Musculoskeletal networks reveal topological disparity in mammalian neck evolution
Abstract Background The increase in locomotor and metabolic performance during mammalian evolution was accompanied by the limitation of the number of cervical vertebrae to only seven. In turn, nuchal muscles underwent a reorganization while forelimb muscles expanded into the neck region. As variatio...
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doaj-4694edf01f994977b50b0e3da938627a2021-09-02T09:57:19ZengBMCBMC Evolutionary Biology1471-21482017-12-0117111810.1186/s12862-017-1101-1Musculoskeletal networks reveal topological disparity in mammalian neck evolutionPatrick Arnold0Borja Esteve-Altava1Martin S. Fischer2Department of Human Evolution, Max Planck Institute for Evolutionary AnthropologyStructure & Motion Lab, Department of Comparative Biomedical Sciences, Royal Veterinary CollegeDepartment of Human Evolution, Max Planck Institute for Evolutionary AnthropologyAbstract Background The increase in locomotor and metabolic performance during mammalian evolution was accompanied by the limitation of the number of cervical vertebrae to only seven. In turn, nuchal muscles underwent a reorganization while forelimb muscles expanded into the neck region. As variation in the cervical spine is low, the variation in the arrangement of the neck muscles and their attachment sites (i.e., the variability of the neck’s musculoskeletal organization) is thus proposed to be an important source of neck disparity across mammals. Anatomical network analysis provides a novel framework to study the organization of the anatomical arrangement, or connectivity pattern, of the bones and muscles that constitute the mammalian neck in an evolutionary context. Results Neck organization in mammals is characterized by a combination of conserved and highly variable network properties. We uncovered a conserved regionalization of the musculoskeletal organization of the neck into upper, mid and lower cervical modules. In contrast, there is a varying degree of complexity or specialization and of the integration of the pectoral elements. The musculoskeletal organization of the monotreme neck is distinctively different from that of therian mammals. Conclusions Our findings reveal that the limited number of vertebrae in the mammalian neck does not result in a low musculoskeletal disparity when examined in an evolutionary context. However, this disparity evolved late in mammalian history in parallel with the radiation of certain lineages (e.g., cetartiodactyls, xenarthrans). Disparity is further facilitated by the enhanced incorporation of forelimb muscles into the neck and their variability in attachment sites.http://link.springer.com/article/10.1186/s12862-017-1101-1Anatomical network analysisNetwork theoryForelimb evolutionMammalian cervical spineSlothsMeristic constraints |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
Patrick Arnold Borja Esteve-Altava Martin S. Fischer |
spellingShingle |
Patrick Arnold Borja Esteve-Altava Martin S. Fischer Musculoskeletal networks reveal topological disparity in mammalian neck evolution BMC Evolutionary Biology Anatomical network analysis Network theory Forelimb evolution Mammalian cervical spine Sloths Meristic constraints |
author_facet |
Patrick Arnold Borja Esteve-Altava Martin S. Fischer |
author_sort |
Patrick Arnold |
title |
Musculoskeletal networks reveal topological disparity in mammalian neck evolution |
title_short |
Musculoskeletal networks reveal topological disparity in mammalian neck evolution |
title_full |
Musculoskeletal networks reveal topological disparity in mammalian neck evolution |
title_fullStr |
Musculoskeletal networks reveal topological disparity in mammalian neck evolution |
title_full_unstemmed |
Musculoskeletal networks reveal topological disparity in mammalian neck evolution |
title_sort |
musculoskeletal networks reveal topological disparity in mammalian neck evolution |
publisher |
BMC |
series |
BMC Evolutionary Biology |
issn |
1471-2148 |
publishDate |
2017-12-01 |
description |
Abstract Background The increase in locomotor and metabolic performance during mammalian evolution was accompanied by the limitation of the number of cervical vertebrae to only seven. In turn, nuchal muscles underwent a reorganization while forelimb muscles expanded into the neck region. As variation in the cervical spine is low, the variation in the arrangement of the neck muscles and their attachment sites (i.e., the variability of the neck’s musculoskeletal organization) is thus proposed to be an important source of neck disparity across mammals. Anatomical network analysis provides a novel framework to study the organization of the anatomical arrangement, or connectivity pattern, of the bones and muscles that constitute the mammalian neck in an evolutionary context. Results Neck organization in mammals is characterized by a combination of conserved and highly variable network properties. We uncovered a conserved regionalization of the musculoskeletal organization of the neck into upper, mid and lower cervical modules. In contrast, there is a varying degree of complexity or specialization and of the integration of the pectoral elements. The musculoskeletal organization of the monotreme neck is distinctively different from that of therian mammals. Conclusions Our findings reveal that the limited number of vertebrae in the mammalian neck does not result in a low musculoskeletal disparity when examined in an evolutionary context. However, this disparity evolved late in mammalian history in parallel with the radiation of certain lineages (e.g., cetartiodactyls, xenarthrans). Disparity is further facilitated by the enhanced incorporation of forelimb muscles into the neck and their variability in attachment sites. |
topic |
Anatomical network analysis Network theory Forelimb evolution Mammalian cervical spine Sloths Meristic constraints |
url |
http://link.springer.com/article/10.1186/s12862-017-1101-1 |
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