scholarly journals Predicted responses to selection across the climatic range of a rainforest Drosophila without local adaptation: environmental variation limits trait divergence along ecological gradients

2021 ◽  
Author(s):  
Eleanor K O'Brien ◽  
Megan Higgie ◽  
Andrew D Saxon ◽  
Ary A. Hoffmann ◽  
Jon R Bridle
Keyword(s):  
Environmental Change ◽  
Cold Tolerance ◽  
Environmental Variation ◽  
Evolutionary Constraint ◽  
Wing Size ◽  
Ecological Gradients ◽  
Heritable Variation ◽  
Elevation Gradients ◽  
Selection Responses ◽  
North East

Evolutionary responses to environmental change require heritable variation in traits under selection. Both heritability and selection vary with the environment, and may also covary, meaning that environmental variation can be an important source of evolutionary constraint. However, estimates of heritability and selection along environmental gradients in the field are rare. We estimated environmental variation in selection on three traits (cold tolerance, heat tolerance and wing size) of the rainforest fly Drosophila birchii by transplanting flies in cages along two elevational gradients in north-east Queensland, Australia, and calculating the genetic covariance of trait values with cage productivity at each elevation. We estimated heritability of each trait from laboratory crosses, and environmental variation in heritability of wing size from the correlation of mothers and daughters in cages at each elevation. We then used estimates of selection and heritability to predict selection responses along the elevation gradients. Laboratory assays revealed low-moderate genetic variation in all traits and low covariation among traits, suggesting the potential for a strong response to selection. Estimated selection responses predicted divergence of cold tolerance with elevation at one gradient. However, this was not observed at either gradient, with no difference between high and low elevation populations for this trait. Despite substantial variation in heritability (and predicted selection response) of wing size, this appeared random with respect to elevation, preventing overall divergence and suggesting that local environmental variation constrains evolutionary responses along natural ecological gradients. Such an effect, if widespread, may significantly slow evolutionary responses to environmental change.

scholarly journals Testing for local adaptation and evolutionary potential along 1 altitudinal gradients in rainforest Drosophila: beyond laboratory estimates

2016 ◽  
Author(s):  
Eleanor K. O’Brien ◽  
Megan Higgie ◽  
Alan Reynolds ◽  
Ary A. Hoffmann ◽  
Jon R. Bridle
Keyword(s):  
Genetic Variation ◽  
Environmental Change ◽  
High Altitude ◽  
Local Adaptation ◽  
Biotic Interactions ◽  
Environmental Variation ◽  
Species Range ◽  
Altitudinal Gradients ◽  
Low Altitude ◽  
The Relationship

ABSTRACTPredicting how species will respond to the rapid climatic changes predicted this century is an urgent task. Species Distribution Models (SDMs) use the current relationship between environmental variation and species’ abundances to predict the effect of future environmental change on their distributions. However, two common assumptions of SDMs are likely to be violated in many cases: (1) that the relationship of environment with abundance or fitness is constant throughout a species’ range and will remain so in future, and (2) that abiotic factors (e.g. temperature, humidity) determine species’ distributions. We test these assumptions by relating field abundance of the rainforest fruit fly Drosophila birchii to ecological change across gradients that include its low and high altitudinal limits. We then test how such ecological variation affects the fitness of 35 D. birchii families transplanted in 591 cages to sites along two altitudinal gradients, to determine whether genetic variation in fitness responses could facilitate future adaptation to environmental change. Overall, field abundance was highest at cooler, high altitude sites, and declined towards warmer, low altitude sites. By contrast, cage fitness (productivity) increased towards warmer, lower altitude sites, suggesting that biotic interactions (absent from cages) drive ecological limits at warmer margins. In addition, the relationship between environmental variation and abundance varied significantly among gradients, indicating divergence in ecological niche across the species’ range. However, there was no evidence for local adaptation within gradients, despite greater productivity of high altitude than low altitude populations when families were reared under laboratory conditions. Families also responded similarly to transplantation along gradients, providing no evidence for fitness trade-offs that would favour local adaptation. These findings highlight the importance of (1) measuring genetic variation of key traits under ecologically relevant conditions, and (2) considering the effect of biotic interactions when predicting species’ responses to environmental change.

scholarly journals Evolvability meets biogeography: evolutionary potential decreases at high and low environmental favourability

