Dynamic similarity and the peculiar allometry of maximum running speed
Abstract Animal performance fundamentally influences behaviour, ecology, and evolution. It typically varies monotonously with size. A notable exception is maximum running speed; the fastest animals are of intermediate size. Here we show that this peculiar allometry results from the competition betwe...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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Nature Portfolio
2024-03-01
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| Series: | Nature Communications |
| Online Access: | https://doi.org/10.1038/s41467-024-46269-w |
| _version_ | 1797259150035517440 |
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| author | David Labonte Peter J. Bishop Taylor J. M. Dick Christofer J. Clemente |
| author_facet | David Labonte Peter J. Bishop Taylor J. M. Dick Christofer J. Clemente |
| author_sort | David Labonte |
| collection | DOAJ |
| description | Abstract Animal performance fundamentally influences behaviour, ecology, and evolution. It typically varies monotonously with size. A notable exception is maximum running speed; the fastest animals are of intermediate size. Here we show that this peculiar allometry results from the competition between two musculoskeletal constraints: the kinetic energy capacity, which dominates in small animals, and the work capacity, which reigns supreme in large animals. The ratio of both capacities defines the physiological similarity index Γ, a dimensionless number akin to the Reynolds number in fluid mechanics. The scaling of Γ indicates a transition from a dominance of muscle forces to a dominance of inertial forces as animals grow in size; its magnitude defines conditions of “dynamic similarity“ that enable comparison and estimates of locomotor performance across extant and extinct animals; and the physical parameters that define it highlight opportunities for adaptations in musculoskeletal “design” that depart from the eternal null hypothesis of geometric similarity. The physiological similarity index challenges the Froude number as prevailing dynamic similarity condition, reveals that the differential growth of muscle and weight forces central to classic scaling theory is of secondary importance for the majority of terrestrial animals, and suggests avenues for comparative analyses of locomotor systems. |
| first_indexed | 2024-04-24T23:04:51Z |
| format | Article |
| id | doaj.art-65b0de1d8c4743d4bd1f6674d719507f |
| institution | Directory Open Access Journal |
| issn | 2041-1723 |
| language | English |
| last_indexed | 2024-04-24T23:04:51Z |
| publishDate | 2024-03-01 |
| publisher | Nature Portfolio |
| record_format | Article |
| series | Nature Communications |
| spelling | doaj.art-65b0de1d8c4743d4bd1f6674d719507f2024-03-17T12:31:24ZengNature PortfolioNature Communications2041-17232024-03-0115111110.1038/s41467-024-46269-wDynamic similarity and the peculiar allometry of maximum running speedDavid Labonte0Peter J. Bishop1Taylor J. M. Dick2Christofer J. Clemente3Department of Bioengineering, Imperial College LondonMuseum of Comparative Zoology, Harvard UniversitySchool of Biomedical Sciences, University of QueenslandSchool of Biomedical Sciences, University of QueenslandAbstract Animal performance fundamentally influences behaviour, ecology, and evolution. It typically varies monotonously with size. A notable exception is maximum running speed; the fastest animals are of intermediate size. Here we show that this peculiar allometry results from the competition between two musculoskeletal constraints: the kinetic energy capacity, which dominates in small animals, and the work capacity, which reigns supreme in large animals. The ratio of both capacities defines the physiological similarity index Γ, a dimensionless number akin to the Reynolds number in fluid mechanics. The scaling of Γ indicates a transition from a dominance of muscle forces to a dominance of inertial forces as animals grow in size; its magnitude defines conditions of “dynamic similarity“ that enable comparison and estimates of locomotor performance across extant and extinct animals; and the physical parameters that define it highlight opportunities for adaptations in musculoskeletal “design” that depart from the eternal null hypothesis of geometric similarity. The physiological similarity index challenges the Froude number as prevailing dynamic similarity condition, reveals that the differential growth of muscle and weight forces central to classic scaling theory is of secondary importance for the majority of terrestrial animals, and suggests avenues for comparative analyses of locomotor systems.https://doi.org/10.1038/s41467-024-46269-w |
| spellingShingle | David Labonte Peter J. Bishop Taylor J. M. Dick Christofer J. Clemente Dynamic similarity and the peculiar allometry of maximum running speed Nature Communications |
| title | Dynamic similarity and the peculiar allometry of maximum running speed |
| title_full | Dynamic similarity and the peculiar allometry of maximum running speed |
| title_fullStr | Dynamic similarity and the peculiar allometry of maximum running speed |
| title_full_unstemmed | Dynamic similarity and the peculiar allometry of maximum running speed |
| title_short | Dynamic similarity and the peculiar allometry of maximum running speed |
| title_sort | dynamic similarity and the peculiar allometry of maximum running speed |
| url | https://doi.org/10.1038/s41467-024-46269-w |
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