scholarly journals With a little help from my friends: Cooperation can accelerate crossing of adaptive valleys

2016 ◽  
Author(s):  
Uri Obolski ◽  
Ohad Lewin-Epstein ◽  
Eran Even-Tov ◽  
Yoav Ram ◽  
Lilach Hadany
Keyword(s):  
Environmental Changes ◽  
Cooperative Behavior ◽  
Natural Populations ◽  
Peak Shift ◽  
Population Diversity ◽  
Stochastic Simulations ◽  
Term Evolution ◽  
Adaptive Peak ◽  
Mixed Populations

AbstractNatural selection favors changes that lead to genotypes possessing high fitness. A conflict arises when several mutations are required for adaptation, but each mutation is separately deleterious. The process of a population evolving from a genotype encoding for a local fitness maximum to a higher fitness genotype is termed an adaptive peak shift.Here we suggest cooperative behavior as a factor that can facilitate adaptive peak shifts. We model cooperation in apublic goodsscenario, wherein each individual contributes resources that are later equally redistributed among all cooperating individuals. We use mathematical modeling and stochastic simulations to study the effect of cooperation on peak shifts in well-mixed populations and structured ones. Our results show that cooperation can accelerate the rate of complex adaptation. Furthermore, we show that cooperation increases the population diversity throughout the peak shift process, thus increasing the robustness of the population to drastic environmental changes.Our work could help explain adaptive valley crossing in natural populations and suggest that the long term evolution of a species depends on its social behavior.

scholarly journals Evolution and coexistence in response to a key innovation in a long-term evolution experiment withEscherichia coli

2015 ◽  
Author(s):  
Caroline B. Turner ◽  
Zachary D. Blount ◽  
Daniel H. Mitchell ◽  
Richard E. Lenski
Keyword(s):  
Environmental Changes ◽  
Carbon Sources ◽  
Dicarboxylic Acids ◽  
Long Term Evolution ◽  
E Coli ◽  
Term Evolution ◽  
Key Innovation ◽  
Evolution Experiment ◽  
Evolutionary Trajectories

Evolution of a novel function can greatly alter the effects of an organism on its environment. These environmental changes can, in turn, affect the further evolution of that organism and any coexisting organisms. We examine these effects and feedbacks following evolution of a novel function in the long-term evolution experiment (LTEE) withEscherichia coli. A characteristic feature ofE. coliis its inability to consume citrate aerobically. However, that ability evolved in one of the LTEE populations. In this population, citrate-utilizing bacteria (Cit+) coexisted stably with another clade of bacteria that lacked the capacity to utilize citrate (Cit−). This coexistence was shaped by the evolution of a cross-feeding relationship in which Cit+cells released the dicarboxylic acids succinate, fumarate, and malate into the medium, and Cit−cells evolved improved growth on these carbon sources, as did the Cit+cells. Thus, the evolution of citrate consumption led to a flask-based ecosystem that went from a single limiting resource, glucose, to one with five resources either shared or partitioned between two coexisting clades. Our findings show how evolutionary novelties can change environmental conditions, thereby facilitating diversity and altering both the structure of an ecosystem and the evolutionary trajectories of coexisting organisms.

scholarly journals Transgenerational dispersal plasticity and its fitness consequences are under genetic control

2019 ◽  
Author(s):  
Hugo Cayuela ◽  
Staffan Jacob ◽  
Nicolas Schtickzelle ◽  
Rik Verdonck ◽  
Hervé Philippe ◽  
...  
Keyword(s):  
Genetic Control ◽  
Phenotypic Variation ◽  
Evolutionary Dynamics ◽  
Environmental Changes ◽  
Critical Role ◽  
Natural Populations ◽  
Model Species ◽  
Transgenerational Plasticity ◽  
Species Response

