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Non-Selective Evolution of Growing Populations
Non-selective effects, like genetic drift, are an important factor in modern conceptions of evolution, and have been extensively studied for constant population sizes (Kimura, 1955; Otto and Whitlock, 1997). Here, we consider non-selective evolution in the case of growing populations that are of sma...
Autores principales: | , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Public Library of Science
2015
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4537121/ https://www.ncbi.nlm.nih.gov/pubmed/26274606 http://dx.doi.org/10.1371/journal.pone.0134300 |
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author | Wienand, Karl Lechner, Matthias Becker, Felix Jung, Heinrich Frey, Erwin |
author_facet | Wienand, Karl Lechner, Matthias Becker, Felix Jung, Heinrich Frey, Erwin |
author_sort | Wienand, Karl |
collection | PubMed |
description | Non-selective effects, like genetic drift, are an important factor in modern conceptions of evolution, and have been extensively studied for constant population sizes (Kimura, 1955; Otto and Whitlock, 1997). Here, we consider non-selective evolution in the case of growing populations that are of small size and have varying trait compositions (e.g. after a population bottleneck). We find that, in these conditions, populations never fixate to a trait, but tend to a random limit composition, and that the distribution of compositions “freezes” to a steady state. This final state is crucially influenced by the initial conditions. We obtain these findings from a combined theoretical and experimental approach, using multiple mixed subpopulations of two Pseudomonas putida strains in non-selective growth conditions (Matthijs et al, 2009) as model system. The experimental results for the population dynamics match the theoretical predictions based on the Pólya urn model (Eggenberger and Pólya, 1923) for all analyzed parameter regimes. In summary, we show that exponential growth stops genetic drift. This result contrasts with previous theoretical analyses of non-selective evolution (e.g. genetic drift), which investigated how traits spread and eventually take over populations (fixate) (Kimura, 1955; Otto and Whitlock, 1997). Moreover, our work highlights how deeply growth influences non-selective evolution, and how it plays a key role in maintaining genetic variability. Consequently, it is of particular importance in life-cycles models (Melbinger et al, 2010; Cremer et al, 2011; Cremer et al, 2012) of periodically shrinking and expanding populations. |
format | Online Article Text |
id | pubmed-4537121 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2015 |
publisher | Public Library of Science |
record_format | MEDLINE/PubMed |
spelling | pubmed-45371212015-08-20 Non-Selective Evolution of Growing Populations Wienand, Karl Lechner, Matthias Becker, Felix Jung, Heinrich Frey, Erwin PLoS One Research Article Non-selective effects, like genetic drift, are an important factor in modern conceptions of evolution, and have been extensively studied for constant population sizes (Kimura, 1955; Otto and Whitlock, 1997). Here, we consider non-selective evolution in the case of growing populations that are of small size and have varying trait compositions (e.g. after a population bottleneck). We find that, in these conditions, populations never fixate to a trait, but tend to a random limit composition, and that the distribution of compositions “freezes” to a steady state. This final state is crucially influenced by the initial conditions. We obtain these findings from a combined theoretical and experimental approach, using multiple mixed subpopulations of two Pseudomonas putida strains in non-selective growth conditions (Matthijs et al, 2009) as model system. The experimental results for the population dynamics match the theoretical predictions based on the Pólya urn model (Eggenberger and Pólya, 1923) for all analyzed parameter regimes. In summary, we show that exponential growth stops genetic drift. This result contrasts with previous theoretical analyses of non-selective evolution (e.g. genetic drift), which investigated how traits spread and eventually take over populations (fixate) (Kimura, 1955; Otto and Whitlock, 1997). Moreover, our work highlights how deeply growth influences non-selective evolution, and how it plays a key role in maintaining genetic variability. Consequently, it is of particular importance in life-cycles models (Melbinger et al, 2010; Cremer et al, 2011; Cremer et al, 2012) of periodically shrinking and expanding populations. Public Library of Science 2015-08-14 /pmc/articles/PMC4537121/ /pubmed/26274606 http://dx.doi.org/10.1371/journal.pone.0134300 Text en © 2015 Wienand et al http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are properly credited. |
spellingShingle | Research Article Wienand, Karl Lechner, Matthias Becker, Felix Jung, Heinrich Frey, Erwin Non-Selective Evolution of Growing Populations |
title | Non-Selective Evolution of Growing Populations |
title_full | Non-Selective Evolution of Growing Populations |
title_fullStr | Non-Selective Evolution of Growing Populations |
title_full_unstemmed | Non-Selective Evolution of Growing Populations |
title_short | Non-Selective Evolution of Growing Populations |
title_sort | non-selective evolution of growing populations |
topic | Research Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4537121/ https://www.ncbi.nlm.nih.gov/pubmed/26274606 http://dx.doi.org/10.1371/journal.pone.0134300 |
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