amphibian metamorphosis is not possible with current data, because no study has considered zero growth in amphibians to identify the transition from growth-dependent to growth-independent development leading to metamorphosis. This transition marks the irrevocable commitment of the organism to an ontogenetic niche shift from an aquatic larva to a terrestrial, dispersing, and reproducing adult. Identifying the proximal causes of this mechanism is fundamental to understanding how flexible growth and ontogeny of complex life cycles have adapted to variable larval environments.
In this study, I examine the effects of natural and experimentally induced variation in life cycle timing on offspring fitness in Arphia sulphurea and Chortophaga viridifasciata, to understand the selective pressures shaping phenology in these two species of nymph-overwintering grasshoppers. Because these species lack embryonic diapause, hatching varies over a two month range under natural conditions. I used a cold treatment to delay hatching of some egg pods and extend the natural range of hatching dates. Due to the shorter time for growth and poorer growing conditions late in the fall, late-hatching nymphs of both species grew to a smaller size before winter and suffered higher overwinter mortality, compared to early nymphs. In addition, late nymphs that did survive the winter became reproductive later in the following year's breeding season. Size-dependent mortality of offspring during the winter is a strong selective pressure favoring early reproduction in these species. Female adult life history traits appear responsive to the seasonal declines in offspring fitness, in that late-maturing females began reproducing sooner after adult maturation and reproduced at a more rapid rate, even at the expense of having shorter adult longevity and producing fewer total egg pods. Experimental manipulations were crucial in under-standing the fitness consequences of intrapopulation variation in the timing of specific life-cycle events for these species.
Although fluctuating asymmetry has become popular as a measure of developmental instability, few studies have examined its developmental basis. We propose an approach to investigate the role of development for morphological asymmetry by means of morphometric methods. Our approach combines geometric morphometrics with the two-way ANOVA customary for conventional analyses of fluctuating asymmetry and can discover localized features of shape variation by examining the patterns of covariance among landmarks. This approach extends the notion of form used in studies of fluctuating asymmetry from collections of distances between morphological landmarks to an explicitly geometric concept of shape characterized by the configuration of landmarks. We demonstrate this approach with a study of asymmetry in the wings of tsetse flies (Glossina palpalis gambiensis). The analysis revealed significant fluctuating and directional asymmetry for shape as well as ample shape variation among individuals and between the offspring of young and old females. The morphological landmarks differed markedly in their degree of variability, but multivariate patterns of landmark covariation identified by principal component analysis were generally similar between fluctuating asymmetry (within-individual variability) and variation among individuals. Therefore, there is no evidence that special developmental processes control fluctuating asymmetry. We relate some of the morphometric patterns to processes known to be involved in the development of fly wings.
Individual differences in developmental stability are often estimated using individual asymmetry for bilaterally symmetric traits. These are expected to reflect intrinsic abilities to cope with adverse environmental conditions, an important aspect of genotypic quality which should be associated with fitness, but this supposition has never been tested. Two experiments which manipulated environmental conditions were used to investigate whether individual asymmetry under good environmental conditions adequately predicts a genotype's capacity to buffer development across environments, and further to test whether individuals with superior buffering capacity against environmental stress, as reflected in less increase in asymmetry between poor and good environments, had higher fitness than those with poor buffering capacity, after controlling for the influence of asymmetry per se on fitness. Individual asymmetry of the outer tail feathers of male barn swallows, Hirundo rustica, was compared between two different kinds of good and poor environments. Although some individuals changed ranks for asymmetry values between environmental qualities, individual asymmetry under good conditions correlated with this trait in poor environmental conditions. Furthermore, asymmetry under good environmental conditions was positively correlated to change in asymmetry in one of the two experiments, indicating that individual asymmetry is a good predictor of developmental buffering ability. Individuals that increased in asymmetry less under poor environmental conditions had higher reproductive success, even after controlling for asymmetry phenotype, indicating that developmental stability reflects individual quality, as expressed in high relative fitness. These experiments demonstrate that intrinsic differences in developmental stability reliably predict an important fitness component.
Morphometrics is the statistical study of biological shape and shape change. Its richest data are landmarks, points such as 'the bridge of the nose' that have biological names as well as geometric locations. This book is the first systematic survey of morphometric methods for landmark data. The methods presented here combine conventional multivariate statistical analysis with themes from plane and solid geometry and from biomathematics to support biological insights into the features of many different organs and organisms. This book will be of value to applied statisticians and geometers, as well as to all biological and biomedical researchers who need quantitative analyses of information from biomedical images.
