The Experts below are selected from a list of 309 Experts worldwide ranked by ideXlab platform
Scott l. Nuismer - One of the best experts on this subject based on the ideXlab platform.
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interactions between Genetic Drift gene flow and selection mosaics drive parasite local adaptation
The American Naturalist, 2009Co-Authors: Sylvain Gandon, Scott l. NuismerAbstract:Abstract: Interactions between gene flow, spatially variable selection, and Genetic Drift have long been a central focus of evolutionary research. In contrast, only recently has the potential importance of interactions between these factors for coevolutionary dynamics and the emergence of parasite local adaptation been realized. Here we study host‐parasite coevolution in a metapopulation model when both the biotic and the abiotic components of the environment vary in space. We provide a general expression for parasite local adaptation that allows local adaptation to be partitioned into the contributions of spatial covariances between host and parasite genotype frequencies within and between habitats. This partitioning clarifies how relative rates of gene flow, spatially variable patterns of selection, and Genetic Drift interact to shape parasite local adaptation. Specifically, by using this expression in conjunction with coevolutionary models, we show that Genetic Drift can dramatically increase the level...
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Interactions between Genetic Drift, Gene Flow, and Selection Mosaics Drive Parasite Local Adaptation
The American Naturalist, 2009Co-Authors: Scott l. NuismerAbstract:Interactions between gene flow, spatially variable selection, and Genetic Drift have long been a central focus of evolutionary research. In contrast, only recently has the potential importance of interactions between these factors for coevolutionary dynamics and the emergence of parasite local adaptation been realized. Here we study host-parasite coevolution in a metapopulation model when both the biotic and the abiotic components of the environment vary in space. We provide a general expression for parasite local adaptation that allows local adaptation to be partitioned into the contributions of spatial covariances between host and parasite genotype frequencies within and between habitats. This partitioning clarifies how relative rates of gene flow, spatially variable patterns of selection, and Genetic Drift interact to shape parasite local adaptation. Specifically, by using this expression in conjunction with coevolutionary models, we show that Genetic Drift can dramatically increase the level of parasite local adaptation under some models of specificity. We also show that the effect of migration on parasite local adaptation depends on the geographic mosaic of selection. We discuss how these predictions could be tested empirically or experimentally using microbial systems.
Sylvain Gandon - One of the best experts on this subject based on the ideXlab platform.
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interactions between Genetic Drift gene flow and selection mosaics drive parasite local adaptation
The American Naturalist, 2009Co-Authors: Sylvain Gandon, Scott l. NuismerAbstract:Abstract: Interactions between gene flow, spatially variable selection, and Genetic Drift have long been a central focus of evolutionary research. In contrast, only recently has the potential importance of interactions between these factors for coevolutionary dynamics and the emergence of parasite local adaptation been realized. Here we study host‐parasite coevolution in a metapopulation model when both the biotic and the abiotic components of the environment vary in space. We provide a general expression for parasite local adaptation that allows local adaptation to be partitioned into the contributions of spatial covariances between host and parasite genotype frequencies within and between habitats. This partitioning clarifies how relative rates of gene flow, spatially variable patterns of selection, and Genetic Drift interact to shape parasite local adaptation. Specifically, by using this expression in conjunction with coevolutionary models, we show that Genetic Drift can dramatically increase the level...
Andrew W Murray - One of the best experts on this subject based on the ideXlab platform.
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Genetic Drift opposes mutualism during spatial population expansion
bioRxiv, 2014Co-Authors: Melanie Ji Mueller, Beverly I Neugeboren, David R Nelson, Andrew W MurrayAbstract:Mutualistic interactions benefit both partners, promoting coexistence and Genetic diversity. Spatial structure can promote cooperation, but spatial expansions may also make it hard for mutualistic partners to stay together, since Genetic Drift at the expansion front creates regions of low Genetic and species diversity. To explore the antagonism between mutualism and Genetic Drift, we grew cross-feeding strains of the budding yeast S. cerevisiae on agar surfaces as a model for mutualists undergoing spatial expansions. By supplying varying amounts of the exchanged nutrients, we tuned strength and symmetry of the mutualistic interaction. Strong mutualism suppresses Genetic demixing during spatial expansions and thereby maintains diversity, but weak or asymmetric mutualism is overwhelmed by Genetic Drift even when mutualism is still beneficial, slowing growth and reducing diversity. Theoretical modeling using experimentally measured parameters predicts the size of demixed regions and how strong mutualism must be to survive a spatial expansion.
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Genetic Drift opposes mutualism during spatial population expansion
Proceedings of the National Academy of Sciences of the United States of America, 2014Co-Authors: Melanie J I Muller, Beverly I Neugeboren, David R Nelson, Andrew W MurrayAbstract:Mutualistic interactions benefit both partners, promoting coexistence and Genetic diversity. Spatial structure can promote cooperation, but spatial expansions may also make it hard for mutualistic partners to stay together, because Genetic Drift at the expansion front creates regions of low Genetic and species diversity. To explore the antagonism between mutualism and Genetic Drift, we grew cross-feeding strains of the budding yeast Saccharomyces cerevisiae on agar surfaces as a model for mutualists undergoing spatial expansions. By supplying varying amounts of the exchanged nutrients, we tuned strength and symmetry of the mutualistic interaction. Strong mutualism suppresses Genetic demixing during spatial expansions and thereby maintains diversity, but weak or asymmetric mutualism is overwhelmed by Genetic Drift even when mutualism is still beneficial, slowing growth and reducing diversity. Theoretical modeling using experimentally measured parameters predicts the size of demixed regions and how strong mutualism must be to survive a spatial expansion.
