Strong evidence for the adaptive walk model of gene evolution in Drosophila and Arabidopsis.
Understanding the dynamics of species adaptation to their environments has long been a central focus of the study of evolution. Theories of adaptation propose that populations evolve by "walking" in a fitness landscape. This "adaptive walk" is characterised by a pattern of dimini...
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Format: | Article |
Language: | English |
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Public Library of Science (PLoS)
2022-09-01
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Series: | PLoS Biology |
Online Access: | https://doi.org/10.1371/journal.pbio.3001775 |
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author | Ana Filipa Moutinho Adam Eyre-Walker Julien Y Dutheil |
author_facet | Ana Filipa Moutinho Adam Eyre-Walker Julien Y Dutheil |
author_sort | Ana Filipa Moutinho |
collection | DOAJ |
description | Understanding the dynamics of species adaptation to their environments has long been a central focus of the study of evolution. Theories of adaptation propose that populations evolve by "walking" in a fitness landscape. This "adaptive walk" is characterised by a pattern of diminishing returns, where populations further away from their fitness optimum take larger steps than those closer to their optimal conditions. Hence, we expect young genes to evolve faster and experience mutations with stronger fitness effects than older genes because they are further away from their fitness optimum. Testing this hypothesis, however, constitutes an arduous task. Young genes are small, encode proteins with a higher degree of intrinsic disorder, are expressed at lower levels, and are involved in species-specific adaptations. Since all these factors lead to increased protein evolutionary rates, they could be masking the effect of gene age. While controlling for these factors, we used population genomic data sets of Arabidopsis and Drosophila and estimated the rate of adaptive substitutions across genes from different phylostrata. We found that a gene's evolutionary age significantly impacts the molecular rate of adaptation. Moreover, we observed that substitutions in young genes tend to have larger physicochemical effects. Our study, therefore, provides strong evidence that molecular evolution follows an adaptive walk model across a large evolutionary timescale. |
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institution | Directory Open Access Journal |
issn | 1544-9173 1545-7885 |
language | English |
last_indexed | 2024-04-11T16:41:15Z |
publishDate | 2022-09-01 |
publisher | Public Library of Science (PLoS) |
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spelling | doaj.art-216adf78c73c4159981ece9271293e102022-12-22T04:13:40ZengPublic Library of Science (PLoS)PLoS Biology1544-91731545-78852022-09-01209e300177510.1371/journal.pbio.3001775Strong evidence for the adaptive walk model of gene evolution in Drosophila and Arabidopsis.Ana Filipa MoutinhoAdam Eyre-WalkerJulien Y DutheilUnderstanding the dynamics of species adaptation to their environments has long been a central focus of the study of evolution. Theories of adaptation propose that populations evolve by "walking" in a fitness landscape. This "adaptive walk" is characterised by a pattern of diminishing returns, where populations further away from their fitness optimum take larger steps than those closer to their optimal conditions. Hence, we expect young genes to evolve faster and experience mutations with stronger fitness effects than older genes because they are further away from their fitness optimum. Testing this hypothesis, however, constitutes an arduous task. Young genes are small, encode proteins with a higher degree of intrinsic disorder, are expressed at lower levels, and are involved in species-specific adaptations. Since all these factors lead to increased protein evolutionary rates, they could be masking the effect of gene age. While controlling for these factors, we used population genomic data sets of Arabidopsis and Drosophila and estimated the rate of adaptive substitutions across genes from different phylostrata. We found that a gene's evolutionary age significantly impacts the molecular rate of adaptation. Moreover, we observed that substitutions in young genes tend to have larger physicochemical effects. Our study, therefore, provides strong evidence that molecular evolution follows an adaptive walk model across a large evolutionary timescale.https://doi.org/10.1371/journal.pbio.3001775 |
spellingShingle | Ana Filipa Moutinho Adam Eyre-Walker Julien Y Dutheil Strong evidence for the adaptive walk model of gene evolution in Drosophila and Arabidopsis. PLoS Biology |
title | Strong evidence for the adaptive walk model of gene evolution in Drosophila and Arabidopsis. |
title_full | Strong evidence for the adaptive walk model of gene evolution in Drosophila and Arabidopsis. |
title_fullStr | Strong evidence for the adaptive walk model of gene evolution in Drosophila and Arabidopsis. |
title_full_unstemmed | Strong evidence for the adaptive walk model of gene evolution in Drosophila and Arabidopsis. |
title_short | Strong evidence for the adaptive walk model of gene evolution in Drosophila and Arabidopsis. |
title_sort | strong evidence for the adaptive walk model of gene evolution in drosophila and arabidopsis |
url | https://doi.org/10.1371/journal.pbio.3001775 |
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