scholarly journals Evolution of trade-offs across environments following experimental evolution of the generalist Drosophila suzukii to different fruit media

2019 ◽  
Author(s):  
Laure Olazcuaga ◽  
Nicolas O. Rode ◽  
Julien Foucaud ◽  
Mathieu Gautier ◽  
Candice Deschamps ◽  
...  
Keyword(s):  
Experimental Evolution ◽  
Reciprocal Transplant ◽  
Ecological Specialization ◽  
Drosophila Suzukii ◽  
Generalist Species ◽  
Specific Adaptation ◽  
Trade Offs ◽  
Specific Performance ◽  
Over Time ◽  
Transplant Experiments

AbstractAdaptation to divergent environments can result in ecological specialization. The detection of trade-offs across environments (i.e., negative correlations in performance between different environments) is the hallmark of specialization. Although such trade-offs are predicted by theory, experimental evidence that trade-offs can readily evolve in the laboratory remains scarce. Here, we investigated the evolution of adaptation to distinct environments, including potential fitness trade-offs by maintaining populations of the generalist fruit pest, Drosophila suzukii, for 26 generations on media made with different fruits. We measured the performance and preference of each evolved population on the different fruits using reciprocal transplant experiments after five generations and at the end of our experiment. After five generations, experimental populations on most fruits had gone extinct, but they had adapted to three test fruit media, without exhibiting trade-offs. By generation 26 on these three fruits, specific adaptation to each fruit media had evolved, with trade-offs across media for some populations. The evolution of fruit-specific performance did not drive the evolution of corresponding preferences (i.e., preferences for the evolution fruit). This study suggests that ecological specialization can evolve in generalist species, even if only transiently, when hosts or habitats are heterogeneous over time and space.

scholarly journals Conflict between biotic and climatic selective pressures acting on an extended phenotype in a subarctic, but not temperate, environment

2015 ◽  
Vol 282 (1817) ◽  
pp. 20151585 ◽  
Author(s):  
V. G. Rohwer ◽  
F. Bonier ◽  
P. R. Martin
Keyword(s):  
Nest Predation ◽  
Reciprocal Transplant ◽  
Nest Construction ◽  
Extended Phenotype ◽  
Trade Off ◽  
Selective Pressures ◽  
Trade Offs ◽  
Non Local ◽  
Temperate Environment ◽  
Transplant Experiments

Climatic selective pressures are thought to dominate biotic selective pressures at higher latitudes. However, few studies have experimentally tested how these selective pressures differentially act on traits across latitudes because traits can rarely be manipulated independently of the organism in nature. We overcame this challenge by using an extended phenotype—active bird nests—and conducted reciprocal transplant experiments between a subarctic and temperate site, separated by 14° of latitude. At the subarctic site, biotic selective pressures (nest predation) favoured smaller, non-local temperate nests, whereas climatic selective pressures (temperature) favoured larger local nests, particularly at colder temperatures. By contrast, at the temperate site, climatic and biotic selective pressures acted similarly on temperate and subarctic nests. Our results illustrate a functional trade-off in the subarctic between nest morphologies favoured by biotic versus climatic selective pressures, with climate favouring local nest morphologies. At our temperate site, however, allocative trade-offs in the time and effort devoted to nest construction favour smaller, local nests. Our findings illustrate a conflict between biotic and climatic selective pressures at the northern extremes of a species geographical range, and suggest that trade-offs between trait function and trait elaboration act differentially across latitude to create broad geographic variation in traits.

scholarly journals Larger bacterial populations evolve heavier fitness trade-offs and undergo greater ecological specialization

2020 ◽  
Author(s):  
Yashraj Chavhan ◽  
Sarthak Malusare ◽  
Sutirth Dey
Keyword(s):  
Escherichia Coli ◽  
Population Genetics ◽  
Population Size ◽  
Experimental Evolution ◽  
Environmental Changes ◽  
Reaction Norms ◽  
Ecological Specialization ◽  
Bacterial Populations ◽  
Trade Offs ◽  
Evolutionary Studies

AbstractEvolutionary studies over the last several decades have invoked fitness trade-offs to explain why species prefer some environments to others. However, the effects of population size on trade-offs and ecological specialization remain largely unknown. To complicate matters, trade-offs themselves have been visualized in multiple ways in the literature. Thus, it is not clear how population size can affect the various aspects of trade-offs. To address these issues, we conducted experimental evolution with Escherichia coli populations of two different sizes in two nutritionally limited environments and studied fitness trade-offs from three different perspectives. We found that larger populations evolved greater fitness trade-offs, regardless of how trade-offs are conceptualized. Moreover, although larger populations adapted more to their selection conditions, they also became more maladapted to other environments, ultimately paying heavier costs of adaptation. To enhance the generalizability of our results, we further investigated the evolution of ecological specialization across six different environmental pairs and found that larger populations specialized more frequently and evolved consistently steeper reaction norms of fitness. This is the first study to demonstrate a relationship between population size and fitness trade-offs and the results are important in understanding the population genetics of ecological specialization and vulnerability to environmental changes.

