Start Date
2023
Description
Locomotion describes how an animal moves through its environment. The driving force behind locomotion in cetaceans (whales, dolphins, and porpoises) is the vertebral column and its associated muscles, tendons, and ligaments. Lumbar vertebrae represent one of several vertebral regions in the column (Fig. 1) that dictate cetacean swimming mode1 . Ancient cetaceans had four limbs and were able to move around on land, with swimming capabilities similar to modern terrestrial/semiaquatic mammals2 . Over time, as cetaceans became more aquatic, they transitioned from using limb-dominated swimming to taildominated swimming, which required drastic functional changes in the lumbar region. Prior work demonstrates that the earliest cetaceans had stable lumbar regions, with increasing flexibility arising in the first fully aquatic forms3 . However, this contrasts with the more stable lumbar regions in many modern cetaceans. When and how these more recent lumbar specializations arose has not yet been determined. Elucidation of when these changes evolved can lead us to a more robust understanding of how cetaceans have adapted to different ecological niches. This project aimed to investigate morphological differences in the lumbar vertebrae of extant cetaceans to interpret when swimming specializations arose phylogenetically
Recommended Citation
Morgret, Caedmon and Bebej, Ryan, "Lumbar Specialization and the Evolution of Swimming Modes in Cetaceans" (2023). Summer Research. 32.
https://digitalcommons.calvin.edu/summer_research/2023/Posters/32
Included in
Lumbar Specialization and the Evolution of Swimming Modes in Cetaceans
Locomotion describes how an animal moves through its environment. The driving force behind locomotion in cetaceans (whales, dolphins, and porpoises) is the vertebral column and its associated muscles, tendons, and ligaments. Lumbar vertebrae represent one of several vertebral regions in the column (Fig. 1) that dictate cetacean swimming mode1 . Ancient cetaceans had four limbs and were able to move around on land, with swimming capabilities similar to modern terrestrial/semiaquatic mammals2 . Over time, as cetaceans became more aquatic, they transitioned from using limb-dominated swimming to taildominated swimming, which required drastic functional changes in the lumbar region. Prior work demonstrates that the earliest cetaceans had stable lumbar regions, with increasing flexibility arising in the first fully aquatic forms3 . However, this contrasts with the more stable lumbar regions in many modern cetaceans. When and how these more recent lumbar specializations arose has not yet been determined. Elucidation of when these changes evolved can lead us to a more robust understanding of how cetaceans have adapted to different ecological niches. This project aimed to investigate morphological differences in the lumbar vertebrae of extant cetaceans to interpret when swimming specializations arose phylogenetically