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Environmental heterogeneity can tip the population genetics of range expansions
The population genetics of most range expansions is thought to be shaped by the competition between Darwinian selection and random genetic drift at the range margins. Here, we show that the evolutionary dynamics during range expansions is highly sensitive to additional fluctuations induced by enviro...
Autores principales: | , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
eLife Sciences Publications, Ltd
2019
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6513619/ https://www.ncbi.nlm.nih.gov/pubmed/30977724 http://dx.doi.org/10.7554/eLife.44359 |
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author | Gralka, Matti Hallatschek, Oskar |
author_facet | Gralka, Matti Hallatschek, Oskar |
author_sort | Gralka, Matti |
collection | PubMed |
description | The population genetics of most range expansions is thought to be shaped by the competition between Darwinian selection and random genetic drift at the range margins. Here, we show that the evolutionary dynamics during range expansions is highly sensitive to additional fluctuations induced by environmental heterogeneities. Tracking mutant clones with a tunable fitness effect in bacterial colonies grown on randomly patterned surfaces we found that environmental heterogeneity can dramatically reduce the efficacy of selection. Time-lapse microscopy and computer simulations suggest that this effect arises generically from a local 'pinning’ of the expansion front, whereby stretches of the front are slowed down on a length scale that depends on the structure of the environmental heterogeneity. This pinning focuses the range expansion into a small number of 'lucky’ individuals with access to expansion paths, altering the neutral evolutionary dynamics and increasing the importance of chance relative to selection. |
format | Online Article Text |
id | pubmed-6513619 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2019 |
publisher | eLife Sciences Publications, Ltd |
record_format | MEDLINE/PubMed |
spelling | pubmed-65136192019-05-16 Environmental heterogeneity can tip the population genetics of range expansions Gralka, Matti Hallatschek, Oskar eLife Evolutionary Biology The population genetics of most range expansions is thought to be shaped by the competition between Darwinian selection and random genetic drift at the range margins. Here, we show that the evolutionary dynamics during range expansions is highly sensitive to additional fluctuations induced by environmental heterogeneities. Tracking mutant clones with a tunable fitness effect in bacterial colonies grown on randomly patterned surfaces we found that environmental heterogeneity can dramatically reduce the efficacy of selection. Time-lapse microscopy and computer simulations suggest that this effect arises generically from a local 'pinning’ of the expansion front, whereby stretches of the front are slowed down on a length scale that depends on the structure of the environmental heterogeneity. This pinning focuses the range expansion into a small number of 'lucky’ individuals with access to expansion paths, altering the neutral evolutionary dynamics and increasing the importance of chance relative to selection. eLife Sciences Publications, Ltd 2019-04-12 /pmc/articles/PMC6513619/ /pubmed/30977724 http://dx.doi.org/10.7554/eLife.44359 Text en © 2019, Gralka and Hallatschek http://creativecommons.org/licenses/by/4.0/ http://creativecommons.org/licenses/by/4.0/This article is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/) , which permits unrestricted use and redistribution provided that the original author and source are credited. |
spellingShingle | Evolutionary Biology Gralka, Matti Hallatschek, Oskar Environmental heterogeneity can tip the population genetics of range expansions |
title | Environmental heterogeneity can tip the population genetics of range expansions |
title_full | Environmental heterogeneity can tip the population genetics of range expansions |
title_fullStr | Environmental heterogeneity can tip the population genetics of range expansions |
title_full_unstemmed | Environmental heterogeneity can tip the population genetics of range expansions |
title_short | Environmental heterogeneity can tip the population genetics of range expansions |
title_sort | environmental heterogeneity can tip the population genetics of range expansions |
topic | Evolutionary Biology |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6513619/ https://www.ncbi.nlm.nih.gov/pubmed/30977724 http://dx.doi.org/10.7554/eLife.44359 |
work_keys_str_mv | AT gralkamatti environmentalheterogeneitycantipthepopulationgeneticsofrangeexpansions AT hallatschekoskar environmentalheterogeneitycantipthepopulationgeneticsofrangeexpansions |