Effects of climate change on life-history traits in populations of Hyphantria cunea (Lepidoptera: Arctiidae) in voltinism boundary area of northern Kanto district

We explored the extent to which two populations of Acanthoscelides obtectus (Coleoptera: Bruchidae), maintained in the laboratory for about 60 generations on common bean (Phaseolus vulgaris) and chickpea (Cicer arietinum) seeds, differ genetically in life history traits. Using a half‐sib breeding design, we screened for genetic variation in oviposition preference for two hosts within both populations, and examined whether this variation is correlated with weevil pre‐adult (egg‐to‐adult viability and egg‐to‐adult developmental time) and adult (female fecundity and longevity) fitness components on these two hosts. Significant differences between the Phaseolus and Cicer population were detected in viability, developmental time and oviposition preference, but not in female fecundity and longevity. The absence of a significant population × host interaction in all traits, except for developmental time in males, indicates that the Cicer population has not attained the status of ‘host race’. The estimated narrow‐sense heritabilities within population within host plant were in the low‐to‐moderate level (range: 1%–79%), with an overall average of about 24%. Within the population maintained on the chickpeas we detected significant genetic correlations between female developmental time on chickpea seeds and preference for chickpeas. In the population maintained on the primary host of this weevil species (the ‘Phaseolus’ population) we found no significant preference/performance genetic correlations. Data are also presented on the genetic correlations of preference and performance across host seeds within both populations. These correlations are found to be positive for all traits in both populations, indicating the absence of trade‐offs in either performance or behavioural response that might impose selection for host specialization within populations.

Additive genetic variances were estimated for several life history traits of north temperate Michigan and subtropical Florida populations of the freshwater copepod Mesocyclops edax (Crustacea: Copepoda). Estimates were obtained by rearing animals at 25° C and using a paternal half sib design. Considerable additive genetic variance was revealed in female and male body sizes of the Florida population and in female and male maturation times in the Michigan population. Female maturation time and clutch size in the Florida population and female body size and clutch size in the Michigan population exhibited low additive genetic variance. These findings provide further evidence of substantial additive genetic variance in life history traits of natural populations. The contrasting trends in additive genetic variance underlying life history traits of these populations are interpreted as reflecting differences in the potential to respond to selection and possibly also the different selective regimes of the Michigan and Florida environments.

Knowing the variances and heritabilities (h(2)) of life history traits in populations living under natural conditions is necessary for a mechanistic understanding of respective evolutionary processes. I estimated heritabilities of several life history traits, including dispersal rate, body mass, age at first reproduction, egg mass, clutch size and lifetime reproductive success, in the Glanville fritillary butterfly (Melitaea cinxia) using parent-offspring regression. Experiments were conducted under field conditions in a large population cage (32 x 26 m). Heritability estimates ranged from zero to almost one and several were significantly different from zero. Body size for both sexes, female age at first reproduction and egg weight were all moderately to highly heritable, whereas heritabilities were low or non-existent in clutch size and lifetime egg production. Heritability estimates for dispersal rate varied between the sexes, so that dispersal was heritable from mother to her female offspring only. This finding is consistent with previous results showing that the F1 female but not male offspring of females that naturally established new populations in the field are significantly more dispersive than butterflies in old populations.

Two populations of Poa annua L., one from an irrigated area and one from a dry area, were studied to test the following hypothesis: different life cycles should be selected in habitats of contrasting mortality regime. Plants from the irrigated area exhibited a typical perennial habit (indeterminate growth and low reproductive effort) while those from the dry area showed traits characteristic of annuals (determinate growth, high reproductive effort and flowering synchrony) although total annuality was not achieved. The antagonism between growth and reproduction was expressed at the individual tiller level and was reflected in the life history traits of the populations. The characters studied exhibited a high broad sense heritability which is required for a rapid evolution of life cycles when selection pressures are strong. Different levels of constraints (ecological, evolutionary, physiological and developmental) have to be taken into account in order to understand this evolution.

