scholarly journals Evolution of nutrient acquisition: when adaptation fills the gap between contrasting ecological theories

2010 ◽  
Vol 278 (1704) ◽  
pp. 449-457 ◽  
Author(s):  
S. Boudsocq ◽  
S. Barot ◽  
N. Loeuille
Keyword(s):  
Evolutionary Dynamics ◽  
Plant Biomass ◽  
Adaptive Dynamics ◽  
Ecosystem Model ◽  
Point Of View ◽  
Mineral Nutrient ◽  
Trade Off ◽  
Ecosystem Properties ◽  
Ecological Theories ◽  
Limiting Nutrient

Although plant strategies for acquiring nutrients have been widely studied from a functional point of view, their evolution is still not well understood. In this study, we investigate the evolutionary dynamics of these strategies and determine how they influence ecosystem properties. To do so, we use a simple nutrient-limited ecosystem model in which plant ability to take up nutrients is subject to adaptive dynamics. We postulate the existence of a trade-off between this ability and mortality. We show that contrasting strategies are possible as evolutionary outcomes, depending on the shape of the trade-off and, when nitrogen is considered as the limiting nutrient, on the intensity of symbiotic fixation. Our model enables us to bridge these evolutionary outcomes to classical ecological theories such as Hardin's tragedy of the commons and Tilman's rule of R *. Evolution does not systematically maximize plant biomass or primary productivity. On the other hand, each evolutionary outcome leads to a decrease in the availability of the limiting mineral nutrient, supporting the work of Tilman on competition between plants for a single resource. Our model shows that evolution can be used to link different classical ecological results and that adaptation may influence ecosystem properties in contrasted ways.

scholarly journals Implications of the evolution of agriculture and resource foraging for the maintenance of species diversity and community structure

2021 ◽  
Author(s):  
Aurore Picot ◽  
Thibaud Monnin ◽  
Nicolas Loeuille
Keyword(s):  
Community Structure ◽  
Opportunity Cost ◽  
Evolutionary Dynamics ◽  
Niche Construction ◽  
Adaptive Dynamics ◽  
Trade Off ◽  
Selective Pressures ◽  
Negative Effect ◽  
The Cost ◽  
Positive Effect

AbstractAgriculture - cultivation of plants, algae, fungi and animal herding - is found in numerous taxa such as humans, but also ants, beetles, fishes and even bacteria. Such niche construction behaviours have evolved independently from hunter/predation behaviours, though many species remain primarily predators. We here investigate when such a transition from predation/hunter behaviour to agriculture is favoured. In these systems where a consumer has a positive effect on its resource, we can expect an allocative cost of agriculture for the farmer, hence modifying the selective pressures acting upon it. The management of the resource may have a negative effect on its consumption: for instance, when the consumer defends the resource against other predators (exploitation cost). In other situations, the cost may occur on the foraging of alternative resources, for instance if the consumer spends more time nearby the farmed resource (opportunity cost). Here, we develop a simple three-species model constituted by a farmer species that consumes two resource species, one of them receiving an additional positive effect from the consumer. We consider two trade-off scenarios based on how the cost of agriculture is implemented, either as an exploitation cost or as an opportunity cost. We use an adaptive dynamics approach to study the conditions for the evolution of the investment into agriculture and specialization on the two resources, and consequences on the ecological dynamics of the community. Eco-evolutionary dynamics generate a feedback between the evolution of agriculture and specialization on the helped resource, that can lead to varying selected intensity of agriculture, from generalist strategies with no agriculture, to farmer phenotypes that are entirely specialized on the farmed resource, with possible coexistence between those two extreme strategies.

scholarly journals Attracting pollinators vs escaping herbivores: eco-evolutionary dynamics of plants confronted with an ecological trade-off

2021 ◽  
Author(s):  
Youssef Yacine ◽  
Nicolas Loeuille
Keyword(s):  
Evolutionary Dynamics ◽  
Plant Traits ◽  
Adaptive Dynamics ◽  
Disruptive Selection ◽  
Stabilizing Selection ◽  
Ecological Communities ◽  
Trade Off ◽  
Trade Offs ◽  
Herbivore Community ◽  
Plant Animal Interactions

AbstractA large number of plant traits are subject to an ecological trade-off between attracting pollinators and escaping herbivores. The interplay of both plant-animal interactions determines their evolution. Within a plant-pollinator-herbivore community in which interaction strengths depend on trait-matching, eco-evolutionary dynamics are studied using the framework of adaptive dynamics. We characterize the type of selection acting on the plant phenotype and the consequences for multispecies coexistence. We find that pollination favors stabilizing selection and coexistence. In contrast, herbivory fosters runaway selection, which threatens plant-animal coexistence. These contrasting dynamics highlight the key role of ecological trade-offs in structuring ecological communities. In particular, we show that disruptive selection is possible when such trade-offs are strong. While the interplay of pollination and herbivory is known to maintain plant polymorphism in several cases, our work suggests that it might also have fueled the diversification process itself.

scholarly journals Cucumber mosaic virus satellite RNAs that induce similar symptoms in melon plants show large differences in fitness

