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Quantitative uniqueness of human brain evolution revealed through phylogenetic comparative analysis

While the human brain is clearly large relative to body size, less is known about the timing of brain and brain component expansion within primates and the relative magnitude of volumetric increases. Using Bayesian phylogenetic comparative methods and data for both extant and fossil species, we iden...

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Detalles Bibliográficos
Autores principales: Miller, Ian F, Barton, Robert A, Nunn, Charles L
Formato: Online Artículo Texto
Lenguaje:English
Publicado: eLife Sciences Publications, Ltd 2019
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6379089/
https://www.ncbi.nlm.nih.gov/pubmed/30702428
http://dx.doi.org/10.7554/eLife.41250
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author Miller, Ian F
Barton, Robert A
Nunn, Charles L
author_facet Miller, Ian F
Barton, Robert A
Nunn, Charles L
author_sort Miller, Ian F
collection PubMed
description While the human brain is clearly large relative to body size, less is known about the timing of brain and brain component expansion within primates and the relative magnitude of volumetric increases. Using Bayesian phylogenetic comparative methods and data for both extant and fossil species, we identified that a distinct shift in brain-body scaling occurred as hominins diverged from other primates, and again as humans and Neanderthals diverged from other hominins. Within hominins, we detected a pattern of directional and accelerating evolution towards larger brains, consistent with a positive feedback process in the evolution of the human brain. Contrary to widespread assumptions, we found that the human neocortex is not exceptionally large relative to other brain structures. Instead, our analyses revealed a single increase in relative neocortex volume at the origin of haplorrhines, and an increase in relative cerebellar volume in apes.
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spelling pubmed-63790892019-02-20 Quantitative uniqueness of human brain evolution revealed through phylogenetic comparative analysis Miller, Ian F Barton, Robert A Nunn, Charles L eLife Evolutionary Biology While the human brain is clearly large relative to body size, less is known about the timing of brain and brain component expansion within primates and the relative magnitude of volumetric increases. Using Bayesian phylogenetic comparative methods and data for both extant and fossil species, we identified that a distinct shift in brain-body scaling occurred as hominins diverged from other primates, and again as humans and Neanderthals diverged from other hominins. Within hominins, we detected a pattern of directional and accelerating evolution towards larger brains, consistent with a positive feedback process in the evolution of the human brain. Contrary to widespread assumptions, we found that the human neocortex is not exceptionally large relative to other brain structures. Instead, our analyses revealed a single increase in relative neocortex volume at the origin of haplorrhines, and an increase in relative cerebellar volume in apes. eLife Sciences Publications, Ltd 2019-01-31 /pmc/articles/PMC6379089/ /pubmed/30702428 http://dx.doi.org/10.7554/eLife.41250 Text en © 2019, Miller et al 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
Miller, Ian F
Barton, Robert A
Nunn, Charles L
Quantitative uniqueness of human brain evolution revealed through phylogenetic comparative analysis
title Quantitative uniqueness of human brain evolution revealed through phylogenetic comparative analysis
title_full Quantitative uniqueness of human brain evolution revealed through phylogenetic comparative analysis
title_fullStr Quantitative uniqueness of human brain evolution revealed through phylogenetic comparative analysis
title_full_unstemmed Quantitative uniqueness of human brain evolution revealed through phylogenetic comparative analysis
title_short Quantitative uniqueness of human brain evolution revealed through phylogenetic comparative analysis
title_sort quantitative uniqueness of human brain evolution revealed through phylogenetic comparative analysis
topic Evolutionary Biology
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6379089/
https://www.ncbi.nlm.nih.gov/pubmed/30702428
http://dx.doi.org/10.7554/eLife.41250
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