The process of selection on a multivariate set of characters subject to functional constraints is considered from the points of view of both evolutionary optimization theory and quantitative genetics. Special attention is given to life-history characteristics. It is shown that, under suitable conditions (including weak selection), useful approximate formulas for the relations between the functional constraints and the additive genetic variance-covariance matrix can be derived. These can be used to show that the conditions for equilibrium under selection according to the two different approaches are approximately equivalent. Although large negative genetic correlations are to be expected between some pairs of life-history traits in populations at equilibrium under selection, in general some small negative genetic correlations and some positive genetic correlations will also be present. Thus, the observation of a positive genetic correlation between a pair of life-history traits does not necessarily refute the possibility of trade-offs among a multivariate set of traits that contains the pair in question. The relation between the pattern of functional constraints and the genetic correlations is often complex, and little insight into the former can be derived from the latter. The effects of mutations that lower the overall efficiency of resource utilization, thereby creating a positive component to the genetic covariances among life-history traits, are also considered for a specific model. Although such mutations can have a substantial effect on the form of the life history, extreme conditions seem to be needed for them to produce a large effect on the pattern of genetic correlations in a random-mating population. They can, however, cause the appearance of positive correlations following inbreeding, due to the exposure of deleterious recessive or partially recessive mutations. The analysis also suggests that the population means of individual components of a constrained multivariate system may often equilibrate at values that are far from the optima that would be attained if they were selected in isolation from the other members of the system.

BackgroundIntroduced species can have profound effects on native species, communities, and ecosystems, and have caused extinctions or declines in native species globally. We examined the evolutionary response of native zooplankton populations to the introduction of non-native salmonids in alpine lakes in the Sierra Nevada of California, USA. We compared morphological and life-history traits in populations of Daphnia with a known history of introduced salmonids and populations that have no history of salmonid introductions.ResultsOur results show that Daphnia populations co-existing with fish have undergone rapid adaptive reductions in body size and in the timing of reproduction. Size-related traits decreased by up to 13 percent in response to introduced fish. Rates of evolutionary change are as high as 4,238 darwins (0.036 haldanes).ConclusionSpecies introductions into aquatic habitats can dramatically alter the selective environment of native species leading to a rapid evolutionary response. Knowledge of the rates and limits of adaptation is an important component of understanding the long-term effects of alterations in the species composition of communities. We discuss the evolutionary consequences of species introductions and compare the rate of evolution observed in the Sierra Nevada Daphnia to published estimates of evolutionary change in ecological timescales.

Sensitivity of marine systems to climate and fishing: Concepts, issues and management responses

Plasticity in life-history traits is thought to be one of the key factors that contribute to adaptation of invasive species to the novel environment at the beginning of an invasion. It has been found that round gobies Neogobius melanostomus from freshly invaded areas (invasion front) exhibit different life-history traits than individuals from core or central areas with well-established populations. The theory of alternative ontogeny and invasive potential predicts such differences. Nevertheless, it is difficult to distinguish between the effects of intrinsic ontogenetic phenomena and the effects of particular ecological factors on life-history traits of populations at various stages of invasion. Thus, the main aim of this study was to test the prediction that two sub-populations of round gobies from two habitats exposed to a different intensity of anthropogenic pressures in the River Danube, but at the same stage of invasion, will have significant differences in their reproductive parameters. Females from the relatively undisturbed habitat were predicted to have 1) larger oocytes, 2) lower absolute number of oocytes, and 3) lower real absolute fecundity. For two parameters (1 and 3), differences were statistically significant, as predicted. For parameter 2, the difference was as predicted, though not significant. Several studies suggest that changes in life-history traits observed over the progressing invasions of fishes are typical rather than accidental. They appear to be related to the stage of the invasion and closely associated with ontogenetic phenomena (the capability to generate alternative ontogenies). However, ecological factors also play an important role in this process. If the habitat is exposed to permanent disturbances, the established invasive population will probably keep the same life-history traits as at the beginning of the invasion.

The state of the art of the studies on the production of Brazilian sandy beach macrofauna was analyzed on the basis of the data available in the literature. For this purpose, the representativeness of the production dataset was examined by latitudinal distribution, degree of exposure and morphodynamic state of beaches, taxonomic groups, and methods employed. A descriptive analysis was, further, made to investigate the trends in production of the more representative taxonomic groups and species of sandy beach macrofauna. A total of 69 macrofauna annual production estimates were obtained for 38 populations from 25 studies carried out between 22º56'S and 32º20'S. Production estimates were restricted to populations on beaches located on the southern and southeastern Brazilian coast. Most of the populations in the dataset inhabit exposed dissipative sandy beaches and are mainly represented by mollusks and crustaceans, with a smaller number of polychaetes. The trends in production among taxonomic groups follow a similar pattern to that observed on beaches throughout the world, with high values for bivalves and decapods. The high turnover rate (P/B ratio) of the latter was due to the presence of several populations of the mole crab Emerita brasiliensis, which can attain high values of productivity, in the dataset. Most of the studies focus on the comparison of production and, especially, of P/B ratio according to life history traits in populations of the same species/taxonomic group. Despite the importance of life history-production studies, other approaches, such as the effect of man-induce disturbances on the macrofauna, should be undertaken in these threatened environments.