2017 ◽  
Vol 284 (1856) ◽  
pp. 20170516 ◽  
Author(s):  
J. Martínez-Padilla ◽  
A. Estrada ◽  
R. Early ◽  
F. Garcia-Gonzalez
Keyword(s):  
Environmental Change ◽  
Morphological Traits ◽  
Evolutionary Dynamics ◽  
Environmental Variation ◽  
Phenotypic Traits ◽  
Published Data ◽  
Evolutionary Potential ◽  
Critical Question ◽  
Climate Conditions ◽  
Environmental Selection

Understanding and forecasting the effects of environmental change on wild populations requires knowledge on a critical question: do populations have the ability to evolve in response to that change? However, our knowledge on how evolution works in wild conditions under different environmental circumstances is extremely limited. We investigated how environmental variation influences the evolutionary potential of phenotypic traits. We used published data to collect or calculate 135 estimates of evolvability of morphological traits of European wild bird populations. We characterized the environmental favourability of each population throughout the species' breeding distribution. Our results suggest that the evolutionary potential of morphological traits decreases as environmental favourability becomes high or low. Strong environmental selection pressures and high intra-specific competition may reduce species' evolutionary potential in low- and high- favourability areas, respectively. This suggests that species may be least able to adapt to new climate conditions at their range margins and at the centre. Our results underscore the need to consider the evolutionary potential of populations when studying the drivers of species distributions, particularly when predicting the effects of environmental change. We discuss the utility of integrating evolutionary dynamics into a biogeographical perspective to understand how environmental variation shapes evolutionary patterns. This approach would also produce more reliable predictions about the effect of environmental change on population persistence and therefore on biodiversity.

scholarly journals Environmental Change and Livelihood Activities in Hadejia-Nguru Wetlands of Yobe State, North East Nigeria

2021 ◽  
Vol 13 (1) ◽  
pp. 1
Author(s):  
Yagana Bukar ◽  
Abubakar K. Monguno ◽  
Abubakar T. AbdulRahman
Keyword(s):  
Environmental Change ◽  
Natural Resources ◽  
Sustainable Use ◽  
Primary Data ◽  
Policy And Practice ◽  
Resource Base ◽  
North East ◽  
Livelihood Options ◽  
Resource Decline ◽  
Policies And Programs

The Hadejia-Nguru wetlands is an extensive area of flood plains located in the Sudano-Sahelian zone of north east Nigeria. The population rely heavily on natural resources for their livelihoods. In recent years, climatic vagaries, increasing populations and unregulated livelihood activities have significantly affected water and other resources availability and communities are faced with constant struggle of survival under a declining resource base. This study assessed the adverse effects of environmental change on resource users and how this influences their livelihood options. Understanding the perceptions, knowledge and practices of local resource users and what shapes their livelihood options is an area of critical importance that is currently under-researched in the area. This paper argues that to effectively influence policy and practice that support sustainable use of natural resources, it is important to not only understand resource user's knowledge and choices about their changing environment but how they utilize this knowledge in their actions and the overall impact on the environment. Mixed methods consisting of semi-structured questionnaire and Focus Group Discussions (FGD) based on two Participatory Rural Appraisal (PRA) tools (Village Timeline and Contextual Change) were utilized to solicit primary data. Environmental change in the area is accelerated by human activities and people have developed several local mechanisms of adapting to change. These adaptive measures could further be explored for developing policies and programs aimed at tackling the challenges of environmental change and resource decline.

scholarly journals Adaptation to a novel predator inDrosophila melanogaster: How well are we able to predict evolutionary responses?

2014 ◽  
Author(s):  
Michael DeNieu ◽  
William Pitchers ◽  
Ian Dworkin
Keyword(s):  
Natural Selection ◽  
Experimental Evolution ◽  
Phenotypic Selection ◽  
Ancestral Population ◽  
Wing Size ◽  
Short Term ◽  
Heritable Variation ◽  
Size And Shape ◽  
Evolutionary Trajectories ◽  
Short Term Prediction