Geometric Morphometrics for Biologists is an introductory textbook for a course on geometric morphometrics, written for graduate students and upper division undergraduates, covering both theory of shape analysis and methods of multivariate analysis. It is designed for students with minimal math background; taking them from the process of data collection through basic and more advanced statistical analyses. Many examples are given, beginning with simple although realistic case-studies, through examples of complex analyses requiring several different kinds of methods. The book also includes URLâs for free software and step-by-step instructions for using the software.
Sterols are essential nutrients for grasshoppers, as well as all other insects, but metabolic constraints can limit which phytosterols support normal growth and development. In the current study, the generalist grasshopper Schistocerca americana was used to address two questions related to grasshopper sterol nutrition: (1) how does sterol quantity influence growth and survival, and (2) how do mixtures of suitable and unsuitable sterols at different concentrations influence growth and survival? Results from the first experiment indicated that this grasshopper species had a minimum sterol requirement of 0.05% dry weight; as sterol quantity increased above this concentration, however, survival and performance were not enhanced. Results from the second experiment revealed two novel aspects of sterol nutrition in grasshoppers: (1) when suitable sterols were limiting, most individuals could not use unsuitable sterols to meet the minimum sterol requirement (i.e. no sparing occurred), and (2) above a certain threshold, unsuitable sterols were deleterious even when suitable sterols were present at a concentration that alone permits normal growth and development. We discuss these physiological findings in terms of how sterol metabolic constraints in grasshoppers might influence foraging.
Increasingly, data on shape are analysed in combination with molecular genetic or ecological information, so that tools for geometric morphometric analysis are required. Morphometric studies most often use the arrangements of morphological landmarks as the data source and extract shape information from them by Procrustes superimposition. The MorphoJ software combines this approach with a wide range of methods for shape analysis in different biological contexts. The program offers an integrated and user-friendly environment for standard multivariate analyses such as principal components, discriminant analysis and multivariate regression as well as specialized applications including phylogenetics, quantitative genetics and analyses of modularity in shape data. MorphoJ is written in Java and versions for the Windows, Macintosh and Unix/Linux platforms are freely available from http://www.flywings.org.uk/MorphoJ_page.htm.
An oak-pine forest in central Long Island, New York, was irradiated chronically with gamma radiation from 9500 Ci of /sup 137/Cesium for a 4 year period. There was a 50% reduction in diversity at 160 R/day during the first 6 months' exposure. Diversity declined regularly in subsequent years despite the influx of several herbaceous successional species in the damaged zones. The reduction in diversity was systematic in that plants with large life-forms were the most sensitive. Survival of trees varied with tree size. Radiation resistance was correlated with life forms of the plants, the most resistant being low growing species. Radiosensitivity of plant populations is correlated with the average size of the chromosomes at interphase. The relationships between radiosensitivity and chromosome size and between radiosensitivity and the ecology of plants suggest that the evolution of radioresistance in plants has paralleled the evolution of other aspects of ecological amplitude. 47 references, 13 figures, 3 tables.
Fluctuating asymmetry (FA) has been proposed as a measure of environmental quality, The premise is that increased levels of environmental stress (e.g., chemical pollutants) are reflected by increased levels of FA within populations of organisms developing at the site. We test this premise by examining the relationship between stress, fitness, and FA among laboratory populations of house fly (Musca domestica L.). Exposures from 0.00 to 1.00 μL/L of the pesticide ivermectin during egg-to-pupal development caused ≤18-fold differences in levels of stress (measured as percentage pupation), and ≤ 18-fold differences in levels of fitness (measured as the average number of first-instar larvae produced by each female in the starting population) among populations. However, no differences were detected among population levels of FA for five wing traits examined. Power analyses estimated that the accuracy of the image analysis method used to obtain measurements would have detected a 10% difference in average FA among populations 95% of the time. Hence, the results of this study do not support the use of FA as a method for monitoring changes in environmental quality. The absence of a treatment effect on levels of FA may reflect the development of surviving flies in "refuges," thereby minimizing or avoiding their contact with ivermectin (the "refuge" hypothesis). Alternatively, flies surviving exposure to ivermectin may represent a "robust" subset of the starting population whose symmetries are relatively unaffected by the effects of stress (the "differential mortality" hypothesis). These two hypotheses have received little attention in the literature, yet may have important implications for interpreting the effect of environmental stress on FA.
