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The costs and benefits of dispersal in small populations
Dispersal has three major effects on adaptation. First, gene flow mixes alleles adapted to different environments, potentially hindering (swamping) adaptation. Second, it brings in other variants and inflates genetic variance: this aids adaptation to spatially (and temporally) varying environments b...
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Formato: | Online Artículo Texto |
Lenguaje: | English |
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The Royal Society
2022
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Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8859518/ https://www.ncbi.nlm.nih.gov/pubmed/35184593 http://dx.doi.org/10.1098/rstb.2021.0011 |
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author | Polechová, Jitka |
author_facet | Polechová, Jitka |
author_sort | Polechová, Jitka |
collection | PubMed |
description | Dispersal has three major effects on adaptation. First, gene flow mixes alleles adapted to different environments, potentially hindering (swamping) adaptation. Second, it brings in other variants and inflates genetic variance: this aids adaptation to spatially (and temporally) varying environments but if selection is hard, it lowers the mean fitness of the population. Third, neighbourhood size, which determines how weak genetic drift is, increases with dispersal—when genetic drift is strong, increase of the neighbourhood size with dispersal aids adaptation. In this note, I focus on the role of dispersal in environments that change gradually across space, and when local populations are quite small such that genetic drift has a significant effect. Using individual-based simulations, I show that in small populations, even leptokurtic dispersal benefits adaptation by reducing the power of genetic drift. This has implications for management of fragmented or marginal populations: the beneficial effect of increased dispersal into small populations is stronger than swamping of adaption under a broad range of conditions, including a mixture of local and long-distance dispersal. However, when environmental gradient is steep, heavily fat-tailed dispersal will swamp continuous adaptation so that only patches of locally adapted subpopulations remain. This article is part of the theme issue ‘Species’ ranges in the face of changing environments (Part II)’. |
format | Online Article Text |
id | pubmed-8859518 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2022 |
publisher | The Royal Society |
record_format | MEDLINE/PubMed |
spelling | pubmed-88595182022-03-07 The costs and benefits of dispersal in small populations Polechová, Jitka Philos Trans R Soc Lond B Biol Sci Articles Dispersal has three major effects on adaptation. First, gene flow mixes alleles adapted to different environments, potentially hindering (swamping) adaptation. Second, it brings in other variants and inflates genetic variance: this aids adaptation to spatially (and temporally) varying environments but if selection is hard, it lowers the mean fitness of the population. Third, neighbourhood size, which determines how weak genetic drift is, increases with dispersal—when genetic drift is strong, increase of the neighbourhood size with dispersal aids adaptation. In this note, I focus on the role of dispersal in environments that change gradually across space, and when local populations are quite small such that genetic drift has a significant effect. Using individual-based simulations, I show that in small populations, even leptokurtic dispersal benefits adaptation by reducing the power of genetic drift. This has implications for management of fragmented or marginal populations: the beneficial effect of increased dispersal into small populations is stronger than swamping of adaption under a broad range of conditions, including a mixture of local and long-distance dispersal. However, when environmental gradient is steep, heavily fat-tailed dispersal will swamp continuous adaptation so that only patches of locally adapted subpopulations remain. This article is part of the theme issue ‘Species’ ranges in the face of changing environments (Part II)’. The Royal Society 2022-04-11 2022-02-21 /pmc/articles/PMC8859518/ /pubmed/35184593 http://dx.doi.org/10.1098/rstb.2021.0011 Text en © 2022 The Authors. https://creativecommons.org/licenses/by/4.0/Published by the Royal Society under the terms of the Creative Commons Attribution License http://creativecommons.org/licenses/by/4.0/ (https://creativecommons.org/licenses/by/4.0/) , which permits unrestricted use, provided the original author and source are credited. |
spellingShingle | Articles Polechová, Jitka The costs and benefits of dispersal in small populations |
title | The costs and benefits of dispersal in small populations |
title_full | The costs and benefits of dispersal in small populations |
title_fullStr | The costs and benefits of dispersal in small populations |
title_full_unstemmed | The costs and benefits of dispersal in small populations |
title_short | The costs and benefits of dispersal in small populations |
title_sort | costs and benefits of dispersal in small populations |
topic | Articles |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8859518/ https://www.ncbi.nlm.nih.gov/pubmed/35184593 http://dx.doi.org/10.1098/rstb.2021.0011 |
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