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‣ SIZE AS A LINE OF LEAST RESISTANCE II: DIRECT SELECTION ON SIZE OR CORRELATED RESPONSE DUE TO CONSTRAINTS?

MARROIG, Gabriel; CHEVERUD, James
Fonte: WILEY-BLACKWELL PUBLISHING, INC Publicador: WILEY-BLACKWELL PUBLISHING, INC
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
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Evolutionary change in New World Monkey (NWM) skulls occurred primarily along the line of least resistance defined by size (including allometric) variation (g(max)). Although the direction of evolution was aligned with this axis, it was not clear whether this macroevolutionary pattern results from the conservation of within population genetic covariance patterns (long-term constraint) or long-term selection along a size dimension, or whether both, constraints and selection, were inextricably involved. Furthermore, G-matrix stability can also be a consequence of selection, which implies that both, constraints embodied in g(max) and evolutionary changes observed on the trait averages, would be influenced by selection Here, we describe a combination of approaches that allows one to test whether any particular instance of size evolution is a correlated by-product due to constraints (g(max)) or is due to direct selection on size and apply it to NWM lineages as a case study. The approach is based on comparing the direction and amount of evolutionary change produced by two different simulated sets of net-selection gradients (beta), a size (isometric and allometric size) and a nonsize set. Using this approach it is possible to distinguish between the two hypotheses (indirect size evolution due to constraints or direct selection on size)...

‣ Os estudos com drosófilas no Instituto de Biociências da USP nas décadas de 1940 e 1950: entrevistas com docentes; Studies with drosophila at the Institute of Biosciences of USP in the decades of 1940s and 1950s: interviews with professors

Sião, José Franco Monte
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 25/10/2013 Português
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Esta pesquisa aborda o episódio histórico do grupo que institucionalizou a genética de populações com drosófilas no Brasil, a partir de 1943. Este grupo fez parte do Departamento de Biologia Geral da antiga Faculdade de Filosofia Ciências e Letras da Universidade de São Paulo (FFCL/USP), e teve como expoentes André Dreyfus (1897-1952) e Theodosius Dobzhansky (1900-1975). O objetivo desta pesquisa é analisar este episódio mediante o cotejamento de uma síntese, fruto de estudos anteriores realizados por este autor (SIÃO, 2007; SIÃO 2008), com cinco entrevistas realizadas com docentes do atual Departamento de Genética e Biologia Evolutiva do Instituto de Biociências da USP, que tiveram contato direto ou indireto com os pesquisadores que atuaram no referido grupo, entre as décadas de 1940 e 1950. A opção metodológica adotada para as entrevistas foi a da História Oral conforme proposto por Meihy e Holanda (2010). Segundo essa abordagem, as entrevistas passam por um tratamento composto de três fases, a saber, transcrição, textualização e transcriação. Em seguida, é realizada a devolutiva social, que é a devolutiva da transcriação ao colaborador entrevistado para validá-la mediante carta de cessão e autorização de o que vem a constituir a apresentação pública do material e serve de subsídio para a elaboração da narrativa histórica da pesquisa. As entrevistas tiveram como objetivos analisar os seguintes aspectos: o percurso histórico dos docentes entrevistados no Departamento de Genética e Biologia Evolutiva; a percepção dos docentes entrevistados sobre o episódio da parceria entre Dobzhansky e Dreyfus para o desenvolvimento da genética no Instituto de Biociências da USP e no Brasil...

‣ Eco-evolutionary feedbacks in community and ecosystem ecology: interactions between the ecological theatre and the evolutionary play

Post, David M.; Palkovacs, Eric P.
Fonte: The Royal Society Publicador: The Royal Society
Tipo: Artigo de Revista Científica
Publicado em 12/06/2009 Português
Relevância na Pesquisa
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Interactions between natural selection and environmental change are well recognized and sit at the core of ecology and evolutionary biology. Reciprocal interactions between ecology and evolution, eco-evolutionary feedbacks, are less well studied, even though they may be critical for understanding the evolution of biological diversity, the structure of communities and the function of ecosystems. Eco-evolutionary feedbacks require that populations alter their environment (niche construction) and that those changes in the environment feed back to influence the subsequent evolution of the population. There is strong evidence that organisms influence their environment through predation, nutrient excretion and habitat modification, and that populations evolve in response to changes in their environment at time-scales congruent with ecological change (contemporary evolution). Here, we outline how the niche construction and contemporary evolution interact to alter the direction of evolution and the structure and function of communities and ecosystems. We then present five empirical systems that highlight important characteristics of eco-evolutionary feedbacks: rotifer–algae chemostats; alewife–zooplankton interactions in lakes; guppy life-history evolution and nutrient cycling in streams; avian seed predators and plants; and tree leaf chemistry and soil processes. The alewife–zooplankton system provides the most complete evidence for eco-evolutionary feedbacks...

