Encontrados 9 documentos, a visualizar página 1 de 1
Genetic diversity in the SIR model of pathogen evolution
Gordo, I.; Gomes, M.G.M.; Reis, D.G.; Campos, P.R.A.We introduce a model for assessing the levels and patterns of genetic diversity in pathogen populations, whose epidemiology follows a susceptible-infected-recovered model (SIR). We model the population of pathogens as a metapopulation composed of subpopulations (infected hosts), where pathogens replicate and mutate. Hosts transmit pathogens to uninfected hosts. We show that the level of pathogen variation is we...
Sex and deleterious mutations
Gordo, I.; Campos, P.R.A.The evolutionary advantage of sexual reproduction has been considered as one of the most pressing questions in evolutionary biology. While a pluralistic view of the evolution of sex and recombination has been suggested by some, here we take a simpler view and try to quantify the conditions under which sex can evolve given a set of minimal assumptions. Since real populations are finite and also subject to recurr...
Patterns of genetic variation in populations of infectious agents
Gordo, I.; Campos, P.R.A.The analysis of genetic variation in populations of infectious agents may help us understand their epidemiology and evolution. Here we study a model for assessing the levels and patterns of genetic diversity in populations of infectious agents. The population is structured into many small subpopulations, which correspond to their hosts, that are connected according to a specific type of contact network. We cons...
Small-word networks decrease the speed of Muller's ratchet
Combadão, J.; Dionisio, F.; Campos, P.R.A.; Gordo, I.; Gomes, M.G.M.Muller's ratchet is an evolutionary process that has been implicated in the extinction of asexual species, the evolution of non-recombining genomes, such as the mitochondria, the degeneration of the Y chromosome, and the evolution of sex and recombination. Here we study the speed of Muller's ratchet in a spatially structured population which is subdivided into many small populations (demes) connected by migrati...
Adaptive evolution in a spatially structured asexual population
Gordo, I.; Campos, P.R.A.We study the process of adaptation in a spatially structured asexual haploid population. The model assumes a local competition for replication, where each organism interacts only with its nearest neighbors. We observe that the substitution rate of beneficial mutations is smaller for a spatially structured population than that seen for populations without structure. The difference between structured and unstruct...
The effect of spatial structure in adaptive evolution
Perfeito, L.; Gordo, I.; Campos, P.R.A.We study the dynamics of adaptation in a spatially structured population. The model assumes local competition for replication, where each organism interacts only with its nearest neighbors and is inspired by experimental methods that can be used to study the process of adaptive evolution in microbes. In such experiments microbial populations are grown on petri dishes and allowed to adapt by serial passage. We c...
Pathogen genetic variation in small-world host contact structures
Campos, P.R.A.; Gordo, I.We introduce a model for assessing the levels and patterns of genetic diversity in pathogen populations, whose epidemiology follows a susceptible– infected–susceptible model. We assume a population which is structured into many small subpopulations (hosts) that exchange migrants (transmission) between their neighbours. We consider that the hosts are connected according to a small-world network topology, and in ...
Muller's ratchet in random graphs and scale free networks
Campos, P.R.A.; Combadão, J.; Dionísio, F.; Gordo, I.Muller's ratchet is an evolutionary process that has been implicated in the extinction of asexual species, the evolution of mitochondria, the degeneration of the Y chromosome, the evolution of sex and recombination and the evolution of microbes. Here we study the speed of Muller's ratchet in a population subdivided into many small subpopulations connected by migration, and distributed on a network. We compare t...
Scaling, genetic drift and clonal interference in the extinction pattern of ase...
Rosa, A.; Gordo, I.; Campos, P.R.A.We investigate the dynamics of loss of favorable mutations in an asexual haploid population. In the current work, we consider homogeneous as well as spatially structured population models. We focus our analysis on statistical measurements of the probability distribution of the maximum population size N(sb) achieved by those mutations that have not reached fixation. Our results show a crossover behavior which de...
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