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Variability and constraint in the mammalian vertebral column.
| Content Provider | Semantic Scholar |
|---|---|
| Author | Asher, Robert J. Lin, Kuei-Hsiang Kardjilov, Nikolay Hautier, Lionel |
| Copyright Year | 2011 |
| Abstract | Patterns of vertebral variation across mammals have seldom been quantified, making it difficult to test hypotheses of covariation within the axial skeleton and mechanisms behind the high level of vertebral conservatism among mammals. We examined variation in vertebral counts within 42 species of mammals, representing monotremes, marsupials and major clades of placentals. These data show that xenarthrans and afrotherians have, on average, a high proportion of individuals with meristic deviations from species' median series counts. Monotremes, xenarthrans, afrotherians and primates show relatively high variation in thoracolumbar vertebral count. Among the clades sampled in our dataset, rodents are the least variable, with several species not showing any deviations from median vertebral counts, or vertebral anomalies such as asymmetric ribs or transitional vertebrae. Most mammals show significant correlations between sacral position and length of the rib cage; only a few show a correlation between sacral position and number of sternebrae. The former result is consistent with the hypothesis that adult axial skeletal structures patterned by distinct mesodermal tissues are modular and covary; the latter is not. Variable levels of correlation among these structures may indicate that the boundaries of prim/abaxial mesodermal precursors of the axial skeleton are not uniform across species. We do not find evidence for a higher frequency of vertebral anomalies in our sample of embryos or neonates than in post-natal individuals of any species, contrary to the hypothesis that stabilizing selection plays a major role in vertebral patterning. |
| Starting Page | 679 |
| Ending Page | 679 |
| Page Count | 1 |
| File Format | PDF HTM / HTML |
| Alternate Webpage(s) | http://treelizard.net/journalclub/Asher2011.pdf |
| PubMed reference number | 21338435v1 |
| Alternate Webpage(s) | https://doi.org/10.1111/j.1420-9101.2011.02240.x |
| DOI | 10.1111/j.1420-9101.2011.02240.x |
| Journal | Journal of evolutionary biology |
| Volume Number | 24 |
| Issue Number | 5 |
| Language | English |
| Access Restriction | Open |
| Subject Keyword | Axial skeleton structure Body tissue Bone structure of rib Bone structure of sacrum Bone structure of spine Embryo Hyperostosis, Diffuse Idiopathic Skeletal Infant, Newborn Jarcho-Levin syndrome Mammals Monotremata Primates Rib Cage Rodent Superorder Marsupalia (organism) Vertebral column |
| Content Type | Text |
| Resource Type | Article |