‣ Language: the perspective from organismal biology

Margoliash, Daniel; Nusbaum, Howard C.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Português
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The evolution of language and its mechanisms has been a topic of intense speculation and debate, particularly considering the question of innate endowment. Modern biological sciences— neurobiology and neuroethology—have made great strides in understanding proximate and ultimate causes of behavior. These insights are generally ignored in the debate regarding linguistic knowledge, especially in the realm of syntax where core theoretical constructs have been proposed unconstrained by evolutionary biology. Taking the perspective of organismal biology offers a principled approach to the study of language that is sensitive to its evolutionary context, a growing trend also in other domains of cognitive science. The emergence of a research program in the comparative biology of syntax is one concrete example of this trend.

‣ Next-generation tools for evolutionary invasion analyses

Hurford, Amy; Cownden, Daniel; Day, Troy
Fonte: The Royal Society Publicador: The Royal Society
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
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Evolutionary invasion analysis is a powerful technique for modelling in evolutionary biology. The general approach is to derive an expression for the growth rate of a mutant allele encoding some novel phenotype, and then to use this expression to predict long-term evolutionary outcomes. Mathematically, such ‘invasion fitness’ expressions are most often derived using standard linear stability analyses from dynamical systems theory. Interestingly, there is a mathematically equivalent approach to such stability analyses that is often employed in mathematical epidemiology, and that is based on so-called ‘next-generation’ matrices. Although this next-generation matrix approach has sometimes also been used in evolutionary invasion analyses, it is not yet common in this area despite the fact that it can sometimes greatly simplify calculations. The aim of this article is to bring the approach to a wider evolutionary audience in two ways. First, we review the next-generation matrix approach and provide a novel, and easily intuited, interpretation of how this approach relates to more standard techniques. Second, we illustrate next-generation methods in evolutionary invasion analysis through a series of informative examples. Although focusing primarily on evolutionary invasion analysis...

‣ In the Beginning Was the Familiar Voice Personally Familiar Voices in the Evolutionary and Contemporary Biology of Communication

Sidtis, Diana; Kreiman, Jody
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Português
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The human voice is described in dialogic linguistics as an embodiment of self in a social context, contributing to expression, perception and mutual exchange of self, consciousness, inner life, and personhood. While these approaches are subjective and arise from phenomenological perspectives, scientific facts about personal vocal identity, and its role in biological development, support these views. It is our purpose to review studies of the biology of personal vocal identity -- the familiar voice pattern-- as providing an empirical foundation for the view that the human voice is an embodiment of self in the social context. Recent developments in the biology and evolution of communication are concordant with these notions, revealing that familiar voice recognition (also known as vocal identity recognition or individual vocal recognition) or contributed to survival in the earliest vocalizing species. Contemporary ethology documents the crucial role of familiar voices across animal species in signaling and perceiving internal states and personal identities. Neuropsychological studies of voice reveal multimodal cerebral associations arising across brain structures involved in memory, emotion, attention, and arousal in vocal perception and production...

‣ Evolutionary consequences of fishing and their implications for salmon

Hard, Jeffrey J; Gross, Mart R; Heino, Mikko; Hilborn, Ray; Kope, Robert G; Law, Richard; Reynolds, John D
Fonte: Blackwell Publishing Ltd Publicador: Blackwell Publishing Ltd
Tipo: Artigo de Revista Científica
Publicado em /05/2008 Português
Relevância na Pesquisa
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We review the evidence for fisheries-induced evolution in anadromous salmonids. Salmon are exposed to a variety of fishing gears and intensities as immature or maturing individuals. We evaluate the evidence that fishing is causing evolutionary changes to traits including body size, migration timing and age of maturation, and we discuss the implications for fisheries and conservation. Few studies have fully evaluated the ingredients of fisheries-induced evolution: selection intensity, genetic variability, correlation among traits under selection, and response to selection. Most studies are limited in their ability to separate genetic responses from phenotypic plasticity, and environmental change complicates interpretation. However, strong evidence for selection intensity and for genetic variability in salmon fitness traits indicates that fishing can cause detectable evolution within ten or fewer generations. Evolutionary issues are therefore meaningful considerations in salmon fishery management. Evolutionary biologists have rarely been involved in the development of salmon fishing policy, yet evolutionary biology is relevant to the long-term success of fisheries. Future management might consider fishing policy to (i) allow experimental testing of evolutionary responses to exploitation and (ii) improve the long-term sustainability of the fishery by mitigating unfavorable evolutionary responses to fishing. We provide suggestions for how this might be done.