AbstractPhenotypic plasticity, the ability of one genotype to produce different phenotypes in different environments, plays a central role in species’ response to environmental changes. Transgenerational plasticity (TGP) allows the transmission of this environmentally-induced phenotypic variation across generations, and can influence adaptation. To date, the genetic control of TGP, its long-term stability, and its potential costs remain largely unknown, mostly because empirical demonstrations of TGP across many generations in several genetic backgrounds are scarce. Here, we examined how genotype determines the TGP of dispersal, a fundamental process in ecology and evolution. We used an experimental approach involving ~200 clonal generations in a model-species of ciliate to determine if and how TGP influences the expression of dispersal-related traits in several genotypes. Our results show that morphological and movement traits associated with dispersal are plastic, and that these modifications are inherited over at least 35 generations. We also highlight that genotype modulates the fitness costs and benefits associated with plastic dispersal strategies. Our study suggests that genotype-dependent TGP could play a critical role in eco-evolutionary dynamics as dispersal determines gene flow and the long-term persistence of natural populations. More generally, it outlines the tremendous importance that genotype-dependent TGP could have in the ability of organisms to cope with current and future environmental changes.SignificanceThe genetic control of the transgenerational plasticity is still poorly understood despite its critical role in species responses to environmental changes. We examined how genotype determines transgenerational plasticity of a complex trait (i.e., dispersal) in a model-species of ciliate across ~200 clonal generations. Our results provide evidence that plastic phenotypic variation linked to dispersal is stably inherited over tens of generations and that cell genotype modulates the expression and fitness cost of transgenerational plasticity.

Link-Level Simulator for Wireless local Area Network

2018 ◽  
Vol 6 (7) ◽  
pp. 314
Author(s):  
Chaithra. H. U ◽  
Vani H.R
Keyword(s):  
Wireless Local Area Network ◽  
Local Area Network ◽  
Local Area Networks ◽  
Local Area ◽  
Long Term Evolution ◽  
Wireless Local Area Networks ◽  
Area Network ◽  
Network Simulator ◽  
Term Evolution

Now a days in Wireless Local Area Networks (WLANs) used in different fields because its well-suited simulator and higher flexibility. The concept of WLAN  with  advanced 5th Generation technologies, related to a Internet-of-Thing (IOT). In this project, representing the Network Simulator (NS-2) used linked-level simulators for Wireless Local Area Networks and still utilized IEEE 802.11g/n/ac with advanced IEEE 802.11ah/af technology. Realization of the whole Wireless Local Area Networking linked-level simulators inspired by the recognized Vienna Long Term Evolution- simulators. As a outcome, this is achieved to link together that simulator to detailed performances of Wireless Local Area Networking with Long Term Evolution, operated in the similar RF bands. From the advanced 5th Generation support cellular networking, such explore is main because different coexistences scenario can arise linking wireless communicating system to the ISM and UHF bands.

Specific features of long-term domestication of australian crayfish Cherax quadricarinatus in conditions of the western part of Russian Federation

2018 ◽  
Vol 194 ◽  
pp. 188-192
Author(s):  
D. I. Shokasheva
Keyword(s):  
Natural Selection ◽  
Russian Federation ◽  
Natural Populations ◽  
Cherax Quadricarinatus ◽  
Local Environments ◽  
Local Species ◽  
Adaptive Ability

Natural populations of crayfish are in depression in Russia and local species are not cultivated. In this situation, experimental cultivation of allochtonous australian crayfish Cherax quadricarinatus is conducted. This species is distinguished by high reproductive abilities and good consumer properties. It has domesticated in Russia spontaneously and produced 9–10 generations in Astrakhan Region. Certain natural selection in the process of domestication provides adaptive ability of this species to local environments and its capabil­ity to reproduce a viable progeny, so there is no doubts in good prospects of its cultivation in industrial conditions.

Simulación de cobertura del modelo de radio propagación 3GPP para un entorno urbano en una red 4G – LTE

2013 ◽  
Vol 8 (15) ◽  
pp. 33-40
Author(s):  
Javier Enrique Arévalo Peña
Keyword(s):  
Long Term Evolution ◽  
Term Evolution ◽  
Nuevas Tecnologías ◽  
4G Lte ◽  
3Rd Generation Partnership Project

En la planeación de las próximas generaciones de redes inalámbricas es importante contar con estudios de radio propagación que permitan establecer diseños adecuados para ofrecer los servicios proyectados por las nuevas tecnologías a los usuarios móviles. En este artículo se presentan aspectos relacionados con el comportamiento de cobertura de radio propagación del modelo propuesto por el 3GPP (3rd Generation Partnership Project) para un entorno urbano en una red LTE (Long Term Evolution) empleando sistemas de antenas convencionales y sistemas de antena adaptativas (AAS). Para ello se utiliza la herramienta de software ICS Designer y se establece como escenario los alrededores la Fundación Universidad Autónoma de Colombia ubicada en el centro urbano de la ciudad de Bogotá D. C.

Sign in / Sign up

Export Citation Format

Share Document