Fluctuating asymmetry is an epigenetic measure of the ability of
individuals to undergo identical development of a usually bilaterally
symmetrical character on both sides of the body. Horns of beetles and
spurs of birds are elaborate structures usually restricted to or
enlarged in individuals of the limited sex and frequently used in
intrasexual combat. Individuals with large horns usually win fights
against individuals with small horns which suggests that horn size may
reliably signal male fighting ability. A comparative study of the
patterns of fluctuating asymmetry in horns of beetles and spurs of birds
showed that the degree of asymmetry in these secondary sex traits was
considerably larger than in elytra and wing length, which are apparently
not subjected to sexual selection. There was a negative relationship
between the degree of asymmetry and size of the secondary sex trait
while the relationship for elytra and wing length was flat or U-shaped.
This demonstrates that horn and spur size may reliably reflect male
quality as determined by the degree of fluctuating asymmetry.
Gametes and offspring are often produced in excessive numbers, and developmental selection against early developmental stages reduces the number of offspring to what can be safely reared. Developmental selection is hypothesized to act mainly against gametes or zygotes with developmentally deviant phenotypes, and surviving offspring will hence give rise to adults with a developmentally more stable phenotype. This hypothesis is supported by observations of unsuccessful gametes or offspring often having developmentally deviant phenotypes or genetic characteristics such as chromosomal aberrations that give rise to developmental instability. Developmental selection against developmentally unstable offspring is furthermore suggested to be a direct outcome of sexual selection often being related to developmental stability. Sexual selection for developmentally stable mates is suggested to result in production of developmentally stable offspring, if a general developmental program gives rise to developmental stability both among adults and among gametes and subsequent offspring.
As a simple and green chemistry procedure, pressurized water extraction (PWE) was developed for removing the terpene trilactones, ginkgolides and bilobalide, from leaves of Ginkgo biloba L. Compared with conventional boiling-solvent extraction methods, PWE is a more effective, selective, economical and environmentally benign technique for the extraction of intermediate to polar compounds from herbal plants. In contrast to high temperature extraction, PWE at low temperature can minimize undesirable reactions such as thermal decomposition or degradation and remove much smaller amounts of impurities from the herbal materials. The other important advantage of PWE is that the extraction efficiency can be quantitatively assessed using a kinetic extraction model. Experimental results were proven to be closely consistent with the predicted values. After PWE, the terpene trilactones could be easily enriched by a liquid–liquid extraction and the extracts readily determined with a GC-FID method.
Secondary sexual characters are large structures of great intricacy of design, and there are many ways in which their development can be disrupted. Both somatic and germ-line mutations affecting the expression of secondary sexual characters are likely to be biased and most frequently reduce performance because of the great complexity of characters. I investigated the degree of fluctuating asymmetry and the incidence of aberrant secondary sexual characters in the monogamous barn swallow Hirundo rustica in two areas in Ukraine, one near Chernobyl, and the other near Kanev. I predicted that developmental disorders should be more frequent in a recent sample of birds from the Chernobyl area than in samples from other areas, and than in museum samples pre-dating the 1986 contamination event. There were apparently no consistent effects of area or time period on the morphology of barn swallows. The level of fluctuating asymmetry in male tail length was considerably elevated in the Chernobyl area in the recent sample, but not in females, and three other morphological variables were unaffected in both sexes. Males with high degrees of asymmetry in their tails bred later than symmetric males. The incidence of aberrant feather morphology in the Chernobyl area was higher for tail ornaments of males than for other morphological characters in males, and than for the homologous character of females, and there were no cases of aberrant feathers in the control area or in the museum samples. Males with aberrant tail feathers bred later than other males.
Laboratory population experiments and theoretical calculations are presented that demonstrate effective population suppression by the introduction of partially sterile cabbage loopers into a native population. The use of partially sterile males is advantageous because they are highly competitive with native moths, and since their progeny are sterile provides for population suppression over at least three generations. It is projected, based on experimental results, that 92% control can be obtained for three generations through a single release of partially sterile males. This modification of the sterile-male technique for Lepidoptera could result in control and sizeable savings in cost. Insecticide and other forms of control can be used simultaneously without any effect on the efficiency of the release program.
The imaginal ecdysis of the desert locust, Schistocerca gregaria (Fo̊rsk.), is described in detail. Ecdysis is considered to begin when the fifth instar nymph ceases to feed and to end when the adult takes its first meal. It is here divided into six stages: Stages 1 and 2 constitute the pre-emergence behaviour; Stages 3 and 4, emergence; Stage 5, the expansion of the new cuticle; and Stage 6, the post-expansional behaviour.