Decision Processes and Value Endogeneity

2018 ◽  
Author(s):  
James G. March
Keyword(s):  
Decision Processes ◽  
Hard Problem ◽  
Trade Offs ◽  
Definition Of ◽  
Over Time ◽  
What Matters

Humans use reasons to shape and justify choices. In the process, trade-offs seem essential and often inevitable. But trade-offs involve comparisons, which are problematic both across values and especially over time. Reducing disparate values to a common metric (especially if that metric is money) is often problematic and unsatisfactory. Critically, it is not that values just shape choices, but that choices themselves shape values. This endogeneity of values makes an unconditional normative endorsement of modern decision-theoretic rationality unwise. This is a hard problem and there is no escaping the definition of good values, that is, those that make humans better. This removes the wall between economics and philosophy. If we are to adopt and enact this perspective, then greater discourse and debate on what matters and not just what counts will be useful and even indispensable.

scholarly journals Sexual conflict drives micro- and macroevolution of sexual dimorphism in immunity

BMC Biology ◽  
2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Basabi Bagchi ◽  
Quentin Corbel ◽  
Imroze Khan ◽  
Ellen Payne ◽  
Devshuvam Banerji ◽  
...  
Keyword(s):  
Sex Differences ◽  
Sexual Dimorphism ◽  
Mating System ◽  
Sexual Conflict ◽  
Experimental Evolution ◽  
Parasitic Infections ◽  
Pathogen Dynamics ◽  
Trade Offs ◽  
Host Pathogen ◽  
Seed Beetles

Abstract Background Sexual dimorphism in immunity is believed to reflect sex differences in reproductive strategies and trade-offs between competing life history demands. Sexual selection can have major effects on mating rates and sex-specific costs of mating and may thereby influence sex differences in immunity as well as associated host–pathogen dynamics. Yet, experimental evidence linking the mating system to evolved sexual dimorphism in immunity are scarce and the direct effects of mating rate on immunity are not well established. Here, we use transcriptomic analyses, experimental evolution and phylogenetic comparative methods to study the association between the mating system and sexual dimorphism in immunity in seed beetles, where mating causes internal injuries in females. Results We demonstrate that female phenoloxidase (PO) activity, involved in wound healing and defence against parasitic infections, is elevated relative to males. This difference is accompanied by concomitant sex differences in the expression of genes in the prophenoloxidase activating cascade. We document substantial phenotypic plasticity in female PO activity in response to mating and show that experimental evolution under enforced monogamy (resulting in low remating rates and reduced sexual conflict relative to natural polygamy) rapidly decreases female (but not male) PO activity. Moreover, monogamous females had evolved increased tolerance to bacterial infection unrelated to mating, implying that female responses to costly mating may trade off with other aspects of immune defence, an hypothesis which broadly accords with the documented sex differences in gene expression. Finally, female (but not male) PO activity shows correlated evolution with the perceived harmfulness of male genitalia across 12 species of seed beetles, suggesting that sexual conflict has a significant influence on sexual dimorphisms in immunity in this group of insects. Conclusions Our study provides insights into the links between sexual conflict and sexual dimorphism in immunity and suggests that selection pressures moulded by mating interactions can lead to a sex-specific mosaic of immune responses with important implications for host–pathogen dynamics in sexually reproducing organisms.

scholarly journals Evolving user needs and late-mover advantage

2016 ◽  
Vol 15 (1) ◽  
pp. 67-90 ◽  
Author(s):  
Adrien Querbes ◽  
Koen Frenken
Keyword(s):  
User Needs ◽  
Nk Model ◽  
Trade Offs ◽  
Managerial Implications ◽  
First Mover ◽  
Over Time ◽  
Late Movers

We propose a generalized NK-model of late-mover advantage where late-mover firms leapfrog first-mover firms as user needs evolve over time. First movers face severe trade-offs between the provision of functionalities in which their products already excel and the additional functionalities requested by users later on. Late movers, by contrast, start searching when more functionalities are already known and typically come up with superior product designs. We also show that late-mover advantage is more probable for more complex technologies. Managerial implications follow.

Current issues and controversies in assessing the environmental impacts of livestock production.