Evolutionary theory is sufficiently well developed to allow for short-term prediction of evolutionary trajectories. In addition to the presence of heritable variation, prediction requires knowledge of the form of natural selection on relevant traits. While many studies estimate the form of natural selection, few examine the degree to which traits evolve in the predicted direction. In this study we examine the form of natural selection imposed by mantid predation on wing size and shape in the fruitfly,Drosophila melanogaster. We then evolve populations ofD. melanogasterunder predation pressure, and examine the extent to which wing size and shape have responded in the predicted direction. We demonstrate that wing form partially evolves along the predicted vector from selection, more so than for control lineages. Furthermore, we re-examined phenotypic selection after ~30 generations of experimental evolution. We observed that the magnitude of selection on wing size and shape was diminished in populations evolving with mantid predators, while the direction of the selection vector differed from that of the ancestral population for shape. We discuss these findings in the context of the predictability of evolutionary responses, and the need for fully multivariate approaches.

scholarly journals Constraints, independence, and evolution of thermal plasticity: Probing genetic architecture of long- and short-term thermal acclimation

2015 ◽  
Vol 112 (14) ◽  
pp. 4399-4404 ◽  
Author(s):  
Alison R. Gerken ◽  
Olivia C. Eller ◽  
Daniel A. Hahn ◽  
Theodore J. Morgan
Keyword(s):  
Cold Tolerance ◽  
Negative Correlation ◽  
Genetic Architecture ◽  
Cold Hardening ◽  
Short Term ◽  
Heritable Variation ◽  
Thermal Plasticity ◽  
Rapid Cold Hardening ◽  
Basal Thermotolerance

Seasonal and daily thermal variation can limit species distributions because of physiological tolerances. Low temperatures are particularly challenging for ectotherms, which use both basal thermotolerance and acclimation, an adaptive plastic response, to mitigate thermal stress. Both basal thermotolerance and acclimation are thought to be important for local adaptation and persistence in the face of climate change. However, the evolutionary independence of basal and plastic tolerances remains unclear. Acclimation can occur over longer (seasonal) or shorter (hours to days) time scales, and the degree of mechanistic overlap is unresolved. Using a midlatitude population ofDrosophila melanogaster, we show substantial heritable variation in both short- and long-term acclimation. Rapid cold hardening (short-term plasticity) and developmental acclimation (long-term plasticity) are positively correlated, suggesting shared mechanisms. However, there are independent components of these traits, because developmentally acclimated flies respond positively to short-term acclimation. A strong negative correlation between basal cold tolerance and developmental acclimation suggests that basal cold tolerance may constrain developmental acclimation, whereas a weaker negative correlation between basal cold tolerance and short-term acclimation suggests less constraint. Using genome-wide association mapping, we show the genetic architecture of rapid cold hardening and developmental acclimation responses are nonoverlapping at the SNP and corresponding gene level. However, genes associated with each trait share functional similarities, including genes involved in apoptosis and autophagy, cytoskeletal and membrane structural components, and ion binding and transport. These results indicate substantial opportunity for short-term and long-term acclimation responses to evolve separately from each other and for short-term acclimation to evolve separately from basal thermotolerance.

scholarly journals Age at First Sexual Intercourse and Teenage Pregnancy in Australian Female Twins

2007 ◽  
Vol 10 (3) ◽  
pp. 440-449 ◽  
Author(s):  
Mary Waldron ◽  
Andrew C. Heath ◽  
Eric Turkheimer ◽  
Robert Emery ◽  
Kathleen K. Bucholz ◽  
...  
Keyword(s):  
Sexual Intercourse ◽  
Teenage Pregnancy ◽  
Environmental Influences ◽  
Environmental Variation ◽  
Genetic Influences ◽  
Shared Environment ◽  
Heritable Variation ◽  
First Sexual Intercourse ◽  
First Intercourse ◽  
Sexual Onset

AbstractGirls who report first sexual intercourse during their early teen years have much higher rates of teenage pregnancy and childbearing than girls who delay sexual onset until older adolescence. In this study, we examine genetic and environmental influences on variation in teenage pregnancy and covariation with age at first sexual intercourse in two cohorts of Australian female twins. In the older twin cohort, born 1893–1964, we observe substantial heritable variation in teenage pregnancy that is largely shared with heritable variation in age at first sexual intercourse, with shared environment contributintablg little to variation in teenage pregnancy. Genetic influences on teenage pregnancy are smaller and nonsignificant in the younger twin cohort, born 1964–1971, where shared environment contributes much more and overlaps entirely with shared environmental variation in age at first intercourse.