2011 ◽  
Vol 92 (8) ◽  
pp. 1930-1938 ◽  
Author(s):  
Mónica Betancourt ◽  
Aurora Fraile ◽  
Fernando García-Arenal
Keyword(s):  
Cucumber Mosaic Virus ◽  
Mosaic Virus ◽  
Evolutionary Dynamics ◽  
Plant Biomass ◽  
Aphid Transmission ◽  
Helper Virus ◽  
Relative Fitness ◽  
Single Infection ◽  
Trade Offs ◽  
Satellite Rnas

Two groups of Cucumber mosaic virus (CMV) satellite RNAs (satRNAs), necrogenic and non-necrogenic, can be differentiated according to the symptoms they cause in tomato plants, a host in which they also differ in fitness. In most other CMV hosts these CMV-satRNA cause similar symptoms. Here, we analyse whether they differ in traits determining their relative fitness in melon plants, in which the two groups of CMV-satRNAs cause similar symptoms. For this, ten necrogenic and ten non-necrogenic field satRNA genotypes were assayed with Fny-CMV as a helper virus. Neither type of CMV-satRNA modified Fny-CMV symptoms, and both types increased Fny-CMV virulence similarly, as measured by decreases in plant biomass and lifespan. Necrogenic and non-necrogenic satRNAs differed in their ability to multiply in melon tissues; necrogenic satRNAs accumulated to higher levels both in single infection and in competition with non-necrogenic satRNAs. Indeed, multiplication of some non-necrogenic satRNAs was undetectable. Transmission between hosts by aphids was less efficient for necrogenic satRNAs as a consequence of a more severe reduction of CMV accumulation in leaves. The effect of CMV accumulation on aphid transmission was not compensated for by differences in satRNA encapsidation efficiency or transmissibility to CMV progeny. Thus, necrogenic and non-necrogenic satRNAs differ in their relative fitness in melon, and trade-offs are apparent between the within-host and between-host components of satRNA fitness. Hence, CMV-satRNAs could have different evolutionary dynamics in CMV host-plant species in which they do not differ in pathogenicity.

scholarly journals Inbreeding parents should invest more resources in fewer offspring

2016 ◽  
Author(s):  
A. Bradley Duthie ◽  
Aline M. Lee ◽  
Jane M. Reid
Keyword(s):  
General Theory ◽  
Evolutionary Dynamics ◽  
Inbreeding Avoidance ◽  
The Other ◽  
Trade Off ◽  
Offspring Number ◽  
Focal Female ◽  
Special Cases ◽  
Selection For ◽  
Joint Consideration

AbstractInbreeding increases parent-offspring relatedness and commonly reduces offspring viability, shaping selection on reproductive interactions involving relatives and associated parental investment (PI). Nevertheless, theories predicting selection for inbreeding versus inbreeding avoidance and selection for optimal PI have only been considered separately, precluding prediction of optimal PI and associated reproductive strategy given inbreeding. We unify inbreeding and PI theory, demonstrating that optimal PI increases when a female's inbreeding decreases the viability of her offspring. Inbreeding females should therefore produce fewer offspring due to the fundamental trade-off between offspring number and PI. Accordingly, selection for inbreeding versus inbreeding avoidance changes when females can adjust PI with the degree that they inbreed. In contrast, optimal PI does not depend on whether a focal female is herself inbred. However, inbreeding causes optimal PI to increase given strict monogamy and associated biparental investment compared to female-only investment. Our model implies that understanding evolutionary dynamics of inbreeding strategy, inbreeding depression, and PI requires joint consideration of the expression of each in relation to the other. Overall, we demonstrate that existing PI and inbreeding theories represent special cases of a more general theory, implying that intrinsic links between inbreeding and PI affect evolution of behaviour and intra-familial conflict.

Effects of pollution on individual size of a single species

2020 ◽  
pp. 2050079
Author(s):  
Bing Liu ◽  
Le Song ◽  
Xin Wang ◽  
Baolin Kang
Keyword(s):  
Growth Rate ◽  
Evolutionary Dynamics ◽  
Function Analysis ◽  
Fitness Function ◽  
Adaptive Dynamics ◽  
Single Species ◽  
Phenotypic Trait ◽  
Evolutionary Branching ◽  
Critical Function ◽  
Individual Size

In this paper, we develop a single species evolutionary model with a continuous phenotypic trait in a pulsed pollution discharge environment and discuss the effects of pollution on the individual size of the species. The invasion fitness function of a monomorphic species is given, which involves the long-term average exponential growth rate of the species. Then the critical function analysis method is used to obtain the evolutionary dynamics of the system, which is related to interspecific competition intensity between mutant species and resident species and the curvature of the trade-off between individual size and the intrinsic growth rate. We conclude that the pollution affects the evolutionary traits and evolutionary dynamics. The worsening of the pollution can lead to rapid stable evolution toward a smaller individual size, while the opposite is more likely to generate evolutionary branching and promote species diversity. The adaptive dynamics of coevolution of dimorphic species is further analyzed when evolutionary branching occurs.

