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Spondylolysis and spinal adaptations for bipedalism: The overshoot hypothesis
BACKGROUND AND OBJECTIVES: The study reported here focused on the aetiology of spondylolysis, a vertebral pathology usually caused by a fatigue fracture. The goal was to test the Overshoot Hypothesis, which proposes that people develop spondylolysis because their vertebral shape is at the highly der...
Autores principales: | , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
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Oxford University Press
2020
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7053264/ https://www.ncbi.nlm.nih.gov/pubmed/32153781 http://dx.doi.org/10.1093/emph/eoaa003 |
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author | Plomp, Kimberly A Dobney, Keith Collard, Mark |
author_facet | Plomp, Kimberly A Dobney, Keith Collard, Mark |
author_sort | Plomp, Kimberly A |
collection | PubMed |
description | BACKGROUND AND OBJECTIVES: The study reported here focused on the aetiology of spondylolysis, a vertebral pathology usually caused by a fatigue fracture. The goal was to test the Overshoot Hypothesis, which proposes that people develop spondylolysis because their vertebral shape is at the highly derived end of the range of variation within Homo sapiens. METHODOLOGY: We recorded 3D data on the final lumbar vertebrae of H. sapiens and three great ape species, and performed three analyses. First, we compared H. sapiens vertebrae with and without spondylolysis. Second, we compared H. sapiens vertebrae with and without spondylolysis to great ape vertebrae. Lastly, we compared H. sapiens vertebrae with and without spondylolysis to great ape vertebrae and to vertebrae of H. sapiens with Schmorl’s nodes, which previous studies have shown tend to be located at the ancestral end of the range of H. sapiens shape variation. RESULTS: We found that H. sapiens vertebrae with spondylolysis are significantly different in shape from healthy H. sapiens vertebrae. We also found that H. sapiens vertebrae with spondylolysis are more distant from great ape vertebrae than are healthy H. sapiens vertebrae. Lastly, we found that H. sapiens vertebrae with spondylolysis are at the opposite end of the range of shape variation than vertebrae with Schmorl’s nodes. CONCLUSIONS: Our findings indicate that H. sapiens vertebrae with spondylolysis tend to exhibit highly derived traits and therefore support the Overshoot Hypothesis. Spondylolysis, it appears, is linked to our lineage’s evolutionary history, especially its shift from quadrupedalism to bipedalism. Lay summary: Spondylolysis is a relatively common vertebral pathology usually caused by a fatigue fracture. There is reason to think that it might be connected with our lineage’s evolutionary shift from walking on all fours to walking on two legs. We tested this idea by comparing human vertebrae with and without spondylolysis to the vertebrae of great apes. Our results support the hypothesis. They suggest that people who experience spondylolysis have vertebrae with what are effectively exaggerated adaptations for bipedalism. |
format | Online Article Text |
id | pubmed-7053264 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2020 |
publisher | Oxford University Press |
record_format | MEDLINE/PubMed |
spelling | pubmed-70532642020-03-09 Spondylolysis and spinal adaptations for bipedalism: The overshoot hypothesis Plomp, Kimberly A Dobney, Keith Collard, Mark Evol Med Public Health Original Research Article BACKGROUND AND OBJECTIVES: The study reported here focused on the aetiology of spondylolysis, a vertebral pathology usually caused by a fatigue fracture. The goal was to test the Overshoot Hypothesis, which proposes that people develop spondylolysis because their vertebral shape is at the highly derived end of the range of variation within Homo sapiens. METHODOLOGY: We recorded 3D data on the final lumbar vertebrae of H. sapiens and three great ape species, and performed three analyses. First, we compared H. sapiens vertebrae with and without spondylolysis. Second, we compared H. sapiens vertebrae with and without spondylolysis to great ape vertebrae. Lastly, we compared H. sapiens vertebrae with and without spondylolysis to great ape vertebrae and to vertebrae of H. sapiens with Schmorl’s nodes, which previous studies have shown tend to be located at the ancestral end of the range of H. sapiens shape variation. RESULTS: We found that H. sapiens vertebrae with spondylolysis are significantly different in shape from healthy H. sapiens vertebrae. We also found that H. sapiens vertebrae with spondylolysis are more distant from great ape vertebrae than are healthy H. sapiens vertebrae. Lastly, we found that H. sapiens vertebrae with spondylolysis are at the opposite end of the range of shape variation than vertebrae with Schmorl’s nodes. CONCLUSIONS: Our findings indicate that H. sapiens vertebrae with spondylolysis tend to exhibit highly derived traits and therefore support the Overshoot Hypothesis. Spondylolysis, it appears, is linked to our lineage’s evolutionary history, especially its shift from quadrupedalism to bipedalism. Lay summary: Spondylolysis is a relatively common vertebral pathology usually caused by a fatigue fracture. There is reason to think that it might be connected with our lineage’s evolutionary shift from walking on all fours to walking on two legs. We tested this idea by comparing human vertebrae with and without spondylolysis to the vertebrae of great apes. Our results support the hypothesis. They suggest that people who experience spondylolysis have vertebrae with what are effectively exaggerated adaptations for bipedalism. Oxford University Press 2020-03-03 /pmc/articles/PMC7053264/ /pubmed/32153781 http://dx.doi.org/10.1093/emph/eoaa003 Text en © The Author(s) 2020. Published by Oxford University Press on behalf of the Foundation for Evolution, Medicine, and Public Health. http://creativecommons.org/licenses/by/4.0/ This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited. |
spellingShingle | Original Research Article Plomp, Kimberly A Dobney, Keith Collard, Mark Spondylolysis and spinal adaptations for bipedalism: The overshoot hypothesis |
title | Spondylolysis and spinal adaptations for bipedalism: The overshoot hypothesis |
title_full | Spondylolysis and spinal adaptations for bipedalism: The overshoot hypothesis |
title_fullStr | Spondylolysis and spinal adaptations for bipedalism: The overshoot hypothesis |
title_full_unstemmed | Spondylolysis and spinal adaptations for bipedalism: The overshoot hypothesis |
title_short | Spondylolysis and spinal adaptations for bipedalism: The overshoot hypothesis |
title_sort | spondylolysis and spinal adaptations for bipedalism: the overshoot hypothesis |
topic | Original Research Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7053264/ https://www.ncbi.nlm.nih.gov/pubmed/32153781 http://dx.doi.org/10.1093/emph/eoaa003 |
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