Using novel modelling approaches to investigate the evolution of symmetry in early animals.

Symmetry is a fundamental property of the major animal body plans that originated over half a billion years ago. Determining why different types of symmetry evolved is difficult because most modern groups are characterized by only a single kind. However, the fossil record reveals that the echinoderms - a major group of modern marine animals - comprised extinct forms with different types of symmetry. Investigating the evolution of symmetry in this group could help uncover the evolutionary significance of symmetry in animals more broadly. To achieve this, virtual modelling and computational fluid dynamics will be used to analyse performance of key fossil taxa, informing on the function and ecology of forms with different types of symmetry. Another major group of animals, sponges, have skeletons made up of spicules which contain many different symmetry types. It is not known why these various shapes evolved. Morphospaces of modern and fossil sponge species will be constructed and their performance evaluated. Palaeoenvironmental parameters will be assembled and interrogated to determine whether trends in symmetry state evolution of sponge spicules were driven by phylogeny, ecology or the environment. The results will transform our understanding of the evolutionary history of symmetry.