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Unpredictable repeatability in molecular evolution
The extent of parallel evolution at the genotypic level is quantitatively linked to the distribution of beneficial fitness effects (DBFE) of mutations. The standard view, based on light-tailed distributions (i.e., distributions with finite moments), is that the probability of parallel evolution in d...
Autores principales: | , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
National Academy of Sciences
2022
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9522380/ https://www.ncbi.nlm.nih.gov/pubmed/36122210 http://dx.doi.org/10.1073/pnas.2209373119 |
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author | Das, Suman G. Krug, Joachim |
author_facet | Das, Suman G. Krug, Joachim |
author_sort | Das, Suman G. |
collection | PubMed |
description | The extent of parallel evolution at the genotypic level is quantitatively linked to the distribution of beneficial fitness effects (DBFE) of mutations. The standard view, based on light-tailed distributions (i.e., distributions with finite moments), is that the probability of parallel evolution in duplicate populations is inversely proportional to the number of available mutations and, moreover, that the DBFE is sufficient to determine the probability when the number of available mutations is large. Here, we show that when the DBFE is heavy-tailed, as found in several recent experiments, these expectations are defied. The probability of parallel evolution decays anomalously slowly in the number of mutations or even becomes independent of it, implying higher repeatability of evolution. At the same time, the probability of parallel evolution is non-self-averaging—that is, it does not converge to its mean value, even when a large number of mutations are involved. This behavior arises because the evolutionary process is dominated by only a few mutations of high weight. Consequently, the probability varies widely across systems with the same DBFE. Contrary to the standard view, the DBFE is no longer sufficient to determine the extent of parallel evolution, making it much less predictable. We illustrate these ideas theoretically and through analysis of empirical data on antibiotic-resistance evolution. |
format | Online Article Text |
id | pubmed-9522380 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2022 |
publisher | National Academy of Sciences |
record_format | MEDLINE/PubMed |
spelling | pubmed-95223802022-09-30 Unpredictable repeatability in molecular evolution Das, Suman G. Krug, Joachim Proc Natl Acad Sci U S A Biological Sciences The extent of parallel evolution at the genotypic level is quantitatively linked to the distribution of beneficial fitness effects (DBFE) of mutations. The standard view, based on light-tailed distributions (i.e., distributions with finite moments), is that the probability of parallel evolution in duplicate populations is inversely proportional to the number of available mutations and, moreover, that the DBFE is sufficient to determine the probability when the number of available mutations is large. Here, we show that when the DBFE is heavy-tailed, as found in several recent experiments, these expectations are defied. The probability of parallel evolution decays anomalously slowly in the number of mutations or even becomes independent of it, implying higher repeatability of evolution. At the same time, the probability of parallel evolution is non-self-averaging—that is, it does not converge to its mean value, even when a large number of mutations are involved. This behavior arises because the evolutionary process is dominated by only a few mutations of high weight. Consequently, the probability varies widely across systems with the same DBFE. Contrary to the standard view, the DBFE is no longer sufficient to determine the extent of parallel evolution, making it much less predictable. We illustrate these ideas theoretically and through analysis of empirical data on antibiotic-resistance evolution. National Academy of Sciences 2022-09-19 2022-09-27 /pmc/articles/PMC9522380/ /pubmed/36122210 http://dx.doi.org/10.1073/pnas.2209373119 Text en Copyright © 2022 the Author(s). Published by PNAS. https://creativecommons.org/licenses/by-nc-nd/4.0/This open access article is distributed under Creative Commons Attribution-NonCommercial-NoDerivatives License 4.0 (CC BY-NC-ND) (https://creativecommons.org/licenses/by-nc-nd/4.0/) . |
spellingShingle | Biological Sciences Das, Suman G. Krug, Joachim Unpredictable repeatability in molecular evolution |
title | Unpredictable repeatability in molecular evolution |
title_full | Unpredictable repeatability in molecular evolution |
title_fullStr | Unpredictable repeatability in molecular evolution |
title_full_unstemmed | Unpredictable repeatability in molecular evolution |
title_short | Unpredictable repeatability in molecular evolution |
title_sort | unpredictable repeatability in molecular evolution |
topic | Biological Sciences |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9522380/ https://www.ncbi.nlm.nih.gov/pubmed/36122210 http://dx.doi.org/10.1073/pnas.2209373119 |
work_keys_str_mv | AT dassumang unpredictablerepeatabilityinmolecularevolution AT krugjoachim unpredictablerepeatabilityinmolecularevolution |