Ecological and life history traits have been used to understand the basic ecology of fishes. This study aimed to examine the existence of plasticity in life history traits of populations of Hollandichthys multifasciatus in ten blackwater streams. This is an inseminating Characidae, endemic to the Atlantic coastal drainages of Brazil. Different aspects of the life-history of the species, such as mean length, sex ratio, absolute and relative fecundity, gonadosomatic index, condition factor, length-weight relationship and the growth parameter (b) of 185 specimens were studied during the period of low precipitation (June-September). Fish samples were obtained along a 100 m stretch of each stream, and some habitat variables recorded. ANOVA and Kruskal-Wallis tests indicated a similarity in most of the analyzed traits, with exception of the mean length of immatures, Gonadosomatic Index of mature males and condition factor of immatures and mature adults. Also, slope tests of the length-weight relationship were significantly different for immatures. The observed differences were attributed to heterogeneity in food availability and/or other site-specific factors, which may influence growth and/or breeding aspects among the studied localities. The approach used herein may improve understanding of trait plasticity under natural conditions, helping to understand fish-community responses to anthropogenic changes.

We studied the ecology of Psammobates oculifer over 13 months near Kimberley, South Africa, to ascertain if the population's life history traits conform to chelonian patterns in arid environments. Capture rates were highest in spring and lowest in winter when environmental conditions were respectively most and least favourable for tortoise activity. Body condition did not change from autumn to spring, but reached lower values during the summer drought. Capture effort averaged 5 hours/tortoise, which corresponds closely to that of species with low population densities in arid regions. Population size structure was skewed towards adults, indicative of low recruitment and/or low juvenile survivorship. Females were larger and heavier than males, confirming sexual dimorphism in this species. Body size of cohorts scaled to annuli counts, indicating a close correspondence between body size and age. Telemetered adults deposited one or no growth ring in the year of study; consequently, annuli counts could underestimate adult age. Regression analyses showed that male and female growth rates did not differ, but males matured at a smaller size and younger age than females. The smallest male showing reproductive behaviour had 12 annuli and a shell volume of 157 cm3, while similar measures for females were 14 annuli and 185 cm3. The sex ratio of the population did not differ from 1:1 but the bias towards males in spring, and towards females in autumn, indicates that studies limited to particular seasons can misrepresent life history traits of populations. We concluded that the life history of P. oculifer conforms to chelonian patterns in arid regions.

Southern part of Bangladesh is one of the most affected areas confronting the effects of climate change especially in agricultural sector. The study was planned to examine effect of climate change on agriculture in the saline prone areas, and estimate the level of contribution of the selected characteristics of the farmers to the effect of climate change on agriculture. For this reason, data were collected from 88 farmers under study group and 30 farmers under control group from 16 March, 2017 to 15 April, 2017. Descriptive statistics, multiple regression, t-test were used for data analysis. There was a negative effect of climate change on agriculture comparing the study and control group changed score from 2015 to 2017. In case of study group, 61.4 percent of the farmers had medium effect, 17.0 percent had low effect and 21.6 percent of the farmers had high effect of climate change on agriculture. It was also found that out of eleven factors, seven namely age, level of education, annual family income, farming experience, training exposure, agricultural knowledge and knowledge on climate change had significant contribution to the effect of climate change on agriculture in the saline prone areas. It is concluded that climate change may play a significant role in decreasing the yield of cereal crops, yield of vegetables, yield of pulses and increasing number of adopted new varieties of agricultural crops by the farmers. It is recommended that the Bangladesh government and NGOs should take initiative for reducing effect of climate change on agriculture for a sustainable agricultural development.