‣ The evolutionary dynamics of functional modules and the extraordinary plasticity of regulons: the Escherichia coli perspective

Moreno-Hagelsieb, Gabriel; Jokic, Petar
Fonte: Oxford University Press Publicador: Oxford University Press
Tipo: Artigo de Revista Científica
Português
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Using profiles of phylogenetic profiles (P-cubic) we compared the evolutionary dynamics of different kinds of functional associations. Ordered from most to least evolutionarily stable, these associations were genes in the same operons, genes whose products participate in the same biochemical pathway, genes coding for physically interacting proteins and genes in the same regulons. Regulons showed the most plastic functional interactions with evolutionary stabilities barely better than those of unrelated genes. Further regulon analyses showed that global regulators contain less evolutionarily stable associations than local regulators. Genes co-repressed by global regulators had a higher evolutionary conservation than genes co-activated by global regulators. However, the reverse was true for genes co-repressed and co-activated by local regulators. Of all the regulon-related associations, the relationship between regulators and their target genes showed the most evolutionary stability. Different negative data sets built to contrast against each of the analysed kinds of modules also differed in evolutionary conservation revealing further underlying genome organization. Applying P-cubic analyses to other genomes might help visualize genome organization...

‣ Flagellated Algae Protein Evolution Suggests the Prevalence of Lineage-Specific Rules Governing Evolutionary Rates of Eukaryotic Proteins

Chang, Ting-Yan; Liao, Ben-Yang
Fonte: Oxford University Press Publicador: Oxford University Press
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
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Understanding the general rules governing the rate of protein evolution is fundamental to evolutionary biology. However, attempts to address this issue in yeasts and mammals have revealed considerable differences in the relative importance of determinants for protein evolutionary rates. This phenomenon was previously explained by the fact that yeasts and mammals are different in many cellular and genomic properties. Flagellated algae species have several cellular and genomic characteristics that are intermediate between yeasts and mammals. Using partial correlation analyses on the evolution of 6,921 orthologous proteins from Chlamydomonas reinhardtii and Volvox carteri, we examined factors influencing evolutionary rates of proteins in flagellated algae. Previous studies have shown that mRNA abundance and gene compactness are strong determinants for protein evolutionary rates in yeasts and mammals, respectively. We show that both factors also influence algae protein evolution with mRNA abundance having a larger impact than gene compactness on the rates of algae protein evolution. More importantly, among all the factors examined, coding sequence (CDS) length has the strongest (positive) correlation with protein evolutionary rates. This correlation between CDS length and the rates of protein evolution is not due to alignment-related issues or domain density. These results suggest no simple and universal rules governing protein evolutionary rates across different eukaryotic lineages. Instead...

‣ Understanding Evolutionary Potential in Virtual CPU Instruction Set Architectures

Bryson, David M.; Ofria, Charles
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Publicado em 23/12/2013 Português
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We investigate fundamental decisions in the design of instruction set architectures for linear genetic programs that are used as both model systems in evolutionary biology and underlying solution representations in evolutionary computation. We subjected digital organisms with each tested architecture to seven different computational environments designed to present a range of evolutionary challenges. Our goal was to engineer a general purpose architecture that would be effective under a broad range of evolutionary conditions. We evaluated six different types of architectural features for the virtual CPUs: (1) genetic flexibility: we allowed digital organisms to more precisely modify the function of genetic instructions, (2) memory: we provided an increased number of registers in the virtual CPUs, (3) decoupled sensors and actuators: we separated input and output operations to enable greater control over data flow. We also tested a variety of methods to regulate expression: (4) explicit labels that allow programs to dynamically refer to specific genome positions, (5) position-relative search instructions, and (6) multiple new flow control instructions, including conditionals and jumps. Each of these features also adds complication to the instruction set and risks slowing evolution due to epistatic interactions. Two features (multiple argument specification and separated I/O) demonstrated substantial improvements in the majority of test environments...

