Functional optimality underpins the repeated evolution of the extreme “saber-tooth” morphology
"Saber teeth"-elongate, blade-like canines-are a classic example of convergence, having evolved repeatedly throughout mammalian history. Within canine teeth, there is a trade-off between the aspects of shape that improve food fracture and those that increase tooth strength. Optimal morphologies strike a balance between these antagonistic functional criteria. The extreme saber-tooth morphology is thought to confer functional advantage for more specialized predatory adaptations and optimization; however, the adaptive bases underpinning their evolution remain unclear. To determine whether saber-tooth shape reflects selection for functionally optimal morphologies, we generated a morphospace of the 3D shape of 70 non-saber and 25 saber-tooth species, a subset of which were used to quantify functional metrics of puncture performance and breakage resistance. These data were combined using a Pareto rank-ratio algorithm to evaluate optimality. We demonstrate that extreme saber-tooth morphologies are functionally optimal, occupying a localized peak in our optimality landscape. Unlike other optimal canine morphologies, extreme saber teeth optimize puncture performance at the expense of breakage resistance. This identifies functional optimality as a key driver underpinning the repeated evolution of this iconic tooth.
Authors
- Olga Panagiotopoulou (ORCID: https://orcid.org/0000-0002-6457-448X)
- David P. Hocking (ORCID: https://orcid.org/0000-0001-6848-1208)
- Pablo S. Milla Carmona (ORCID: https://orcid.org/0000-0002-0396-6244)
- Justin W. Adams (ORCID: https://orcid.org/0000-0002-6214-9850)
- William J. Deakin (ORCID: https://orcid.org/0000-0001-5612-7738)
- Narimane Chatar (ORCID: https://orcid.org/0000-0003-0449-8574)
- Emily J. Rayfield (ORCID: https://orcid.org/0000-0002-2618-750X)
- William M. G. Parker (ORCID: https://orcid.org/0000-0001-9289-5646)
- Douglass Rovinsky (ORCID: https://orcid.org/0000-0003-4356-9523)
- Alistair R. Evans (ORCID: https://orcid.org/0000-0002-4078-4693)
- Tahlia I. Pollock (ORCID: https://orcid.org/0000-0001-5605-9069)
- Philip C. J. Donoghue (ORCID: https://orcid.org/0000-0003-3116-7463)
Institutions
- Australian Museum (AU)
- University of Liège (BE)
- Touro University California (US)
- Discovery Institute (US)
- Museums Victoria (AU)
- University of Bristol (GB)
- Acupuncture & Integrative Medicine College (US)
- Museum of Old and New Art (AU)
- Monash University (AU)
- University of California, Berkeley (US)
Publication Details
- Journal
- Current Biology
- Published
- 2025-01-09
- DOI
- https://doi.org/10.1016/j.cub.2024.11.059
- Citations
- 9
- Primary Topic
- Evolution and Paleontology Studies
- Type
- article
- Field-Weighted Citation Impact
- 38.96
Funders
- National Science Foundation
- John Templeton Foundation
- Belgian American Educational Foundation
- American Museum of Natural History
- Holsworth Wildlife Research Endowment
- Ecological Society of America
- Equity Trustees
- Monash University
- Fonds De La Recherche Scientifique - FNRS
- Muséum National d'Histoire Naturelle
- Ecological Society of Australia
- Fonds pour la Formation à la Recherche dans l’Industrie et dans l’Agriculture
- Division of Biological Infrastructure
- University of California Museum of Paleontology