The purpose of this paper is to summarize the international assessments of the radiological impact of the Chernobyl accident. The Chernobyl accident was a technological disaster that went beyond the most pessimistic scenarios of nuclear engineers. It was more sever than a maximum credible accident to which nuclear engineers referred before it happened. In spite of its severity, the consequences of the accident at Chernobyl, seen in perspective, seem not to be so catastrophic. The number of fatalities was small compared with the figures for other common types of accidents, and the radiation doses incurred are only a small fraction of those inevitably incurred due to natural background radiation.
Sensitivity of natural plant populations to ionizing radiation seems to follow known ecological patterns.
The first edition of Geometric Morphometrics for Biologists has been the primary resource for teaching modern geometric methods of shape analysis to biologists who have a stronger background in biology than in multivariate statistics and matrix algebra. These geometric methods are appealing to biologists who approach the study of shape from a variety of perspectives, from clinical to evolutionary, because they incorporate the geometry of organisms throughout the data analysis. The second edition of this book retains the emphasis on accessible explanations, and the copious illustrations and examples of the first, updating the treatment of both theory and practice. The second edition represents the current state-of-the-art and adds new examples and summarizes recent literature, as well as provides an overview of new software and step-by-step guidance through details of carrying out the analyses. Contains updated coverage of methods, especially for sampling complex curves and 3D forms and a new chapter on applications of geometric morphometrics to forensics Offers a reorganization of chapters to streamline learning basic concepts Presents detailed instructions for conducting analyses with freely available, easy to use software Provides numerous illustrations, including graphical presentations of important theoretical concepts and demonstrations of alternative approaches to presenting results.
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When normal female cabbage loopers, Trichoplusia ni (Hübner), were mated with adult males that had received 20 krad of gamma radiation, 15-20% of their eggs hatched. The progeny of this cross were sterile when they mated with normal moths of the opposite sex. Thus, the F1 progeny are more sterile than their irradiated male parents.
Irradiation of the parental and F1 generations with 10 krad each did not cause more or less sterility in the F1 generation than 20 krad of irradiation to the P1 generation.
Apparently the inherited sterility in the F1 generation is caused by the induction of large numbers of reciprocal chromosome trans locations. The abnormally high frequency of induced trans locations was probably the result of a unique chromosomal structural feature of Lepidoptera; namely, diffuse centromeres.
The complete sterility obtained in the F1 generation when only a substerilizing dose of radiation was given to the male parent may prove of added value in using the sterile-male technique for eradication of Lepidoptera. Reducing the amount of radiation administered to an individual to effect sterility could well improve the competitiveness of the sterile male, a limiting factor thus far in the sterile-male release of Lepidoptera.
The severe nuclear accident at Chernobyl in 1986 resulted in the worst reported accidental exposure of radioactive material to free-living organisms
Les asymétries Fluctuantes (Fa) Sont De Petites déviations aléatoires entre les mesures du côté gauche et du côté droit de caractères d'un organisme donné qui sont normalement symétriques. On a souvent proposé d'utiliser les changements dans les FA comme biomarqueurs chez des organismes exposés au stress durant leur développement; ces changements pourraient être utiles pour déceler des concentrations faibles de résidus chimiques ou d'autres facteurs de stress dans le milieu. Nous avons examiné cette hypothèse dans chacune de trois expériences répétées de laboratoire et n'avons pas réussi à trouver d'effet de résidus chimiques (ivermectine) dans les bouses de bétail sur les niveaux des FA (caractères des ailes et des pattes) chez la mouche Scathophaga stercoraria L. (Diptera: Scathophagidae) qui se reproduit dans le fumier. En essayant de comprendre le désaccord entre nos résultats et ceux d'études antérieures, nous observons que plusieurs études avaient négligé de répéter les mesures des caractères de FA dans les expériences, ce qui augmente la possibilité de faux résultats positifs. De plus, les expériences étaient rarement répétées au sein d'une étude ou entre différentes études, si bien que la répétabilité des résultats positifs demeurait invérifiée. Ces problèmes ont été signalés par d'autres chercheurs, mais ils continuent d'être négligés. Les discussions sur la valeur des FA comme biomarqueurs ne pourront progresser tant qu'on ne tiendra pas compte de ces problèmes. [Traduit par le Rédaction]