‣ Indirect evolutionary rescue: prey adapts, predator avoids extinction

Yamamichi, Masato; Miner, Brooks E
Fonte: John Wiley & Sons, Ltd Publicador: John Wiley & Sons, Ltd
Tipo: Artigo de Revista Científica
Português
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Recent studies have increasingly recognized evolutionary rescue (adaptive evolution that prevents extinction following environmental change) as an important process in evolutionary biology and conservation science. Researchers have concentrated on single species living in isolation, but populations in nature exist within communities of interacting species, so evolutionary rescue should also be investigated in a multispecies context. We argue that the persistence or extinction of a focal species can be determined solely by evolutionary change in an interacting species. We demonstrate that prey adaptive evolution can prevent predator extinction in two-species predator–prey models, and we derive the conditions under which this indirect evolutionary interaction is essential to prevent extinction following environmental change. A nonevolving predator can be rescued from extinction by adaptive evolution of its prey due to a trade-off for the prey between defense against predation and population growth rate. As prey typically have larger populations and shorter generations than their predators, prey evolution can be rapid and have profound effects on predator population dynamics. We suggest that this process, which we term ‘indirect evolutionary rescue’...

‣ Evolutionary Dynamics in Set Structured Populations

Tarnita, Corina Elena; Antal, Tibor; Ohtsuki, Hisashi; Nowak, Martin A.
Fonte: National Academy of Sciences Publicador: National Academy of Sciences
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
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Evolutionary dynamics are strongly affected by population structure. The outcome of an evolutionary process in a well-mixed population can be very different from that in a structured population. We introduce a powerful method to study dynamical population structure: evolutionary set theory. The individuals of a population are distributed over sets. Individuals interact with others who are in the same set. Any 2 individuals can have several sets in common. Some sets can be empty, whereas others have many members. Interactions occur in terms of an evolutionary game. The payoff of the game is interpreted as fitness. Both the strategy and the set memberships change under evolutionary updating. Therefore, the population structure itself is a consequence of evolutionary dynamics. We construct a general mathematical approach for studying any evolutionary game in set structured populations. As a particular example, we study the evolution of cooperation and derive precise conditions for cooperators to be selected over defectors.; Mathematics; Organismic and Evolutionary Biology

‣ Positively Selected Sites in Cetacean Myoglobins Contribute to Protein Stability

Dasmeh, Pouria; Serohijos, Adrian; Kepp, Kasper P.; Shakhnovich, Eugene Isaacovitch
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Português
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Since divergence ∼50 Ma ago from their terrestrial ancestors, cetaceans underwent a series of adaptations such as a ∼10–20 fold increase in myoglobin (Mb) concentration in skeletal muscle, critical for increasing oxygen storage capacity and prolonging dive time. Whereas the (O_2)-binding affinity of Mbs is not significantly different among mammals (with typical oxygenation constants of ∼0.8–1.2 (µM^{−1})), folding stabilities of cetacean Mbs are ∼2–4 kcal/mol higher than for terrestrial Mbs. Using ancestral sequence reconstruction, maximum likelihood and Bayesian tests to describe the evolution of cetacean Mbs, and experimentally calibrated computation of stability effects of mutations, we observe accelerated evolution in cetaceans and identify seven positively selected sites in Mb. Overall, these sites contribute to Mb stabilization with a conditional probability of 0.8. We observe a correlation between Mb folding stability and protein abundance, suggesting that a selection pressure for stability acts proportionally to higher expression. We also identify a major divergence event leading to the common ancestor of whales, during which major stabilization occurred. Most of the positively selected sites that occur later act against other destabilizing mutations to maintain stability across the clade...

‣ Loss of male secondary sexual structures in allopatry in the Neotropical butterfly genus Arcas (Lycaenidae: Iheclinae: Eumaeini)

Robbins, Robert K.; Martins, Ananda Regina P.; Busby, Robert C.; Duarte, Marcelo
Fonte: APOLLO BOOKS; STENSTRUP Publicador: APOLLO BOOKS; STENSTRUP
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
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Male secondary sexual characters in Lepidoptera may be present or absent in species that otherwise appear to be closely related, an observation that has led to differences of opinion over the taxonomic usefulness of these structures above the species level. An evolutionary issue raised by this debate is whether male secondary sexual characters (1) can be regained after being lost evolutionarily, (2) are not lost after being evolved, or (3) are 'switched on and off' by genes that regulate development. A second evolutionary issue is the conditions under which male secondary sexual characters might be lost or gained evolutionarily. Because these structures are thought to promote species recognition, theory predicts evolutionary losses to be most likely in allopatry; evolutionary gains to be most likely during the process of secondarily establishing sympatry or during sympatric speciation. We updated the species-level taxonomy of the brilliant emerald winged Neotropical lycaenid butterfly genus Arcas and performed an analysis of phylogenetic relations among species to assess these evolutionary issues. We morphologically detail a scent pouch on the ventral hindwing of Areas and report that six species possess the pouch with androconia, one possesses the pouch without androconia...

