Travis Park Honours Projects

The adaptive soundscape of echolocation

Background: The adaptive landscape is one of the most useful concepts in evolutionary biology. Phenotypic variation is represented with height on the landscape corresponding to fitness, and selection acting on species to direct them towards adaptive peaks where fitness is optimised. In recent years, methods have been developed that allow functional traits to be measured and used to create adaptive landscapes that visualise the trade-offs in functional performance of a morphological structure. In this project, the structure of interest is the inner ear (cochlea) of toothed whales. These animals have highly specialised inner ears that they use to detect high-frequency sounds used in echolocation, a form of biological sonar. Toothed whales use echolocation to hunt for prey, communicate with one another and navigate their environment, making it an essential component of their biology.

Project aims: This project will investigate what the adaptive landscape of echolocation looks like in toothed whale inner ears. It will determine if the different types of echolocation abilities seen in living species form separate adaptive peaks, and if fossil toothed whales possessed similar echolocation abilities.

Techniques: This project will use a variety of 3D and 2D imaging and analysis techniques to measure the shapes of toothed whale inner ears (e.g. micro CT imaging), and then process data in 3D software (Avizo, Geomagic, Checkpoint, Slicer). Adaptive landscapes are then made using the Morphoscape package in the R programming language.