2021 ◽  
Vol 16 (044) ◽  
Author(s):  
Judith L. Capper
Keyword(s):  
Environmental Impacts ◽  
Resource Use ◽  
Management Practices ◽  
Ghg Emissions ◽  
Livestock Production ◽  
Environmental Indicators ◽  
Environment Impact ◽  
Trade Offs ◽  
Specific Practice ◽  
Over Time

Abstract The environment impact of livestock production is one of the most significant issues within agriculture. Global concerns over climate change, resource use, pollution and other environment indicators means that producers must implement practices and systems to reduce environmental impacts, yet this may only be achieved through assessments that allow impacts to be quantified, benchmarked and improved over time. Although environmental indicators are widely accepted, the metrics by which these are assessed continue to evolve over time as assessment objectives gain clarity and focus, and as the science relating to controversial topics (e.g. global warming or carbon sequestration) becomes more refined. however, significant negative trade-offs may occur between different metrics and denominators such that a specific practice or system may appear to have greater or lesser impacts, depending on assessment methodology. A number of tools and models have been developed to empower producers in quantifying environmental impacts, which will be increasingly important is satisfying future consumers' hunger for information as well as food. These tools must be supplied in tandem with information as to the potential consequences of changing management practices and systems. At present however, tools available are based on differing methodologies, are often opaque in their background calculations and do not necessarily account for all the factors that influence environmental impacts from livestock. There is a clear need for robust tools that can be used as standards for assessing environmental impacts from the global livestock industry and that go beyond GHG emissions to produce a more rounded holistic assessment.

scholarly journals Persistence of a Yeast-Based (Hanseniaspora uvarum) Attract-and-Kill Formulation against Drosophila suzukii on Grape Leaves

Insects ◽  
2020 ◽  
Vol 11 (11) ◽  
pp. 810
Author(s):  
Flavia Bianchi ◽  
Urban Spitaler ◽  
Irene Castellan ◽  
Carlo S. Cossu ◽  
Timothy Brigadoi ◽  
...  
Keyword(s):  
Fermentation Broth ◽  
Exchange Chromatography ◽  
Liquid Chromatography Mass Spectrometry ◽  
Drosophila Suzukii ◽  
Potato Dextrose Broth ◽  
Hanseniaspora Uvarum ◽  
Leaf Surfaces ◽  
Volatile Organic ◽  
Attract And Kill ◽  
Over Time

The production of phagostimulant and attractive volatile organic compounds (VOCs) by yeasts can be exploited to improve the efficacy of attract-and-kill formulations against the spotted wing drosophila (SWD). This study evaluated the persistence over one week of a yeast-based formulation under greenhouse conditions. Potted grape plants were treated with: (i) potato dextrose broth (PDB), (ii) PDB containing spinosad (PDB + S), and (iii) H. uvarum fermentation broth grown on PDB containing spinosad (H. u. + S). Laboratory trials were performed to determine the survival and the oviposition rate of SWD after exposure to treated leaves. Ion-exchange chromatography was performed to measure carbohydrates, sugar alcohols, and organic acids on leaf surfaces, while amino acids were assessed through liquid chromatography–mass-spectrometry. Additionally, the VOCs released by plants treated with H.uvarum were collected via closed-loop-stripping analysis and compared to those emitted by untreated leaves. A higher mortality was observed for adult SWDs in contact with H. uvarum containing spinosad compared to PDB containing spinosad. Generally, a decrease in the amounts of non-volatile compounds was observed over time, though numerous nutrients were still present one week after treatment. The application of the yeast-based formulation induced the emission of VOCs by the treated leaves. The concentration of 2-phenylethanol, one of the main VOCs emitted by yeasts, decreased over time. These findings describe the presence of potential phagostimulants and compounds attractive to SWD in a yeast-based attract-and-kill formulation and demonstrate the efficacy of the formulation over one week.

Evidence for competition and facilitation trade-offs: effects of Sitka alder density on pine regeneration and soil productivity

2006 ◽  
Vol 36 (5) ◽  
pp. 1286-1298 ◽  
Author(s):  
Suzanne W Simard ◽  
Steven R Radosevich ◽  
Donald L Sachs ◽  
Shannon M Hagerman
Keyword(s):  
Resource Availability ◽  
Pinus Contorta ◽  
Soil Productivity ◽  
Deciduous Species ◽  
Competitive Effects ◽  
Trade Offs ◽  
Alnus Viridis ◽  
Pine Regeneration ◽  
Over Time

We suggest that the net outcome of interactions between regenerating conifers and early seral deciduous species depends on trade-offs between competition and facilitation over time. Vegetation management treatments that dramatically reduce competitive effects of deciduous species may constrain the ability of conifers to optimize resource trade-offs (e.g., increased growth response to light at the expense of increased drought mortality), potentially affecting long-term productivity. In a 15-year study in southern interior British Columbia, we investigated whether lodgepole pine (Pinus contorta Dougl. ex Loud. var. latifolia Engelm.) survival, growth, and resource availability differed among manipulated stand compositions, from pure pine stands to mixtures with native N2-fixing Sitka alder (Alnus viridis subsp. sinuata (Regel) Á. Löve & D. Löve) or herbs. We found that pine growth increases were sustained only in pure stands, where alder and herbs were completely removed, corresponding with short-term increases in light, soil and air temperature, and soil nitrate. However, this came at a significant cost to survival (through loss of protection from browsing, desiccation, and sun scald), as well as dramatic depletions in soil nitrogen mineralization over the longer term. Our results support a competition–facilitation trade-off hypothesis, suggesting that treatment-imposed shifts in resource availability over time could negatively affect forest productivity.

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