scholarly journals Study of Optimal Cam Design of Dual-Axle Spring-Loaded Camming Device

Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 1940 ◽  
Author(s):  
David Rybansky ◽  
Martin Sotola ◽  
Pavel Marsalek ◽  
Zdenek Poruba ◽  
Martin Fusek
Keyword(s):  
Topology Optimization ◽  
Bearing Capacity ◽  
Fall Prevention ◽  
Computational Models ◽  
Point Of View ◽  
Load Bearing Capacity ◽  
Parametric Curves ◽  
Trade Off ◽  
Cam Design ◽  
Operating Element

The spring-loaded camming device (SLCD), also known as “friend”, is a simple mechanism used to ensure the safety of the climber through fall prevention. SLCD consists of two pairs of opposing cams rotating separately, with one (single-axle SLCD) or two (dual-axle SLCD) pins connecting the opposing cams, a stem, connected to the pins, providing the attachment of the climbing rope, springs, which simultaneously push cams to a fully expanded position, and an operating element controlling the cam position. The expansion of cams is thus adaptable to allow insertion or removal of the device into/from a rock crack. While the pins, stem, operating element, and springs can be considered optimal, the (especially internal) shape of the cam allows space for improvement, especially where the weight is concerned. This paper focuses on optimizing the internal shape of the dual-axle SLCD cam from the perspective of the weight/stiffness trade-off. For this purpose, two computational models are designed and multi-step topology optimization (TOP) are performed. From the computational models’ point of view, SLCD is considered symmetric and only one cam is optimized and smoothened using parametric curves. Finally, the load-bearing capacity of the new cam design is analyzed. This work is based on practical industry requirements, and the obtained results will be reflected in a new commercial design of SLCD.

scholarly journals The evolutionary dynamics of influenza A virus adaptation to mammalian hosts

2013 ◽  
Vol 368 (1614) ◽  
pp. 20120382 ◽  
Author(s):  
S. Bhatt ◽  
T. T. Lam ◽  
S. J. Lycett ◽  
A. J. Leigh Brown ◽  
T. A. Bowden ◽  
...  
Keyword(s):  
Avian Influenza ◽  
Adaptive Evolution ◽  
Influenza A ◽  
Evolutionary Dynamics ◽  
Adaptive Dynamics ◽  
Swine Influenza ◽  
Influenza Viruses ◽  
Viral Fitness ◽  
Influenza A Viruses ◽  
Entire Genome

Few questions on infectious disease are more important than understanding how and why avian influenza A viruses successfully emerge in mammalian populations, yet little is known about the rate and nature of the virus’ genetic adaptation in new hosts. Here, we measure, for the first time, the genomic rate of adaptive evolution of swine influenza viruses (SwIV) that originated in birds. By using a curated dataset of more than 24 000 human and swine influenza gene sequences, including 41 newly characterized genomes, we reconstructed the adaptive dynamics of three major SwIV lineages (Eurasian, EA; classical swine, CS; triple reassortant, TR). We found that, following the transfer of the EA lineage from birds to swine in the late 1970s, EA virus genes have undergone substantially faster adaptive evolution than those of the CS lineage, which had circulated among swine for decades. Further, the adaptation rates of the EA lineage antigenic haemagglutinin and neuraminidase genes were unexpectedly high and similar to those observed in human influenza A. We show that the successful establishment of avian influenza viruses in swine is associated with raised adaptive evolution across the entire genome for many years after zoonosis, reflecting the contribution of multiple mutations to the coordinated optimization of viral fitness in a new environment. This dynamics is replicated independently in the polymerase genes of the TR lineage, which established in swine following separate transmission from non-swine hosts.

scholarly journals “Carrefour Louisiane”

2014 ◽  
Vol 7 (1) ◽  
pp. 124-153 ◽  
Author(s):  
Ingrid Neumann-Holzschuh
Keyword(s):  
Language Contact ◽  
Language Change ◽  
Evolutionary Dynamics ◽  
Point Of View ◽  
New Variety ◽  
Dialect Contact ◽  
Cajun French ◽  
Louisiana French ◽  
History Of ◽  
Linguistic Behavior

The history of Louisiana French (LF) is closely related to Louisiana’s particular societal and linguistic ecosystem, characterized by a mixed society where new forms of societal organization emerged and were reflected in new forms of linguistic patterns and linguistic behavior. From the beginning, language contact has been of crucial importance for the emergence, evolution and gradual decline of Louisiana French (“Cajun French”). In colonial times, contact between related French lects resulted in the formation of a new variety of regional French in North America with its own features and its own evolutionary dynamics. The continuing contact with English, however, which takes place in an entirely different ecological frame, results in the ongoing attrition of the minority language. The first part of the article deals with early stages of dialect contact in Louisiana; it will be shown that from a diachronic point of view Louisiana French has to be seen as a product of language mixing and dialect leveling. In the second part two specific aspects of current English-French language contact will be discussed. Both aspects serve to illustrate particularities of the linguistic situation in Louisiana now and then as well as the importance of certain universal mechanisms of contact-induced language change.

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