‣ Beyond Arabidopsis. Translational Biology Meets Evolutionary Developmental Biology

Irish, Vivian F.; Benfey, Philip N.
Fonte: American Society of Plant Biologists Publicador: American Society of Plant Biologists
Tipo: Artigo de Revista Científica
Publicado em /06/2004 Português
Relevância na Pesquisa
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Developmental processes shape plant morphologies, which constitute important adaptive traits selected for during evolution. Identifying the genes that act in developmental pathways and determining how they are modified during evolution is the focus of the field of evolutionary developmental biology, or evo-devo. Knowledge of genetic pathways in the plant model Arabidopsis serves as the starting point for investigating how the toolkit of developmental pathways has been used and reused to form different plant body plans. One productive approach is to identify genes in other species that are orthologous to genes known to control developmental pathways in Arabidopsis and then determine what changes have occurred in the protein coding sequence or in the gene's expression to produce an altered morphology. A second approach relies on natural variation among wild populations or crop plants. Natural variation can be exploited to identify quantitative trait loci that underlie important developmental traits and, thus, define those genes that are responsible for adaptive changes. The possibility of applying comparative genomics approaches to Arabidopsis and related species promises profound new insights into the interplay of evolution and development.

‣ Evolutionary dynamics from a variational principle

Klimek, Peter; Thurner, Stefan; Hanel, Rudolf
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 20/11/2009 Português
Relevância na Pesquisa
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We demonstrate with a thought experiment that fitness-based population dynamical approaches to evolution are not able to make quantitative, falsifiable predictions about the long-term behavior of evolutionary systems. A key characteristic of evolutionary systems is the ongoing endogenous production of new species. These novel entities change the conditions for already existing species. Even {\em Darwin's Demon}, a hypothetical entity with exact knowledge of the abundance of all species and their fitness functions at a given time, could not pre-state the impact of these novelties on established populations. We argue that fitness is always {\it a posteriori} knowledge -- it measures but does not explain why a species has reproductive success or not. To overcome these conceptual limitations, a variational principle is proposed in a spin-model-like setup of evolutionary systems. We derive a functional which is minimized under the most general evolutionary formulation of a dynamical system, i.e. evolutionary trajectories causally emerge as a minimization of a functional. This functional allows the derivation of analytic solutions of the asymptotic diversity for stochastic evolutionary systems within a mean-field approximation. We test these approximations by numerical simulations of the corresponding model and find good agreement in the position of phase transitions in diversity curves. The model is further able to reproduce stylized facts of timeseries from several man-made and natural evolutionary systems. Light will be thrown on how species and their fitness landscapes dynamically co-evolve.; Comment: 13 pages...

‣ Structural and evolutionary tunnels of pairwise residue-interaction symmetries connect different structural classes of proteins

Banerji, Anirban
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
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Studying all non-redundant proteins in 76 most-commonly found structural domains, the present work attempts to decipher latent patterns that characterize acceptable and unacceptable symmetries in residue-residue interactions in functional proteins. We report that cutting across the structural classes, a select set of pairwise interactions are universally favored by geometrical and evolutionary constraints, termed 'acceptable' structural and evolutionary tunnels, respectively. An equally small subset of residue-residue interactions, the 'unacceptable' structural and evolutionary tunnels, is found to be universally disliked by structural and evolutionary constraints. Non-trivial overlapping is detected among acceptable structural and evolutionary tunnels, as also among unacceptable structural and evolutionary tunnels. A subset of tunnels is found to have equal relative importance, structurally and evolutionarily, in different structural classes. The MET-MET tunnel is detected to be universally most unacceptable by both structural and evolutionary constraints, whereas the ASP-LEU tunnel was found to be the closest approximation to be universally most acceptable. Residual populations in structural and evolutionary tunnels are found to be independent of stereochemical properties of individual residues. It is argued with examples that tunnels are emergent features that connect extent of symmetry in residue-residue interactions to the level of quaternary structural organization.; Comment: 23 pages...