Global climate change is predicted to result in the decline and/or extinction of a large number of animal populations worldwide, and the risk of extinction is likely to be greatest for those species already vulnerable — i.e. those with limited climatic range and/or restricted habitat require- ments. To date, predictive models have failed to take into account the fact that climate change will alter many of the key life history and ecological parameters which determine a species' inherent risk of extinction, such as body mass, size of geographic range and a suite of reproductive traits. Herein, I review contemporary research on the effects of climate change on extinction risk in mammals, focusing on the capacity of climate change to modify those life history traits that inherently alter spe- cies' extinction risk. This review finds strong evidence that climate change has already had marked effects on key life history traits in many mammals. These changes have resulted in both negative and positive effects on reproductive success and adult and offspring survival, with implications for extinc- tion risk in affected species. While the capacity of climate change to alter life history traits in mam- mals is clear, there is currently little research to clarify how these changes have influenced popula- tion growth and dynamics. Other currently overlooked areas of research are also identified.

Resource competition is frequently strong among parasites that feed within small discrete resource patches, such as seeds or fruits. The properties of a host can influence the behavioural, morphological and life-history traits of associated parasites, including traits that mediate competition within the host. For seed parasites, host size may be an especially important determinant of competitive ability. Using the seed beetle, Callosobruchus maculatus, we performed replicated, reciprocal host shifts to examine the role of seed size in determining larval competitiveness and associated traits. Populations ancestrally associated with either a small host (mung bean) or a large one (cowpea) were switched to each other's host for 36 generations. Compared to control lines (those remaining on the ancestral host), lines switched from the small host to the large host evolved greater tolerance of co-occurring larvae within seeds (indicated by an increase in the frequency of small seeds yielding two adults), smaller egg size and higher fecundity. Each change occurred in the direction predicted by the traits of populations already adapted to cowpea. However, we did not observe the expected decline in adult mass following the shift to the larger host. Moreover, lines switched from the large host (cowpea) to the small host (mung bean) did not evolve the predicted increase in larval competitiveness or egg size, but did exhibit the predicted increase in body mass. Our results thus provide mixed support for the hypothesis that host size determines the evolution of competition-related traits of seed beetles. Evolutionary responses to the two host shifts were consistent among replicate lines, but the evolution of larval competition was asymmetric, with larval competitiveness evolving as predicted in one direction of host shift, but not the reverse. Nevertheless, our results indicate that switching hosts is sufficient to produce repeatable and rapid changes in the competition strategy and fitness-related traits of insect populations.

ABSTRACTBackgroundClimate change is the most important problem that threatens the health of individuals, public health, and health systems on a global scale. The International Council of Nurses emphasizes that nurses should strive to reduce the effects of climate change and help individuals and systems adapt. In addition, it is stated that climate change should be integrated into nursing education curricula and nursing students, who are future healthcare providers, should be prepared to reduce the effects of climate change and promote a healthier environment.AimThe aim of this study is to examine the effect of the Climate Change and Health course on global warming knowledge and attitude, environmental literacy, and eco‐anxiety levels in nursing students.Design and MethodsIn this study, a pretest–posttest comparative quasi‐experimental design type was used. The research was conducted with 117 students taking the “Climate Change and Health” course added to the curriculum at the Nursing Department of a private university in Istanbul between February 2023 and June 2023. Data were collected before and after the intervention using the Descriptive Characteristics Form, Global Warming Knowledge Questionnaire, Global Warming Attitude Scale, Environmental Literacy Scale for Adults, and Eco‐Anxiety Scale.ResultsAfter taking the Climate Change and Health course, nursing students' global warming knowledge and attitude total scores increased, and a statistically significant increase was detected in the eco anxiety total and behavioral symptoms subscale mean scores. There was no statistically significant change in the Environmental Literacy Scale total and subscale mean scores.ConclusionsIt can be stated that the Climate Change and Health course positively improved nursing students' knowledge and attitudes toward global warming and increased their sensitivity about climate change. Nurses, who constitute the most important part of the healthcare workforce worldwide, have an important role in creating a healthy and safe environment and in combating the effects of global warming and climate change. For this reason, in order to train knowledgeable and equipped health professionals on this subject, it is recommended that courses on the effects of climate change, adaptation, and coping with it be added to the nursing curriculum and integrated into all subjects every year to ensure continuity.