scholarly journals Ephemeroptera (Mayflies) Assemblages and Environmental Variation along Three Streams Located in the Dry-Hot Valleys of Baima Snow Mountain, Yunnan, Southwest China

Insects ◽  
2021 ◽  
Vol 12 (9) ◽  
pp. 775
Author(s):  
Muhammad Farooq ◽  
Xianfu Li ◽  
Lu Tan ◽  
Davide Fornacca ◽  
Yanpeng Li ◽  
...  
Keyword(s):  
Species Richness ◽  
Species Composition ◽  
Community Composition ◽  
Environmental Variation ◽  
Diversity Indices ◽  
Freshwater Ecosystems ◽  
Environmental Data ◽  
Elevation Gradients ◽  
Depth Analysis ◽  
The Impact

Mountain freshwater ecosystems are threatened all over the world by a range of human-induced stresses, ensuing in a rapid loss of habitats and species diversity. Many macroinvertebrates are reactive to habitat disturbance, and mayflies (Ephemeroptera) are amongst the most sensitive groups. Despite they are susceptible to environmental deviation, knowledge concerning their species richness and diversity is still unknown in remote areas. The objectives of this study were to (1) investigate the mayfly species assemblage and community composition along different mountain streams and assess potential differences, and (2) identify the environmental variation and its influence on the structure of mayfly communities within such freshwater systems. We collected biological and environmental data from 35 sites situated along elevation gradients in the Baima Snow Mountain, northwest Yunnan, China. Multivariate analyses were performed on the environmental variables and the mayfly species composition, as well as on richness and diversity indices. We found that the community composition of mayflies was different across all three watercourses. Among the 18 Ephemeroptera taxa identified, Baetis sp. and Baetiella marginata were highly dominant, accounting for over 50% of the dissimilarity of each stream. In terms of species assemblages, almost all sites in the Yeri stream hosted good-quality habitats for several mayfly species, as reflected by the highest species richness. The Benzilan stream followed, whereas the Sharong stream showed relatively low mayfly assemblage. This variation was explained by the high environmental heterogeneity between the three watercourses. In particular, the RDA model revealed that among the different environmental factors analyzed, altitude, conductivity, total dissolved solids, water temperature, dissolved silicon, and pH explained most of the variation in species composition. Moreover, the altitude alone explained 17.74% of the variation, and in-depth analysis confirmed its significant effect on diversity indices. Further research should focus on evaluating the scale of threats to this important group of insects in the mountain freshwater ecosystem, particularly the impact of human-induced disturbances such as land use/landcover alterations.

Estimation of genetic and phenotypic parameters for growth and reproductive traits for red deer on an upland farm

1991 ◽  
Vol 53 (2) ◽  
pp. 227-235 ◽  
Author(s):  
C. M. McManus ◽  
W. J. Hamilton
Keyword(s):  
Growth Rate ◽  
Cervus Elaphus ◽  
Red Deer ◽  
Genetic Parameters ◽  
Selection Criterion ◽  
Reproductive Traits ◽  
Heritable Variation ◽  
Weaning Weight ◽  
North East ◽  
The North

AbstractGenetic and phenotypic parameters were estimated for farmed red deer (Cervus elaphus) in an upland environment in the north-east of Scotland. Genetic parameters were estimated using restricted maximum likelihood analyses. Heritabilities of pre-weaning traits associated with growth were moderate for birth weight (0·27 (s.e. 0·04)), weaning weight, generally in September at 3 months of age (0·21 (s.e. 0·06)) and growth rate from birth to weaning (0·15 (s.e. 0·03)). Heritabilities for post-weaning traits were 0·10 (s.e. 0·05) for turn-out weight in April/May, 0·14 (s.e. 0·06) for September weight, at 15 months of age, 0·08 (s.e. 0·05) for growth rate weaning to turn-out and 0·12 (s.e. 0·06) for growth rate turn-out to September. Correlations between weaning weight and post-weaning traits were high indicating the usefulness of weaning weight as a selection criterion for red deer on upland farms. While Wapiti (Cervus elaphus canadensis) crosses grew faster than pure red deer they also tended to have higher mortality rates pre-weaning. Older dams were more likely to have a successful pregnancy and also tended to calve earlier. Date of calving was found to show no heritable variation in this study.

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