Bilateral asymmetry of the mammalian and avian inner ear
- Autor(en)
- Anna Pyttlik, Guillermo Bravo Morante, Cathrin Pfaff, Anne Le Maitre, Lumila Menendez, Philipp Mitteroecker
- Abstrakt
Mammals may owe part of their evolutionary success to an increased evolvability of their ear. The incorporation of jaw elements into the middle ear enhanced the genetic, regulatory, and developmental complexity of the mammalian ear, potentially providing greater evolutionary flexibility for the independent evolution of its functional components. The mammalian ear may thus be more evolvable than the simpler ear structure of other vertebrates, such as birds with one auditory ossicle. Very little research exists regarding the extent to which properties of the developmental system have contributed to the evolvability of the mammalian ear. The higher genetic and developmental complexity in mammals may on the other hand increase the risk of developmental instabilities, which can be assessed through the study of bilateral asymmetry. In contrast, the fewer genetic and developmental factors involved in avian ear development may limit its evolutionary potential, yet this simplicity may simultaneously reduce the risk of developmental disorders. This study focuses on the different patterns of fluctuating asymmetry, which refers to the random deviations from directional mean asymmetry. We compare intra-specific patterns of asymmetry across four species: two bird species (Passer domesticus and Buteo buteo) and two mammal species (Homo sapiens and Sciurus vulgaris), with sample sizes of around 30 individuals per species. For both mammals and birds, a large and a small species was chosen in order to test for the effect of size on asymmetry. Landmark-based geometric morphometrics is employed to quantify and analyze morphological shape differences of the inner ear across species as well as discern the different patterns of asymmetry. We test the expectation that mammals show greater fluctuating asymmetry in ear shape compared to birds, owing to the former’s increased developmental complexity.
- Organisation(en)
- Department für Evolutionsbiologie, Institut für Paläontologie
- Externe Organisation(en)
- Konrad-Lorenz-Institut für Evolutions- und Kognitionsforschung, Université de Poitiers
- Seiten
- 25
- DOI
- https://doi.org/10.57827/978-3-903096-81-3
- Publikationsdatum
- 11-2024
- Peer-reviewed
- Ja
- ÖFOS 2012
- 106012 Evolutionsforschung
- Link zum Portal
- https://ucrisportal.univie.ac.at/de/publications/9f577f22-1de2-42f5-bbe6-0706119d5b69