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Facilitated Variation: How Evolution Learns from Past Environments To Generalize to New Environments
One of the striking features of evolution is the appearance of novel structures in organisms. Recently, Kirschner and Gerhart have integrated discoveries in evolution, genetics, and developmental biology to form a theory of facilitated variation (FV). The key observation is that organisms are design...
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Formato: | Texto |
Lenguaje: | English |
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Public Library of Science
2008
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Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2563028/ https://www.ncbi.nlm.nih.gov/pubmed/18989390 http://dx.doi.org/10.1371/journal.pcbi.1000206 |
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author | Parter, Merav Kashtan, Nadav Alon, Uri |
author_facet | Parter, Merav Kashtan, Nadav Alon, Uri |
author_sort | Parter, Merav |
collection | PubMed |
description | One of the striking features of evolution is the appearance of novel structures in organisms. Recently, Kirschner and Gerhart have integrated discoveries in evolution, genetics, and developmental biology to form a theory of facilitated variation (FV). The key observation is that organisms are designed such that random genetic changes are channeled in phenotypic directions that are potentially useful. An open question is how FV spontaneously emerges during evolution. Here, we address this by means of computer simulations of two well-studied model systems, logic circuits and RNA secondary structure. We find that evolution of FV is enhanced in environments that change from time to time in a systematic way: the varying environments are made of the same set of subgoals but in different combinations. We find that organisms that evolve under such varying goals not only remember their history but also generalize to future environments, exhibiting high adaptability to novel goals. Rapid adaptation is seen to goals composed of the same subgoals in novel combinations, and to goals where one of the subgoals was never seen in the history of the organism. The mechanisms for such enhanced generation of novelty (generalization) are analyzed, as is the way that organisms store information in their genomes about their past environments. Elements of facilitated variation theory, such as weak regulatory linkage, modularity, and reduced pleiotropy of mutations, evolve spontaneously under these conditions. Thus, environments that change in a systematic, modular fashion seem to promote facilitated variation and allow evolution to generalize to novel conditions. |
format | Text |
id | pubmed-2563028 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2008 |
publisher | Public Library of Science |
record_format | MEDLINE/PubMed |
spelling | pubmed-25630282008-11-07 Facilitated Variation: How Evolution Learns from Past Environments To Generalize to New Environments Parter, Merav Kashtan, Nadav Alon, Uri PLoS Comput Biol Research Article One of the striking features of evolution is the appearance of novel structures in organisms. Recently, Kirschner and Gerhart have integrated discoveries in evolution, genetics, and developmental biology to form a theory of facilitated variation (FV). The key observation is that organisms are designed such that random genetic changes are channeled in phenotypic directions that are potentially useful. An open question is how FV spontaneously emerges during evolution. Here, we address this by means of computer simulations of two well-studied model systems, logic circuits and RNA secondary structure. We find that evolution of FV is enhanced in environments that change from time to time in a systematic way: the varying environments are made of the same set of subgoals but in different combinations. We find that organisms that evolve under such varying goals not only remember their history but also generalize to future environments, exhibiting high adaptability to novel goals. Rapid adaptation is seen to goals composed of the same subgoals in novel combinations, and to goals where one of the subgoals was never seen in the history of the organism. The mechanisms for such enhanced generation of novelty (generalization) are analyzed, as is the way that organisms store information in their genomes about their past environments. Elements of facilitated variation theory, such as weak regulatory linkage, modularity, and reduced pleiotropy of mutations, evolve spontaneously under these conditions. Thus, environments that change in a systematic, modular fashion seem to promote facilitated variation and allow evolution to generalize to novel conditions. Public Library of Science 2008-11-07 /pmc/articles/PMC2563028/ /pubmed/18989390 http://dx.doi.org/10.1371/journal.pcbi.1000206 Text en Parter 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 Parter, Merav Kashtan, Nadav Alon, Uri Facilitated Variation: How Evolution Learns from Past Environments To Generalize to New Environments |
title | Facilitated Variation: How Evolution Learns from Past Environments To Generalize to New Environments |
title_full | Facilitated Variation: How Evolution Learns from Past Environments To Generalize to New Environments |
title_fullStr | Facilitated Variation: How Evolution Learns from Past Environments To Generalize to New Environments |
title_full_unstemmed | Facilitated Variation: How Evolution Learns from Past Environments To Generalize to New Environments |
title_short | Facilitated Variation: How Evolution Learns from Past Environments To Generalize to New Environments |
title_sort | facilitated variation: how evolution learns from past environments to generalize to new environments |
topic | Research Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2563028/ https://www.ncbi.nlm.nih.gov/pubmed/18989390 http://dx.doi.org/10.1371/journal.pcbi.1000206 |
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