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Understanding the Evolution of Mammalian Brain Structures; the Need for a (New) Cerebrotype Approach

The mammalian brain varies in size by a factor of 100,000 and is composed of anatomically and functionally distinct structures. Theoretically, the manner in which brain composition can evolve is limited, ranging from highly modular (“mosaic evolution”) to coordinated changes in brain structure size...

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Autor principal: Willemet, Romain
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2012
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4061787/
https://www.ncbi.nlm.nih.gov/pubmed/24962772
http://dx.doi.org/10.3390/brainsci2020203
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author Willemet, Romain
author_facet Willemet, Romain
author_sort Willemet, Romain
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description The mammalian brain varies in size by a factor of 100,000 and is composed of anatomically and functionally distinct structures. Theoretically, the manner in which brain composition can evolve is limited, ranging from highly modular (“mosaic evolution”) to coordinated changes in brain structure size (“concerted evolution”) or anything between these two extremes. There is a debate about the relative importance of these distinct evolutionary trends. It is shown here that the presence of taxa-specific allometric relationships between brain structures makes a taxa-specific approach obligatory. In some taxa, the evolution of the size of brain structures follows a unique, coordinated pattern, which, in addition to other characteristics at different anatomical levels, defines what has been called here a “taxon cerebrotype”. In other taxa, no clear pattern is found, reflecting heterogeneity of the species’ lifestyles. These results suggest that the evolution of brain size and composition depends on the complex interplay between selection pressures and constraints that have changed constantly during mammalian evolution. Therefore the variability in brain composition between species should not be considered as deviations from the normal, concerted mammalian trend, but in taxa and species-specific versions of the mammalian brain. Because it forms homogenous groups of species within this complex “space” of constraints and selection pressures, the cerebrotype approach developed here could constitute an adequate level of analysis for evo-devo studies, and by extension, for a wide range of disciplines related to brain evolution.
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spelling pubmed-40617872014-06-19 Understanding the Evolution of Mammalian Brain Structures; the Need for a (New) Cerebrotype Approach Willemet, Romain Brain Sci Article The mammalian brain varies in size by a factor of 100,000 and is composed of anatomically and functionally distinct structures. Theoretically, the manner in which brain composition can evolve is limited, ranging from highly modular (“mosaic evolution”) to coordinated changes in brain structure size (“concerted evolution”) or anything between these two extremes. There is a debate about the relative importance of these distinct evolutionary trends. It is shown here that the presence of taxa-specific allometric relationships between brain structures makes a taxa-specific approach obligatory. In some taxa, the evolution of the size of brain structures follows a unique, coordinated pattern, which, in addition to other characteristics at different anatomical levels, defines what has been called here a “taxon cerebrotype”. In other taxa, no clear pattern is found, reflecting heterogeneity of the species’ lifestyles. These results suggest that the evolution of brain size and composition depends on the complex interplay between selection pressures and constraints that have changed constantly during mammalian evolution. Therefore the variability in brain composition between species should not be considered as deviations from the normal, concerted mammalian trend, but in taxa and species-specific versions of the mammalian brain. Because it forms homogenous groups of species within this complex “space” of constraints and selection pressures, the cerebrotype approach developed here could constitute an adequate level of analysis for evo-devo studies, and by extension, for a wide range of disciplines related to brain evolution. MDPI 2012-05-18 /pmc/articles/PMC4061787/ /pubmed/24962772 http://dx.doi.org/10.3390/brainsci2020203 Text en © 2012 by the authors; licensee MDPI, Basel, Switzerland. http://creativecommons.org/licenses/by/3.0/ This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution license (http://creativecommons.org/licenses/by/3.0/).
spellingShingle Article
Willemet, Romain
Understanding the Evolution of Mammalian Brain Structures; the Need for a (New) Cerebrotype Approach
title Understanding the Evolution of Mammalian Brain Structures; the Need for a (New) Cerebrotype Approach
title_full Understanding the Evolution of Mammalian Brain Structures; the Need for a (New) Cerebrotype Approach
title_fullStr Understanding the Evolution of Mammalian Brain Structures; the Need for a (New) Cerebrotype Approach
title_full_unstemmed Understanding the Evolution of Mammalian Brain Structures; the Need for a (New) Cerebrotype Approach
title_short Understanding the Evolution of Mammalian Brain Structures; the Need for a (New) Cerebrotype Approach
title_sort understanding the evolution of mammalian brain structures; the need for a (new) cerebrotype approach
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4061787/
https://www.ncbi.nlm.nih.gov/pubmed/24962772
http://dx.doi.org/10.3390/brainsci2020203
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