‣ Evolutionary stable strategies in networked games: the influence of topology

Kasthurirathna, Dharshana; Piraveenan, Mahendra; Uddin, Shahadat
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 21/03/2015 Português
Relevância na Pesquisa
36.980168%
Evolutionary game theory is used to model the evolution of competing strategies in a population of players. Evolutionary stability of a strategy is a dynamic equilibrium, in which any competing mutated strategy would be wiped out from a population. If a strategy is weak evolutionarily stable, the competing strategy may manage to survive within the network. Understanding the network-related factors that affect the evolutionary stability of a strategy would be critical in making accurate predictions about the behaviour of a strategy in a real-world strategic decision making environment. In this work, we evaluate the effect of network topology on the evolutionary stability of a strategy. We focus on two well-known strategies known as the Zero-determinant strategy and the Pavlov strategy. Zero-determinant strategies have been shown to be evolutionarily unstable in a well-mixed population of players. We identify that the Zero-determinant strategy may survive, and may even dominate in a population of players connected through a non-homogeneous network. We introduce the concept of `topological stability' to denote this phenomenon. We argue that not only the network topology, but also the evolutionary process applied and the initial distribution of strategies are critical in determining the evolutionary stability of strategies. Further...

‣ Eco-evolutionary feedbacks in community and ecosystem ecology: interactions between the ecological theatre and the evolutionary play.

Post, DM; Palkovacs, EP
Fonte: Universidade Duke Publicador: Universidade Duke
Tipo: Artigo de Revista Científica Formato: 1629 - 1640
Publicado em 12/06/2009 Português
Relevância na Pesquisa
36.980168%
Interactions between natural selection and environmental change are well recognized and sit at the core of ecology and evolutionary biology. Reciprocal interactions between ecology and evolution, eco-evolutionary feedbacks, are less well studied, even though they may be critical for understanding the evolution of biological diversity, the structure of communities and the function of ecosystems. Eco-evolutionary feedbacks require that populations alter their environment (niche construction) and that those changes in the environment feed back to influence the subsequent evolution of the population. There is strong evidence that organisms influence their environment through predation, nutrient excretion and habitat modification, and that populations evolve in response to changes in their environment at time-scales congruent with ecological change (contemporary evolution). Here, we outline how the niche construction and contemporary evolution interact to alter the direction of evolution and the structure and function of communities and ecosystems. We then present five empirical systems that highlight important characteristics of eco-evolutionary feedbacks: rotifer-algae chemostats; alewife-zooplankton interactions in lakes; guppy life-history evolution and nutrient cycling in streams; avian seed predators and plants; and tree leaf chemistry and soil processes. The alewife-zooplankton system provides the most complete evidence for eco-evolutionary feedbacks...

‣ Plasticity, life history and inclusive fitness: an evolutionary demography perspective on individual variation in fertility and fertility preferences in contemporary Britain

Mathews, Paul Samuel
Fonte: London School of Economics and Political Science Thesis Publicador: London School of Economics and Political Science Thesis
Tipo: Thesis; NonPeerReviewed Formato: application/pdf
Publicado em /08/2012 Português
Relevância na Pesquisa
37.03861%
This thesis consists of three papers that explore variation in individual fertility and fertility preference. The setting for all three papers is the contemporary UK, though the conclusions have utility for a general understanding of human fertility. All three papers are motivated by theories arising from evolutionary biology, principally inclusive fitness theory and life history theory. The first two papers investigate actualised fertility and whether patterns of fertility in contemporary Britain are consistent with inclusive fitness theory. Both papers conduct secondary data analysis of the British Household Panel Study. Inclusive fitness theory predicts that because relatives share genes an individual may obtain fitness benefits by increasing the reproduction of a relative. Results support this hypothesis showing that for contemporary British women kin having more opportunities to influence reproductive decision-making is associated with pro-fitness fertility outcomes. In the first paper I find kin accelerate the transition to first birth, and the second paper shows kin also accelerate the transition to second birth. The final paper tests a different hypothesis derived from evolutionary theory. Life history theory predicts that reproductive strategy should have ‘plasticity’ and be liable to alter as perceived environmental risk changes. This paper uses primary data collected from University students using an internet experiment and finds that priming respondents using preceding questions on mortality does alter reported fertility preferences...