David R Nelson - One of the best experts on this subject based on the ideXlab platform.
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Genetic Drift opposes mutualism during spatial population expansion
bioRxiv, 2014Co-Authors: Melanie Ji Mueller, Beverly I Neugeboren, David R Nelson, Andrew W MurrayAbstract:Mutualistic interactions benefit both partners, promoting coexistence and Genetic diversity. Spatial structure can promote cooperation, but spatial expansions may also make it hard for mutualistic partners to stay together, since Genetic Drift at the expansion front creates regions of low Genetic and species diversity. To explore the antagonism between mutualism and Genetic Drift, we grew cross-feeding strains of the budding yeast S. cerevisiae on agar surfaces as a model for mutualists undergoing spatial expansions. By supplying varying amounts of the exchanged nutrients, we tuned strength and symmetry of the mutualistic interaction. Strong mutualism suppresses Genetic demixing during spatial expansions and thereby maintains diversity, but weak or asymmetric mutualism is overwhelmed by Genetic Drift even when mutualism is still beneficial, slowing growth and reducing diversity. Theoretical modeling using experimentally measured parameters predicts the size of demixed regions and how strong mutualism must be to survive a spatial expansion.
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Genetic Drift opposes mutualism during spatial population expansion
Proceedings of the National Academy of Sciences of the United States of America, 2014Co-Authors: Melanie J I Muller, Beverly I Neugeboren, David R Nelson, Andrew W MurrayAbstract:Mutualistic interactions benefit both partners, promoting coexistence and Genetic diversity. Spatial structure can promote cooperation, but spatial expansions may also make it hard for mutualistic partners to stay together, because Genetic Drift at the expansion front creates regions of low Genetic and species diversity. To explore the antagonism between mutualism and Genetic Drift, we grew cross-feeding strains of the budding yeast Saccharomyces cerevisiae on agar surfaces as a model for mutualists undergoing spatial expansions. By supplying varying amounts of the exchanged nutrients, we tuned strength and symmetry of the mutualistic interaction. Strong mutualism suppresses Genetic demixing during spatial expansions and thereby maintains diversity, but weak or asymmetric mutualism is overwhelmed by Genetic Drift even when mutualism is still beneficial, slowing growth and reducing diversity. Theoretical modeling using experimentally measured parameters predicts the size of demixed regions and how strong mutualism must be to survive a spatial expansion.
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Genetic Drift at expanding frontiers promotes gene segregation
Proceedings of the National Academy of Sciences of the United States of America, 2007Co-Authors: Oskar Hallatschek, Pascal Hersen, Sharad Ramanathan, David R NelsonAbstract:Competition between random Genetic Drift and natural selection play a central role in evolution: Whereas nonbeneficial mutations often prevail in small populations by chance, mutations that sweep through large populations typically confer a selective advantage. Here, however, we observe chance effects during range expansions that dramatically alter the gene pool even in large microbial populations. Initially well mixed populations of two fluorescently labeled strains of Escherichia coli develop well defined, sector-like regions with fractal boundaries in expanding colonies. The formation of these regions is driven by random fluctuations that originate in a thin band of pioneers at the expanding frontier. A comparison of bacterial and yeast colonies (Saccharomyces cerevisiae) suggests that this large-scale Genetic sectoring is a generic phenomenon that may provide a detectable footprint of past range expansions.
Lindsay S Miles - One of the best experts on this subject based on the ideXlab platform.
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gene flow and Genetic Drift in urban environments
Molecular Ecology, 2019Co-Authors: Lindsay S Miles, Ruth L Rivkin, Marc T J Johnson, Jason Munshisouth, Brian C VerrelliAbstract:Evidence is growing that human modification of landscapes has dramatically altered evolutionary processes. In urban population Genetic studies, urbanization is typically predicted to act as a barrier that isolates populations of species, leading to increased Genetic Drift within populations and reduced gene flow between populations. However, urbanization may also facilitate dispersal among populations, leading to higher Genetic diversity within, and lower differentiation between, urban populations. We reviewed the literature on nonadaptive urban evolution to evaluate the support for each of these urban fragmentation and facilitation models. In a review of the literature with supporting quantitative analyses of 167 published urban population Genetics studies, we found a weak signature of reduced within‐population Genetic diversity and no evidence of consistently increased between‐population Genetic differentiation associated with urbanization. In addition, we found that urban landscape features act as barriers or conduits to gene flow, depending on the species and city in question. Thus, we speculate that dispersal ability of species and environmental heterogeneity between cities contributes to the variation exhibited in our results. However, >90% of published studies reviewed here showed an association of urbanization with Genetic Drift or gene flow, highlighting the strong impact of urbanization on nonadaptive evolution. It is clear that species biology and city heterogeneity obscure patterns of Genetic Drift and gene flow in a quantitative analysis. Thus, we suggest that future research makes comparisons of multiple cities and nonurban habitats, and takes into consideration species' natural history, environmental variation, spatial modelling and marker selection.